Help with fixie/ss conversion please!

doubleforwards
doubleforwards Posts: 26
edited January 2011 in Workshop
I expect this topic has been done to death so feel free to point me to other posts but any responses will be appreciated

I've been given an older road bike which I'm going to fiddle about with and experement with my mechanical skills. I fancy trying to turn it into a fixie, is this possible without buying a new rear wheel? Will it only be possible to run as a single speed due to the fixie body unlocking when I try to brake?so really my question is can I convert the wheel to a fixed one?

Thanks

Comments

  • I believe it is possible (Surly I think do some sort of conversion kit) but whether it's safe or not I don't know. Maybe others can comment on that. I have seen some cheap and nasty DIY jobs which look lethal to me so my advice would be to bite the bullet and get a proper back wheel.

    I made a fixed wheel bike out of an old frame, a chainset I had lying around and other odds and ends I had knocking around. The only 'new' bits I bought were a fixed wheel for the back and a decent bottom bracket (it's important to get the chainline right - if you don't then you run the risk of the chain coming off at the most inopportune moment!).

    I ride it all the time these days when I'm not on a club ride. It's well worth the investment.Riding fixed really is addictive.
  • I originally hoped I'd be able to convert the rear wheel to a fixie and then dispose of of one of the front rings on the the cranks. However I'm not sure this is possible or maybe safe anymore after a bit of research!
  • P_Tucker
    P_Tucker Posts: 1,878
    Well, you could somehow jam the freewheel (firing a blowtorch at it for say 30 seconds or hammering in a few nails) which would have the desired effect. The other point is that unless you have horizontal dropouts you'll need some sort of bodge to maintain chain tension.
  • There are various ways around most of these problems.

    Check out the single speed section of the Sheldon Brown and / or 'Charlie the bike monger' websites.
  • John C.
    John C. Posts: 2,113
    Yes you can convert. I used a wheel with a spin on block ( not sure of technical name). First job is to centre the rear hub on the axle ( you will/may need different spacers ) This is basically strip the hub and after cleaning etc... replace with the hub in the centre, if you look before stripping it is offset to the left to accommodate the block. So measure the spacers and you will need the same on either side. You will then have to recentre the rim , to do this slacken all spokes on the drive side by a turn and tighten all on the non drive side. Now spin and see how much the rim has moved across . Repeat until the rim is in the centre . You now have a fixed wheel, all you need now is a fixed cog and lock nut which any DECENT LBS should be able to sell you. If the bike has vertical dropouts you may need a 1/2 link to go in the chain.

    Have fun, and remember if you stop peddling and you're not clicked in you will go over the handlebars :oops:
    http://www.ripon-loiterers.org.uk/

    Fail to prepare, prepare to fail
    Hills are just a matter of pace
  • My dropouts are horizontal or at least appear to be so should give enough movement to sort out the chain tension. So with a lock ring I should be able to get it up and going. I think I'll stick with 2 brakes at least for the start! I'm keen to do it all myself but think I might struggle a bit with centring the wheels, will I be able to do this without a stand to spin it in?
  • amaferanga
    amaferanga Posts: 6,789
    I could be wrong, but I don't think a lockring will work unless you have a fixed hub. Fixed hubs have one thread for the sprocket and a second opposite thread for the lockring. If both are screwed on in the same direction I can't see the lockring making much difference. Some say they're not necessary anyway though....
    More problems but still living....
  • John.T
    John.T Posts: 3,698
    amaferanga wrote:
    I could be wrong, but I don't think a lockring will work unless you have a fixed hub. Fixed hubs have one thread for the sprocket and a second opposite thread for the lockring. If both are screwed on in the same direction I can't see the lockring making much difference. Some say they're not necessary anyway though....
    Correct. The lockring will not have much affect. The bike would then be technically illegal with only one brake. Best to run 2 anyway.
    Also a hub built for gears will be narrower across the flanges than one built for fixed/SS. This will make getting a good chain line difficult. The narrow flange spacing will not be ideal for the extra side thrust that spinning down hill puts on the wheel.
    Best get a proper wheel.
  • redvee
    redvee Posts: 11,922
    I've respaced a screw-on hub from 130OLN to 120OLN for my SS recently using the spacers that came with the hub and a few spares, total cost for the wheel including Mavic Open 4CD was £20 :D If you use a normal screw-on hub without the smaller thread for the fixed lockring and you have enough space then a BB lock-ring is the same size, 1.37"x24tpi.
    I've added a signature to prove it is still possible.
  • John.T
    John.T Posts: 3,698
    If you use a normal screw-on hub without the smaller thread for the fixed lockring and you have enough space then a BB lock-ring is the same size, 1.37"x24tpi.
    Better than nothing but is still not a lockring. It will just unscrew if you stamp on it hard enough. The reason for a LH thread LR is it will tighten if the sprocket tries to unscrew thus locking it.
    It is quite posible to space a130mm axle to 120. My point was that the wider flange spacing on a fixed/SS hub makes a stronger wheel. Riding down hill at 150 rpm on fixed puts a lot of side forces on the wheel (unless you are a much smoother pedaler than me).
    Even a centralised and dished wheel using a screw on block hub will give poor chain line. You will need to use the inner ring position on double cranks to get near. And at 150 rpm you do need to have it right.
  • redvee
    redvee Posts: 11,922
    Forgot about the LH thread :oops:
    I've added a signature to prove it is still possible.