Single/Fixed chainline question

smurfylicious

I'm looking to convert my old Dawes Super Galaxy to Single/Fixed. It has an old screw-on 6 speed Shimano SIS freewheel. The chainset is a triple Shimano Deore. The bike dates from about 1990.

My questions are:
1. Will it be easy to get the correct chainline on this bike? How can I adjust the chainline if it's wrong? Can I get spacers to position the freewheel/sprocket slightly differently on the screw-on hub? Will I need a new chainset to get the correct chainline?

2. Where can I get good quality 3/32 components?

Thanks

stickman

If it was me i'd get 1/8th chain + parts, the chainset you have is designed to have the chain shift off it easily, and you'd need a shorter BB.

smurfylicious

Fair enough.

Where can I get some good 1/8 bits from?

Should I order a new single-chainring chainset?

Thanks

stickman

Yes, get a single chainset, having said what I did above I recently completed a bike with a 1/8 freewheel and chain and a 3/32 single chainring and it works fine, it's a Stronglight chainring, i've see them on ebay, also the Mighty brand which are cheaper but i've had no problem with them, got the freewheel from a bike shop, if a shop's good the stuff they sell should be fine.
Put the new chainring on your old BB to check how much shorter you need to get.

smurfylicious

So I went to my LBS, and they told me:
1. A fixed sprocket will never go on my screw-on hub as the threads are different from the 6-speed shimano freewheel it was designed for
2. The chainline will always be wrong unless I buy a track hub or re-dish my wheel

:-(

stickman

I've never used fixed so can't comment but done it with singlespeed freewheel. Chainline should be equal to small chainring and largest cog on a derailleur set-up, so try it first see if it rides ok, if not, get it re-dished.

(Unless you only want fixed)

Monty Dog

smurfylicious wrote:

So I went to my LBS, and they told me:
1. A fixed sprocket will never go on my screw-on hub as the threads are different from the 6-speed shimano freewheel it was designed for
2. The chainline will always be wrong unless I buy a track hub or re-dish my wheel

:-(

Suggest you find a new LBS who knows about singlespeed - check out sheldonbrown.com on the subject

Stellite

Check out some good FAQ here

http://www.velosolo.co.uk/faq.html

GarethPJ

Don't worry about redishing. It's really simple if you're methodical about it. I did one on saturday. Swap round the spacers so you have the same OLN dimension as before but equal amounts of spacer on each side. Then pop the wheel back in the frame. Set up a marker on the brake mounts so you can judge when the wheel is centred. Starting at the valve hole I alternatively loosened each spoke on the none drive side and tightened a quarter turn on the drive side. After each complete trip round the wheel check the alignment and check for trueness. If it's going out of true then true it up. When it's centred you're done.

Bear in mind that after a few miles of bedding the spokes will probably need some more attention.

As for swapping to 1/8" you don't really have to bother. 1/8" is no stronger than 3/32", but it is best to go for a proper single speed ring at the front because the chain is less likely to unship. There's no need to use single ring bolts, it's easy enough to slim down doubles. And while you're at it buy a single speed 3/32" chain to suit. You shouldn't have any trouble getting hold of 3/32" single speed components, most track drivetrain components are available in both sizes.

However don't put a fixed sprocket on a hub intended for freewheel, even using an old BB ring as a lockring and loctite it may still come loose. BTDT. More than once. Far safer to use a proper fixed wheel hub with the reverse thread for the lockring.