I understand that the swingarm pivot point you have may be the same as a stock Raptor. However, the issue I was discussing was the relationship of the front sprocket to the swingarm pivot point. On the stock Raptor (and every other atv or off-road bike I have ever seen) the front sprocket is as close as physically possible to the swingarm bolt. This is done to ensure limited driveline geometry changes as the rear suspension moves. If the swingarm was solidly mounted to the frame then the sprocket-to-pivot relationship would not matter. Your problem of not being able to control the front-end lift is most definitely exacerbated by having your front sprocket so far from the pivot. Whenever you put power through the chain, you are pulling up on the rear of the swingarm. Ideally, the front sprocket would be EXACTLY at the pivot point. That way the chain length/tension would stay the same even as the rear suspension is working. Of course, overlapping the pivot and sprocket would GREATLY complicate a machine's design. Thus the manufacturers just put them as close as possible. I'm not sure if I am explaining my point very well…

 

This would have been a design issue on the bike as well.

 

Will take to cecil when finished ,will be a month or two.By chance did you have a 300 foot dirt track?If so you and your dad come look at the raptor he knows me used to keep some banshees around.[img]i/expressions/face-icon-small-smile.gif[/img]

 

yea we got a track. it hasnt been wet in a while but pm me and we'll come out and open it up.

 

how many horses we talkin here tintman?

 

Real power at the back tire on the bike was 138.6 on a friends dyno(Valdosta Super Cycles).

 

The motor is mounted as close to the pivot of the swigarmas we could get any closer and extensive mods on battery trey and shock would have to be made.Which if so would have coused more weight to the rear and more front end air time.This bike was built to be reliable and riden.I have riden it on a track in north ga and it was pretty balanced had no problems with suspension travel and I way around 250.I understand what you are saying and I will post pics off suspension under full load as well as no load and see if that helps.

 

Having more weight bias to the rear (by shifting the motor back) is NOTHING compared to having 138 horses trying to pry up the swingarm! In other words, your front-end lift problem would become better not worse if the engine were just a few inches to the rear of the quad.

Imagine locking the rear tires in place (perhaps with an EXTREMELY good parking brake). Now imagine revving up into the power zone and slowly releasing the clutch. With the front sprocket so far from the swingarm, the motor is going to try to shorten up the top of the chain (since the rear sprocket is now locked in place). All motor load is going into trying to compress the rear shock and pulling up the swingarm. If, however, the front sprocket was EXACTLY at the pivot point, the rear shock would not be affected at all! Like I said before, the compromise that most manufacturers make is to place the pivot and sprocket right next to each other to have both a simple design and also descent drive line action.

I totally understand your reasoning for placing the motor so far forward. That was my original point. Placing the motor so far forward makes the engine swap MUCH easier but, at the same time, makes the design much less than ideal. Ride an equally motored/set-up quad with the sprocket and pivot close and THEN you will feel the difference. I know that I have now hammered this issue into the ground! ...Sorry... I was actually hoping that you had some "new-fangled" way of engineering that allowed your contraption to work as good as the traditional method. That would have made my future morphing efforts quite a bit easier than past ones if I didn't have to worry about cramming everything to the rear.

Thank you for your responses.

 

Dissimilar, I can see that what your saying would have an effect on the rear suspension but I can't picture it having any effect on the front end being lighter. Having a jack shaft on the pivot would be a pretty easy and effective way to eliminate the problem your talking about.