82 yamaha xj110j maxim- binding brake issue....alignment?

[service writer]

Hi Folks,


I bought my first bike from my brother a few weeks back. It is the xj1100j. It has sat for 17 years and I have had my share of challenges. While I may hit more brick walls, but I have one I’m stumped on. A little background: The last time my brother rode it, he just put new tires on. After taking it, he said it had a handling problem, like the bike wanted to tip back and forth. For whatever logic, he got disgusted and just parked it. About 5years later, he got the bug again, started it drove it out of the garage and found he had brake problems. Disgusted again, he parked until I picked it up.

Seeing that the rear brake pads were worn down to nothing, I decided to change them. For worn pads, the caliper was still stiff to pry off. When I put the new pads on the bolt didn’t line up, I can force it on, but will completely lock up the rear wheel and looks out of whack from forcing it. Pads are correct.

http://www.flickr.com/photos/10336364@N02/870035454/

I suspect that when the tires were changed that the alignment or positioning of the rear wheel was messed up. Although the caliper was pretty stiff from setting so long. I had to flush out the brake fluid as it looked like mud. Caliper is seating back far enough but still the bolt is ¼ or better away. The tires have about 5 miles on them, and still question if there could have been a reassembly problem.

I tried to loosen the rear axle pinch bolt and axle nut to try shifting the position

http://www.flickr.com/photos/10336364@N ... otostream/

Is there any rear axle adjustment to move the caliper bracket/ swing arm closer to the wheel?

I adjusted the front swing arm adjustment as far as I could go without going over spec of 1/16th difference.


What gives?

Thanks, Paul

[Sev]

Hrmmm... well first take the caliper off and push the piston itself as far into the body as you possibly can.

Then take the rear wheel off and lay it flat on the brake disc, check to see if it's warped at all. From there... hmmm, your swingarm may be bent, the axle could be installed incorrectly, the wheel could be bent. There's a lot of stuff to line up in there.

But I would start with just pushing the piston back, remember, you've replaced old thin pads with thick new ones, that means the original spacing won't work anymore, the slot will be smaller.

Don't tell my instructors this, but you can stick a large flat-head screwdriver between the pads and pry them apart - you risk breaking the pads this way.

OR you can take it off and press one pad against the other in order to squish the piston back in.

Sitting 17 years means it's possible that the piston itself has seized inside the caliper. In which case, I'd probably just go looking for a new working caliper to replace it with.

[service writer]

Thanks for the reply Sev.

I have new thoughts. If the swing arm or axle is out of alignment, the caliper bracket that is affixed to them would also be out, but would then rub on the rotor. Since the caliper bracket is just about centered on the rotor, I'm ruling out alignment. Caliper is fully compressed.

I need to get another set of pads from another manufacturer to compare, unless anyone else can verify this. The old pad is worn on the opposite angle from the new pad. For that matter the thickest point of the old pad is thicker than the thinnest point ( or corresponding point) of the new pad. Take a look:
http://www.flickr.com/photos/10336364@N02/?saved=1

[Sev]

I dunno, it's tough to tell based on just the pictures. It would be a lot easier to get in close and fiddle with it. Only thing I can advise is to make sure the rotor isn't bent, and then quadruple check all the alignments. Make sure that the axle is evenly adjusted, make..

OHH OHH OHHH, what stops the caliper from spinning? Is it a slot in the swingarm? Does that make sense? Make sure that is aligned correctly. I've "messed" that up before, the part that stops the brake from just spinning with the rotor can be attached to the swingarm in a slot welded onto it. If you don't get that in there right, then it won't sit right.

[service writer]

The picture gets bigger if you click on it.

The wheel will not turn when the caliper is assembled and installed because of the pads binding. the wheel spins true otherwise.

[Sev]

The wheel will not turn when the caliper is assembled and installed because of the pads binding. the wheel spins true otherwise.

Doesn't really mean anything.

[service writer]

Not following your logic OR we aren't on the same page in any event. I know you would understand if you sitting here. I probably didn't explain it well enough....long time fault

What I did learn is that if I use the old inside pad and the new outside, it will work. I'm leaning toward the pad set being incorrect...that is packaged wrong.

[BuzZz]

I'm betting the shop got an axle spacer on the wrong side or mixed up with one from the other side when they re-installed the wheel. If you had a chaindrive, I bet it would show the mis-alignment too, but the shaftdrive hides all that inside. Still not doing it any favors being run cocked off to the side like that, although it probably has a cv-joint of somekind to compensate.

You need to remove the axle and mess with the spacers until the rotor lines up centered in the caliper, with the caliper installed.

The pads are tapered like that because the leading edge is pulled into the rotor as the brakes are applied harder, wearing them faster but giving more stopping friction. The old ones look like that due to being worn at the front more for their service life, and the new ones look as they do to supply pad material to the wear area over it's service life so it ends up looking like you old ones. Everything worn basically off more or less evenly at the end of it's usefulness.

[service writer]

I emailed EBC and Talked with Yamaha Tech line a week or more ago. The guys at xs11.com kinda thought it was wrong pads too. After researching and taked with the two companies I was comforatable enough to order new pads and risk gettng stuck with two wrong ones. I spent time moving the swing arm and rear axle around enough that I am concerned about alignment now (I really thought the pads were wrong and should have stuck with what I thought). Whatyagonnado?

I picked up the pads today and verified 100% that the pads were packaged wrong. Better yet I got to ride it finally! First time I rode a bike in 30 years, ( and that was only for a have hour then).

Anyways, wanted to update and thank everyone for their 2 cents