Hi all,

Firstly, sorry if this has been posted a hundred times before but I could find something that was specific to what I needed to know.

SO, I will attempt to convert my old crescent bike into a single speed. For this first bike I want to spend as less money possible, simply because I want to get used to a single speed before spending loads of money on it.

I've been reading quite a bit about the process and it all seems pretty straight forward until you get to the hub, cog and ratio. I understand that 42/17 is a fairly good ratio for a flat city but what about the use of the existing cogs? I'm guessing it's an old Shimano uniglide hub?

I recently read the article published by Tim on The Sustainable Cyclist (https://thesustainablecyclist.com/200...the-wrong-way/) which kind of scared me a little bit since I had been thinking about using one of the existing cogs (if that eve would have worked) Otherwise I might just buy one of those surlybikes.com/parts/fixed_cogs to slap on there (again if that works...)

Saw this video where the dude made it look fairly easy:
https://www.youtube.com/watch?v=93M9l...eature=related

The thing is that I've got about 2 days, in about 2 weeks, to spend on it and I want to make sure I've got all tools/parts needed to complete it then.

Really appreciate your help and, again, sorry if a similar thread has been posted already.

H

Get a bmx freewheel,flip the bb spindle to the non drive side,use the inner ring and see what the chainline is like.If it's off by more than 3 or 4 mm,respace and redish the wheel(or have a shop do it,although some may refuse to do it).More info here:https://www.sheldonbrown.com/singlespeed.html

Thanks for your quick reply! Luckily I've got an old BMX laying around back home so might use that.
Just out of curiosity, why can't I simply slide on another spocket instead and fill out with spaces?

Like Sheldon is talking about under 'Cassette Hubs'?

"The better way to convert a cassette Freehub ® is to remove the 7-, 8- or 9-speed cassette and replace it with a single sprocket. You will also need a bunch of spacer washers to hold the single sprocket in place. You can often get a suitable number of spacers by taking apart a couple of discarded, worn-out cassettes."

Couldnt i do this but using a new rear sprocket?

Thanks,
H

I guess mine is not a cassette freehub but a freewheel...?
Pretty sure it's a freehub though...

If it's a freehub you're all set,keep the cog you like and use spacers (or make one out of copper pipe) to set up your chainline.Seeing the big metal pieplate i guessed your bike would pre date freehubs.I've seen mostly smaller clear plastic spokeguards on wheels with freehubs.Have fun with your build.

Fingers crossed! Will find out in 2 weeks. I'll keep you updated on the process.

Thanks again for your help! Can't wait to get started!

H

Before you go any further, find out for sure whether you have a freewheel or cassette: https://www.sheldonbrown.com/free-k7.html On a bike that old I'd be very surprised if you have a cassette.

I think you should redish the wheel no matter what, because it will be stronger that way.

That's the main question, if it's a freehub or freewheel... As I really need to have everything before I start I might be best off getting a single sprocket (since I don't want to use one from the actual cassette) as well as a single speed freewheel (BMX style). Doesn't seem to expensive.

So another question would be, which sprocket for a freehub should I get? Been looking at this Surly sprocket (surlybikes.com/parts/fixed_cogs) but pretty sure it wouldn't fit on a freehub. Any suggestions?

Also found this photo, not sure if it helps in trying to determine if it's a freehub or freewheel...



Cheers,
H

First, see this thread:
https://www.bikeforums.net/showthread...bikes-to-SS-FG

As far as ID'ing freewheel vs. freehub: Take the wheel off and look around the axle end and see if there's a hole with splines, ala the Sheldon Brown link. If there is, it's a freewheel and you can just take it off and screw on an ISO thread (16t+) BMX/single speed freewheel. If you're lucky, it will line up with your inner chainring.

If the freewheel was made before 1984, it requires a hard-to-find tool (see pictures in the thread above.) Your best bet is to take it into a bike shop and have them remove it. Otherwise, you can get a standard Shimano freewheel tool to remove the freewheel that's on there, then screw the new SS freewheel on by hand.

Do this...

Remove the derailleurs and the inner chain ring... lay the chain across the middle of the freewheel on a cog that is 18-20 teeth and shorten the chain to fit that gearing.

Voila... a single speed that cost nothing.

Sixty Fiver, thing is though that I'd like to get rid of that nasty cassette. That would have been a great option though.

Sillygolem, unfortunately I won't have access to the bike until about 1 week so I can't determine physically if it's a freewheel or freehub.
Since the bike is in Sweden and I will have about 2 days to spend on it before I have to get it back down to Paris I need to know before what kind of wheel it is so that I can order necessary parts etc.

I found really cheap single speed freewheels on velosolo.co.uk/shopsingle.html called Dicta Singlespeed Freewheel.
They're only about 10 bucks and might be a good start. I might just order a Andel Cro-Mo Singlespeed Cog just in case it's actually a freehub.

Would these work in case it's a freehub/freewheel?

H

i'd bet that's a freewheel, not a freehub.. how many gears is it? i count only 5 on the hub which would mean it is for sure a freewheel

if you want to try single speed for cheap, just use 65er's method. then if you like it, get the singlespeed freewheel and redish the wheel and all that

Cool, also found out just now that the bike is from before 1985 so it might use the old style thinner cassette...
I could do 65er's method but I'm really keen on a nice little bike projekt this summer

Thanks for your help!

if it is from before 1985 it is freewheel.. you can't use a "cassette" on a freewheel. cassette is specific only to freehubs. it's a freewheel gear "cluster"

Cool, that makes sense! Thanks!

So all I need then is a cog like this? I guess there's a risk that the size is not the same since this pre 1985 freewheel is, as I understand it, smaller than the later ones...

https://surlybikes.com/parts/fixed_cogs/

Apologies if I seem totally lost but simply want to make sure I order the right stuff.

I'm the editor of a website called Projekt (www.projektblog.info) and I will put up this bike project as a post there when I'm finished.
Will def also put up a link and recommendation to www.bikeforums.net, great help!

i'm not sure about older freewheels being smaller.. i know they are smaller width-wise, but i think the part that screws onto the freewheel is the same size regardless of year.

when you switch to a single speed freewheel, you will need to respace and redish your wheel to make sure that the cog is lined up with your front chainring. re-dishing an old wheel can be a pain in the butt if you have any stuck spokes so make sure to lube them all before trying to turn any of them

I saw it in this post earlier poster by sillygolem:
https://www.bikeforums.net/showthread...bikes-to-SS-FG

Sorry, got a bit confused before. It's one of those I need right?
https://www.velosolo.co.uk/dxfw.html

I guess I won't need any kind of lock ring or anything?

If it is a 5 speed freewheel, removing that and swapping in a single freewheel and running the chain ring on the inside of the spider should give you a near perfect chain line and a single speed with a multi speed chain is more forgiving of a less than perfect chain line than a fixed gear.

If that has a cassette an SS kit for a freehub can be used.

You just have to know first what the rear block is before you can get parts.

I'm pretty sure it's a freewheel based on the feedback and comments on this post so I'm keen on ordering some parts.
What will I need? A freewhell and a lock ring? Do I even need a lock ring?

A freewheel will thread on on with no need for a lock ring.

So all I need to get is one of these?
https://www.velosolo.co.uk/dxfw.html

got my dad to snap a photo of my BMX bike I've got laying around at home and it seems it has a suitable freewheel! Lucky me.

The splines on the earlier Shimano freewheels are smaller which means you need a different tool to remove them, but the threads will be ISO regardless. The splines are only on the outside of the freewheel, and only to give you something to grip and unscrew it.

I have a cheap Dicta freewheel on my bike, and it works fine. They're also sold under a lot of house brand names (Diamondback, Sunlite, etc.) The freewheel on the BMX above looks like it has 16 teeth, so it should work, too.

FINALLY FINISHED!
Thanks to everyone who helped me on the way.

https://projektblog.info/2011/06/convert-a-road-bike/