Freewheel width

[FrodoBaggins]

I have spent most of the year building and tweaking an old hybrid bike with a Yose Power 350W rear hub.
It has gone pretty well, most of the issues are with the base bike itself
Annoyingly I bought a freewheel kit not the cassette one so had to swap out my cassette for a freewheel, which seemed like no biggie

I have had a nightmare of a time getting the rear gears to index. I went to put on some new rear brake pads the other day and suddenly realised that the frame/ dropouts had been stretched out on the side with the freewheel. This was very noticeable with the v-brakes and also probably why I couldnt index the gears

I have filed the dropouts down a bit to create more room, but the locking nut pushes the side with the freewheel out so that the frame is skewed.
If I remove the locking nut then it sits true, but the freewheel is too close to the frame to use the little gears and doesnt feel like a safe thing to do.
Basically its too big specifically one side (the freewheel side) and bending seems to not bend evenly.

One solution would be to buy a smaller freewheel (as in total width).

Does this actually exist, I bought a non branded 8 speed one off ebay as the previous cassette was 8 speed.

I am fine with dropping down to 7 or 6 cogs, but not sure if the overall width of the freewheel will be shorter. If it isnt then there is no point.

If this doesnt work, I probably need to find a way of making the other side bend out, its just really really tight to try and do that

Any ideas?

 

[Kwozzymodo]

Sounds like you have a few issues to sort out.

First off, check the wheel is sitting correctly in the dropouts. If it is off-centre, this will make indexing tricky. (I am assuming that your shifter, rear derailleur and freewheel are compatible/same speed, etc. Shimano and SRAM shifters pull cable at different rates, for example)

Have you measured the distance on the motor axle, locknut to locknut. This should be 135mm. What thickness is the driveside locknut? You can sometimes replace it with a thinner nut, which should give you a little more room to play with. Is the smallest cog on the freewheel clearing the seatstay when the chain is engaged on that gear?

Pictures are always helpful.

 

[FrodoBaggins]

Thanks for the reply

So your suggestion of a slightly thinner locking nut sounds a feasible and logical first shout. It does seem quite thick so maybe just a few mm might help

With the locking nut out of place it sits totally straight and true (of course I cant ride it like that)
All the brakes line up perfectly and the wheel seems completely straight, its just as soon as I try and add the locking nut and tighten it in on the drive side.
It pulls it out on that side and the wheel no longer sits straight

Logically to me there seems like 2 feasible options

1. Stretch the rear forks on the left side to try and even things up
2. But a smaller freewheel (if such a thing exists)
3. Get a smaller locking nut

Gear wise I am confident that if I can get this straight, all will be good. I have read enough forums about stretched chains and cables.

 

[vfr400]

Your frame isn't bending unevenly. It's just that if you add more off-set (width) on one side, the rim will move half that extra width distance from the centre.

As a general rule, 7 speed freewheels are OK with a bit of dishing, but 8 speed needs more dishing to get the rim central, which then makes the spokes too loose on the left side.

Many bikes are built with the rear forks off-set a bit from the centre, but I've always had to dish wheels to some extent when building a wheel with a rear motor.

 

[sjpt]

Are you sure the spacing (between the cogs) is the same on the cassette as it was on the freewheel? They should be if both are 8 speed, but not necessarily. If not you will never get the indexing right.

 

[esuark]

are your dropouts actually "parallel" to each other and in line with the frame...........

 

[FrodoBaggins]

are your dropouts actually "parallel" to each other and in line with the frame...........

Yes appear to be OK

 

[peter.c]

This is a screw on 10 speed which replaced a 7 speed redished the wheel to re-centre it had to add washer to clear the frame

 

[FrodoBaggins]

So if I am correct it seems that

1. Get a thinner lock nut (if I can)
2. Make sure the freewheel is definitely the same
3. Get to the best I can and then re-dish

Hopefully I can sneak down the garage a few times over Xmas and have a fiddle!

Ha ha I just realised that last line sounds very wrong!

 

[peter.c]

The 10 speed freewheel was 1mm wider than the 7 so while the freewheel was off , removed the axle had a tube spacer and a locknut , unscrewed the nut removed the spacer tube added the washer first then tube last then the lock nut [ saves time if removal of wheel required just slots back ]
The rim/tyre was not in the centre so tyre off then re-dished pulled over in this case just loosen one set of spokes and tighten the other side
PS fitting the freewheel was easy the fat bike rim will not fit in the wheel jig so alignment had to be done in the frame with cable ties as guides

 

[vfr400]

This is a screw on 10 speed which replaced a 7 speed redished the wheel to re-centre it had to add washer to clear the frameView attachment 39879

it looks like you have a wide hub and rim, so you can dish it a lot further tha a typical 18mm or 19mm bicycle rim. Is it a fatbike? What's the width between the drop-outs?

 

[peter.c]

Yes it is a fat bike with 155mm between the dropouts drop outs all my non fat bikes take a cassette
Next build will probably be a charge cooker maxi, which also is a boost frame 155mm which will take 26 fat or 27.5 -29er boost

 

[vfr400]

Yes it is a fat bike with 155mm between the dropouts drop outs all my non fat bikes take a cassette
Next build will probably be a charge cooker maxi, which also is a boost frame 155mm which will take 26 fat or 27.5 -29er boost

Yes, but OP is having a problem with his width, then you show him a 10 speed freewheel on your bike as if he can fit one on his. Supposing OP didn't realise that you had a fatbike, and spent his hard earned money on the same freewheel only to find that it didn't solve his problem.

 

[peter.c]

see your point

 

[harrys]

WIth your original question, yes, a 6 speed is usully thinner than a 7 speed. Depends on maker, but SHimano makes all of mine, A year ago, I was a too tight on an alloy frame with a 135mm Q100H motor, but it uses a nut and spacer under the freewheel to set the O.L.D. I took off 5mm on the spacer, and switched down to a 6 speed freewheel.

The bike was 20", with an integrated luggage rack, so there were effectively three chainstays to spread, and I like the motor/wheel to drop in.

 

[Sturmey]

Sheldon Brown has a list of freewheel spacing's. But where is says total width, he is really measuring from the sprockets but the list is useful for comparison.

Sheldon Brown's Bicycle Frame and Cassette Spacing Crib Sheet

Useful dimensions and conversions for the cyblist/mechanic: hub and sprocket cluster spacing

www.sheldonbrown.com