Help from the Rupp experts

[older then dirt]

I'm rebuilding the driven half of the TC on my 1971 Rupp black widow. I have multiple questions so I will list them individually.

1: I have new bearings for the jackshaft. They fit the shaft well, but are not tight in the frame tube. Is this normal on the Rupps? They push in with minimal finger pressure. Should they be tighter then that? It seems like they could spin in the frame tube when operating the bike.

2: I have new pads that ride on the ramps of the inner driven pulley. These are the white nylon pads that slide up and down the ramps. My driven pulley ramps show some wear/cupping in the ramp centers from years of use. Can this be compensated for with a spring adjustment, or should the pulley be replaced with the new pads?

3: I have a new spring for the driven unit. What is the stock setting for the spring? There are 3 holes. What is the effect of one hole as opposed to the other?

As far as greasing everything goes, am i putting a light coat on the jack shaft and driven bearing only, or is there more that needs to be greased? Im hesitant to over do it and get grease on the belt and inner drive surfaces of the driven pulleys.

Thanks for any and all help.

Jeff

 

[danford1]

I'll talk about item 3.
The stock setting is the center hole. When you install it on the bike, you twist it to the next tower. You want the two sheaves to be under spring torsion so they twist back into position and also get pushed together by the spring.
The other holes are for personal adjustment. One hole will make the torsion less and the other will increase it. The lower torsion will go from low "gear" to high "gear" faster. That would be more for level, hard surface riding. The stiffer setting will hold it in lower gear longer and is good for hilly or rough terrain. Rider weight can enter into this also. Light riders might like the softer setting where heavy riders would benefit from the stiffer setting.
You will really have to experiment with the different settings and choose the one you like best.
Keep us posted. A Black Widow is one of the Holy Grail bikes in my opinion.

Cheers
Danford1

 

[older then dirt]

Thanks danford,
Hoping someone else will chime in on the other 2 questions. The worst part about restoring this thing is the waiting for the parts to show up.:censure:

 

[creia]

Re: Question # 1-
Sounds like they are too loose. You want a tight fit that requires some pressure to push in with your fingers. You should NOT be able to spin it in the hole after it is installed. We used metal tape on ours. It will most likely take only a wrap or 2 around the bearing to do the job.
Michael
***Edit- They make adhesive for mounting bearings as well. I have never tried any, but maybe other members have? https://www.permatex.com/products/t...unds/permatex-bearing-mount-for-relaxed-fits/

 

[older then dirt]

Thanks Michael,
I have some metal tape in the basement. Great idea. I just got off the phone with Jim Kise from Black Widow. He got me dialed in on the inner driven pulley question. It's getting closer....

 

[tmack1]

Item #2........ Sorry to say this but when the ramps start to wear and get more of a curve in them, the bike will start to have issues "down-shifting". What I mean is, when you slow down to take a turn or bend in the trail and then hit the throttle to come out of it and the bike did not lower the "gear" ratio (maybe I should say pulley ratio) and it's as if you're trying to pull out in the wrong gear.

How do I know..... happened to me. On the '71 Roadster I had, I fought with cleaning the pulleys, new belts and making sure the drive and driven pulleys were properly aligned.
Then I happened to buy a NOS pulley half (driven ramp side) at a show and when installed, it was if I had a new bike.