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Stuck in gear and need expert advice? Ask Andy the Mechanic (a.k.a. Andy Wallen), the proprietor of Wheelcraft Bicycles of Wheeling, WV. (Please, no old bike & antique questions.) E-mail to firstname.lastname@example.org, subject "ask the mechanic," and tell us where you live. Or, mail your question directly to Ask the Mechanic, c/o Wheelcraft Bicycles, 2185 National Road, Wheeling, WV, USA 26003. Andy will e-mail your advice and we may post it afterward (do not submit a question if you don't want your Q&A posted in a future column). Take a look at our back issues to find answers to all kinds of bike fix-it questions.
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Winter 2005 Q & A's (40 posted this season.)
When the pedals are turned on my bike, everything looks okay, but the rear wheel doesn't turn. It's not locked up, it's just freewheeling. It's a GT mountain bike that belongs to a friend. He figures since I'm an auto mechanic I should be able to fix it.
Thanks for your time,
You either need a new freewheel or freehub. In many cases, it's cheaper and easier to buy a new wheel rather than replace the freehub. Freewheels require specific tools to remove, and wheels come with freehubs attached, but you need cassette lockring removal equipment to transfer cassettes.
Dear Mechanic Guy,
I have a 2003 Haro Backtrailx x3 and the braking on it is horrible. I asked the mechanic at a local shop over the phone what I could do to increase my braking. The guy told
me that the best and least expensive way is to take off my gyro and just leave an extra long cable, considering I do tailwhips and barspins frequently. After hanging up with him, I called another mechanic about disadvantages and advantages of having a gyro. This guy said the gyro won't make a difference as long as it's set up correctly. I know for a fact that it is set up correctly because I never touched it since the time I bought the bike. So
the bottom line: I need to know the advantages/disadvantages of a gyro and if
it's worth it to spend $2.99 on a new brake cable.
Thanks for your time,
The brakes on this particular bike usually present no problems. Anything that interferes with a direct connection between the brake lever and the brake will reduce braking performance. This includes sharp bends in the cable housing, excessive length of said housing, and most of all, the gyro. Gyros can be made to work better, but you must understand that your brakes will never be as good as they would be without one. Two things to look at: 1) Brake pad/rim interface. If the rim is dirty, oily, or still has color, clean/degrease and lightly sand it. If the pads are shiny where they contact the rim, sand until they are dull, or buy new ones, and don't be cheap. 2) Both upper and lower cables. If there are any kinks, if the housing is bent where the endcaps fit on, or if it is at all frayed, get new ones. The Teflon cable sets are worth the investment (Odyssey brake lines). If you don't mind spending the money, the gyro XL is a big improvement in that there is not much flex in the gyro unit itself, and it has sealed bearings. Bottom line: buy new cables and/or brake pads. Don't waste money on stuff like modulevers--they look cool, but do not improve performance.
After a bad crash, my bmx's front brakes have not been working properly. They are a gyro system and now after I apply the brakes they stay on instead of being released. I have tried tightening some things but I think I have just made things worse!
Thank you for your time,
Brakes won't release for two reasons: the cable is not moving smoothly through the housing, due to rust or a kinked cable housing, or the brake springs are not pulling the brake away from the rim. You can check the cable by disconnecting the brake, and sliding the cable through the housing. If it is not easy to pull through, get a new cable and housing. If it feels alright, look at your brake springs. If the studs on the fork are rusty, this can be cleaned off with emory cloth, and put grease on the studs before you reinstall the brake arch. Spring tension is adjusted by turning the flats on the spring cover in the direction that you want the brake to go with a wrench, and holding it in position while you tighten the 5mm allen bolt (this bolt holds the brake on).
Dear Bike Mechanic,
After a fruitless search to locate information on my "Bell" bike trailer, I came across your column, and was distressed to learn that no replacement parts are available for the trailer I purchased at Wal-Mart. The bearing on the outside of the left wheel has failed, which after a mere two years is ridiculous. Nonetheless, the aluminum frame, the spoke wheels, and the fabric are all in fine shape. It seems a pity to have to trash the thing for want of a bearing. Each wheel has a short three-inch axle that mounts through a hole in the frame and is secured with a pin that has a clip on it. If there is no way to rebuild the axle itself (no parts), are there some other wheels that would work on the trailer body? I can't help but think that if I were in the third world this would be fixable.
Thanks for your time,
You won't get parts from Bell or Wal-Mart; however, wheel bearings is wheel bearings. Either take the remains of the bad bearing, or the wheel with the good bearing to a bike shop, and you should have no problems in procuring a replacement.
I have a problem with my rear Dura Ace 2002-2003 shift lever. At the end of my ride this morning I could not release the rear shifter to the smaller gears. It would climb but not drop down. I'm not sure want to do. I am a good mechanic but don't want to take the shift lever apart without a little advice first.
Thanks for any help you can send my way!
Don't screw with it. When they're broke, they're broke, and there's no fixing them. Get your warranty period documentation together and send it back.
I have an old style bmx bike. I need to remove the forks and the old style stem is stuck! Please help! I'm planning on upgrading to a newer system.
The first thing you do is loosen, but don't remove, the stem bolt. Tap it with a mallet (a hammer's okay if you don't plan to reuse the bolt). The bolt should go down flush with the stem; this happens when the wedge gets unwedged. The stem should come out, unless it is corroded or cold welded in, which will require cutting. You can cut the top off, use a keyhole saw or hacksaw blade to cut it into sections, which may peel out if you are lucky. The cutting process is a slow, painful and difficult one. If you need the stem cut out, check with a good machinist first.
I've bought a used bike with RSX 7-speed STI levers and a RX100 front mech.
When the left lever is operating in its three positions, there is a lot of cable
slack in its least tensioned position. If I eliminate the slack with the cable tensioner,
I lose the lowest position. Apart from the slack, it works fine.
Is there a method for the adjustment of this combination or is it trial and error? Is an RX100 compatible with the RSX?
RSX components are a sort of experiment in low cost STI, and unfortunately for you and other RSX owners, the experiment didn't turn out well. I think that your problem is that the RSX levers may work somewhat with other equipment, but they really like only RSX front derailleurs. This is because the RSX front is a bottom swing derailleur, and it reacts to nuances in cable tension differently than do top swing ders. The problem is that RSX is the only road bottom swing der, and it only likes the RSX crank, which had some sort of funky useless gearing, as opposed to standard 30-42-52. So you can't change cranks because the shifters don't like normal derailleurs, and you don't have much choice in ders (you might look at bottom swing mountain bike ders-- I've had some success with Nexave and Deore) that work well with your shifters. Don't get me wrong--the stuff you have can be made to work, but it won't work well ("optimal performance" won't happen).
I'm trying to remove all the parts from my frame for painting. I have a MTB from Giant with cranks of square spindle type. I removed the left crank arm quite easily after unscrewing the nut using pressure from two flat screwdrivers. But after unscrewing the left bolt, I tried pulling the crank arm off with the two flat screwdrivers again. But they just won't budge. So I'm wondering if there is a special tool for removing the left crank (I heard about a crank puller). Is it normal for it to be hard to remove? Finally, does the crank arm usually come off with the gears?
Any suggestions or tips would be appreciated...
How many times do I have to say it: "Use the right tool for the job!" Guess what? A screwdriver is a tool used to drive screws, hence the term "screwdriver". If it was designed to be used as, say, an ice pick, it would be called "icepick", or if it were to be used to pull cranks, we might call it a "crankpuller". If you want to pull cranks, buy a crank puller. If you want to drive screws use a screwdriver. Do not attempt to drive screws with a crank puller, or pull cranks with a screwdriver. The only exception to this rule involves the multitasking hammer, which won't help in your case. If your crank arm came off easily, chances are it is wallowed out, and will come off even if it is put back on with much force. These things have to be pulled off with a puller, and usually require great effort, even when the proper tool is employed. Your next problem will probably be the removal of the bottom bracket. Guess what the tool is called that you use for this? (Hint: it is not a screwdriver).
PS: The chainrings remain attached to the right crank arm.
I have an inexpensive Huffy mountain bike that is four years old. The size of the hole in the crank for the pedals doesn't match newer, better bikes or new pedals. I'd like to add clipless pedals to the bike, but because the size of the hole in the crank doesn't match the Shimano pedals I just bought, they won't fit. Can I replace the crank and the three chain rings with something more modern/standard so the pedals will fit? It has a one-piece crank now.
I use the bike off-road and in wet and snowy conditions so I don't mess up my nice road bike. Is there a company I can contact to get a conversion kit? The only branding I see on the bike is the Shimano SIS rear derailluer. It's a cheap bike, but I'd like to ride it in messy conditions and have the benefit of clipless pedals.
You're going to have to spend a good bit of money on a cheap bike. The 1-piece crank has to be replaced with a 3-piece. The best way to do this is with a device made by MAP, which allows you to install a threaded bottom bracket into the Ashtabula shell, which accepts pressed in bearing cups. Figure on around $40 for this, plus at least $20 for a bottom bracket, and $20 or more for a crankset. You'll need to get a crank with similar gearing, or replace the front derailleur, as Huffy most likely does not have a compact crank.
Happened to be at my local Goodwill and came across a Bridgestone mb-2. It was a little dirty, but with no rust and a few scratches. It has Shimano em gears and brakes with thumb shifters. Rims are Araya and it has Sakae. Anyway, my question is about the handlebar which is unique to me. Also the Shimano brakes jut out. The handlebar rises straight up from the stem, then forms a Y for support I guess, and the handlebar sits on top of the V or Y. All in all a pretty solid bike for the price (mucho cheap). Can you give me an idea when it was made? It is grey and j415123 is the serial number.
The bars on this bike indicate that it was made in the mid '80s. Bridgestone always made decent stuff, this one is very old for a bike, so don't pour much cash into it. Buy tyres, tubes and brake shoes, but don't upgrade it to XTR 9-speed.
I am looking for a set of Ultegra levers for an 8-speed double drive train. Can you
help? The existing train is 600 EX. Everything works great except the down-shift from
the large to small chainring is getting spotty.
Thanks for any help,
Sorry, but these have not been available for at least five years. It may be possible to find a relatively unused set, but I don't recommend buying used STI parts as a rule, because they have a rather limited life span, and you don't want to buy levers that are just like yours or worse. If you only need a left hand shifter, I think that a new Shimano shifter may work. I'm not sure what will happen if you use a shifter indexed for 9-speed on an 8-speed crank, but it probably won't be too problematic. I'm quite sure that any of the Ergopower shifters will work (left side only), but won't match your Ultegra. Good luck, and be careful about used shifters.
I got a flat on my street bike a couple of days ago and continued to ride for a couple of miles after it occurred, thinking that the road was just more rough than usual. When I realized that, I had the flat I fixed, but I have noticed since that there seems to be a bit of a drag on the back wheel when riding. It feels like the brake is on. I made sure that the wheel isn't contacting the frame and the brakes are not either.
Would it be possible that I damaged the hub or bearings? I noticed a slight grinding sound every so often when the wheel spins. Any advice would be happily received.
Riding on a flat may damage the tyre or rim, but it's not likely to have caused any hub damage, in and of itself. If you had a loose locknut, especially on the drive side, and removed it, then reinstalled the rear wheel, it's very likely that the cone on that side tightened, causing your problem. The grinding sound could also come from a bad bearing adjustment, but is often symptomatic of a bad freewheel or freehub. Check to see if it is difficult to turn the axle with the wheel off the bike. If it is, your bearings are too tight. The freewheel/freehub problem is more difficult to diagnose, but if you cogs wobble, that's a sure sign.
I have a conversion question. I need to buy parts for my new Schwinn Aluminum Cruiser Single Speed to convert it to the Schwinn Aluminum
7-speed, which means I need to buy:
Freewheel Shimano 14-34T, 7-speed MegaRange (hub, sprocket, derailleur)
Brakes/Levers Tektro Alloy Linear Pull/Alloy Comfort (rear brake, cable and lever)
Can you sell me these?
D. Adair Crow
There are a few things that you may not have considered. In order to mount cantilever or V brakes on a frame, you must have studs welded to the frame and fork. If your cruiser is a single speed coaster, it's unlikely that they would have put studs on it, for safety and aesthetic concerns. One option is to put side pull brakes on it, but you may run into problems with the fenders, and these brakes would not have near the stopping power of cantis or Vs. Another problem would be the rear wheel spacing. Most coaster wheels are at 110mm, but you need 135 for a 7-speed wheel. If your frame is made of steel, this can be spread to accept 135, but aluminum frames should not be spread.
My advice is to get a Shimano Nexus or Sram Spectro hub. You can get these with either coaster or drum brakes. The ratio may not be quite as wide as the Megarange freewheel, but it is pretty impressive, especially after riding a single speed. You can also get a matching front wheel with a drum brake, or just deal with a rear brake only. A built rear wheel with shifter an brake lever is going to cost about $250 ( pricing for SRAM and Shimano 7-speed is almost the same). This is quite a bit more than the cost of your specified parts (about $100), but it will work with little or no modifications.
I own a '99 model Wheeler 6000 DZX. Recently I trashed the rear derailleur and (more tragically) the derailleur hanger. I haven't been able to find one anywhere. Any idea what to do besides junk my bike and buy another one?
Your frame was most likely manufactured by Kinesis fabrications, and you should be able to find a matching hanger at a savvy bike shop. If not, it is sometimes possible to modify a frame to accommodate a readily available hanger, such as the Cannondale unit.
Would you be kind to give your opinion on the Shimano Nexus 8R Sport? I also want to know its ratio, durability and its compatibility to a frame. Thank you.
I don't have first hand experience with this product. I can tell you about it based on the 7-speed model. Most people complain about imprecise shifting, but I think that this is largely due to the crappy Revo shifters with three cables supplied with most Nexus equipped bikes. Shimano does make a trigger style shifter, and it works much better. Another cause of perceived bad shifting is that we are so used to derailleurs, and this system does not work like a derailleur. It requires a bit of a learning curve; it doesn't like to be shifted under pressure, it is not high performance. The benefits are obvious. You won't ever (never say ever) throw off your chain, bend a der or hanger. You have less parts to lube, and you can shift to any gear from a dead stop. This product is a hard sell because people think they want 27 gears on a commuter, and it just doesn't have the coolness factor, the mountain bikeyness that people expect on their comfort bikes. Personally, I like it a lot, it makes a lot of sense, and therefore, will probably never catch on, except for the European market, where people ride bikes instead of hummers. Prior nexus hubs use more or less standard spacing, 130-135mm depending on the brake, I think. You should be able to adapt either type to your frame.
I am building up a cross frame that has 135mm rear hub spacing but
I have road wheels with 130mm hubs. Is there any way to use spacers or washers to make this work or do I need to build a set of
You just need a longer axle and spacers for the left side. Don't mess with the drive side spacing. That should do it.
I just bought a new fork, 2003 Marz Z1 Fr Doppio Air. The steerer tube is too short, what can I do?
Buy a new one. You might get an upper leg assembly for slightly less than a new fork, but that's your only option. Well, you could have a small amount of material machined off your head tube, but only a few millimeters.
I found there are so many definitions on the (effective) length of top tube which differ a lot.
"...the effective top tube length would be measured horizontally from the center of the head
tube at the height of the top tube intersection to the center of the seat "
"TT", effective top tube: (//www.fisherbikes.com/utility/glossary.asp?type=geometry)
"The horizontal measure from the center of the headset to the center of the seatpost. The most
important measurement when buying a bike, because it cannot be changed."
And many others are out there. Could you please tell us which one is right (especially for BMX racing)?
Much like frame sizes, this number can be arrived at in different ways, so it's always best to actually try a bike of a given size before buying. I measure from the center of the headset cap to the center of the seat tube, but that doesn't apply to all brands.
I was wondering if you could help me. I am a complete novice trying to get into the mountain bike world. My problem is, I am struggling a bit to replace my brake pads and set-up my v-brakes to my satisfaction. I would like to know the best way to set-up the brakes in a dumbed-down, step-by-step guide right from the start, please. I have searched the Web and came up with very little. I have managed to get the brakes working after a lot of hard work; however, they do not seem to be efficient enough, and it took me ages to do it. There must be an easy way of doing it. Any help would be gratefully accepted.
To a point, dirt cheap V brakes (sub $15 each) work much better than canti or caliper brakes. If they don't, it is most likely the brake lever--either not compatible or incredibly cheap--that is to blame. If you have the flimsy, stamped steel, so called brakes found on Huffy and Pacific products (Magna, Murry, Pacific, Mongoose, Schwinn, etc.) your only hope is to buy some new, cast aluminum brakes, such as Shimano Alivio at about $12 per wheel.
If you have decent brakes, you want the shoes to hit high on the rim, about 1-2mm below the tyre, and perfectly flat when viewed from the top, front or rear. Sometimes, we toe the shoe in to eliminate noise, but the brakes work better without toe in. Each shoe should be 2-3mm from the rim. Centering is accomplished by turning the screws on either brake arch. Use the shortest cable housing that your bike will allow. If you have steel rims, nothing will work well.
If you think that left-hand threads are there for no good reason I think you should quit giving technical advice. If any of the left-hand thread bits on a bike were right-hand thread they would unscrew unless tightened very hard. Ironically in view of the comment about Presta valves, French bottom brackets were right-hand thread both sides, but I believe they are now the English way around. Oh, and Presta valves are better than Schrader in my opinion.
If you could put a RH thread on a LH pedal the market for tandem crossover sets would shrink--everyone would just buy a normal chainset for half the price and swap pedal spindles. The reality is that the pedals would unscrew.
My opinions are my opinions and I usually don't see much point in trying to defend them here. You're right, I should stop giving technical advice. I should sell it instead. Many years ago, I drove a 1951 Plymouth. It was a great car, except that some engineer had the opinion that some of the lug nuts should go clockwise, but others should go counterclockwise, I suppose to prevent unwanted wheel loosening. None of my wheels ever came off in that car, but you'd have a hell of a time changing a tyre, what with the heat of the moment, usually in the pouring down rain or driving snow, you'd curse a few times, and curse few more times after realizing that you are tightening, not loosening, the nut. Another engineer thought that a 6-volt positive grounded electrical system was a good idea. Well, I've owned countless cars since this one, and none of them have had any reverse threaded lug nuts, and surprisingly enough, none of my wheels have ever fallen off! French and Italian nondrive side cups are clockwise. I've heard people swear that their Italian adjusting cup unadjusted itself, but I've dealt with far more people with loose English cups. Why? Well, there are a lot more English bottom brackets out there, but the reason cups are loose is that they need to be torqued to spec from time to time. You're implying that engineering can overcome poor assembly! French, Italian, Swiss, English, it doesn't matter. If it ain't tight, it'll come loose. By the way, if your reverse threaded cups are so great, why don't the Italians use them? Do you think that people would pay $5000+ (or $16,500 for the Pinorello Dogma Ego) with an inherently bad bb? Are you dismissing such legends as Colnago, DeRosa, and Perogetti as hacks because they put Italian bb shells on all their bikes? I'll concede that in some cases a reverse threaded bolt is in order, like the nondrive axle nut used on Sturmey archer 3 speeds (I'm being sarcastic here, har har har), but most of the time, they are there for reasons of tradition.
Now, about this valve thing. An opinion is that there is no good reason to put Presta valves on mountain bikes. This is clearly a case of unsolicited Frenchification. The typical American mountainbiker just wants to put air in his tyres, and this only when there is absolutely no alternative. He does not want to fumble with skinny, overly complicated valves, especially when he is at the petrol depository using a high pressure air compressor to blow up his tyres. He just wants to follow the same procedure that he uses for airing up the Hummer or Ford Execution, no adapters or valves to unscrew. What is it that people like or dislike about Presta valves, anyway? I find it difficult to get excited about either one. Does either offer a mechanical or ergonomic advantage? Does one make you faster or allow you to go further than the other? Americans think that since expensive bikes get presta valves, then they must be better. Well, maybe. I will concede that on a very narrow or aero rim, the smaller hole makes more sense, but if you're riding a downhill rig with double wide rims, who cares? What about dunlop valves?
Oh, please, please help me!
My stationary exercise bike squeaks horrifically, not immediately, but about 10 minutes into my cycling routine. I've tried spraying it with WD 40 to no avail. The bike is a DXC 5000 Dual Action Cycle. The initials "BH" are on the hardware. I'm not at all technically minded, but the screeching sound seems to be coming from somewhere around either the chain or the gears, I guess you would call them. It sure isn't the brakes, 'cause I'm not going anywhere! It kicks in after I've been pedaling for about ten minutes.
While I do some servicing of exercise equipment, I can tell you that most of it, unless it came from a fitness specialty shop, is worthless, much like the department store bike counterparts. If it's not Cat eye, accursed Schwinn, Cybex, Lifecycle, etc. you won't be able to get parts for it, and if you could, repair costs can quickly exceed the value of the product. From what you describe, my best guess is dry or deformed crank bearings, which can be fixed for less than $30 in most cases. It's only a guess, though.
Hi, "is the Mechanic in?"
I have a 2002 Cannondale Cyclocross bicycle: //www.cannondale.com/bikes/02/images/xr800_02.jpg
It has Shimano components and it has a triple chain ring with the outer ring having 52 teeth and the middle one 42T. I want to modify it by putting a 56T on it. By doing so will I need to use a larger size middle sprocket or will this combination of 42t/56t shift ok? Or will there be problems? Is there recommended sizing of chainring groupings to acquire trouble free shifting and the preventing of such problems as "chain suck?" If I make this modification, are there other things I need to do to make it work? Do I need a longer chain? Should I change the position of the derailleur or use a different type for larger sprocket?
Thanks for your help!
You will have probably have shifting problems that can't be solved. No one makes a front derailleur with that much capacity. If they did, Shimano does not make a 56T chain ring that is shift-able--they are flat, designed for time trial bikes with one front chainring. Most people shouldn't try to push a gear that big, especially on a cross bike. Look at Page and Gully's bikes, or Dunlaps. These are the best in the country, and they either have a moderate single ring, or the same or lower gearing that you have. If you must gear up, try an 11-23 cassette. This won't present any shifting problems, and is much more reasonable, both for your legs and the bike. Nobody needs bigger than 53-11 on the road except in time trials, and most of us can't effectively push anything bigger than than in any case. If you use this bike as intended, unless you are superhuman or on EPO, you'll probably find a need for the new FSA compact crank, not a bigger one.
My left Time Impact pedal is stuck in the crank arm. None of the bike shops have been able to remove it, and have broken many allen wrenches in the process. Any idea on how to salvage the pedal and crank?
You can't get enough leverage with an allen wrench, so your best bet is to cut the crank away. Use ti prep next time.
I am in the process of replacing my front derailleur (upgrading to 9-speed) and have been given a brand new front derailleur (XTR-953) with a clamp size of 34.9mm. However, I should be using a clamp size of 28.6. Is there any way that this can be made to fit securely?
Thanks and regards,
While it's not the best idea in the world, you can shim the derailleur to fit. I think that Wheels Manufacturing makes these.
I have a question. I have a rear wheel with a 14mm axle and a 18-tooth, 2-prong freewheel and I didn't have a freewheel remover, so I took it upon myself to try and remove it to put a 16-tooth on because a friend told me that he got his off with a screwdriver and a hammer. So I tried that and it messed up the groves. Now I can't get a freewheel remover in it and I must get it off because it has been left outside and is rusted and must be replaced. Also I am restoring my '02 Haro Zippo frame and had it sandblasted. I am going to spray paint and need to know what grit of sand paper to use on it to get a glossy black look.
If you can't use the correct tool to remove the freewheel, you'll have to destroy it. Using the aforementioned hammer and screwdriver, remove the outer race--it has two little holes that you can beat on with the screwdriver--by turning it clockwise. Empty the contents of the freewheel, and clean off the grease. You can then unscrew it by grabbing what's left of it with a pair of vise grips or by sticking it in a big vice. If you have all the paint off the frame by sandblasting, you don't need to sand, except between coats. I use 400 grit, but it depends somewhat on what kind of paint you are using.
I had a run-in with a rock on my new mountain bike, resulting in a nice gouge and sharp raised spot on the stanchion of the Fox suspension fork, sort of like the rim on a meteor crater, looks like this will damage the oil seal as the shock works up and down. The question is: What is the best way to sand down the rough spot on the stanchion? Many thanks.
Victoria, British Columbia, Canada
If possible, replace it. If you can't, use a fine grit sandpaper(400 or 600) and do it by hand, and only sand off enough material to get it past the seal. I'd presume that this may compromise the integrity of the stanchion, so look to replace it soon.
I have a fairly new Trek Fuel 80 that needs constant
adjustment to keep the the index shifter in adjustment and prevent the chain
from slipping on the rear gear. I have also had some problem with the front gear
slipping and the chain coming off. I take it into the bike shop every time
I ride for adjustments but that isn't helping, plus its very inconvenient. I
read a few bad reviews on this bike with similar issues. My biggest problem is every time I hit a hill on the trails and have to downshift to the lower gears the chain slips and won't settle into gear. I am really frustrated as I have never spent this kind of money on a bike before, and previous cheaper Trek models I have had have worked fine. I am kind of heavy (220 lbs) which may contribute to the problems.
A troubled rider
Fairly new? What year? How many miles? Did it slip from day one, or did it develop over time? True slipping occurs when the chain will not stay on the teeth of a cog or chainring. This is due to elongation of the chain, deformation of the said cogs/chainrings, or both, and can be caused by defective machining, but usually develops at about 1000 miles (Shimano says to get a new chain at 500), and is attributable to normal wear and tear, whether you paid $199 or $8000, it happens, and it is not warrantable. If your indexing is out of whack, that's something else, and any idiot working in a bike shop should be able to fix that.
Two issues that may apply to your specific bike: Trek (Fisher, Klein) used non-Shimano parts on these bikes, primarily to avoid dealing with Shimano, and thereby saving money. The Bontrager labeled cranks, along with Sram chains and cassettes, sometimes don't provide the crispest shift. The other issue is that these swingarms, particularly on smaller frames, could be ever so slightly out of alignment. This problem supposedly was solved with the 2003 products. In some cases, simply using a shorter crank spindle solves the problem. In others, I've had to replace all the non-Shimano stuff with Shimano stuff, and had excellent results. In a nutshell, a full suspension bike can work pretty well with the Bontrager/Sram stuff or a misaligned swingarm, but not both.
I like the compliant feel of steel, but most of the lighter bikes in my price range are aluminum, usually with a carbon fork. Should I just pay more for a light steel bike, or would aluminum with carbon forks and "bent" rear triangles (e.g., the Scanttate 550 which Supergo sells) give me a soft enough ride to do a century and not feel beaten up?
Since I don't know what your price range is, I'll make a few suggestions. Don't buy from Supergo. Check out the new Lemond spine bikes. They are pretty light, very efficient, and comfortable. About $1900 for the BA with 105, to about $3500 for the Maillot Jaune with Dura Ace.
Is is practical to convert a 10-speed to a 15-speed?
I have a 1987 Trek 330 road bike (//www.vintage-trek.com/TrekBrochure1987.htm). It meets most of my needs as I am a fairly leisure rider. To push myself I like to ride some of the Kansas Survival Series rides. There is one infamous hill near Lawrence, Kansas (yes, that's right, there are some hills in Kansas), where I really could use some lower gears. After climbing that hill last summer my knees were so sore I cut short my ride that day.
I like the fact that I ride a 17-year old bike that I bought used for a $100. I just can't bring myself to drop 10 to 20 times that amount for a new road bike. I would like to order a 3-ring crank set with a matching front derailleur, but my local bike shop told me "it couldn't be done." Is that because of the frame geometry or something?
If you know what parts I need to do the job, I'll gladly order them from you!
I see no reason you couldn't run a triple. Some of the old Suntour stuff had indexed front shifting, which can be switched off if necessary. You will need a long cage rear derailleur, new front der, crank and bb. Expect to spend at least $125 (Shimano Sora).
I'm an NC State student majoring in Mechanical engineering trying to design a bike with a top gear ratio of about 8:1 for an English project of all things. In my design, I have the frame going in between the wheel and the gears. All the gears will be welded to each other so that the axle need only run through the center of the large gears and not through the small gears so that the small gears will not be limited by the axle size. My aim is to make the small gear with 3-5 teeth (preferably 3). I need to know the standard dimensions of bicycle teeth (how long and how wide) and the standard spacing between chain links to know how far apart to space the teeth. I need the tooth dimensions to calculate how much shear stress one tooth can handle before it strips off. I don't know how a freewheel works--if you have or know where I can find a really good diagram of one, I'd appreciate that too.
Just wondering: Why don't they don't make bikes where the front gear has the same radius as the crank length? What's the largest gap a front derailleur can derail across?
The paper's due a week from today, so please get back to me soon. I really appreciate it!
This is a little outside the realm of this column, but I'll tell you what I can. Your best bet is to contact a more technical, engineering sort of a person. I'm the guy who fixes stuff that's already designed. Gear tooth dimensions and shear strength are irrelevant, as we have to work with the parts provided by Shimano, and it's almost stupid to try anything that Shimano says not to try. We are slaves to Shimano, and maybe some guy like you might start a company and change that, but most likely, all the American drive train designs will go the way of the Paul derailleur: elegant, light, expensive, Shimano compatible, and quirky. In reverse order, they don't make a hugeass chainwheel for obvious reasons. Most people just want to ride from point A to point B without straining themselves too much. Superhuman feats, like trying to set an HPV record, or going after the hour record, may require more than 56 teeth up front, but even guys like Lance and David Millar couldn't push that for very long. I consider gearing that high beyond impractical, it's actually dangerous. You'll hurt yourself if you try much higher than the standard 53/12 high gear (119.3 gear inches). Front derailleurs are limited to 22-23 teeth capacity. No freewheel diagrams, but it's a pretty simple concept: pawls, pawl springs, and a ratchet ring. As for chain and tooth dimensions, there are currently two sizes of single speed chain in use, as well as 5 through 10 speed chains and corresponding cogs. The pitch of the single speed chain is 1/2" x 1/8" (some are 1/2" x 3/16") and a multi speed chain is 1/2" x3/32". Multi gear chains range from 6.1 mm wide for campy 10 speed, to 7.3 mm for a basic 5/6 speed chain. The only specs I have for cogs are center to center and thickness. Campy 10 c to c is 4.12 mm with 1.7 thickness. Shimano 9 is 4.34 and 1.78, and 7 speed cogs are 1.8 and 3.2.
You might try Lennard Zinn. He'd know a lot more about the engineering and physics involved here. I'm not sure how long it would take Lennard to get back to you, though.
I'm currently having problems with my chain/cog (not sure which). I have a 21-speed bike and I haven't maintained it as much as I should. The chain slips (particularly on the large cog) and I'm not sure if this is due to the chain or not.
The chain slips on all three cogs when in low gear and when there is higher pressure on the chain. How do I know when to change the chain or cog or both?
Confused and neglectful
Chains and cogs wear together. If the chain is worn out, most likely the cogs are worn out, or at least a frequently used cog or 2 is. These parts wear out with incredible frequency, and the only way to stave off frequent cassette replacement is with even more frequent chain replacement. Replace the chain every 1000 off road miles, and don't use one gear more often than any other. You'll still have to replace this stuff often, but a new chain twice a year is cheaper than a new chain and cassette, or wearing out a chain ring with an elongated chain, or crashing because your chain slipped off a cog.
We have a 1992 Ross Pegasus 21-speed bike. It is ridden between 20-40 miles a week. Last week we had a problem where the freewheel would spin but not engage the wheel. We took it to a bike shop (the rim was also bent a little) they sold us a new rim and installed the same freewheel and gears on it. It worked well for two days and then the same problem. We brought the bike indoors to work on it and several hours later everything was fine. Took the bike back outside in the cold at 20 degrees F and after several hours same problem. What could be going on that is affected by the cold?
It is unlikely that cold causes this problem. What is likely is that a 14-year-old freewheel is begging to be replaced. When this happens, it is usually due to a broken pawl. Your freewheel has two pawls that engage a toothed ring when you pedal forward, but retract when coasting or backpedaling. You can ride with only one, but it sometimes doesn't catch until you pedal for a while, or not at all. It is possible that both pawls are intact, but dried out lubricant or rust is preventing them from performing as designed. Before you trash it, try flushing it out with Tri-Flow, and dripping some heavier stuff, like gear oil, or 30 weight in. Don't try to take it apart.
I have a creaking coming from my freehub and want to
re-grease it and see if that solves the problem. Can you tell me how to remove the freehub, or regrease it, on a 2001 Specialized FSR with a Specialized S-Works rear hub? I don't see any places a wrench of any type would fit.
God Bless and Love,
Denise and Steve
Denise and Steve,
Generally, freehubs are removed via a large bolt in the center, with a 10 or 12mm allen wrench. Some are reverse threaded, and most, especially generic ones, which is what specialized is in spite of it's brand name, are extremely difficult to remove. However, removing it is not going to help in your case. I service these by removing the axle and dust cap, and plugging in a Morningstar freehub service tool. With this, you can pump solvent into the freehub, and then whatever lubricant you see fit--Morningstar makes a freehub soup for this purpose, Paul and I have discussed exactly what should be put in here, and the soup seems to work pretty well. Morning star also makes tools to remove dust caps, and serviceable dust caps to replace the one than probably got all bent out of shape upon removal.
I have a inexpensive Roadmaster bicycle. The brakes make a noise when applied. The brake pads appear to be made of a hard material not rubber. Could this be the reason for the noise.
Brake noise, and poor performance can be caused by a number of features found on many Roadmaster bicycles. Hard or glazed pads, chrome plated steel wheels, excessive play in the brake pivots, flexy brake arches, flex in the frame, improper assembly, you name it. Softer brake pads usually work better and are quieter than harder ones, but they wear out quicker, especially when applied to steel wheels. Brake pads should hit flat when viewed from the front, with a slight toe in to prevent sqwawks. There is no cure for substandard equipment.
Had a search through your website for some clues to my problem but couldn't find a similar problem! I ride a 2002/3 Cannondale and have put approximately 6500km of road on it. I noticed a ticking from the bottom bracket early into my mileage, and prompted the store, who informed me that my spds (Shimano m515's) were responsible.
Shortly thereafter the crank arms were having to be pulled up after every ride as they were loose. Bottom bracket was eventually replaced, and I queried about replacing the crank arms as well, but was told it wasn't necessary. Now it's two months since the bottom bracket was replaced, and the ticking has returned. I have no lateral movement in the crank arms that I can detect. Any ideas to the ticking?
If you are sure that the sound is coming from the crank and not elsewhere, you most likely need a new crankset. If the arms loosened, chances are the taper is worn, and they will never stay on. If you have an ISIS or Hollowtech crankset, then I'm probably wrong, but it sounds to me like a case of square taper wallow out. Another common problem with Cannondales is creaking due to cups not perfectly fitted to the bb shell. This is easily remedied with plumber's Teflon tape on both bb cups.
I'm an American living in Belgium and use my trusty bike to get around town (Antwerp). I recently bought a dynamo-powered light set, but can't for the life of me figure out how to get the thing set up and running. I have inquired with friends and always steal peeks from other bikes on the street.
For me, the wires are the issue. I have easily attached the lights to their particular location, though I had to put the dynamo on my back tire because my front fork is too fat for a secure, tight fit for the dynamo. What I've come up with is that I need to "complete the circuit" as there is only two wires--one connects to the dynamo from the rear light and one connects from the front light to the dynamo. It's driving me completely bonkers, as my frame is supposed to complete the loop somehow. Do you have any suggestions as to how I can make it work?
Andrea (currently roaming streets of Belgium without headlamp)
Most of these systems require the use of the bike frame as a ground. You have to scrape off some paint and there should be a pointed set screw which digs into the frame a little bit to complete the circuit. I suppose if you don't want to scratch your paint, you could hardwire the thing, but that would be kind of sloppy.
I ride a 2001Giant OCR 1. I've put about 2,500 miles on it and have been very satisfied. Have had normal maintenance and recently had all cables replaced. For the last two weeks there has been a very annoying clicking or creaking sound coming from the front crank. I thought it might be my pedals at first, but have determined that it is not. There is a distinct click with each rpm when I pedal and sporadic "non rhythmic" clicks as well. Any advice on what it could be and how to fix it? It's driving me crazy.
You have many possibilities. Loose crank, loose bb cup, bb shot, chainring loose, pedal, either bearings or bindings, wheel skewers, especially ti--grease them--check your new cables for rubbing or ends catching on the crank. Remember that it's hard to localize noises while on the bike because the frame acts as an acoustical conductor, so sometimes a wheel, seat, or handlebar noise sounds like it's coming from the crank. Check your seat/seatpost and all related bolts. You may grease the seat rails as well.
I have a Specialized Allez that is about 10 years old (or so). It has Shimano 600 Components with horrible Biopace chainrings. I hate them. My question is: In order to replace them, as I have suffered long enough, can I just replace the chainrings or do I replace the crank arms too? Do I need to replace the entire drive train?
Thanks for the help,
You can replace them with almost any 130mm bolt circle chainrings. I suspect that along with the Biopace, you have downtube shifters, which means that cheap chainrings will work fine. The ramped and pinned rings may work better, but if you had STI shifters, you really need Shimano type chainrings.
I have a Diamondback Vectra mountain bike and up until an accident I had six months ago I have never had much of a problem with it. This accident bent my front wheel and generally gave the bike a good bashing.
I had the bike repaired and serviced, but since then I have had troubles with the v-brakes. Braking on a flat surface is fine, but downhill the brakes start to slide and make a loud friction sound.
I took the bike to a different mechanic and they replaced the brake pads and cable as well as tested the bike thoroughly around their workshop (which of course is flat). The problem remains and whilst braking downhill always works to some extent, I don't have much confidence in the front brakes which consistently skid against the rim of the wheel. The steeper the hill the worse it is, and even if I go very slowly down the hill the brakes skid badly.
One final clue is that releasing the brakes and reapplying them gives them renewed strength and stops the skidding momentarily.
Any idea what could be causing this annoying problem?
Thanks very much,
It's hard to diagnose these types of problems. If you are using a good quality brake pad, and your rim is not ground down too far, I'd look for a loose brake mounting boss, or look at your fork while braking, and observe whether the legs flex out or not. If you have flex--and this is much more common in the rear than with suspension forks--a brake booster may solve the problem.
I plan to buy/build a road/racing bicycle. I want to use Sturmy Archer 8-Speed (roller brake). The problem is to choose the frame that can accommodate the application of the internal gear hub, especially the kind of drop out. Would you give me a suggestion on the aluminum frame (brand name) that I should use? My budget for the frame is about $230US.
Thank you very much for your help.
Off hand, I don't know of any aluminum frames that fit your needs. The best price for something like this (new) would be a Surly 1x1 or Steamroller, but they are made of cromoly and cost about $400.
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