Tram tracking.... causes?

[VladTepes]

I thought I'd asked this before but can't find any reference.. perhaps was on the old org.. anyway...

Tramlining/ tram tracking.

What are the possible causes? What is the process of elimination?


I think my bike is doing this much more than it ever used to, and I'm totally at as loss as to why.
It's not the most confidence inspiring thing....

Tyres?
I have Michelin PR4's with plenty of life in them, running pressures of 38F 40R

Suspension?
Rear shocks have been rebuilt, AFAIK front hasn't been touched since I've owned it.

Wheel alignment?
The rear is obviously loosened periodically to adjust chain slack, but is tightened back in place using the marks on the swingarm for alignment - which checking with a straight edge seems to be pretty on the money.


Any suggestions are welcome !!!!

[KiwiCol]

Michys, well, PR4's, seem to do this as they wear, dunno why though. 
When they're new (ish) they don't seem to do it, but as they get more & more worn in, this is one of the tendencies they develop, along with an aversion to painted white lines & anything shiny on the surface of the road when cornering in the wet.
Whilst I had them on, they were never a 'bad' tyre, just had these little idosyncrasies that I adjusted to.  Yep, it can be a bit off putting, but ya get used to it, never felt unsafe with them though, else they'd have been off quick smart.

I've got Angel GT's on atm 190/50. No issues like the PR4's, but then I haven't done the mileage yet to where the others started their little traits.

[Tony Nitrous]

Steering head bearings ?

You need the front end off the ground.
Turn the bars lock to lock in smooth slow sweeps.

Worn bearings often "notch" central and you'll feel the steering hesitate as you turn the bars.

[KiwiCol]

I think Grog has some similar experience with the PR4's too.

@grog

[Kiwifruit]

Tony, would you expect to feel a clonk from the steering head when you hit the front brake ??

[Timothy Spencer]

I have never had a bike on any tyres that did not do this and it nearly always becomes worse the more the tyres are worn. I do not even see it as a problem.

[grog]

michelins tram track, just what they do. pirellis dont. from experience that is answered. i thought it was all normal, changed to pirelli, long cracks, tar snakes, all just no movement. plus  biggest bonus, bike turns into corners so much easier. 15 th ks on michys, nearly 20 on pirellis. my choice is easy.

[Sweaty]

I also found that Bridgestones done this as well. Changed to Pirelli Angel GT's and the problem was gone.

[VladTepes]

OK well I'll consider Pirellis when the time comes - that won't be for a while yet though these aren't that old...

Tony I'll check the bearings ta.

[Globalrider]

Mine was head bearing

[Hooli]

Even if the head bearings feel ok when checked they can be knackered. The first time I changed mine they felt ok, I dropped the yokes out anyway as I was greasing everything & the lower bearing was a ball of rust.

Fork bushes are another option if you've done some miles on it, mine had almost no bearing material left at 108k. Since changing them it rides like a new bike again.

[Andre]

Even if the head bearings feel ok when checked they can be knackered.

That is true for all bearings! Just can't go by feel inspection alone. Has to be visual as well. Some you can't visually inspect without taking them out and/or breaking their seal (like them wheel bearings). Bearings are so cheap, just replace them buggers after they got some mileage