nath981

right front caliper: pistons on the inside extend twice what outside pistons do. I imagine that the carrozzeria wheel is about a mm too wide at the rotor mounting position thus positioning the rotor more to the outside of the caliper. The other side caliper pistons are centered.

Anyone run into this issue? How much off center is acceptable?

cliby

how much is twice as much in mm? Is it the same on both calipers? same side?
First be sure your wheel is centered properly with the spacers you are using. After market wheels sometimes require different spacers as i recently discoverd! The calipers will have a portion where they ride close to the disc that is specified in the manual for a minimum clearance. be sure you have this equal on both sides. If all those things check out and both pistons are clean and retract well I wouldn't be too concerned. Its all a fluid system and once it hits the disc if both can move freely they should exert equaly pressure

nath981

On the left side of the bike, the pads are centered indicating that the rotor is spaced correctly. The right side is a diff ballgame: the inner pads are extended twice that of the outer pads(2/3 to 1/3). Looks like 4 or 5mm. I tried adding a spacer on the right side but this makes the wheel off center.

cliby

that different its surprising you have clearance for the calipers on the disc - there is not rubbing caliper to disc, correct?

The disc to disc distance must be different than stock. I don't have a stock set up anymore but perhaps ask someone to give you a careful measurement of the inter-disc distance so you can compare. Wheel spacers won't help that - the only fix it to use spacers to move the caliper or spacers to move the disc. Or to be sure there are no safety issues and if not, live with it.

nath981

that's a good way to do it. I'll have to install my old rotors on the OEM wheel and contrast that to the Carrozzeria set up. thanks for the idea. I'll do this and get back.

nath981

Bill,

I started over to make sure: loosened front forks and retightened according to manual. Loosened axle and pinch bolts, let the bike down and compressed the forks to align, and raised up and tightened acc to manual(axle nut, right side pinch bolts, and calipers). Then put the bike down again and compressed forks several times to align. Raised again and tightened left side pinch bolts. This yielded somewhat diff results. Now, both sides caliper pistons are unevenly displaced instead of one side only.

Removed wheel again and measured shanghai rotors from inside to inside, then took them off and installed OEM rotors and measured. It turns out that the Shanghai rotors are 128.5 mm and the OEM rotors are 126.5mm inside to inside. So this explains the pistons being unevenly displaced to accommodate the more flared out shanghai rotors. Also, the OEM rotors are .5 mm thicker than the Shanghais.

So I know that the OEM and Carrozzeria wheels are the same in terms of measurements and the rotors are responsible for uneven piston extension. So I’m putting the stock rotors back on. PIA, but should have more vigilant form the beginning.

Sometimes I can’t see the forest for trees. Thanks for the ideas and the comments that helped me to clear this up. That’s what makes this forum so great. Apersheate it, Nathan

cliby

double check with new rotors. I still would have thought with the slightly wider rotor spacing and the thinner rotor (as I understand your description), that on center to center of the rotors would be very close. but depends on rotor thickness. Guessing you are right.

Are the rotors flared out more than stock? or are the disc mounting points wider then stock - that is going to be the key difference. If rotor design is different and you love them you still have options by shimming things. Hard to imagine why an aftermarket rotor made for this bike isn't same space and same on-center spacing. So double check the stock ones fit perfectly. If so certainly easier to go with stock. But, If the hub is wider at the disc mounting points, than you could always have it altered to meet stock specs which would make rotor swaps very simple..

nath981

actually i interchanged wheels and rotors ad nauseum to make sure I was understanding what the problem was, and the Shanghai rotors are definitely flared 1mm more on each side and are .5mm narrower in thickness. You'd think it wouldn't be noticeable, but it is responsible for off center piston extension. That said, I don't know if this condition is causing the annoying roughness under heavy braking. It doesn't appear that shimming is possible since the rotors are too far to the outside already.

This roughness is even more aggravated since I've been utilizing the Nick/freddie style trail braking i was describing on the other thread.

thanks, nathan

nath981

went back to oem rotors, sandblasted rotors and sanded galpher pads. We'll see what happens now?