Avon Tour master

[chasgrips45]

What pressure should I be running in this tire. 1975 R90s. Front & rear cold. Making right turns ,I notice a tendency to start a head shake,not a good thing. I recently replaced the head bearings ,But they just feel to me ok. Too much more & I think the bike start wandering. One other question: the bike starts & runs great ,on trailing throttle (especially down a hill ,I notice a surging through the bike. Similar to the surging on the older oilheads . Shut throttle, no surge ,accelerate good power ,surge gone.

[Major Softie]

Headshake after replacing the steering head bearings would make me immediately suspect that either the bearings were not adjusted correctly, or the front fork was not correctly aligned on reassembly.

[Jean]

I think the forks are tweaked or tire might not be balanced just right.
OH and to answer the question...although I don't have Avons, I'm running 32-35 in the front on everything. The higher pressure cured a shake I had on the R75/5 when running at 28 psi.
Setting the head bearings is quite a trick...You may have to do the preload procedure again.

Once again, I don't have Delortos...But when holding the "trailing throttle" position, you MAY be introducing gas thru an intermediate port in the carb, which causes a richer condition, hence the surging. Surging might also be caused by sticky weights on your advance unit.

What are you going to do about your seat?

[chasgrips45]

What are you going to do about your seat?[/quote]
Hey Jean ,got any ideas? It`s always just following me around anyway!

[Jean]

fortunately mine does too.
I try hard not to loose my butt...or get it chewed off.
So, what happened with the wobble?
I see Major Softie and I were thinking the same thing.
I think its BOTH of those things!!

[chasgrips45]

I took the front wheel off today The shop is going to true & balance the wheel. I checked,& found that the Avons I was talking about run 32-34 front & 34-35 rear. I think I was light there also. If a wheel & tire combo is going to tend to wobble,I think it would be on an overinflated tire ,no?

[Jean]

NO. (last question)
so you think the wheel may not be true?
Maybe has some uneven tension is the spokes?
I'd still check for tweaked forks and head bearing set-up.
Could be a little bit of ALL the things mentioned.

[chasbmw]

I think that headbearings 'settle in' during the first few hundred miles, possibly due to the grease getting spreadaround a bit, A little bit of retightening is then required. Good instructions can be found on the motobins 'hint and tips' pages.

Charles

[Jean]

Chasgrips45...I have another thought. You've OBVIOUSLY been working on this bike a lot.
DO check the swing arm bearings...if the swing arm can move from side to side, you will ALSO have a soiled-britches experience.

[Major Softie]

I think that headbearings 'settle in' during the first few hundred miles, possibly due to the grease getting spreadaround a bit, A little bit of retightening is then required. Good instructions can be found on the motobins 'hint and tips' pages.
Charles

I think that more frequently the races were not perfectly seated, and the pounding of actual use finishes seating the races.