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

I noticed lately that I hear a brief screech from the rear when upshifting. I'd say it lasts less than half a second. This can't be an uncommon thing as there are specific clutches against that (slipper clutch, anti hopping clutch, or whatever they are called). It seems to happen from 2nd to 3rd and only when the engine is still cold, i.e. within a mile after starting.

I can't recall hearing this in the past. There are two possibilities: either something is wrong or it's the new rear tire, Metzeler Z8. Clutch feel seems unaltered. The bike doesn't break out of a straight line when it happens. Do others observe this?

I've not experienced that.
I don't think our bikes have a slipper clutch.

Something else is wrong.

Rear tire should not chirp on shifting unless you are not letting off the throttle at all then on my bike it would raise up the front wheel.

Listen closer for the noise.

It would give one heck of a jerk.

Are you sure its not the alternator belt?

David

David R wrote:Rear tire should not chirp on shifting unless you are not letting off the throttle at all then on my bike it would raise up the front wheel.

Are you sure its not the alternator belt?

It's coming from the rear and sounds just like a blocking tire, lasts maybe 1/10 - 2/10 of a second.
I am assuming the opposite, i.e. not too much power on the transmission (open throttle) but on the rear wheel (closed throttle, engine breaking).
The fact that it started after mounting a new rear tire is suspicious. I will continue to monitor.

David R wrote:I don't think our bikes have a slipper clutch.

They don't, but they are available to address rear wheel chatter. I was assuming they are offered for a reason.

So you are hearing something but are you feeling anything?

A chirping tire would be quite a jolt.

David

I hear something but feel nothing beyond the regular transition you feel when engaging the clutch after a shift. There is no jolt.

Since nobody else seems to observe this I consider myself special.

I have only owned one boxer and am still riding it a R850R and i have noticed on the upshift if you are not applying throttle into the shift after winding it up from the lower gear you will get a compression chirp from the rear tire , I have noticed this on a 1100 gs and a 1150 gs and a 1150r ,friends bikes. I know this comparison might sound crazy but these bikes remind me of old 1950,s pickup trucks which would do the same thing if you wound them up when shifting.(trans were about as clunky as well)
Next time you are riding, wind the bike up in second or third make a shift but dont give it any throttle I bet your rear tire will chirp if not let me know maybe my hearing is just going , i have been wondering if my down shifting has been causing the rear tire to wear more than it should as i only got 4900 miles out of a metzler 880 the front seems to wear normal .
I blew the rear master cylinder on the way to CycleRobs hse last year and rode it home on backroads with no rear brakes no problem because of the compression holding the bike back when letting off the throttle and good front brakes.
Mike

captaincable wrote:you will get a compression chirp from the rear tire

I believe that's exactly it. However, I have a feeling it's connected to my new rear tire, Metzeler Z8. That's the only variable that changed, and with previous tires I never got the chirp.

Sorry I did not catch it started after new tire , diff. compound ? The chirp on my new pr3 does seem a little louder or maybe because I am paying more att.
Mike

Not sure what the difference in compound is, but there may be some. The last one I used was the Conti RA2, now Metzeler Z8. It's just too suspicious that it started after that change.