Rear disc brake

[Triplehelix]

Hello. I am helping a friend build a bike with disc brakes. I have the hub adapter installed and the chain line looks good. But the thickness of the the disc brake hub adapter won't allow me to mount the rear caliper with the stock mounting hardware. Does anyone know how I can make this work? Thanks in advance.

 

[HumanPerson]

180mm IS Adapter, if you are stayin at 160mm rotor for that...

200mm IS adapter for the 180mm rotor.

bike shops should have them for around 16 to 23 bux.

 

[HumanPerson]

use a belt sander to make the IS adapter thinner to fit how it needs to fit.
may have to make the mount bolts shorter as well

 

[HumanPerson]

might even need some washers between roto and frame

 

[DAMIEN1307]

Hello. I am helping a friend build a bike with disc brakes. I have the hub adapter installed and the chain line looks good. But the thickness of the the disc brake hub adapter won't allow me to mount the rear caliper with the stock mounting hardware. Does anyone know how I can make this work? Thanks in advance.

Mine is done with a 203MM disk as that has the best clearance for real wheel usage...There seems to be a black caliper to frame to caliper mounting adaptor missing from your pic to get better perspective of how your trying to attach what you are working with...(see my second pic to see how that adaptor attaches to your caliper and frame mount), 2 pics of mine provided below...be aware of the difference in both of our ways of attaching to frame...your frame has it built in...i hand made my adapted frame support and its bolted to the frame with a hand fashioned fork that slips over the spindle...DAMIEN

 

[Triplehelix]

Here is another pic with the is adapter in place.

 

[DAMIEN1307]

Here is another pic with the is adapter in place.

use a belt sander to make the IS adapter thinner to fit how it needs to fit.
may have to make the mount bolts shorter as well

Your going to need to shave down both the adapter and the adapter holder on the frame so you do not weaken either of them too much to enable that to fit.

Unless someone else comes up with a better idea that is...DAMIEN

Ps...There is one other thing you could do. What i did on my bike was, because i had to hand stretch the frame to be able to clear the sprocket properly so chain wouldnt be pressing against the frame...To keep it that way, before putting it all together, i used one of those 15 MM nuts that usually hold the wheel, on the drop down as a spacer between the disk itself and the inner part of the frame drop down...USE BLUE LOCKTITE to hold the nut in place...it was exactly the right width, (around a 1/4 inch or so), to keep the chain from rubbing, but also allowed perfect spacing to allow attachement of the caliper adapter to attach to the frame holder...I Just remembered how i did that...i have CRS because im old now...lol...DAMIEN

 

[Triplehelix]

Thanks Damien. This build is for a cancer patient. I hope this gives him something to look forward to and get some fresh air. And the will to live.

 

[wan37]

I had to use a bigger rotor mm to clear the drive chain . Seems to work for me. I got a 180 mm it’s real tight I need to go bigger rotor like 203mm and stretch frame a little.

 

[wan37]

So if you got aluminum frame it’s not supposed to be stretch only steel frames.