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converting a road bike to a singlespeed/ fixed gear(14 posts)

converting a road bike to a singlespeed/ fixed gearwaynebiker
Nov 26, 2001 3:42 PM
I have a colnago BiTitan built up with shimano 9speed. I would like to make this bike into a singlespeed/fixed gear.
To do this from what I understand i would need:
-a rear wheel with a flip-flop hub(fixed one side freewheel on the other)
-a new chain
-new chainring
Is this all that I would need?
-the rear dropout spacing on my bike is 130mm. do they make track hubs in that spacing?
-will the vertical dropouts be able to hold the torque of fixed gear in place?
any ideas or suggestions will be greatly appreciated
thanks for the help
dave
waynebiker@aol.com
let me be the first to say....sorghum
Nov 26, 2001 4:24 PM
for all your fixed gear conversion needs ....
Sheldon Brown!!!

http://sheldonbrown.com/fixed/index.html

I just built one up myself for the grand total of $77. including the frame!

AS

p.s. - the vertical dropouts will be a touch tricky
how will they be tricky????????????waynebiker
Nov 26, 2001 4:27 PM
thank you
how will the vertical dropouts be tricky?
'cause you can't adjust the chain tensionohio
Nov 26, 2001 4:35 PM
You'll need to use a bolt on-tensioner, or an old derailleur with the top-out screws set to your single cog.

That's why I looked for an old frame with semi-horizontal dropouts. Track frames (true horizontal dropouts) will work the best, but they're kind of funny handling on real roads according to good 'ol sheldon...
Might get lucky ...Humma Hah
Nov 26, 2001 6:30 PM
For any given vertical dropout to crank spacing, there are certain gearing combinations that just happen to give perfect chain slack. Sheldon has some guidance on that. No need to adjust if it starts out perfect.

Me, I have horizontal dropouts.
gear combo to fit vertical dropoutssorghum
Nov 26, 2001 7:34 PM
you can get to this from sheldon browns site but here is the direct link to a site that has a java program that will figure what gearing combinations will work with your vertical dropouts. pretty neat!

http://www.peak.org/~fixin/
Did mine for less than $20cory
Nov 26, 2001 4:39 PM
As Sorghum said, the vertical dropouts may cause you some minor problems, and Sheldon Brown is one place to go for a fix (if you get unlucky, a Singleator or other chain tensioner, about $40, will fix you up, or you can make a tensioner out of an old rear derailleur). My old Trek has semi-verticals (slanted back about 45 degrees), which gave me about half an inch of adjustment, and that was enough. It had a freewheel, so all I had to do was spin off the old freewheel and spin on a one-cog BMX freewheel ($14.95) with a spacer ($1). In front, I took off all but the middle chainring. Most people recommend 2:1 gearing. I went a little lower (38:20) because I live in the mountains and I'm a sissy--but I'll probably drop to a 19 or 18 in the back when I get in shape next spring.
It's big fun to ride, and winter maintenance is easy--just hose it off and lube the chain. I'm surprised how much I like it.
Cory, is your new conversion a FIXED or a single-speed?nigel
Nov 26, 2001 5:29 PM
It sounds like a single-speed.

I've been considering doing this, but am really low on dough right now. I could turn my old Atala into gold (or at least something worth something again) by making it a fixed.

Any further suggestions are greatly appreciated!

Cheers, and enjoy.
Nige
It's a single...cheapest possible conversioncory
Nov 27, 2001 9:46 AM
Sorry--it's a single, not fixed. I sort of wanted to try SS, but I wasn't sure I'd like it and didn't want to spend a lot of money. I've had the bike for years, and it hardly got ridden anymore.
The freewheel (vs. a cassette) made it easy to swap because the BMX freewheel spun right on, and any BMX shop will have spacers to get the chainline right. Mine used one 4.5mm spacer and came out near-perfect with the middle ring. As I said, the semi-vert dropouts gave me just enough adjustment for tension. No problems with throwing the chain, even with the standard (designed for shifting) chainring (ss rings and cogs have a teeth designed to hold the chain rather than let it go).
There's lots of stuff online about this. If you have vertical dropouts, sometimes you can adjust chain tension by going up or down one tooth. Close enough appears to be close enough--at least on my bike, tension doesn't seem to be critical.
If you can't get the tension right, one cheap fix is to keep the rear derailleur for the tension alone, turning in the limit screws so it doesn't move side to side. In fact, I set mine up like that originally, but I wanted it to look cleaner and was able to do it without the der. Total investment (if you don't count the bike...) was $15.95, but then I had to get new bar tape and 700x40 tires, of course...
flip flop not neccesary.vanzutas
Nov 26, 2001 5:21 PM
A flip flop hub gives the best of both worlds but it is by no means the only way to go. The best thing to do is to go to sheldon brown and take it all in. there are many ways to go about this. I do not believe that they make track hubs with your spacing.

Adam
Would not be my first choice of bikes to convert, but ...Humma Hah
Nov 26, 2001 6:26 PM
... it can be done.

If you have not already done so, visit

sheldonbrown.com

and click on Harris Cyclery, for a wealth of singlespeed and fixed gear options. Sheldon is the fixie/singlespeed guru, knows all, sells the stuff, too.

Vertical dropouts usually require some form of tensioner to take out the chain slack, tho there are exceptions. Horizontal dropouts are preferred by most SS enthusiasts, although I know a couple who dispise horizontal because they feel they are inclined to slip out of alignment.

You can very likely use the existing chainring, if the alignment works out OK.
re: converting a road bike to a singlespeed/ fixed gearStampertje
Nov 27, 2001 2:27 AM
Track hubs don't usually come in 130mm but I know Phil Woods do (but they're hugely expensive). You can just respace the axle on another hub - Harris / Sheldon Brown can do that for you if you order there.

A chain tensioner would not work with a fixed gear because the chain will pull it tight and lock up if you don't move your legs fast enough. Some gear combinations will work with the vertical drops, and they will definitely hold the wheel in place, but you could also get an eccentric bottom bracket. I forgot who makes them.

And you don't really have to change the front ring (unless you want a different size) - my old front ring works just fine with my singlespeed chain.
re: converting a road bike to a singlespeed/ fixed gearwalter
Nov 27, 2001 10:14 AM
I made a fixed gear with a old Schwinn LeTour frame. If you want to try fixed I definitely recommend an older frame (126mm spacing) and horizontal dropouts. A tensioner will not work with a fixed gear. One reason is listed right above the other reason is that you will stop by resisting the pedals even if you have an "assist" from a front brake. Chain tensioners will not stand up to that.

For a freewheeler you should be fine and there's lots of good advice already posted. For what it's worth I'd get a tensioner so I could use whatever gear combos I felt like. There are BMX flip-flops that take a freewheel on both sides.
BMX spacing is 110nm
Nov 27, 2001 10:40 AM
nm