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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 ibike@bikexchange.com, subject "ask the mechanic," 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. Take a look at our back issues to find answers to all kinds of bike fix-it questions.

Backyard Bike Mechanics Should Always Have a Handy Copy of ...
Bicycling Magazine's Complete Guide to Bicycle Maintenance and Repair
 by Jim Langley, May 1999
OR...
Zinn and the Art of Road Bike Maintenance
by Leonard Zinn, April 2000
OR...
Zinn and the Art of Mountain Bike Maintenance
by Leonard Zinn, February 1998.

Spring 2001 Questions & Answers ...

(40 Q&A's Posted This Season.)

Andy,

I've got a '99 Lemond Zurich - 853 steel (the only really nice thing I own) and I put a pressure dent in the top tube about 7 inches from the seatpost (I had my shoes in my hand as I was carrying the bike). The paint is fine - no cracking, bike tracks straight as an arrow, etc., just an unsightly ding in my baby. Is this fixable?

Thanks,
bob t

bob,

I probably wouldn't fix the dent. You can't pull it out like you can a car, and if you fill it, you'll have to paint it. Painting would be the most expensive and difficult part of this operation. The only way to really fix it would be to have the top tube replaced and repainted, and this would surely out price a new frame (less than $800, including fork).

Andy

Andy,

I am an aspiring triathlete who is looking to upgrade my bike for next years races. I am 6' and 190 pounds. I need advice as to go with 650 or 700cc wheels. What are the advantages/disadvantages of each option?

Thanks,
Dean

Dean,

Primarily, smaller wheels accelerate better, due to reduced rotational mass at the outermost point of the wheel. For time trials/triathlon, this is a good thing. However, whether real or imagined (there is some technical support for this point), 650 wheels tend to be squirrelly on descents. Many riders (mostly climbers) opted not to use 650s in last year's Tour, because the advantages of better climbing would be completely lost in a 65 mph crash, which they felt was much more likely with the little wheels. Tire selection for 650 wheels is almost limited to the most expensive, although we have some orange Kenda tyres that aren't too expensive. If you want to do anything other than triathlon, you might consider 700c wheels for versatility.

Andy

Andy,

Just received an Impel 700 Sugino crankset. Are there different size tapers to BB shafts? Or overall lengths? Although these cranks are sitting in the same spot as the old ones on the tapers, the rings are 1/2-inch off so the front derailleur won't travel that far. Thanks!

TIM O

TIM O,

You need a shorter spindled bb. How much shorter is hard to say, but probably 110 to 113. If your current spindle is 118, get a 110.

Andy

Andy,

About the Rohloff internal geared hub: I'm interested in info on it. I'm told that it may be the up and coming thing after the SRAM internal geared hub.....less resistance to 95-98%. Also, no redundancy within the gear ratios. Can this be true?

Thanks,
Don Peters

Don,

This hub is incredible. If you can put it in your budget, buy it. I'm one of the only guys around who deals with internal geared coaster hubs, and the SRAM is quite nice, but the gear ratio and overall quality of the Rohloff make it outstanding. The only drawbacks are price and weight, but if you offset the weight by the weight of a 24-speed drivetrain, and offset the price by the virtually eliminated maintenance, it's still heavy and expensive.

Andy

Hello,

I have a three-year-old Roadmaster. I like to ride a lot, about 30 miles a day. I just stopped this because of a breakdown. The 7-speed freewheel spins freely in both directions, also cranks have side-to-side play, plastic brake parts are bending...is it worth fixing or junking? The bike is 21-speed Altus shifters.

Sraygor

Sraygor,

Junk it.

Andy

Hi,

I have a question about drivetrain. I currently have a $440 msrp bike. It is the Marlin from Gary Fisher. I guess it has a pretty low end drivetrain. It has both Shimano Altus and Acera components. The bike is pretty new. I do like the bike. I am just starting to ride mountains and getting into it very much. I am not very satisfied with the shifting. I seems to shift rough.

How long will the components on my bike last about? If I were to upgrade, what components should I upgrade? How much does decent "groupo" drivetrains cost? Is it worth it to upgrade? Please help? Thanks! This is a great deed you are doing.

bl

bl,

Depending upon the amount of upgrading you want to do, you may be further ahead to trade in the bike. A partial (mostly) XT upgrade is going to be close to $500, and you can buy a Kaitai with partly XT parts, a Rockshox, better wheels, US built genesis frame, etc, for only $750. This frame and low end fork do not warrant much in the way of upgrades, and the only way to get significantly better shifters is to go 9 speed, which is going to cost more than it is worth.

Andy

HI,

I have a mongoose d40r. It has duel suspension. I was wondering how you adjust the front suspension.

KM,

This procedure requires great upper body strength. You find the nearest dumpster, preferably one with low sides. Grasp the fork with both hands, and hurl for all your worth. With luck, it'll land in the middle of the dumpster without hurting any bystanders.

Good luck,
Andy

Andy,

I just bought a bike, pre-assembled, and have only put about 10 miles on it. The crank is making a cracking noise on the left side, right at about 10 o'clock of every stroke with weight on it. Sounds to me like either crank is put together too tight and a bearing or two is binding, or not enough grease. What do you think? It's a Jeep Wrangler Tsi Bike.

Eddie Ford

Eddie,

Usually a cracking sound is caused by a loose crank arm and is heard shortly before the arm is ruined. It could be something else, like a loose bb cup, but it is most likely the sound of the crank arm taper being enlarged.

Andy

Andy,

My daughter's bike has a squeaky back wheel. I've tried adjusting the the chain, spraying it with WD40 and shouting at it. No luck so far! Any ideas?

Dave Kerslake

Dave,

The squeaky wheel gets the grease, as they say. The trick is that the grease must go inside the hub, so you'll need to disassemble the hub and grease either the bearings and/or the coaster brake parts. If it is a coaster, leave the side with the brake arm together and take it apart from the drive side. Don't loose anything, and look carefully at the orientation of parts before proceeding. You may want to take Polaroids as you go.

Good luck,
Andy

Andy,

I purchased a Lemond Zurich about 10 days ago. I wanted a comfortable bike that could also perform a little without breaking the bank. I am about 183 pounds and 45 years old. I did a fair amount of time trialing in my 20s.

The bike makes a lot of noise if I climb hard out of the saddle. I think that it is the front wheel. The shop says the wheel is in proper condition.

I am going to borrow a set of wheels and see if things quiet down and I am almost certain that it will. Can you tell me if others have had this problem with Rolf wheels? The bike sounds like it came from K-Mart. Do you know of any Italian earplugs?

I enjoy your advice page. Thanks.

Craig Klomparens
Petoskey, MI

Craig,

I doubt that the front wheel is the problem. It's possible, but there are only a few things in the wheel that could cause noise, and we've never experienced problems with this particular wheel. The only way to find sources of noises is to replace suspected parts, so put a new front wheel on and see what happens. Unfortunately, most ear plugs are Asian made, but the Zurich is all Shimano, so there you are.

Andy

Hi Andy,

I have an old Klein Pulse Comp - circa 1995. I ride it quite a bit (everything from class-to-class riding to low-key X-country races to 60+ mile road rides) and I take pretty good care of it, but the paint job is starting to look pretty pitiful. I recently upgraded some components and bought some rock-climbing gear, so money is really tight. With that in mind, I'd like to repaint it myself and I have some questions pertaining to that:

1) Assuming I just want to have a chipless paint job and don't care about a super-glossy finish, will regular spray paint do?

2) I assume I'm going to have to get rid of the old paint first. How do I do that?

3) I also assume I'm going to have to plug up some holes (like the holes for the seat-post, the cranks, the fork...) while I'm painting the thing. What is a good way to do that?

4) Is this whole thing just a disaster waiting to happen? Should I just leave it alone and accept the chips as patina?

Thanks.
Justin

Justin,

If you don't have the tools and equipment, don't do it. You must completely disassemble the bike, and remove most, if not all, of the paint, and if by "regular spray paint" you mean the stuff in the can, forget it. You may as well use a brush and some house paint. For about $150, The Color Factory (1-800-gleam) will paint the bike properly. It won't be a show stopping finish, but it's cheap and quite durable.

For about three times that amount, you can buy a compressor, touch up gun, and maybe enough high quality paint and primer to put runs and overspray all over your frame.

Andy

Andy,

My daughter's Huffy bike brakes don't stop her; they only slow her a little. How do I tighten them? Both the front and the back need tightened.

Thanks,
Lynn

Lynn,

The combination of very poor brakes and slick chrome plated rims usually found on Huffys will result in poor, if any, stopping power. Essentially, the shoes should be less than 2mm from each side of the rim, which is achieved by loosening the cable anchor bolt and pulling the cable tight, or loosening the cable adjusting barrel. In addition, the center bolt should be tight enough to prevent play between the arches, but loose enough to freely move, and the shoes should hit the rim more or less parallel with a slight toe in. You may have cantilever brakes (not likely) in which case you should have them adjusted at a bike shop.

Andy

Andy,

I have been experiencing a lot of problems with my Manitou FS-Ti Stroker Dampening cartridge. I have been doing a lot of trials, but that shouldn't affect the cartridge. Oil is spewing out of the stanchion/Fork leg seal. I replaced the cartridge internals last fall, and now I'm back to square one. I called Manitou, and they sent me an upgrade kit ('98) and it still spews. Is there some special way of installing the seals or some trick, that I should know about? If not, where can I find adequate schematics of the internal components? Thanks for your help.

turbine

turbine,

Some products have earned a well deserved place of honor on the old Wheelcraft fecal roster, and you have one. While I do not refuse to work on these mini geysers, I prefer not to. I have spent hours trying to get all the plastic crap to stop leaking and actually damp the fork, only to have something go wrong after a few rides. Of course, Answer products says that nothing's wrong, that it's a perfectly good product. Take it to a nonferrous recycling center and buy a Marzocchi.

Andy,

I need help.

I recently had a Reynolds carbon fiber steerer fork installed on my Trek OCLV. I have a Cane Creek headset and a TTT Forgie stem (one bolt). The fork refuses to stay tight. It has to be tightened after every ride. I am not doing anything crazy when I ride. I am a 6'1", 175-pound rider. My local bike shop has been unable to fix this problem. I have had the fork tightened 10 times and it always comes loose after 50 miles or so.

Thanks,
Mike Colbach

Mike,

Did a torque wrench ever enter into this situation? Many mechanics and most doityourselfers do not own a Nm/inch lbs calibrated torque wrench. For expensive lightweight stuff, this is vital. It is beyond stupid to install ti, scandium, carbon, or even butted aluminum parts and not use the torque wrench every single time you tighten bolts on such stuff. My suspicion is that somebody over did it and deformed the steerer tube. It could have a very small crack. A stock chromo steerer can take an infinite number of hamfisted over-tightening, but something like this is, well, too delicate for most folks to use at all.

Andy

Hi,

I am looking to upgrade some of the components on my Bianchi Nyala. These are older generic Shimano 7-speed components. I purchased some new Shimano LX cranks, 8-speed shifters, cog and rear der, and a new front der. My question is how do I determine what size bottom bracket I need (length wise)?

Thanks,
Mike

Mike,

BB spindle length is specified by Shimano. If you bought a new crank from a half-decent bike shop, they'd have told you. If you bought it from one of those horrible mail order/internet predatory pricing places, you should have gotten some instructions with your stuff, and if you'd bother to read the English part, it very clearly specifies what works with the crank.

Andy

Andy,

I e-mailed you before about my wheels stopping on the dime. What I really wanted to know is there anything I can wipe or spray on my rims to make them stop on the dime? And if there is, where can I buy it?

Acetone. Windex. Belt Dressing. Sand the brake shoes. Spend $150 on ceramic coating. Fastack. Molasses. Maple syrup. Everclear. Yukon Jack.

Andy

Andy,

I ride a 20-inch freestyle bike and I have only 2 problems:

1) I have aluminum rims and I would like to make them to stop on the dime. How do I do that?

2) I really cannot explain this but my SST gyro all ways tightens up; then, when I loosen it, my handlebars start rocking. How do I fix that?

Hoffman

Hoffman,

You must accept the fact that routing cables through stems and gyros are going to rob braking power, and very good cables and housing, cut to the exact length, well-lubricated and professionally-installed, might actually stop your bike. Most folks lack the ability to fine tune freestyle braking systems, especially the front. I have no idea about the rotor, and I can only suggest that you locate a good mechanic who has experience with this type of stuff (not the stock boy at Wal-Mart).

Andy

Andy,

How is the bolt spacing measured on chainrings? I have a new (to me) crank and my old campy rings are too large, so I need to replace them and don't know what size (110, 130, etc.) to use.

Thanks,
Adam

Adam,

Most road cranks, other than Campy, use 130mm bolt circle pattern, which is easiest to determine with a template. You can probably get one of these from Sutherland's, or you can take my word for it that only Campy uses 135; everything else except for a few odd triples (older RSX) use 130. Mountain bikes use 56-58/94,6/104,58/104, and 74/110, which causes a lot of confusion, but road bikes generally either use Campy or Shimano spacing.

Andy

Andy,

I've got a problem that I think you may be able to help me out with. I am currently in Virginia, but will be off to Romania (Eastern Europe) in two weeks. I am going to be taking a three to five month trip through a bunch of countries out there (Romania, Hungary, Slovenia, Croatia and Greece) and am in the market for a bike. I don't know if this is the type of question that you generally get (probably not) but I have been visiting shops here and they are giving me a ton of conflicting advice. The main issue is the condition of the roads. Often I will be on poorly-maintained roads (huge potholes) as well as occasional gravel, cobblestone and dirt roads. What should I be looking for? A road bike with fatter, stubby tires? Or a modified mountain bike?

Any advice would be GREATLY appreciated...

James

James,

Your choice will be a personal matter. Pros ride the pave on relatively small 700c tyres. If you are interested in speed, get a touring or possibly consider a cross bike. If you want to be safe and comfy, look at a good hybrid. Don't screw around with a real mountain bike. It'll be too slow and uncomfortable on a long day and you'll waste money on stuff that won't contribute to your goal. I really hate to see people buy a bike that's intended for aggressive use and put slicks and hoopdie handlebars on it, and ask to put a 53-tooth big ring on it. Get the right tool for the job, ATB are not for roads!

Andy

Andy,

When changing from a threaded steel to a threaded carbon fiber fork, is it necessary to retap threads after cutting? And how difficult is it--and what is the best way--to change bearing races on fork?

Todd Harper

Todd,

If you use the proper tools (namely a saw guide) to cut the fork, it'll clean the threads after the cut is made. If you're buying tools or paying someone to do the job, it's much cheaper to buy the saw guide than a fork die, and it's much less labor intensive to do the job right than it is to clean up a mess made with a vice and a hacksaw. There are crown race removers and slide hammers. Most forks don't work too well with crown race removers so, unfortunately, I usually employ unsound methods (hammer and old screwdriver, very carefully, I might add). I don't know of anything other than a slide hammer that can set a crown race, and I usually don't advise the average joe to perform this operation.

Andy

Andy,

Can you give me a spoke calculation for a XT parallax 32-hole rear hub and sun cr-17 rim. I'm looking to 3-cross drive side and radial lace the non-drive side.

Thanks,
L.G.

L.G.,

We charge $5 per wheel for spoke calculations if spokes are not purchased from our store. There used to be an online service connected with MTBR, but I'm not sure where to find it. If you want to buy spokes from us, reply with what gauge and whether you want aluminum or brass nips and, if aluminum, what color, and I'll get you a price on the correct length.

Andy

Andy,

What make and model would be a good choice for a 6'2", 290-pound male who last rode a ten speed over 20 years ago?

I plan to ride around the block a few times weekdays and bike trails on weekends. Some of the trails may be a little rough.

If there's a possibility of rough trails, I'd get a mountain bike. Most hybrids just aren't that maneuverable in the rough stuff. I'd spend around $500, if possible. The Gary Fisher Tassajara is a very nice bike in this price range. Bikes I like in the $500 range are the Fisher Marlin, Fuji Thrill and Nevada, Giant Iguana SE.

Andy

Andy,

I was wondering if I could put a front shock on my Dx 3.3 mongoose and wanted to know what to look and not look for.

Thanx,
Brian

Brian,

There should be no problem in installing a shock on your bike. You need to know what size head set (probably 1-1/8) you have and whether you need threaded or threadless (aheadset). If you have a threaded fork, then you must know how long the steerer tube is.

Andy

Dear Andy,

I recently bought a new Shimano Alivio crankset, but the crank arms slide all the way down into the square tapered end of the spindle. This does not allow the arms any room to snug up when tightened. My spindle is a Shimano 68mmx113mm.

Are there different sizes of tapers or square ends on the spindles? The spindle is also new.

M.A.M.

MAM,

The tapers on all non-campagnolo cranks and spindle girth should be roughly the same. You either have a defective crank arm or two, or it is possible that the spindle is too short to engage the taper of the crank arm.

Andy

Andy,

Does my 3-year-old dd60 headshock need to be overhauled? It seems to work fine. This would be preventive maintenance. How is it done? Can I do the work myself? Do I need any special tools? I am pretty handy for an amateur.

AC

AC,

You need some special tools and it would be a good idea to get a Cannondale service manual or the service video for your fork. Over the years, they've changed a few things in the process of rebuilding these forks, and some specific tools are needed to get stuff apart. It probably should have been overhauled two years ago, but at least your taking a step in the right direction by asking. Most shocks should be overhauled every 60 or so hours of use; most people wait until something is gushing out the top of  the fork to ask questions like these.

Andy

Andy,

I have a 1999 GT Outpost with Pro-Max brakes with stainless steel hardware. And I can't figure out how to keep the brakes nice and tight, so they don't rub against the wheel all the time. Can you help me out?

Thanx

You have simple V brakes, and they should work fairly well if you pull the cable so that the brakes are pretty close to the rim. The spring tension may not be adequate to pull the brake away from the rim when released. This is adjusted by turning the screws on the brake arches clockwise. Sometimes on these cheap brakes, I bend the springs outward to increase the spring tension.

Andy

Andy,

Hello there from East Central Illinois. Gotta question about a front shock for my bike. I have a Schwinn Woodlands model that was made in Hungary. I would like to put a front shock system on it but it has a 1-inch steerer tube. Is there a lower price model that would fit my bike?

Pretty cool site! I am new to mountain biking and so far am having a blast. Two months ago I found out I had diabetes and the doctor said to exercise . I wanted to do something fun so here I am.

Sincerely
Dave Huffman

Dave,

We have been well pleased with the low end RST shocks. They have replaceable steerer tubes and brake cable hangers, so they can fit anything. A heavy, decent-quality adjustable fork can be had for about $100, and lest you think RST is a no name brand, they now manufacture low end shocks for RockShox, and they make the Xmo, lightweight high-performance forks.

Andy

Andy,

I have a Dura Ace 8-speed STI about five years old with 12,000 miles. Something popped while shifting the rear deraileur and I had to replace the cable, but the shifter will not click, i.e., it doesn't hold the position as you move to bigger cogs. I was told these things never wear out. It doesn't look repairable. So do I have to buy a new 9-speed shifter and use with my 8 cogs or do I have to replace it all?

Thanks
Sajones

Sajones,

You can still buy Dura ace shifters, or parts, such as just the blade, if that's all you need. They are expensive, but much less than the 9-speed replacement.

Andy

Yeah,

I need some kind of instructions on how to tighten my front and rear brakes on my bicycle? If you could send a picture or step-by-step instructions it would help greatly.

Thanx,
Kyle McLaughlin

Kyke,

To tighten the brakes, you just need to tighten the cable, which can be done with the adjusting barrel on the brake lever, or sometimes (road bikes, for example) on the brakes themselves. If your adjusting barrel is maxxed out, you can pull the cable while holding the brakes at the desired level. This is much easier with the right tools. There is much to cantilever brake adjustment, but V-brakes and road brakes are quite easy. Since I don't know which of the above you have, there's not much I can tell you about that.

Andy

Andy,

I recently put together a road bike with Look PP247 pedals. On occasion, the left pedal makes a periodic (i.e., once per crank revolution) clicking sort of noise, which I can also feel with my foot. It seems to occur more often in high-power, lower-cadence situations. Any suggestions on what to do?

Thanks,
Mark

Mark,

Noises are tough, especially when I can't hear them. Once a guy in Canada sent me an audio file of a noise that his bike was making, and even then, all I could do was give some educated guesses. You probably have one or more of the following maladies: 1) loose crank 2) loose bb cup 3) bad pedal bearing 4) bad bb bearing 5) cleat, or shoe related problem or 6) something completely unrelated, such as loose seatpost, faulty seat rail, loose stem or bar pinch bolt, etc.

Andy

Andy,

I cannot find any info on repairing Headshoks. I recently did a nosedive on my P-BONE M HEADSHOK . Needless to say there's no more spring in it's step. Nothing appears to be broken, just a loss of tension or pressure. Can I just replace a seal or something or should I let a Cannondale shop handle it. I am somewhat mechanically inclined and enjoy doing my own repairs (when they're successful). Any money I spent must not be known to the wife so the less the cost the easier to hide.

Stew

Stew,

Headshocks are tough, and there are several variations on the Headshock theme. You need a few Headshock specific tools, and a corresponding manual, which you'll have to order from a Cannondale dealer. Some tasks are best left to the experts, and this may be one of them. You'll probably need to buy some sort of Cannondale replacement parts, like a damper cartridge or air cap, so even if you do this yourself, you'll spend over $150 in parts and tools, unless you just broke a spring or something like that.

Andy

Andy,

What is the difference between the Sutherland's and Barnette's bike maintenance/repair manuals, and which one would you recommend?

thanks,
Bob

Bob,

Both these books are quite expensive. Sutherland's is a list of specifications and compatibility issues that has very little relevance to the home mechanic. Barnette's is more of a "how to" book, or an actual repair manual. Sutherland's lists what's what and what works with whatever, but does not explain procedures.

Andy

Craig,

I am switching out my XT V-brakes to Avid Supremes. Do I NEED to switch my XT Levers? Thanks for your help.

Craig Allmendinger

Craig,

No.

Andy

Andy,

I want to buy a suspension fork that has clearance for Continental top touring 700 x 47 tires. Do you know which one does?

Thanks,
Don Blansett
Murrysville, Pennsylvania

Don,

I'm fairly sure that the RST hybrid forks will work for this tire. I'm not sure about Rock Shox, as it's primarily a roadie fork, but I think that the RST forks will work.

Andy

Andy,

I have a low-mileage D70R with a crankshaft that knocks (must have been a real fatboy who had it before me). I can't even get the arm off as the first step in looking at it. Should I call Brunswick for advice or can you tell me how to disassemble it?

Thanks,
James

James,

You won't get the arm off (at least not "prettily") without a crank puller. We have portable pullers for about $6, and a real good Park tool for about $12. You'll probably need a bottom bracket, and a bottom bracket tool to eliminate the knock.

Andy

Dear Andy,

A new bike rider at the age of 50, I bought a Bianchi Boardwalk. I ride mostly on roads and some light off-road paths such as rail trials and towpaths. I'd like to change to a suspension seat post but can't get any clear help about my options and appropriate types, models, brands. If I understand the purpose of your web site, can I get some help?

Thanks,
Roy Zipris

Roy,

Suspension posts are everywhere. The price, like everything else in cycling, has come way down, to the point where that if you don't care about weight, you can get one for about $20. A good post without a lot of slop will cost closer to $100, but you may be ok with a lower-priced model, like the Delta post. The more you pay, the lighter and tighter things get. You will notice that cheap posts wiggle around a lot, and this can be real annoying. My picks:
<$50 - Delta
$50-100 - Zoom (I think) Bracer
$100+ - Rock shox or Cane Creek (formerly Thudbuster)

Andy

Andy,

Hey, I would like to know about how much it would cost to get a small bend in my rim fixed, or how to fix it myself.

Spider

Spider,

About $10, usually, and you can do it yourself if you have a spoke wrench, a truing jig, a "rim saver" type tool, and you know how to improve the situation rather than to make it worse, i.e.. experience.

Andy

Hi,

I recently discovered that my dad, who used to be quite the bike enthusiast, has an old set of Shimano Biopaces laying around. Being an obsessive mountain biker and always looking for a cheap way to upgrade, I'm interested in putting them one my bike. What can you tell me about these? All that I know is that for some reason they were taken out of Shimano's lineup, and that they seem to be a legend in the history of MTB fads and lingo. What were some of the problems with them, do they have any real advantages over regular chainrings, and would you recommend using them?

Thanks for your help,
Noah

Noah,

In the early 80's, researchers, probably at some place like MIT or Cornell, discovered that there was a "dead spot" in the pedal revolution. In those days, it was hip in sports medicine to use words like " biomechanical", or "biofeedback". Upon the discovery of this dead spot, manufacturers scrambled to find a way to eliminate this dastardly loss of power. I wish I had a working unit of the exceedingly complex and boat-anchor-heavy Power cam crankset, just for historic interest. Another goofy item was the Allenax (I think I got that right) transpedal system. This was an entire bike, that used a propulsion system much like a Ketler car.

As is still the case, Shimano led the technological charge to eliminate the dead spot with Biopace chainrings. By marketing, advertising, and muscling this product onto bikes, Shimano shut down all competitors.

Bicycling Magazine raved about the performance benefits of Biopace, and consumers demanded that all racing bikes, and eventually mountain bikes had them (Bicycling also raved about such crap as "safety levers"). Now a few bike shop guys didn't like them. They discovered new problems like chainsuck. Front derailleurs were notoriously hard to set up. Some of the knock off Biopace rings were extremely oval, to the point of being diamond shaped.

But, who wants to listen to a bunch of arrogant bike shop folks? After all, these are the same guys who told you that you'd get killed if you used safety levers, that indexed shifting would never work, that front suspension was a gimmick, and that the $20 Taiwan steel frame is superior to the $7 Chinese aluminum frame. For about five years, these chainrings had to be on bikes. Bike companies proudly listed them in their specs, and you'd be foolish to build a bike without some sort of miss-shapened chainring, because nobody would buy it. Eventually, after two million sawed into chainstays, several thousand lost or cracked teeth, and enough mechanics said "you can't adjust this thing," they quit making them. Over the years, "biopacing" has come to mean unwanted suspension bobbing than mimics the motion the biopace chainrings forced upon the rider.

Since the time of  biopace, there have been a few products that actually help to force a correct pedal stroke. The best available is Powerpedals, and actually the Softride bicycle accomplishes this to an extent.

Andy

Andy,

I have recently acquired a '99 Cannondale frameset with a Headshok. I can't seem to find a Cannondale stem that I like to go on the steering tube. Are there other manufacturers that make stems for this thing and is so, how do I find them? I have checked with every online parts supplier that I can find and done extensive searches and come up empty on this one.

Maybe you can supply one?
Thanks,
Claud

Claud,

Profile and Kore, among others, make Headshock stems. Most of these tend to be of the high performance variety (less than 5 degree).

Andy

Andy,

I am installing a 7-speed cassette on a second rear wheel with a 8/9-speed hub to permit quick change from MTB road slicks to knobbies. I found that the 11-tooth gear of the Shimano 11x28, 7-speed cassette isn't cut through to permit mounting it next to the spokes for perfect wheel-to-wheel interchangeability (with the spacer on the outside). I read somewhere that the Shimano 12-gear was cut through and I should be able to use a 12x28. If not, then my options are to find a wheel with a 7-speed hub, or buy another 8/9-speed wheel and mount the 7-speed cassettes the same way on both hubs. What do you recommend other than converting the bike to an 8-speed drive train?

Thanx,
Mark

Mark,

Compact 7-speed cassettes fit on 8/9 speed bodies with 4.5mm of spacers on the inside. If you have bolts through the cassette, they must either be removed, or you can use a spare 1mm spacer with cut outs, such as the one that comes with most cheap cassettes, with 3.5 mm.

Andy

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