Single speed conversion?

Question

i want to convert my bike to a single speed because i only ever use 1 gear on my bike and there is no need for all that extra weight and stuff to go wrong

i saw people using a bmx freewheel in place of a 7 8 9 speed freewheel but u have to respace your wheen then get it re dished and i cant do that and ive only just got my wheels trued (by local bike shop £40 for the pair abit expensive) i have found a way to tension the chain (vertical dropout) but i need help with the freewheel. would this work? using a 7 speed freewheel and taking the sprokets of and some how locking the selected gear on the granny gear (last 1) with 2 lock rings, 1 eather side. i will sort out a chinset by moving the selected chainwheel inwards towards the frame with some washers to get a good chainline .

whould this work? any 1 know of any 1 who have done this

thanks for any ideas put foward

Answer 1

That sounds like a lot of trouble for something that will probably slip under torque.   I guess you could rig up a metal spacer to slip over the freewheel body and position the cog, locking it in place with the threaded cog (and probably a second, thinner spacer on the outside of the cog).....but.    

I think it'd just be alot simpler to put a singlespeed bmx freewheel on there, switch spacers on the axle, and re-dish the wheel.  I just did this with an old road bike of mine.  I do all of my own work, though, so it was cheap and done correctly.   A bike shop shouldn't charge much to redish your wheel, though.....it's very simple and only takes a few minutes really.  

As for the chainwheel....you can try washers to space it, but it looks a little ugly and you need to be sure that it sits squarely in the tabs on the crankarm for strength.  Most people put the chainwheel in the inside position (as long as you have clearance with the chainstays....if not, use a smaller gearing combo or a longer bottom bracket spindle).  You may need to pick up a set of narrower singlespeed chainring bolts, too.  

If you have the ss freewheel already, or can borrow one, thread it onto your hub and use a long straightedge (a straight one!) to see how far off your chainline is.  Then, you can swap, add, or subtract spacers on the axle as needed....you can do this part yourself if you have cone wrenches.  If you can get it within a couple millimeters of lining up with the chainring, then you can take the wheel to the shop to be re-dished for a few dollars....err, pounds.   :o)

I don't think people need to go full-bling on ss conversions, but doing it sorta the "right" way sure pays off in the end.  If you rig things too much, it might give you trouble and just be a hassle in the end.   Worst case, you spend money on the rigging, and then have to spend more money setting it up proper later on.  

Hope this helps...have fun with it, tinkering with bikes is a good way to spend time!    :o)

Answer 2

Hum...  Do you have a freewheel or a freehub?  Most modern bikes use a removable cassette on a freehub that is affixed to the wheel.  Old bikes have integrated hub and cogs called a freewheel.

Because you mention a locking cog, I am going to assume you have a modern cassette and freehub.  This means all your really need is some spacers, a chain tensioner, and a locking ring to take the place of your smallest cog.  You can use one of the cogs of your cassette.  Many companies make single speed conversion kits with a bunch of spacers, a chain tensioner and a locking ring.

Here is the page of all conversion kits at Universal.  I am sure there are a number more available if you look about.

http://www.universalcycles.com/shopping/...

No doubt, you can find what you need somewhere in the land of pounds.

Hope this helps.