R1150RT alternator belt -- Thanks to all

Thanks to all of you who posted to old threads on this topic, and especially DR for encyclopedic recall. I have one of those late production RTs with a free-wheeling pulley on which the factory had installed the old poly-V belt. After reading about the job, I was expecting a battle to get the old belt off, and when it just flopped off, I was uncertain that I had the correct replacement in hand.

But the correct elast belt was installed without too much drama, and all is well. I will just add my two cents to the "how to get the elast belts on, off, and properly tensioned" debate:

1. Getting belt on: I tried the Jim Von Baden method of using a large crescent wrench, but had no success. Instead I used this $9 tool I bought on Amazon: Gates belt tool

I needed to widen the notch in the tool to accommodate the flange on the lower pulley, but once the notch was wide enough, this tool worked like a charm.

2. Getting belt off: I am sure the tool above would work perfectly well for that

3. Proper tension: I used Jim Moore's advice to tension to the previous witness marks. I just made sure the witness marks were visible by scribing the upper extent of the washer before loosening. I used a 40-inch crow bar to apply leverage. A previous thread described using a floor jack and a block of wood to push up on the bottom of the upper pulley -- I thought that was brilliant, but could not make it work on my bike with the headers and lower A-arm in the way. I tested the spacing before loosening, and verified the witness-mark method produced the correct spacing. One caution here: when using a long lever to move the alternator up, the entire motorcycle will tip to the left. I found that I could stabilize the bike with one hand while applying leverage with the other. Of course, this means you need a third hand available to tension the adjusting nut.

Cap

Thanks to all of you who posted to old threads on this topic, and especially DR for encyclopedic recall. I have one of those late production RTs with a free-wheeling pulley on which the factory had installed the old poly-V belt. After reading about the job, I was expecting a battle to get the old belt off, and when it just flopped off, I was uncertain that I had the correct replacement in hand.

 

But the correct elast belt was installed without too much drama, and all is well. I will just add my two cents to the "how to get the elast belts on, off, and properly tensioned" debate:

 

1. Getting belt on: I tried the Jim Von Baden method of using a large crescent wrench, but had no success. Instead I used this $9 tool I bought on Amazon: Gates belt tool

I needed to widen the notch in the tool to accommodate the flange on the lower pulley, but once the notch was wide enough, this tool worked like a charm.

 

2. Getting belt off: I am sure the tool above would work perfectly well for that

 

3. Proper tension: I used Jim Moore's advice to tension to the previous witness marks. I just made sure the witness marks were visible by scribing the upper extent of the washer before loosening. I used a 40-inch crow bar to apply leverage. A previous thread described using a floor jack and a block of wood to push up on the bottom of the upper pulley -- I thought that was brilliant, but could not make it work on my bike with the headers and lower A-arm in the way. I tested the spacing before loosening, and verified the witness-mark method produced the correct spacing. One caution here: when using a long lever to move the alternator up, the entire motorcycle will tip to the left. I found that I could stabilize the bike with one hand while applying leverage with the other. Of course, this means you need a third hand available to tension the adjusting nut.

 

Cap

Afternoon Cap

How do you know that you NOW have the proper pulley spacing for the elastomer belt?

Lining the alternator marks back up just put the alternator back to where it was set for the poly-V belt, that doesn't assure it is now spaced correctly for the elastomer belt.

You might do a rough measurement of the pulley spacing to verify correct spacing for the elastomer belt.

Correct pulley spacing is 118.5mm between the crankshaft & alternator pulleys, measured at the belt ribs on the pulley's inboard of the outer flanges. Or measured at the outer pulley flange's, about 116mm between pulley's.

How do you know that you NOW have the proper pulley spacing for the elastomer belt?

Yes, I wondered that too. So, being paranoid, I measured the gap. Spot on. Thanks for your help.

 

1. Getting belt on: I tried the Jim Von Baden method of using a large crescent wrench, but had no success. Instead I used this $9 tool I bought on Amazon: Gates belt tool

I needed to widen the notch in the tool to accommodate the flange on the lower pulley, but once the notch was wide enough, this tool worked like a charm.

 

Cap

Can you please post a picture of the modified Gates 91030 tool?

Can you please post a picture of the modified Gates 91030 tool?

Here are some pics. The pulley has a thick front edge, greater than the width of the notch in the unmodified tool. So, a friend of mine widened the notch to about 0.25" which happened to be the smallest size mill bit that he had laying around. The depth of the cut matches the original notch. You can see that it grabs on nicely. Just clip it on the edge of the pulley, and rotate it into place until the belt (either already installed, or about to be installed) holds it in place. Then, rotate the crankshaft. I took two tries to get my elast belt installed: first time around, the belt was off by one groove. So, one more time around, and it was perfect.