New Shinko, bumping front end

[Slamfire]

Hi Every body!

Last week I put a new Shino on the front of my max. I did so because my old tire was scalloped badly.

I also discovered my steering head bearings were quite loose. So I adjusted the bearings, installed the new tire and checked its ballance ( was right on no weight needed).

Ive noticed the front end seems to bounce alot more, almost like riding on a gravel road.

So I checked my tire pressure 33-34 psi and re torqued my caliper bolts, axle nut etc. Checked the calipers to make sure they arnt draging.still does it.

Now it doesnt do it all the time, It seems to come and go. Anyone ever have a problem with the front Shinco Tour masters? I ve got one on the rear and love it

 

[alorio1]

You may have bent one of your front rotors changing the tire if it came in contact with the floor. They bend easily.....

 

[Slamfire]

Thanks for the reply,

I dont think it touched the floor. I even took one off when i change dthe tire to make sure

 

[alorio1]

I would jack the bike up and check for run out on the tire and rim, also check the small rubber bead around the tire to make sure tire is seated on the rim properly.

 

[2 wheel]

Check the radial runout, maybe "egg" shaped:worthy:. Certain speed sets up the vibration. Spin the tire on the bike & while standing in front have an eye for any side to side or up & down movement. Had a metzler on the rear with runout that was excessive, balance ok, had to "match mount" tire on wheel. Break the tire down on the rim & turn the tire on the wheel so runout is minimal.unk: Larry

 

[Miles Long]

I would jack the bike up and check for run out on the tire and rim, also check the small rubber bead around the tire to make sure tire is seated on the rim properly.

+1. Check the run-out both radially and axially. If within tolerances.....
you say that the bounce "comes and goes". Testing on a smooth road surface, is it related to the speed you are going? . If so, I'd suggest taking it to a reputable shop, and have them check the balance carefully . Automobile tires - probably bike tires as well - are balanced to "G40" (40mm/sec velocity) which is one of the lowest scales of rotating equipment balancing standards. A good bike mechanic should be able to improve wheel/tire balance to a much higher scale.
Cheers!

 

[scuff]

My new Shinko's doing the same thing, took it back to the shop and he said they would turn it in for warranty and get me a new one, sounds like this might be a common prob with Shinko ???

 

[Mr. Max]

I changed rear tire and had bumping front end ever since at around 40mph. Shop didn't find nothing wrong with rear or front wheels (balanced etc), I have had a minor leak at fork seals for a while now (leaves just a barely noticeable rings to fork tubes) but I believe oil levels are down in forks and that may be why it bumps? Two-up riding bumping is almost gone..!
I'm getting all kind of nice parts from Sean, installing them in winter and hope bumping is gone at spring.
One maxer had same problem, solved after he changed front tire.. That may be my case too.

Try riding two-up, is it better or worse? Might help figure out that is problem on front or rear of the bike.

 

[jfeagins]

When's the last time your fork oil was changed out? If your new tire was bad, radially, I'd think it would be hopping up/down constantly, rather than intermittently. If you now have your neck bearings snugged properly, and you are having bounce, my money is on a bad tire, but I still think it'd be bouncing constantly.

Also, if you want this tire to last longer, and without cupping, I'd suggest running your pressure closer to 40psi. just my 2 cents.

 

[Slamfire]

About the fork oil, I'm not sure. I bought it in December and have yet to change it. I will up my tire pressure. So 40 psi?

I do know when my previous tire was on, the problem was not there that I could notice but it was also scalloped badly and handled bad all the time.

Ill also look at the run out.

 

[jfeagins]

I have always ran mine around 40psi, and have yet to cup an OEM raised white lettered Dunlop. I've never ran any different tire on the front of my 85, and so, can't comment on the correct air pressure for anything else. I also run between 8-10psi in my air shocks - also still OEM for the 85.

I try to change out the fork oil every 20k or so, and can notice a slight difference when doing it. It always feels smoother taking small bumps after a change out. 10w oil called for, but I put autotrans fluid in the last change, and I don't like it - I think it is closer to 20w. I will be changing my fork oil again next spring and go back to regular bike 10w.

 

[sdt354]

I've gotten bad rear Shinko tires in the past. Bad as far as Run-out. I've noticed the shop where I used to go put a lot of weights on my Shinko's. I've since started using dyna-beads and changing them myself. +1 to more pressure. When they are ok and balanced well, they are a good tire as far as traction goes. Decent on wet pavement too.