Fixed geared bike to internal hub gear conversion??

[Sore Thumb]

I have a specialised langster fixed gear bike 120mm rear axle spacing.

I would like to change this to an internal geared hub.

I was looking at the Sturmey Archer 8 speed

X-RF8(W)

http://www.sturmey-a...hubs/cid/5/id/6


Would this hub work for my bike or are there any other options that you would consider.

I would like to do some touring around the UK on this bike.

I can maintain my own bikes no problem, but I am a bit clueless when it comes to internal gears.

What items will I need to get if the sturmey archer option will work. eg cables, shifters. Do I need a grip shifter or can I use a bar end shifter that I have seen advertised below

http://jtekengineeri...end_shifter.htm

If you could help me out with these questions I would be most grateful.

Thanks

 

[MartinC]

The main thing is the OLN of the hub must match the frame - the langster and the 175mm axle SA8 are both 120mm so this is fine.

IIRC your langster will have a Sugino crank on a 103mm BB giving the standard track chainline of 42mm. The SA8 chainline will depend whether you use a flat or dished washer (and which way round it is) - you'll need to get it as close to 42mm that you can 'cos SA's specs say it's on the low side.

You'll have to fit a shifter. The JTEK one is for Alfine hubs so won't be any good - the cable pull must be spot on or you'll damage the hub. SA might make a bar end shifter for the SA8 though and this would be a good option. If not you can get adaptors (SJS cycles) that allow you to fit a twist grip shifter to a bar end or the headset spacer stack.

Be aware that in the SA8 hub all the gears are an increment on the lowest gear i.e. the 1:1 gear is the lowest so if you're touring you'll need a tiny chainring and a massive sprocket. 24 is the biggest sprocket you'll find. You may be better off finding a 3 or 5 speed hub with a 120mm (ish) OLN 'cos the middle gear will be the 1:1.

You'll have to cable tie the cable to the frame because the langster tubes aren't a standard size.

I've just got a 2 speed kickback hub (S2) to build into a wheel for my langster - it saves all the change issues and gives me a gear for hills.

 

[GrumpyGregry]

I've just got a 2 speed kickback hub (S2) to build into a wheel for my langster - it saves all the change issues and gives me a gear for hills.

I've had the 2 speed kickback hub with coaster brake (S2C) in my Charge Plug for a good while now. Really rather good. Not toured with it but have done a few day rides.

 

[corshamjim]

Looking at the SA site, the technical pdf and the parts available at sjsc here http://www.sjscycles.co.uk/sprocket.../#filterkey=brand&brand=STURMEY_ARCHER&page=2, it would seem the standard sprocket on the 8-speed SA hub is 25t.

Using Sheldon's gear calculator http://www.sheldonbrown.com/gears/ you can work out what size chainwheel will give you the range you need.