Topic: Wear on 150 rear tire: Pictures included

[drdreas]

For the past couple months I took on the project of lacing a 4.5" harley rim to my cb750 k7 rear hub, and moving the stock rear rim (2.5 X 17) to the front. I mounted Avon Roadriders, 150/70-17 to the rear, and 120/80-17 to the front.

Everything cleared ok except for the rear brake stay, but I moved it out 1/4" and it clears the tire. I've checked everything for clearance and nothing that I can see touches. Took the bike for a ride and when I got back noticed a band of wear along the outside edge of the rear tire:




I can't see anything at all that is touching; swingarm, brake stay, brake arm. I thought maybe when I sit on the bike the loading of the suspension caused something to rub, but nothing I could see. Any ideas? Is it possible this isn't from contact with the a part on the bike?

Thanks for the help

[martino1972]

got a fat girl friend.. put her on the back of your seat and see how close the tire is coming to the fender etc....

[kghost]

Its only on the right side?

[Alan F.]

Centerstand?

[MCRider]

Centerstand?

Aah the centerstand! sneaky. I wonder...

[babyfood1217]

Centerstand?

Aah the centerstand! sneaky. I wonder...

If it is, the best solution would be to rip it off, and then...uhm... that's all.  Just rip it off.

[Mdub]

Just out of curiosity, how close is the chain? I run a 130 and it's close.

[Alan F.]

OK, I've found it, this is who and where I remembered reading about a 150 rear tire and the centerstand trying to occupy the same space at the same time... http://forums.sohc4.net/index.php?topic=36459.195 page 14   The only difference is that you're running a 150/70-17 and he's running a 150/90-16 I calculate the difference in tire radius is 17mm smaller on your tire, so it's plausible if you run a centerstand.

That looks great Ron, well done mate! I can't remember if you've already done this but be aware, to run a fat rear tire you also need to modify your centre stand.

I run a 16 inch, 150/90 rear tire on my K1, and when I installed it I had the bike up on the centre stand and just "tweaked" the brake rod out of the way, no problem.

I came back from that first ride, and noticed that one side of my tire was badly "gouged". WTF? I put it back up on the centre stand, spun the wheel, and nothing touched. WTFF?? Then I realised, the "foot" on the left side of the stand was contacting the tire. Damn. I took the stand off and ground about half an inch of metal out of that thing, and it no longer touches.

As I said, you probably already know this, but I thought I'd remind you so you don't have to suffer the ignominy of gouging a new tire, like I did. Cheers, Terry.

[MCRider]

OK, I've found it, this is who and where I remembered reading about a 150 rear tire and the centerstand trying to occupy the same space at the same time... http://forums.sohc4.net/index.php?topic=36459.195 page 14   The only difference is that you're running a 150/70-17 and he's running a 150/90-16 I calculate the difference in tire radius is 17mm smaller on your tire, so it's plausible if you run a centerstand.

That looks great Ron, well done mate! I can't remember if you've already done this but be aware, to run a fat rear tire you also need to modify your centre stand.

I run a 16 inch, 150/90 rear tire on my K1, and when I installed it I had the bike up on the centre stand and just "tweaked" the brake rod out of the way, no problem.

I came back from that first ride, and noticed that one side of my tire was badly "gouged". WTF? I put it back up on the centre stand, spun the wheel, and nothing touched. WTFF?? Then I realised, the "foot" on the left side of the stand was contacting the tire. Damn. I took the stand off and ground about half an inch of metal out of that thing, and it no longer touches.

As I said, you probably already know this, but I thought I'd remind you so you don't have to suffer the ignominy of gouging a new tire, like I did. Cheers, Terry.

Hey that's my build thread and I didn't even remember that interchange. I guess I will be looking at centerstand clearance. I'm running (will be) a 140/70/17 but on a 3.5 rim which will open it up some. Is it the width or the radius of the wheel making the contact?

[Alan F.]

Hey MC, check the pic in his first post, looks like tread contack like Terry mentioned, bu much less intense due to the 17mm difference.
-A

[MCRider]

Hey MC, check the pic in his first post, looks like tread contack like Terry mentioned, bu much less intense due to the 17mm difference.
-A

Yup.

[Soos]

Centerstand?

Aah the centerstand! sneaky. I wonder...

If it is, the best solution would be to rip it off, and then...uhm... that's all.  Just rip it off.

I like your style!



l8r

Have you checked framerail to tire clearance?

Try putting some clay, or something sticky(but removable) to your frame(or other suspected rub points) and go for a short hop, try to get in as many bumps as possible to get the rub point to show.



l8r

[drdreas]

Guys thanks for the responses. The wear is only on that side, and there is no visible interference with the frame of the bike nor the centerstand. The overall diameter of the tire is less that that of the original that was on there 130/90-17, so its actually further back in the swingarm than it originally was, and I used a stock chain replacement 88 link 630 non o-ring.

I guess I need to find a way to load the suspension and check the centerstand clearance when its rolling.

The idea did cross my mind that the wear mark could have been there before I put the tire on the bike, and I just never noticed it before. This doesnt really seem plausible though, as I feel this is pretty distinct.

[Gordon]

Draw a heavy line of chalk around the tire at the same spot as the wear mark ,then go ride around the block a couple of times and look to see if anything has chalk on it that didn't before.   

[ChrisR]

I've just fitted an oversize rear tyre (freebie) to my 550K and it is fine everywhere except it comes very close to the centrestand spring which is on the right side where I think your wear is? Might be worth a look if you haven't already.
Chris