Mountain Bike Reviews Forum banner

1 - 2 of 2 Posts

·
Registered
Joined
·
89 Posts
Discussion Starter · #1 ·
Here are the parts:
Sram MTH 506 R hub on Alex Rims DP20
Specialized Rockhopper
Avid BB7 brakes

As the title says the rear disc is rubbing the caliper mounting bracket when the rear wheel is installed (outisde of disc to inside of mounting braket). This is a new install. The bike orginally had rim brakes. The mounting braket is installed on the inside of the of the frame side of the frame mounting holes. I'm using the 160 R braket that came with the disc set. I inquired at LBS about purchasing a different braket and they said the brakets are the same for the rear unless you are adjusting for disk size. I'm at a loss. Disc appears to be mounted flush to the wheel and is torqued to spec. Wheel set is brand new out of box and brakes were lightly used and undamaged from my bike. These are going on my 10 year old daugeters bike and we're both eager to get her back up and running and of course I'm working on this in the evening when Sram and Alex Rims are closed. If anybody has any suggestions I'd greatly appreciate it. I'm trying to find a tech manual for the hub but having no luck.

Thanks
Bryan
 

·
Registered
Joined
·
6,762 Posts
Here are the parts:
Sram MTH 506 R hub on Alex Rims DP20
Specialized Rockhopper
Avid BB7 brakes

As the title says the rear disc is rubbing the caliper mounting bracket when the rear wheel is installed (outisde of disc to inside of mounting braket). This is a new install. The bike orginally had rim brakes. The mounting braket is installed on the inside of the of the frame side of the frame mounting holes. I'm using the 160 R braket that came with the disc set. I inquired at LBS about purchasing a different braket and they said the brakets are the same for the rear unless you are adjusting for disk size. I'm at a loss. Disc appears to be mounted flush to the wheel and is torqued to spec. Wheel set is brand new out of box and brakes were lightly used and undamaged from my bike. These are going on my 10 year old daugeters bike and we're both eager to get her back up and running and of course I'm working on this in the evening when Sram and Alex Rims are closed. If anybody has any suggestions I'd greatly appreciate it. I'm trying to find a tech manual for the hub but having no luck.

Thanks
Bryan
Sorry I didn't see this sooner and I hope you have it sorted out. However if you don't it is a simple fix. Specialized has been known to not face the disc mounting tabs on bikes that originally come speced with v-brakes. So they are a bit too thick and the adapter sits too far inboard and rubs the rotor. Had the same issue on my Wife's Hardrock when I went to set it up for discs. The solution is to have the mounting tabs properly faced. This can take some doing depending on how much material needs to be removed. With the Wife's HR it took about an hour as about 4mm of material had to be removed before things could be set up correctly. You'll likely have to have this done at the LBS as the tools are rather expensive, and it does require a specific tool to do it right.

Good Dirt
 
1 - 2 of 2 Posts
Top