My BRP Belt Tensioner Fix

[PW2013STL]

As many have done I installed the F3 belt tensioner on my RT.
I made a extension plate and mounted the stock BRP F3 tensioner. I read with interest the posts about them failing and Doc's improved arm and roller, but since my was working fine I waited to see if I would have that issue. Well after 11,000+ miles mine started to sing a song that reminded me of the saying that it's over when the fat lady sings.

My wife was driving at the time so I have her pull over into a parking lot and I laid on the ground and checked the roller. I could move it around quite a bit so I tied it up so it was off the belt and removed it when we got home.

The roller itself looked good so I assumed it was the single little bearing that was the issue. I decided I would make it a two bearing roller.

I machined out the roller so that the two bearings would be equally spaced in the roller with a presss fit that would trap the outer race and keep it from moving. I machined a spacer that goes between the two bearings that captured the inner races. My mastake on the bearings I chose was going with a larger inner opening (ID) which forced me to machine a stepped shaft. I used washers on the out side that only touched the inner races, and lock nuts on both ends. By doing it this way when all was assembled the roller only turns on the ball bearings.

I also machined off .28 of the arm that the new roller assembly mounts to as this was needed to keep the distance correct due to the added bearing.

The roller now rolls smooth and easy without any side play.

Time will tell how well this works, but since I have less then $25 tied up in material it's a low $ risk.

 

[Bob Denman]

:congrats: :clap: :2thumbs:
For those who aren't so mechanically inclined: I believe that you can buy a roller from Doc, that has the same improvement.

 

[Chupaca]

Nicely done...

Now you need to become a sponsor and package the repair kits to sell to all the folks without all those machining skills...:roflblack: but not a bad idea. Congrats on a great job and it will last you a long time no doubt....:2thumbs:

 

[Road-Kill]

As many have done I installed the F3 belt tensioner on my RT.
I made a extension plate and mounted the stock BRP F3 tensioner. I read with interest the posts about them failing and Doc's improved arm and roller, but since my was working fine I waited to see if I would have that issue. Well after 11,000+ miles mine started to sing a song that reminded me of the saying that it's over when the fat lady sings.

My wife was driving at the time so I have her pull over into a parking lot and I laid on the ground and checked the roller. I could move it around quite a bit so I tied it up so it was off the belt and removed it when we got home.

The roller itself looked good so I assumed it was the single little bearing that was the issue. I decided I would make it a two bearing roller.

I machined out the roller so that the two bearings would be equally spaced in the roller with a presss fit that would trap the outer race and keep it from moving. I machined a spacer that goes between the two bearings that captured the inner races. My mastake on the bearings I chose was going with a larger inner opening (ID) which forced me to machine a stepped shaft. I used washers on the out side that only touched the inner races, and lock nuts on both ends. By doing it this way when all was assembled the roller only turns on the ball bearings.

I also machined off .28 of the arm that the new roller assembly mounts to as this was needed to keep the distance correct due to the added bearing.

The roller now rolls smooth and easy without any side play.

Time will tell how well this works, but since I have less then $25 tied up in material it's a low $ risk.

My concern would be with alignment, like car tires going out of alignment causing both tread wear and the shakes as tires fight each other. I'm leaning towards keeping my BRP idler for that very reason. I "think" the one bearing system and looseness of the BRP idler was designed so that precision alignment was unnecessary. Even with a precision alignment, like a car alignment, systems do go "out of wack" and need realignment. I would monitor outside belt wear in addition to bearing wear. The lettering on the outside of the belt would be an excellent area to keep an eye on. My Idler/belt has over 11,000 miles and looks new. My thoughts.

 

[Wildrice]

:congrats: :clap: :2thumbs:
For those who aren't so mechanically inclined: I believe that you can buy a roller from Doc, that has the same improvement.

Doc's roller needs Doc's Tension arm--his roller won't fit into the BRP tension arm.
Darrell

 

[Bob Denman]

:shocked: I didn't know that... Thanks! :thumbup:

As far as my original advice:

 

[JayBros]

I'd love to have your machining capability, would give me a lot of ideas to play around with.

 

[Roadster Renovations]

Doc's roller needs Doc's Tension arm--his roller won't fit into the BRP tension arm.
Darrell

Thanks, Wildrice. You are correct. Our roller and bearing system will NOT fit on the BRP arm. I had contemplated about making a better roller kit with double bearings for the BRP arm, but the amount of material that would have to be taken off for correct placement could cause it to fail, so we came up with the kit #1 for the RT and F3.

http://dochumphreys.wixsite.com/roadster/ultimate-vibration-damper-products

Pretty much bulletproof so far. We've had a few springs fail, but we now have a upgraded spring that will solve even those few.

 

[Gordy]

This is what I did .i used 3 bearings the same outer diameter as the wheel ,machined a bushing to go in the cantre of the bearings that a 1/4 inch bolt would go through a 7/16 lock washer between them for spacers and flat washers on the ends 2ooo km and working fine

 

[bscrive]

Gordy,

Having metal on the rubber belt is not a good idea. I was going to get an aluminum roller made and the machinist told me that it would not be a good idea. The metal will heat up and the belt will probably fail much sooner than normal. The plastic roller is there to minimize the heat.

Belts are NOT cheap!!!

 

[bscrive]

My concern would be with alignment, like car tires going out of alignment causing both tread wear and the shakes as tires fight each other. I'm leaning towards keeping my BRP idler for that very reason. I "think" the one bearing system and looseness of the BRP idler was designed so that precision alignment was unnecessary. Even with a precision alignment, like a car alignment, systems do go "out of wack" and need realignment. I would monitor outside belt wear in addition to bearing wear. The lettering on the outside of the belt would be an excellent area to keep an eye on. My Idler/belt has over 11,000 miles and looks new. My thoughts.

:agree:
I came to this conclusion as well, so I just replaced the bearing with a better quality one. I have an extra one on hand in case this one starts to fail. My original one was still fine, but I figured that since I had the tensioner off I might as well change the bearing. We had about 7k miles on it anyways.

 

[4 MARIE]

Twenty five dollars in materials, twenty five THOUSAND dollars in machinery, and an education that is priceless.

 

[Gordy]

Gordy,

Having metal on the rubber belt is not a good idea. I was going to get an aluminum roller made and the machinist told me that it would not be a good idea. The metal will heat up and the belt will probably fail much sooner than normal. The plastic roller is there to minimize the heat.

Belts are NOT cheap!!!

i have watched to make sure that heat is not going to be a problem that is why I separated bearings ,I can reach up and feel the bearings after 100 miles and hold the bearings in my hand