Caliper rubbing rotor...using mix'n'match Ducati parts. UPDATE w/ ride.

b. · June 16, 2009, 10:01:20 AM

Some info:

'05 M620
'04 S4R forks
'05 MTS1K 4-pot calipers
Galfer Wave rotors

I'm swapping my stock forks for S4R forks and have hit a snag during installation. The brake pad "guide" (hard part on caliper) is making contact and rubbing against the rotor on one side. I'm still able to spin the wheel, but the rotor is shaving off the lower tab on the caliper. The donor forks have no visible damage and I don't suspect them to be bent. Prior to the S4R forks, this brake set up worked perfectly with my stock M620 forks.

I'm considering filing this tab down a little so that there's enough clearance...any reason not to do this? It is possible to get the brake pad in on that side, which pushes the caliper far enough away so that no hard parts are scraping the rotor, but this can't possibly be good for pad wear. Also, the caliper only starts to hit when it is tightened. The last few turns of the bolts seem to kink the caliper in such a way that this lower tab contacts the rotor. The wheel moves freely when the caliper is mocked up with the bolts still loose.

TIA for any insights/suggestions. Pictures of exactly what's hitting what to come this evening...

Speeddog · June 16, 2009, 10:09:57 AM

That collection of parts should work with no problems, AFAIK.

Do you still have the OEM rotors to try?

Pics will help...

b. · June 16, 2009, 10:37:15 AM

I do still have the OEM rotors, but they're only the 310mm Brembos as my stock 620 had the crappier 2-pot calipers.

Pics are coming...I ran out of patience last night after being defeated by the installation and was too lazy to upload pics.

Spidey · June 16, 2009, 11:15:06 AM

Did you already try to loosen everything and then re-tighten? I'd start by reinstalling the forks, the front wheel, the rotor and the caliper. It shouldn't take too long and that'll often solve the problem if something is binding or rubbing.

Also, you have a caliper carrier on your 620 that goes between the calipers and the forks, right? If so, are you using it with your current set-up?

b. · June 16, 2009, 11:24:53 AM

Not yet, but that's the next plan of attack. Everything will be coming off and be reinstalled to make sure all is seated properly.

Yes, caliper carriers were necessary with the stock set up, but the ones from the MTS are the larger 4-pot Brembos and bolt directly to the forks.

Thx Speeddog & Spidey for the initial advice.

Norm · June 16, 2009, 02:44:33 PM

Shim, grind, or.......................
Whatever works, it's not precision work.

b. · June 16, 2009, 09:53:33 PM

No time to work on the bike tonight, but here's a couple pics of what's going on. The brake pad is not in and you can see where the "guide/tab" of the caliper (where the pad would rest) is making contact with the rotor.

If reinstalling everything doesn't work, would it be better to file this piece down a little on the caliper or to put in a spacer between the caliper and the fork leg?

Thx again, everyone.

Speeddog · June 16, 2009, 10:15:23 PM

From the pictures, it appears a spacer is just going to make it worse.
IMO, don't go filing on that piece just yet.

Are you *sure* those are the right Galfer rotors?

Maybe the MTS forks have a different location for the caliper mount bosses, and thus a different caliper.
That might explain it.

m9hundo · June 16, 2009, 10:18:11 PM

how much play do you have on the other end? Could a washer/spacer move it out? That looks sketchy, I wouldn't fudge with the brakes.

b. · June 16, 2009, 10:44:05 PM

Quote from: Speeddog on June 16, 2009, 10:15:23 PM
Are you *sure* those are the right Galfer rotors?

They are identical to S4R snowflake rotors in diameter and offset and worked with my stock forks and MTS calipers. I don't see why they then would cause problems with S4R forks. I was under the impression that there was no difference between the S4R fork bottoms and my stock 620's. Maybe there is and I didn't do my homework?

It's just odd because it's only happening on this one side. The right side mounts up just fine with the pads and has no issues with clearance.

Quote from: m9hundo on June 16, 2009, 10:18:11 PM
how much play do you have on the other end? Could a washer/spacer move it out? That looks sketchy, I wouldn't fudge with the brakes.

I agree...I don't feel good about filing the calipers. There's a lot more clearance on the top end. Something is just odd about how the caliper kinks and pushes the bottom of it into the rotor when tightening the bolts that hold it to the fork--especially when it's only happening on the left side.

I'm still definitely going to pull everything off first and reinstall. I really hope that something funky is going on there...

DucHead · June 17, 2009, 05:49:24 AM

Maybe that fork is tweaked a bit.

corey · June 17, 2009, 06:40:01 AM

Quote from: pompetta on June 17, 2009, 05:49:24 AM
Maybe that fork is tweaked a bit.

Or maybe you over-torqued your axle? wouldn't that pull the fork in a bit?

Norm · June 17, 2009, 07:03:35 AM

If one side is different from the other, it's time to get out a tape measure and figure out why.

corey · June 17, 2009, 07:24:08 AM

could you possibly have put the wheel spacer on the wrong side? making the wheel much closer to one for than the other? i don't know, just throwing out thoughts...

ducatiz · June 17, 2009, 07:39:00 AM

can you say how much interference it has ? i am surprised but could be a minute variation in the fork.

loosen and retorque everything

i would loosen and "finger tight" all the bolts and see how it fits before retorqing. feels like soemthign is pushing it.

News:

Caliper rubbing rotor...using mix'n'match Ducati parts. UPDATE w/ ride.