Rear Brake Centering

[Pearson]

There is no 'adjustment'. If things don't line up, either parts are missing, or in the wrong place, or backwards, or something is warped or bent...

Thanks ptm..I'm still learning and last night was a lesson I don't want to repeat. I'm still PO'd about what I did to my rear brake....but wouldn't the chain adjusters change the angle of the tire and therefore the disk in relation to the caliper?

[turkish]

pearson
''''wouldn't the chain adjusters change the angle of the tire and therefore the disk in relation to the caliper?'''

i don't think so because doesn't every thing gets bolted together through the spindle there for should always be aligned automaticly........
may be caliper support is twisted

[Pearson]

i don't think so because doesn't every thing gets bolted together through the spindle there for should always be aligned automaticly........
may be caliper support is twisted

Hi turkish...I completely overhauled the rear end of my bike and just saw no evidence of damage. That's part of what made me ask.

What about overtorquing the axle nut or other associated caliper hardware?

[ptm]

Thanks ptm..I'm still learning and last night was a lesson I don't want to repeat. I'm still PO'd about what I did to my rear brake....but wouldn't the chain adjusters change the angle of the tire and therefore the disk in relation to the caliper?

Yep, we're all still learning and have lessons we don't want to repeat. Oh, the stories I could tell...

Regarding your question, the disk and caliper both move together. They are all attached or fixed in relation to the axle. That is obvious for the wheel/disk, but the axle also runs through the bottom of the support that the caliper is bolted to. If that weren't the case it would be very hard to get the caliper and disk lined up precisely.

[Billyboy]

If you tighten one side of the adjusters more than the other it could change the angle/alignment of the wheel and disc.

[Pearson]

I also noted my chain is favoring one side of the rear sprocket over the other, it's not right down the middle. With what I did to my brakes last night, I'm going to have to take most everything back off and double check my work.

[diesel]

Here are a couple more pics, one is again from the rear and the other is from the rear, but kind of underneath the bike.




Luke

Wow you folks have me totally messed up. I've been around a while and I don't recall EVER seeing or hearing of a GS850 that was chain drive. So these photos have me wondering what's going on.

Regarding misalignment caused by unequal setting of the chain adjusters. I agree with the post that said that wasn't possible. The bracket alignment is maintained by axle so the adjusters are out.

IMO the possibilities are:

incorrect placement of spacers or washers on the axle - this could also account for the reported chain misalignment (though that actually could be cause by the adjusters)

missing spacers or washers on the axle

a bent axle - rotate the axle with the wheel in place. If the clearance changes / caliper wobbles, then the axle is bent.

worn or bent caliper mounting bracket

[lukehan]

The photos are from a 79 GS850 shaft drive. I think other posts on the thread are from someone else who has a similar problem on a chain drive model. I have not done it yet, but my next step is to take the rear wheel off and check everything for straightness/correct position. The clearance is fine on the front of the calipers, so I am thinking the mounting bracket is tweaked.

Luke

[Pearson]

The photos are from a 79 GS850 shaft drive. I think other posts on the thread are from someone else who has a similar problem on a chain drive model. I have not done it yet, but my next step is to take the rear wheel off and check everything for straightness/correct position. The clearance is fine on the front of the calipers, so I am thinking the mounting bracket is tweaked.

Luke

Yeah sorry about that, I kinda half hijacked the thread 'cause the 750 and lukehan's 850 appear to be identical on the right side of the bike. We both appear to be having the same problem. I'm starting disassembly once the weather warms up to check my spacers because it's clear in my case I'm off a good 2mm's and my caliper is rubbing against the rotor.