Convert Geared to single speed?

I picked up an old bike from ebay, with the intention of doing it up and using it as a winter/tourer. Alas, it just wasnt good enough for that but I dont want to waste it so i'm going to turn it into a single speed bike.

Never had a fixie/single speed before so I have a few things i'm not sure about and hope some people here can help....

If i whip off the old (5 speed) block, can i just replace with a single speed freewheel? (i.e. can you get compatible screw-on, single speed freewheels?) I've looked on eBay but they all look like they're for BMX's !!

The rear dropouts are the normal forward-facing dropouts (with a gear hanger) but normally, fixies have rear-facing drop outs. Whats the significance of that and does it make a difference?

Lastly, Whats the recomended gear ratio? (I'll probably cheat a bit and use the original double-ring crank so i'll have a choice of 42T or 52T at the front)

Any other advice/suggestions/top tips?

Thanks
Rob

One of these is all the kit you need, you just need to ensure the sprocket is inline with the chainring when fitted, and your chain has been shortened to within an inch of its life! http://www.retrobike.co.uk/forum/viewtopic.php?t=232111&highlight=

spacer kit for the rear - make sure to line everything up as straight as possible. Tighten the chain so there is a nominal amount of flex. you may want to consider replacing q/r skewers with a bolted axle.

ratio depends on what your local terrain is like - no point setting a high gear if you've got hills and have to do the walk of shame after getting off half way up

too low a gear and you'll just be spinning. I chose a rear gear based on my road bike and what felt decent so ended up with a 53/15 configuration.

You can use the bmx type freewheels or there are specific ones for fixies - ive always found these guys very helpful - http://velosolo.co.uk/intro.html

also you can use this to help you choose.. http://www.bikecalc.com/gear_inches

I was sceptical about doing a fixie but i now use one everyday as my work bike and it's great fun and does help in building fitness.

I didnt even realise that you could get "freewheel spacers" but just searched on ebay and loads of results!! Great, thanks for your advice.

And searching on ebay, looks like i can get the freewheel i need for about a fiver so thats good.

Thanks for your help.
Rob

Are you going fixed or SS?
The latter is easy. Buy a cheap ss freewheel.They don't last long but I got a couple of thousand miles out of one on my CX bike. Keep them full of oil.
Remove old freewheel. Screw on new one. Put in frame . It may not line up with chainrings but you maybe able to move that from oone side to another on the spider. If you have an old BB you may be able to move that to one side a bit. Try those before messing with hub. If not move spacers and wahsers from one side of hub to other to line up sprocket/chainring. Rim may be out now and need re dish. May not.
Those dropouts are fine. Track neds face backwards and will be on bikes made specifically for single speeds. What you have is the norm before verticaldropouts became fashionable.
Converting to fixed might be slightly more trouble in that ideally you need a hub that takes a fixed sprocket and lock ring. you can however bung a fixed psprocket on you freewheel thread and use an old BB lock ring to hold it in place. Poor mechanical sympathy ie no grease helps heres as the damn thing will seize on eventually !
Not sure what you mean by freewheel spacers. If its those rings you buy to replace all but one of the rear sprockets they are meant for cassette hubs. you have a freewheel and it doesn't work like that. Well it could but its not worth the trouble.
Might I suggest a visit to Sheldon Browns website for more info.

Also, not mentioned yet, there is a labour-intensive but cheap and efficient way of sorting this, which is to rebuild your back wheel with the shorter drive-side spokes moved to the other side of the hub, and vice-versa. You will end up with a reverse-dished wheel, and a combination of juggling the axle-spacers between the sides, and then fine-tuning the dish to centre the rim, will get you a good chainline. This puts your drive-side wheel bearings close to the drop-out, and gives you non-dished drive-side spoking, which is good...

This approach possibly turns your back wheel into an unholy freak which nobody else wants anything to do with, which, depending on circumstances, may be an advantage or a disadvantage.. plus you will kick yourself when you decide you want a multi-speed block again, because you will have to reverse the whole process..

Another option is redish your wheel so it's running centrally rather than offset. With a 5-speed block there will be a wide spacer on the freewheel side, so you put half-size spacers on both sides of the axle. This happens to be pretty much the width of two nuts. Use the 52 tooth chainring on the outside but get a narrower bottom bracket to line up the chain. This is my preferred way of doing it.

Fixed - One giant step back for mankind

Whoa! So many options! :shock:

I don't think I will tackle rebuilding a wheel and I don't want to pay for it either. I dont even know how much ill use it yet!!
For now, I will just go with the easy option and straight swap the 5speed with a single speed and see how that goes.

Thanks for the tips tho.