Sprocket for a modern Aturmey 3 speed ??

[BADGER.BRAD]

Hello All,

I have a modern Raleigh 20 type bike fitted with the 3 speed AW hub I wish to change the gearing but am unsure whether I need a dished sprocket or flat. I am trying to go from the fitted 16 tooth to a 20 to make the thing a little easier for the other half who has a damaged leg.

Any help appreciated

 

[hubgearfreak]

replace like with like. and you'll possibly also need a chain

 

[BADGER.BRAD]

I'm guessing from what you say it could still have either type of sprocket on ? I was going to mail order the sprocket from Fleabay as my local bike shops are not too good. I may even try a single speed BMX wheel I have.

 

[tyred]

These usually have a few shims which can be moved around if necessary. On my (original type) R20, I was able to change a straight 15t sprocket for a dished 18t and still maintain the correct chainline by moving the shims around but if you are in doubt, the best thing is to double check what you already have by removing it if necessary.

The BMX sprocket will be no use. It is a thread on freewheel.

 

[hubgearfreak]

I'm guessing from what you say it could still have either type of sprocket on ?

sorry, no. what i mean by replace like with like is take off the old one, noting which way the dish (if any) is orientated and order one the same. ie. like the old one.

tyred's quite right. you'd struggle to get a bmx one to work.

 

[BADGER.BRAD]

I have now temporarily replaced the Sturmey hubed wheel with the BMX wheel and must say the gearing is much better, that way I can now still use the bike while I strip the other one to find out which type of sprocket it uses , it’s the full wheel not the sprocket Tyred. I must say the change is not the best in the first place not sure if this is created by the grip shift or the hub itself? It doesn’t seem to be very positive and I struggle to tell what gear the thing is in. Do they normally improve with age to some degree? This one is very low mileage at the moment but doesn’t seem a patch on the older bike we had with the old British Sturmey 3 speed!

 

[bobg]

Watch out for the spring washer that holds the sprocket in place...
One of 4 things normally happen
1. Its a pig to get off
2. Its a pig to get on
3. Its a pig to get off and on
4. It shoots across the room/shed/garden etc into a parallel universe

 

[BADGER.BRAD]

Right , I had a word with my local bike/toy shop !!!! Which used to be a Raleigh specialist when I was a kid. He said bring the sprocket down and we will try and match it, as he has various old tat ( sorry should I say hard to find items) in the lock up across the road. I took the said sprocket down and he matched its type with a 18 tooth instead of the 16 tooth I had. He seems to like me as I'm never doing the normal thing building bikes out of junk, Suicide fixed hubs,Racing levers on my bar ends and parts for all the local kids BMX/Mountain bike fixes. Have a guess how much he charged ? One quid !!!! The spring clip came off O.k and went back on with only a minor amount of grief and I even used the original chain (what a miracle !).
The only problem is my lad had a go and found he could wheelie the thing with ease ? now the thing needs locking away as he has already taken the paint off the end of the rear guard Little git.

 

[BADGER.BRAD]

Ps may I add I spent Half an hour looking for the spring clip which I had left on the wheel axle and got told off by the misses for doing bike repairs in her lovely kitchen ! I mean what are kitchens for on a horrible wet day ?