Thread: Pulsing brakes on Tuono 1100 '15

Hi!

I've recently purchased a Tuono 1100 Factory '15, with 4500 km on it.
The bike is great, except for the front brake, which has an annoying pulsing/vibrating problem:
* It comes and goes a bit. One time it's much of a problem and another time much smoother.
* It's worse on partial braking than full braking.
* It exists also when ABS is fully off.

This weekend I chatted with another owner of a Tuono 1100 Factory, who had exactly the same problem, while an owner of a Tuono 1100 (non-factory) did not recognize this at all, so I think it may be a common problem, but not omnipresent (or I guess potentially still Factory-specific).

Does anyone recognize these issues?

Any ideas of the root cause of the problem, and potential fixes?

Cheers

Anders

sounds like you have a warped disc, Try seeing if it binds against the pads at any point when walking the bike.

As stated, sounds like a warped disk.

You could also put the wheel on a front paddock stand, and spin it. You might see some lateral movement of the disk, but if not you need a surface guage to measure how flat the disk is when spun.

Having said that, I once read a Girling brake experts report on warped disk. He claimed in several decades of car disk assessment he'd never seen a warped disk. On every occasion the disk was flat, but what happens is driver (or rider) brakes heavy, disks get very hot, then driver (rider) leaves brakes depressed. This causes pad material to burn onto the disk in one spot. If that happens the only way to get the material off is to grind it off... Which would ruin a bike disk.

If you bought it from a dealer then maybe covered by a warranty ?
Might be something simple like sticking bobbins on the disks... easy to check and cost nothing...

Originally Posted by 999Gav

sounds like you have a warped disc, Try seeing if it binds against the pads at any point when walking the bike.

Thanks for the advice. Since the problem comes and goes, I still have hope that something is stuck...

Originally Posted by felix

If you bought it from a dealer then maybe covered by a warranty ?
Might be something simple like sticking bobbins on the disks... easy to check and cost nothing...

Yes, the stuck bobbins is an advice that has also come up in the Swedish Aprilia forum, and when googling for bobbins (there are always new words to learn... ;-)) I came across some really neat Youtube videos of how to get them unstuck. That could explain why it comes and goes and others have reported vibrations due to stuck bobbins. Yet others have reported warped disks due to the same problem though... :-(

Originally Posted by felix

If you bought it from a dealer then maybe covered by a warranty ?
Might be something simple like sticking bobbins on the disks... easy to check and cost nothing...

Thanks for the input!

Well, it's bought privately, but factory warranty is still in place.
Factory warranty usually doesn't cover disks and pads, I think, but especially if one can show that others have the same issues and the bike has <6000 km, it should really be an obvious factory defect.
Maybe some material issue or too tight bobbins on one batch of disks?

I'll try and contact a local dealer and see what they say. In any case, it may be good to get the problem documented if I manage to e.g. unstick the bobbins and it later re-appears, or whatever.

Originally Posted by Paul D

As stated, sounds like a warped disk.

You could also put the wheel on a front paddock stand, and spin it. You might see some lateral movement of the disk, but if not you need a surface guage to measure how flat the disk is when spun.

Having said that, I once read a Girling brake experts report on warped disk. He claimed in several decades of car disk assessment he'd never seen a warped disk. On every occasion the disk was flat, but what happens is driver (or rider) brakes heavy, disks get very hot, then driver (rider) leaves brakes depressed. This causes pad material to burn onto the disk in one spot. If that happens the only way to get the material off is to grind it off... Which would ruin a bike disk.

Thx for the input!

Worth double checking the warranty and don't let local dealer fob you off! Brakes and disks won't be covered... but only in respect of wear and tear!

If there are any safety issues with the brakes, they not only are covered, but the dealer would have to undertake a recall! That would be a legal obligation. So... point is, if the bobbins are faulty, and disk not floating properly, the warranty should cover it. If they try to dodge the issue, ask them, "is it really safe?". You might find they'd rather just fix the problem than get into a dialogue over safety and proper design of a safety related part.

But if the disk is warped or brake pad lining burnt on, that will be outside warranty.

PS: Appreciate the " thanks ". FYI: You can also hit the button on right lower corner to leave thanks. Neat feature!