Singlespeed & Fixed Gear - First Lazy conversion: Do I really have to re-dish?

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Sawtooth
03-20-06, 08:26 AM
I did my first conversion this weekend and simply swapped the freewheel on my 1982 peugot for a cog and BB lockring. After screwing around for hours with the chainline/tension (all big changes at the crank end), I managed to get it rideable. It is nothing to brag about but I am pretty sure it is safe and have enjoyed the first 30 miles on it without incident. I did almost go over the bars a couple of times on a 20 mile group ride when I forgot about the bikes new rules. Also, going from advice on this forum, I rode it hard and then re-tightened the lockring.
I notice, however, that I see almost no conversions that have simply left the rear wheel as-is. I know it would be stronger to re-dish, but I am not certain I will never want to replace the freewheel. Moreover, I think I would prefer to save up and buy a nice set of wheels with flip-flop hubs or something and a real reverse-thread lockring option.
Is it safe/sound to ride without re-dishing? How precise does that chainline really have to be?
Thanks
I had a chainline off by about 3mm, rode it successfully for about 20 miles and then the chain broke, I believe caused by the mis-alignment. Caused me to be picky about it, now.
Did you use spacers in the front to move the ring inboard?
Sawtooth
03-20-06, 08:52 AM
I had a chainline off by about 3mm, rode it successfully for about 20 miles and then the chain broke, I believe caused by the mis-alignment. Caused me to be picky about it, now.
Did you use spacers in the front to move the ring inboard?
Yes, and I swapped to a shorter spindle length bottom bracket. It is visually off, but working for now. Your story makes me somewhat concerned. I wonder if one could make up for just a bit of that by going with a 1/8 inch chain (the cog is 3/32)?
Sawtooth
03-20-06, 08:56 AM
[QUOTE=colinm]I had a chainline off by about 3mm, rode it successfully for about 20 miles and then the chain broke
QUOTE]
Thanks for the warning. That reminds me that I probably need to be carrying a link or 2 in order to avoid walking home someday.
powers2b
03-20-06, 10:10 AM
Yes, and I swapped to a shorter spindle length bottom bracket. It is visually off, but working for now. Your story makes me somewhat concerned. I wonder if one could make up for just a bit of that by going with a 1/8 inch chain (the cog is 3/32)?
I use 1/8" chains on all my SS/FG bikes.
I get them at Xmart for $5 and change them every riding season.
You really should go ahead and re-dish the wheel.
It only takes about 1/2 hour on a truing stand for a first timer and it is a great learning exp.
Enjoy
If the derailleur chain (1/2" x 3/32") fits the chainring & cog, the chainline doesn't have to be perfect 'cause the chain is made to flex sideways. Think of how your chain was flexing as you were using the various cogs/chainring combinations before you switched. Your current chainline probably isn't as bad as what is occurring on most derailleur-equipped bikes all the time!
If the wheel was strong enough as a multi-speed wheel, it's strong enough as a single-speed wheel.
All else being equal, a no-dish wheel is stronger than a dished wheel, but there are lots of radically dished wheels out there that are working fine. A 1/8" chain works OK on 3/32" teeth, but may wear the driven side of the teeth unevenly 'cause there's some slop in the width/fit. Probably not enough to matter....
On the other hand, a near-perfect chainline & minimally dished wheel does look better..... ;)
Sawtooth
03-21-06, 03:54 PM
Thanks for the feedback everyone. I may or may not redish. It is nice to know that I don't have to. By the way, it has been very fun to have my buddies here at the office take it for a spin around the parking lot.
worker4youth
03-21-06, 06:10 PM
I had a chainline off by about 3mm, rode it successfully for about 20 miles and then the chain broke, I believe caused by the mis-alignment. Caused me to be picky about it, now.
Did you use spacers in the front to move the ring inboard?
Not likely. Geared bikes almost always have the chainline > 3mm off. Plus, the chain on the newer 9, 10 speed road bikes are much narrower (and hence, weaker).
huhenio
03-21-06, 06:12 PM
tell me about it ..... clink clink clicnk ........snap
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