Front Pulley Issues

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jbruney said:
Which reminds me that I need to go run mine down because sooner or later...
It is a real pain to search for something you need when you need it then. Dave...you are a good influence to help control my bad habits.
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I’m concerned if you think I should be a role model. o_O
 
Not a role model...just pretty well organized. Which in turn forces me out of my daydreams when I watch/read of this stuff...you aren't the only one which forces me to think of where I've put things.
 
jbruney said:
Not a role model...just pretty well organized. Which in turn forces me out of my daydreams when I watch/read of this stuff...you aren't the only one which forces me to think of where I've put things.
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"Pretty well organized" is quite the stretch. I do try to put things back where they belong, but I get lost when I have something without a home.
 
SteveA said:
For a race bike I would only consider a belt drive. For a road bike I would just work on keeping oil in the primary and save my money for other more important stuff!

The key is in the words......'you won't notice the difference when riding!'

Keep servicing the real life issues :)
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I disagree wth not using a beltdrive system on a road bike. The triplex chain and steel drum is a lot harder on the Gearbox and cause a huge flywheel effect than the lighter alloy clutch basket and lighter belt which tends to cushion the shock on the tooth faces in the gears. IMHO. Most beltdrive have a slightly different ratio than chain and then to ease the Gearbox. Remember the AMC box was originally designed for about 35 hp. Giving the box all the help you can is a good thing.
 
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CanukNortonNut said:
I disagree wth not using a beltdrive system on a road bike. The triplex chain and steel drum is a lot harder on the Gearbox and cause a huge flywheel effect than the lighter alloy clutch basket and lighter belt which tends to cushion the shock on the tooth faces in the gears. IMHO. Most beltdrive have a slightly different ratio than chain and then to ease the Gearbox. Remember the AMC box was originally designed for about 35 hp. Giving the box all the help you can is a good thing.
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A Commando box in good condition will handle the power of a mildly tuned Commando engine, and certainly it will do that in the hands of most road riders.

The increased primary ratio is a separate issue. In late '75 I had a 33 tooth front sprocket made to spin the gearbox faster, this gave a 1.727:1 ratio. This wasn't my idea, it was a works Norton idea.

I didn't take the inner cover off of the gearbox in the following 4 race seasons, at a time when others were blowing up boxes every weekend! (I will clarify I chose a stonger 4 speed over a 5 in the era of push starts...those with 5 speeds pushed off in 2nd, me in 1st...actually the same ratio. Changing the ratio is a great idea on a race bike, which belts were developed for. For most the change of ratio isn't their motivation.

Most just want to end the drip of oil on their garage floor. A belt drive is a very expensive solution to that.

Yes you reduce weight, the one I have chosen is even lighter than most by being smaller, so less weight again.

Do belts cushion shock? Not everyone it seems agrees with that, and indeed not every belt is constructed the same, and in particular, not every belt is set up correctly!

For most users, it is a solution to a problem they didn't have. But hey, it is each individual's choice regarding what he spends on as a priority.

I would argue that a good gearbox overhaul should be prioritised over fitting a belt drive. And should certainly be done before fitting a belt drive badly!
 
You just reaffirm my choice for belt over chain on your 3rd paragraph. For most users a good overhaul on the box for either system is a good idea. The first gear bush and the two in the 4th sleeve take the most abuse.
A belt doesn't whip with as much violence in an up/down harmonics as do triplex chains which cause the pitting on the spur gears that are selected during acceleration and de-acceleration . Power on power off transitions.
I agree with everything from your post but I am a believer in using the belt system over chain in a road bike that does lots of mileage. If your going to trailer Queen your bike to the shows or do less than 400 miles in a season then a chain drive is ok. The belt needs to run on the loose side and track straight.
Cheers,
Tom
 
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SteveA said:
A Commando box in good condition will handle the power of a mildly tuned Commando engine, and certainly it will do that in the hands of most road riders.

The increased primary ratio is a separate issue. In late '75 I had a 33 tooth front sprocket made to spin the gearbox faster, this gave a 1.727:1 ratio. This wasn't my idea, it was a works Norton idea.

I didn't take the inner cover off of the gearbox in the following 4 race seasons, at a time when others were blowing up boxes every weekend! (I will clarify I chose a stonger 4 speed over a 5 in the era of push starts...those with 5 speeds pushed off in 2nd, me in 1st...actually the same ratio. Changing the ratio is a great idea on a race bike, which belts were developed for. For most the change of ratio isn't their motivation.
Snip...
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I have a 29 tooth ( I think) front sprocket and the longer primary chain in my box of stuff. I had been intending to fit it, but ended up with a Maney belt instead. If someone is looking for such an item, please give me a shout.
When I get a chance to rummage around and dig it up, I'll put an ad up in the For Sale section as well.
Might as well go to someone who wants to use it..
 
Swooshdave,
How is the bearing on your clutch basket for fit on this system? I have a buddy that has this set up and unfortunate for him the belt was too tight which destroyed itself after 25 or so miles. When I inspected the basket and bearing (he pointed it out to me) , it was so loose I could pull it out with my fingers. There must have been so much force as to open up the tolerance from press fit to loose slide fit. The bearing now rocks in the pocket. I'm trying to figure out how to salvage the basket for him. E.g. speedy sleeve the bearing O.D. and open the bore to a new press fit to include the speedy sleeve. The bearing actually rocks. Not good.

Tom
 
CanukNortonNut said:
Swooshdave,
How is the bearing on your clutch basket for fit on this system? I have a buddy that has this set up and unfortunate for him the belt was too tight which destroyed itself after 25 or so miles. When I inspected the basket and bearing (he pointed it out to me) , it was so loose I could pull it out with my fingers. There must have been so much force as to open up the tolerance from press fit to loose slide fit. The bearing now rocks in the pocket. I'm trying to figure out how to salvage the basket for him. E.g. speedy sleeve the bearing O.D. and open the bore to a new press fit to include the speedy sleeve. The bearing actually rocks. Not good.

Tom
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No problem on the clutch basket.

Can you open up the bore on the basket to get a different sized bearing in?
 
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