Couple of questions..

[charliehorse]

Hi All

Sorry, I am out of touch with bicycles for years so I am not up to speed on adjustments etc.
I got my rear wheel onto my Carrara Kraken MTB this evening, 9 speed 11t DNP freewheel fits too without much stretching of the rear forks. I had to put two of the washers that came with the conversion inside the freewheel on top of the spacer to space the forks enough to stop the chain fouling them. I could reduce the last washer by 3mm or so which I will do.
I adjusted the derailleur stops to stop the chain at the 11t cog. I have about six sprokets available which is loads.
I noticed that the rear wheel is about 8mm off centre due to the thicker 9 speed freewheel. I can get that to about 5mm by replacing the aforementioned washer with a thinner one.
Is was wondering if this 5mm off center is a problem maybe with tracking or something?
The other question is regarding the disc brake. I cannot find a disc to fit my 48mm adaptor so I thought I would adapt an ISO disc or make a new one using a 2mm steel disc.
Does anyone know if its possible to just make one or are they made from some exotic material.
Charlie

 

[Deleted member 4366]

The offset is not too much of a problem with disc brakes. You probably won't notice anything different handlingwise. We normally re-centre it by going round the rim loosening the spokes on the disc side by 1/2 a turn and tightening them on the drive side by the same amount. You'll need to go round several times to get the rim central, probably about three complete turns on each. Finally, you'll have to make the rim run true, so have a look at the various Youtube video guides. It's not difficult.

You'll probably be OK to make the disc out of stainless steel plate of the right thickness. You could make just the centre part and weld or screw the outer bit too it if a complete one doesn't work.

 

[charliehorse]

Thanks Dave for that info.
I will see how bad it is when everything is snugged down. Trying to find an ISO disc with enough meat left around the existing holes to drill new ones is not easy. They are all lightened to the last. Possibly a small adaptor plate on the adaptor would work and would also help to get the disc closer to aligning with the caliper. Really need that back brake, the bike is wicked fast.

 

[D8ve]

CharleyH.
It's the front brake that NEEDS to be a disk.
It's only nice ish to have a disk at the back call callepers are fine.
Look up motorcycle braking to find out about weight shift and loss of grip at the rear

 

[anotherkiwi]

I agree with D8ve. With feeble V-brakes you do tend to use both brakes when riding fast because the front one is not enough alone. On my last motorbike I don't think I ever used the rear brake once and on the rare occasion I have riden a bike with disks I did the same. For my conversion I am putting a hydraulic rim brake on the front and better brake pads on the standard rear V-brake.

Tony

 

[RobF]

Agree with the others, a hydraulic disc on the front is all you need, unless you want to do broadside stops.