Can anyone confirm if this is right or wrong. When bike is on paddock stand and in gear, rotate rear wheel CW a few deg to take up slack in gearbox, then turn wheel CCW. MY wheel has to turn a few deg to take up the slack in GB before it starts to try and rotate the clutch. I fitted a new slipper clutch last week, tried it for the 1st time today, came up to a LH bend and started the tip the bike in, rear wheel locked for a split second with a loud clunk noise. This was within 3 miles of my ride, it then did it again 3 miles later. Both were when tipping in to a LH bend. Needless to say I rode home after this and checked bike, couldn't find any problems, stripped plates in the clutch and checked the slipping mechanism, all looked perfect. Any ideas? Does it sound like a gearbox problem?
Moving a few deg sounds ok. Have you adjusted the chain? Could it be knocking on swingarm? If clutch is fitted properly of course. Are plates in the right order and right way round? What slipper is it?
Thaks all. yes I have checked the Sigma clutch again, took off the pressure plate, took out the plates, no sign of any issue. The center clutch is not jammed and moves up the ramps under pressure. Could the clutch casue case the rear wheel to lock?? The chain was a bit slack and I have now tightened that. If that was the cause would I see some damage some where? I'm now very nervous about testing the bike again until I can find something abvious. It happening at 30mp is one thing, 60+ will not be fun.
How about putting the bike back to standard and then see if you still have a problem. If you do, it's not the slipper. If you don't it is.
Do you have the clutch plates in the correct order? because if not then it can cause problems. I have seen someone fit them in the wrong order and the clutch locked up after in had been used a couple of times.
I had thought about putting it back to std. If the clutch locked then surely my only issue would be that i would have a problem changing gear? It wouldn't lock-up the rear wheel?
Of course, coincidences happen but it does seem one hell of a coincidence that you modify the clutch and then get a problem. Returning to standard will allow you to check if it's the modification that's causing the problem or not. If the clutch were to initially slip but then grip, on a closed throttle, imho that could easily course the wheel to lock up.
The clutch plates go in in a different order on a slipper clutch, if you put them in exactly how they are in the stock setup then it's a very fair bet that is what is causing the problem. The innermost plate can fall out into the back of the basket if the order is incorrect and then you can have a lock up if it jams, and pulling the clutch in is not going to stop it locking the back wheel!!!
I will check the plates again, I installed them exactly how they came from sigma (48T pack). I did strip them after it happened, they all looked good, no sign of any damage, if a plate had dropped off the back my guess is it would have stayed there. Thanks for your help.
Maybe help eliminate the obvious other than clutch incorrectly fitted: - the clunking: did you feel it or hear it most ? - do you ride with earplugs and if so did you have them in? - could it have been too slow in too high a gear hence chain slapped about (no plugs at low speed this would be quite loud) - where you using a lot of engine braking, i.e. Coming from high speed and just down gears and dump clutch ? A slipper will reduce lock up but sometimes it will momentarily slow a bit more than it should and can feel out of alignments Ignore if not relevant
Thanks Bradders. Yes the cluncking was loud and I could feel it through my seat. It was just a gentle ride, I had just fitted new discs and pads at the front also, all this happened within the first 3 miles. Locked rear wheel 2 times. This afternoon I ran the bike on its paddock stand in 1st gear, just low revs. I could feel the slipper clutch clicking through the clutch lever as it was engaging then disengaging! The chain was bouncing around like mad. Not sure if this is a fair test. I then decided to completely strip the clutch, it looked perfect. After this I installed the original clutch to compare the results, I got exactly the same, chain bouncing around. Obviously no clicking through the clutch lever. Not sure this is a fair test at low revs, so could be normal! I'm just nervous about testing it on the road.
Engaging and disengaging? Never even ridden a bike with a slipper, so I know sod all about them. I'm surprised it would disengage under almost no load though. Isn't the idea that they slip under strong engine braking?
The clutch won't engage/disengage on its own, assume its how the OP has described it... I have had a sigma slipper, and it allows you to dump several gears and just let the clutch go. If going from say 6th to 3rd under heavy braking, it will snake a little but dents totally lock. Sounds like a chain issue to me
I agree, it should activate under engine braking load. I could however, on the paddock stand, feel it doing something through the clutch lever, it was clicking as the chain was bouncing.
Its a new chain!! + sprockets and renthal carrier. the lesson I'm learning is make small changes at a time and then test.
You didn't admit this cardinal sin before now did you ? Lol So, not necessarily a coincidence after all... Is the chain properly aligned with both sprockets??
