Has anybody ever used an "A-Track"?

[terry]

Nothing to do with audio guys, in my favourite book "Great Bikes of the '70's" there is a small review of an accessory that consists of a couple of toothed wheels in a bracket that apparently mount above and below your swingarm near the front sprocket and the chain runs over the two toothed wheels.

Supposedly this accessory stops the rear end of the bike becoming virtually rigid when coming out of corners etc under hard accelleration, although I'm not sure how. I'm looking for trick accessories for my "racer" project and I thought one of these would be interesting?

I know they were manufactured in the US, but a google search proved fruitless, so I thought that if anyone would have any knowledge about this thing, I could rely on the thousands of years of collective experience from you guys? If anybody has one, or knows where I can get one, let me know? Thanks in advance, Cheers, Terry. :twisted:

 

[cbxchris]

Tried it on a TT500 yamaha with mixed results. I raced for the local yamaha shop. We finally decided it wasn`t worth it. If I`m not mistaken they came out with a complete bike at one time.

 

[Anonymous]

a-trac

a-trac

The intention of the product was to eliminate the effects of the chain pull tourqe reaction on suspension. As swingarm angle or droop increases the effect of tourqe reaction along the chain increases untill in an extreme situation the suspension locks right up solid. Some of the dirt bikes have wicked swing arm angles due to their very long suspension travel requirements. Modern high performance pavement bikes use this tourqe reaction to their benefit to cancel the compression of the rear suspension when the throttle is opened and weight is tranfered to the rear wheel. If this collapse of the rear end is allowed unchecked, the rake and trail increase and the weight on the front wheel decrease enough to make the bike run wide on the exits to corners. Like most things there is a happy medium and while it is possible to have too much of a good thing, it really is not that easy to acheive on these old bikes. Bottom line, you do not want to cancel this tourq action on a modern high powered pavement bike, you want to use it in your faver. It was probably a good Idea on dirt bikes, especially ones with very long swing arms and or very long travel, but this is not my area of semi-expertise so I am not sure. Steve

 

[Anonymous]

ATK

ATK

The company did go on to produce complete motorcycles under the ATK brand name. They used high end componentry and I believe were a serious weapon targeted at hardcore dirt enthusiasts.

 

[Anonymous]

Tricks for roadracers.

Tricks for roadracers.

My advice, Terry is to stick with the basics on your racer project. Contrary to popular believe, most races are won on proven and properly sorted designs and not by the latest trick technology. Trick, in my mind, is light, simple, and effective.

 

[terry]

G'Day Steve, thanks for that mate, I'm guessing by the amount of posts you er, posted, that you've put a lot of thought into this question? I appreciate your well thought out comments and obvious technical know-how.

My racer project (actually based on an old Honda CB750 project) is gonna be "more show than go" so although it'll be a potent old boat anchor with an 836CC kit, "Mike the Magician" headwork and big cam, flatslide carbs and electronic ignition etc, it's not actually gonna be raced, but will just be a nice weekend toy, and I'm trying to keep it "period" so am looking for any "performance" accessories from the era.

Apparently the A Track worked quite well on musclebikes of the era, there was even a "Superbike School" in the US that fitted them to all their bikes and stated that this accounted for a huge drop in the amount of students crashing, but who knows, I just want one because it looks trick, ha ha!

I might just have to make my own, I just wish I could find one to copy, even some pics would be good, and a set of fitting instructions would make it easier to understand how it works? Cheers, Terry. :twisted:

 

[Anonymous]

CBX A-trac swing arm

CBX A-trac swing arm

I saw a complete A -trac swing arm on ebay this winter that was for a cbx. It had a built in brace and was pretty neat.

 

[Anonymous]

old school cafe racer.

old school cafe racer.

AHHH, now that I know what you are doing I am very jazzed about your project. It sounds very cool. i love the stuff from that era. A good freind of mine had a Rickman with a cb750 motor. He used to call it his Dickman. Another guy I knew had a single cam motor in a Seeley frame. Both bikes are long gone now. I liked the Rickman better, a much more finished product.