Bicycle Mechanics - Converting to fixed gear

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.
Bikesalot
03-20-02, 01:29 PM
Hello all-
I have an older Cannondale Black Lightning 12-speed (with vertical dropouts) that I would like to convert to a fixed-gear road bike. I recently acquired a more modern and lighter 18-speed road bike, so the Canny is gathering dust in the garage. I've already been through Sheldon Brown's (and others') writings on this topic, but I'd like to solicit some advice from members of this board. A few main questions:
1) Does anyone here know the status of Fixed Innovations' eccentric rear hub? I've heard that it is being discontinued.
2) Any special tips on converting a bike w/vertical dropouts? Any other special parts like eccentric hubs or bottom brackets out there for sale?
3) I was told by a fellow rider last year that the Black Lightning was a rare limited edition bike built in the late '80's. He said that the bike was valuable enough to hang onto for a while. Can anyone confirm or disprove this?
Cheers!
bikeman
03-20-02, 03:10 PM
Last question first. Found this link on Cannondale's site Black Lightning (http://www.cannondale.com/bikes/02/cusa/model-2BL.html)
You'll notice it is 30th Anniversary. Longer ago than you were told. Nice bike and very pricey. Maybe C-dale would want to buy your bike back to put in a museum;)
Vertical drop-outs can be a problem. I remember seeing (Sheldon's site??) that there is a chain tensioner device that attaches to the chain stay that keeps the chain in line and taught. Do a search on single-speed and fixed gear and you'll find it.
Sorry, don't know anything about the eccentric hub.
Good luck. Fixies are fun!
RainmanP
03-20-02, 03:32 PM
I can't speak to your questions but I will offer a couple of ideas. With vertical dropouts chain tension will be a challenge. The problem is you may have to experiment with different chainring/cog combinations to get the chain tight enough. You don't want any slack in that chain. It takes very little slack for the chain to jump off under pressure. For instance if you want, say, about a 70 inch gear you could use 42/16 (71), 40/15 (72), 39/15 (70), etc., each of which will provide slightly different chain tension. But it would be difficult to determine which is best without trying them which would be tedious and possibly expensive. I don't think you can count on a chain tensioner for fixed gear. They are designed for single speed freewheels. If anyone knows of one sturdy enough for fixed gear use I would like to get one. Starting and stopping on a fixed gear puts tremendous stress on the chain, and the tensioners won't take it.
As far as wheels, I just used a handbuilt wheel from Quality Bicycle Products built on a Suzui fixed/free flipflop hub and MA3 rim. Retail is $100. Your LBS can order one from QBP. The fixed side uses a thread on track cog and left hand thread track lockring; the other side doesn't have the thread for the lockring. You can put on a single speed freewheel. An inexpensive way to try it out is just use your existing wheel. Just take off the freewheel, thread on a track cog, and use a bottom bracket lockring to lock it up good and tight. Pedaling forward will constantly tend to tighten it, but resisting to slow down will try to unscrew it. So you have to lock it TIGHT. That's why a track hub has the left hand lockring threads. One day I may spring for a Phil Woods track hub. What a work of art.
If you use Shimano track cogs I believe you can use regular 3/32 inch chain (any 5,6,7,8,9 speed chain) Other cogs may require a 1/8 inch BMX chain.
Too bad you don't live here. I'd give you a Trek 10-speed with horizontal dropouts that I rescued from someone's trash pile Monday. I'm looking for a good home for it. Rainbabe says I can't keep it even though it followed me home.
When you start off on a fixed gear, sit down AS SOON as you start pushing the first pedal down and be prepared for that pedal to come on up. You can't just push the pedal and take your time sitting down. That pedal is going to try to come up and can push you off balance or off the bike. And remember you can't just stop pedalling when you want to slow down. Those feet have to keep moving. It really only takes a few starts/stops to get the hang of this and a couple of days to get really comfortable with it. Then when you ride a freewheel it feels like something is wrong with it. You'll see.
I can't think of anymore right now.
Regards,
Raymond
Any sort of chain tensioner is likely to defeat the purpose of the fixed-gear, at least partially. The easiest solution is to keep searching for something with horizontal dropouts.
Richard D
03-21-02, 03:49 AM
Originally posted by RainmanP
I'd give you a Trek 10-speed with horizontal dropouts that I rescued from someone's trash pile Monday. I'm looking for a good home for it. Rainbabe says I can't keep it even though it followed me home.
Raymond
:D, I'll have to try that one, it worked with a stray kitten that followed me in last year ;)
Richard
Feldman
03-21-02, 07:19 PM
Used road frames are a buyer's market; there are bargains by the pile! Just hold out for something good with long horizontal dropouts. Ideal frames from the 70's, for instance, would be Raleigh International and Schwinn Super Le Tour. Both feature long dropouts, good tire clearance, and neither is worth much money.
A Peugeot PR-10/PKN-10 might be a good choice, as well, because of the relatively high bottom bracket and low weight. I still think a hand-controlled freewheel clutch would be a nice safety/convenience feature for a fixed gear, giving one the best of both worlds, and allowing a multispeed fixed-gear application of a Cambio Corsa. That would almost be enough to convince me to try it. (I REALLY like my gears!)
Powered by vBulletin® Version 4.1.12 Copyright © 2012 vBulletin Solutions, Inc. All rights reserved.