Rear pulley / belt hugging tire

TapioK

Well-Known Member
So since the bike is on lift I figured I get rid of belt about scraping the tire.
I asked my friend to machine me a 2 mm thick 100mm radius aluminum shim between pulley and hub. That moves pulley out and gives me extra 2mm room between tire and belt.
Effectively the bolts will be 2mm shorter, but that doesn’t really matter, those bolts
are long enough.
 

41bigdawg

Let the Big Dawg eat !
Nice work Tapio...I used a spacer that I got from Derek and Donna to shim the pulley out for the same purpose :chopper:
 

Rottweiler

Well-Known Member
Supporting Member
So since the bike is on lift I figured I get rid of belt about scraping the tire.
I asked my friend to machine me a 2 mm thick 100mm radius aluminum shim between pulley and hub. That moves pulley out and gives me extra 2mm room between tire and belt.
Effectively the bolts will be 2mm shorter, but that doesn’t really matter, those bolts
are long enough.
I did something like that also. When I got my bike the tire had rubbed through the left rear light wires. I geuss they had two people on it? Later when I kept hearing the belt chirp every time I left off the gas. I ended up taking one of the right side spacers and put it on the left side. That center the tire back to the fender. Also helped with the chriping. Replaced the spacer with a flat washer that I modified.

Make sure your tire is still center of rear fender!

Sent from my Life One X3 using Tapatalk
 

TapioK

Well-Known Member
I did something like that also. When I got my bike the tire had rubbed through the left rear light wires. I geuss they had two people on it? Later when I kept hearing the belt chirp every time I left off the gas. I ended up taking one of the right side spacers and put it on the left side. That center the tire back to the fender. Also helped with the chriping. Replaced the spacer with a flat washer that I modified.

Make sure your tire is still center of rear fender!

Sent from my Life One X3 using Tapatalk
That chirpinng you mentioned may also be caused by bit too loose belt and/Or wheel axle not being on line. It is belt against the side of the pulley and only when lifting throttle.
 

Rottweiler

Well-Known Member
Supporting Member
Yeah when I put the tire back center it helped. I believe it was against the edge of the pulley.

Sent from my Life One X3 using Tapatalk
 

TapioK

Well-Known Member
Yeah when I put the tire back center it helped. I believe it was against the edge of the pulley.

Sent from my Life One X3 using Tapatalk
Thats how it feels, but funny thing is the belt is ”floating” on front pulley, so straight rear pulley should adjust belt into a straight line, thus no pressure against rear pulley? Belt does always climp uphill so that may have something to do with the phenomenon. Don’t know really...
 

pknowles

RETIRED
I bet you would be surprised about how many of our bikes rear tires are more than 2 mm off center. Just a thought.

This comment is just an observation of the 4 different big dogs that I have owned.
 
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TapioK

Well-Known Member
I bet you would be surprised about how many of our bikes rear tires are more than 2 mm off center. Just a thought.

This comment is just an observation of the 4 different big dogs that I have owned.
My shim doesn’t move the wheel, but the rear pulley.... wheel being bit offset doesn’t matter really. I was trying to setup a Honda Shadow half summer before I actually looked the manual. Rear tire is almost an inch on the side from the factory... Doesn’t really affect riding but it pissed me off riding behind and seeing tires run different path...
 

PAUL NOBBS

Member
I bet you would be surprised about how many of our bikes rear tires are more than 2 mm off center. Just a thought.

This comment is just an observation of the 4 different big dogs that I have owned.
Yep... my 05 Bulldog was same, I just trimmed a shave off the tire edge. Not recommended obviously!!!!!
 

TapioK

Well-Known Member
Just to clarify, my tire is not scraping the belt, I just like to have a bit more space between tire and belt. Also the “belt guard” above the belt would sit nicer , more in the middle of the belt.
And Dent, I’m pretty sure I know how to, and can adjust the wheel/belt line correctly. It’s not rocket science after all.
Tire manufacturers do have tolerances on tire widths. If I remember correctly Metzeler has almost ½” on 300 tire.... could be a bit less.
Our frames are not necessary exactly all the same, I believe even say Ducati or Jap bikes do have some variations on measures even if those frames are made by a robot in a real factory, not a guy welding a tube on a jig
Good example is HD softail. Take say 5 softails and remove the rear rocker boxes. Some have nice room between the frame and box , some are tight as hell... And no, loosening front engine mounts doesn’t help when engine is bolted straight to the frame with no rubber between. Or maybe it does help and I just can’t do that right either after all I’m no mechanic, nor do I claim to be.
 

TapioK

Well-Known Member
For those who don’t understand the nuances of basic English, hugging also means being extremely close
To stay close to: a sailboat hugging the shore.
 

Brent Herridge

Active Member
So belt rubbing the rear tire is common ?

Last time I had my bike in for some other repairs, my mechanic said it was rubbing but he had adjusted it. Now I'm noticing it's still crazy close, but when examining it in the garage there appears be maybe 1/8" or less clearance.

The bike always has lots of gray clumps of dust all along the inside of that big fat rim. I thought it was brake dust, but after learning of the belt alignment, figured it might actually be belt shavings. 2 rides ago it only accumulated on the belt side of the wheel. But last time, it was everywhere. Now I don't know what's making all that dust. My front brake thankfully produces no noticeable dust.

Anybody else have this problem with the rear wheel ?
 

TapioK

Well-Known Member
So belt rubbing the rear tire is common ?

Last time I had my bike in for some other repairs, my mechanic said it was rubbing but he had adjusted it. Now I'm noticing it's still crazy close, but when examining it in the garage there appears be maybe 1/8" or less clearance.

The bike always has lots of gray clumps of dust all along the inside of that big fat rim. I thought it was brake dust, but after learning of the belt alignment, figured it might actually be belt shavings. 2 rides ago it only accumulated on the belt side of the wheel. But last time, it was everywhere. Now I don't know what's making all that dust. My front brake thankfully produces no noticeable dust.

Anybody else have this problem with the rear wheel ?
It is common and widely discussed. I don’t remember seeing a proper solution for it except removing some rubber from tire or a shim like I did.
For a reason I am not clever enough to figure our belts like to ride “in” a bit on front pulley when pushing bike back or just turning the wheel backwards.
I know belt always rides uphill, but would the problem be miss-aligned tranny or rear sprocket the belt would like to climb same direction both ways?
Maybe there is some wear on old belt or front pulley. This phenomenon never bothered me enough to really examine the parts.
One day I met a guy who used to work on business where they made long belt lines (like 100’s of feet) he just said if the belt moves bit left forward and right reverse it sounds like the line is pretty straight. yes, we were in Pub and took another beer after that amazing revelation.
I suppose wide belt is more prone to do that than narrow?
 
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