BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

Hi everyone. I'm experiencing the "front wheel won't spin" issue that I guess has come up before from a few other posters.

About a month ago I had the tires changed by an independent mechanic. (I don't know if this has anything to do with the following symptoms).

I noticed that my front wheel wasn't spinning; maybe one revolution with a good hard tug. Then, after riding back and forth to work, I noticed a squealing noise coming from the front brakes just as I was about to stop <5 mph.

I tried the following things:

Loosened the pinch bolts, axle bolt and caliper bolts, did the bounce on the forks centering; no joy there.

Cleaned the rotors with brake cleaner, scrubbed them with scotchbrite and then lightly sanded w/ extra fine grit paper; no joy.

Did the stuff test and when I got back both rotors were hot, but not burning hot. Let everything cool down and then went out for another ride and only used rear brake. The brake side rotor was warm, but not hot, and the clutch side rotor was hot.

Is this the pistons not retracting or a bent rotor?

Many thanks in advance.

Probably your mechanic has changed the pads but has not thought about adjusting the fluid level? New brake pads usually require that some brake fluid is removed from the circuit in order for the brake pistons to be able to fully retract ... If your mechanic has not looked after this and if this is the case then this guy is trying to kill you.

Brgds
Oliver

Welcome Moralehazard. Sorry to hear about your problem. I would suggest you take the bike back to the mechanic and ask him to rectify the problem he created.

And if he won't, sue him for all he's got...no, just kidding.

Actually, the alignment technique is to loosen the pinch bolts and axle nut so they are not quite snug, but the caliper bolts should be torqued to 30nm before you bounce the front end by rolling forward slightly and trouncing on the seat while stabbing the front brake...at least that's how I do it! This technique aligns the fork tubes to the rotors. Try it!

You don't say if the pads were changed or not.

I'd be more inclined to think that the pistons just need a good clean, and the seals replacing - are the callipers Brembo or Tokico?

Many thanks for the replies. No the pads weren't changed; just the tires. The brakes are Tokico's.

I'm going to try the re-alignment again, and stab the brake as I push down.

Some other questions; to clean the pistons, etc. do I need to drain the bike of fluid?

Can riding the bike in this condition warp my rotors?

Any idea what's causing part of the pad to get chipped off?


BMW R1150R Clutch Side Front Brake Pad by MoraleHazard, on Flickr


IMG_3590IMG_3595BMW R1150R Brake Side Front Brake Pad by MoraleHazard, on Flickr

I think the wear is okay, but with the chipping, time for new pads?


IMG_3591IMG_3595BMW R1150R Brake Side Front Brake Pad by MoraleHazard, on Flickr

Also is this how far the pistons are supposed to retract or are they supposed to retract flush, or almost flush?


BMW R1150R Front Caliper by MoraleHazard, on Flickr

With both calipers off, the wheel spins very nicely, so I don't think any bearing issues.

Again, thank you.

The pads were probably damaged when the calipers were reinstalled...They'll go on easily if you press the pistons back in a little by wiggling the caliper on the rotor before removing it. Now that they're off you can press them in by hand. They will go in flush, but you don't need that much room to get them on if your careful. Position the wheel so they'll fit in between the spokes and cover the rim with a rag or masking tape to prevent dings.

I'd clean them first with a toothbrush dipped in eihter soapy water, or better yet, isopropyl alcohol. Don't use any petroleum-based cleaners like mineral spirits or Brake-Kleen which will deteriorate the rubber piston seals.

You have plenty of pad thickness left. Make sure they are not cracked through. Brakes...your life depends on them.

I cleaned the pistons and pads last night; pumping the lever to get the pistons out a little further to clean them better. I cannot, at all, push the pistons back into the calipers. A careful review of Clymers says that I should be opening up the main reservoir and suctioning off some fluid?

Are they correct?

My bike is a 2004 Rock w/ ABS.

When you press the pistons into the caliper the displaced fluid will go back in to the master cylinder's reservoir, with some force. You can place a razor blade over the hole in the bottom of the reservoir to prevent fluid from spurting out and getting on your paint, which it will destroy. Covering painted surfaces (tank, beak) to keep fluid off them is a good idea.

If you have to, you can press the pistons back using C-clamps and a piece of wood across the pistons to squeeze them in most of the way. You really don't need to get them pressed in that far though to reinstall the calipers with pads.

Also, you shouldn't let the caliper hang by the hose when it's not mounted on the fork...tie it up with piece of string.