Hi all,
First post here.... and I need some help, in a rather frustrating in desperate situation. Two years ago I bought a K75C, in very good condition. Last summer I had a slow speed spill on the bike (front tyre hit a piece of metal), only cosmetic damage.
After the spill I changed the tyres for Michelin Pilot Activ, front is 100/90 18 and rear is 120/90 18, since the day I changed the tyres (but never before this) I've noticed a strange sensation that feels like there's a vibration which seems to come through the rear. I can feel it particularly if I sit with my feet clamped against side of the bike on the pegs. I can only explain it as the feeling when a bearing is dead, almost as if I'm riding on sand paper, sometimes it's very present, sometimes hardly at all. Here's what I have noticed:
1. It doesn't happen all of the time. For instance, I had parked it over the past three months, rode it for the first time in a long time on Saturday morning, no (or almost no) strange vibration feeling.
2. It can vary in intensity one ride to the next. Today at midday I rode to work (5km) there was little in the way of vibration. Got on the bike after work and it got progressively worse the more I rode. I should note it's about 8°C out today.
3. It doesn't happen most of the time if the bike is leaned over in a corner, but sometimes it's lessened but still present.
4. It will sometimes go away of I back off on the throttle, sometimes not
5. It will sometimes go away if I pull in the clutch, sometimes not.
6. It will sometimes go away if I apply the brakes, sometimes not.
7. The longer distance I ride, the worse it seems to get.
8. It "appears" over 15kph, goes away around 70 to 80 (still present but not as bad as before).
9. There is no sound that accompanies it.
10. It does not seem to lessen on different roads/surfaces (concrete or tarmac)
Here's what I've tried so far:
Refitting the front and rear wheels, using correct toque settings. No difference.
I thought it was the front wheel bearings, so I replaced those.. That wasn't it (they did need replacing though, not horrid, but not great either).
Swingarm is in good shape (no lateral movement)
There's no lateral play in the rear wheel (at all).
I thought it also might have been the u-joint in the drive shaft, but on greasing the splines this past weekend, it's not that (the driveshaft is in perfect condition, splines and all, looks almost new). Oddly enough though, there was almost none of this vibration/sensation after having greased the splines yesterday, it only came back today with a vengeance.
Now I'm thinking it might be coming from the Final Drive. I've changed the FD oil each year since owning it, never seems to be much if anything in the way of metal particles in the oil. Will change it again this week to check.
Could the FD cause these sort of on/off symptoms? Or could it be a problem with the clutch? (but it comes and goes and isn't constant?)
Could the wheels be out of balance?
Or, could it possibly be the tyres themselves? I rode my brother's K75S, it had a slightly similar feeling but much much much less pronounced, he has the same Pilot Sport Activ tyre, but in a different size.
Any help would be much appreciated! I love my K....
Thanks,
Awfers
