attex, belt rubs chain

[racerone3]

on my 6 chain attex, the belt can rub the chain on the bottom side of the driven clutch. this is a racer, so i'm not sure if the driven clutch has been changed, but the stock belt fits fine. is there an adjustment somewhere that i'm missing? the chain is adjusted properly. it can only happen when the belt is at the very top of the clutch, but in 10 min of driving it has already scuffed a brand new belt

[whipper-ag]

Can you post a pic of it?

Whipper

[racerone3]

the first pic is looking down on the top of the belt, showing the rub. the second is looking back from the front of the machine. it must only happen when the chain bounces up... coasting, so the clutch is disengaged, my hand in the second pic is pulling the chain up to the belt. i suppose it could also be that someone has put larger sprockets in the machine at some time?????

[George]

I can't help with this one, I've never owned a 6 chain setup.

Sorry Race

[jpswift1]

Are you running a 1 1/4" wide belt? Just a thought, but if you ran a 1 3/16" wide belt it might sit in there just a hair farther, and enough clearance so that it won't rub. Also, you might want to get a real thin piece of metal, maybe something that is about 1/16" thick and put it between the frame and the T-20 cradle to act as a shim. Hope it works out for you.

[racerone3]

ok, i'm wondering if the slots in the frame were filed deeper at some point to get the T-20 lower. perhaps a chain was too short and that was the quick fix. my T-20 chains are already really tight, so i think i'll throw the old belt back on and kill it while those chains stretch a bit, then try to shim the front of the t-20 back up. if someone has a frame with no trany installed can you measure the depth of the front t-20 mounting slots for me? also if anyone has a 6 chain setup together, could you see how much room yours has between the clutch and the rear chain?
thanks guys

[Don]

I think I have an engine/trans trolly out in the shed for a six-chain. If I can find it, I'll measure the depth of the T20 mounting slots. Sorry I can't help out more, but this one's got me stumped.

[whipper-ag]

Maybe someone did put bigger sprockets on. How many teeth are on your final drive sprockets?

Whipper

[racerone3]

Sorry I can't help out more, but this one's got me stumped.

Don, that in it's self is a huge help if i've got you stumped, there are pretty good odds that i'm not missing something simple!

whipper, how many teeth should there be on the sprockets? i'll go out and count them tomorrow... it's too darn cold out tonight!

[whipper-ag]

You can run anything you want on the final drive as long as they are 1:1's. I run 20T sprockets on the Spider & Scorpion. It keeps the chains up from rubbing the tub.

Whipper

P.S. Sorry about your cold Carolina night. It was sunny & 75 today.

[Don]

if someone has a frame with no trany installed can you measure the depth of the front t-20 mounting slots for me?

The straight slots (front?) are 1 3/16" at the deepest point, and the angled slots are 7/8". Hope this helped.

[racerone3]

thanks Don, i'll check mine out tomorrow night, i tightened the left rear chain up a little more, and also the belt, and it didn't rub on todays test run... looks like i'll just have to keep a real close watch on it. i'm still going to try to shim the t-20 up a little if the chains stretch enough to allow it. on another subject, i found that my low speed jet was a bit on the rich side, so hopefully that will help with the plug fouling. also, the throttle response is a lot better.

[Don]

also, the throttle response is a lot better.

Cool. Let's line 'em up!

[racerone3]

hoping to do a "terminal velocity test" at McCoy's on sunday. i am waiting (not at all patiently) on the ups guy to show up with my last 2 tires, so it still has the chevrons on the center axle. trying to remember back to buzco, i think the bud racer has a little more pep, but i haven't gotten to open this thing up much yet. not to mention that the bud racer was a little hard to hang on to by the time i got a turn... i might have been mistaking vibration for speed can't wait to find out!

[LarryW]

Mine is not t20 so I may be wrong but... If the adjustment is on the top and it is pulling the chain up to tighten, maybe your chain is to long and you need to take a link or a half link out. This would put the chain lower??? Also seems how it is a racer maybe its been modified for the T20 to sit lower??? Just some thoughts to throw at you.
Good luck
Larry