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APT belt drive system?

Posted: Tue Jul 03, 2012 5:56 am
by mniwagn
anyone have any info on this old setup? It's never been used and there is a picture of it in the Vizard book. thanks

Re: APT belt drive system?

Posted: Tue Jul 03, 2012 3:45 pm
by Frogeye61
They are supposed to be good for 3-5 additional HP

Re: APT belt drive system?

Posted: Tue Jul 03, 2012 8:39 pm
by medwaybeat
http://www.aptfast.com/
Looks like a good bit kit as it can be adjusted with the cover in place.
Why not have a word with David at APT, he's a good guy.

Re: APT belt drive system?

Posted: Wed Jul 04, 2012 1:08 am
by graham in aus
Looks very much like the original 'triger' sets, converted (presumably by APT) to an adjustable type.

Belt is supposed to not stretch like a chain. I've used the static ones with no issues, I believe there are good and 'poor' quality belts about, I think the good ones were Pirelli manuf.

:mrgreen:

Re: APT belt drive system?

Posted: Wed Jul 04, 2012 5:43 am
by Michael7
These sets work fine, but pay particular heed to the thin material thickness at the crank sprocket keyway. If the crank key is not fully home in the crank key slot, the sprocket can not be pressed home without doing damage to the sprocket. You may want to machine or file a small amount off the flat surface of the key in order to give clearance in the sprocket's keyway. Make sure the key is in the slot evenly.

I have seen the sprockets cracked through when installed over a crank key that is too high above the crank slot. Even if it does not crack there, if it encounters any undue resistance during installation, it can raise a bump on the seal surface of the crank sprocket that will forever cause an oil leak.

You can get heavy-duty kevlar reinforced Gates belts, custom made in Japan, here, as well as replacement seals.

http://www.7ent.com/products/timing-bel ... 048hd.html

Michael

Re: APT belt drive system?

Posted: Thu Jul 05, 2012 8:24 am
by mk1
Looks very much like the original 'triger' sets, converted (presumably by APT) to an adjustable type.

That's what I thought. Very similar to the one I used on my first hillclimber back in the early 80's.

Re: APT belt drive system?

Posted: Thu Jul 05, 2012 8:34 pm
by mniwagn
Thanks for all the answers!!