offset on long travel arms

[t29sab]

hi just bought a set of lonestar dc4 long tavel a arms and a set of hipers wheels offset being 3+2 is this a good set up for mx tracks thanks

[TRX450RACER174]

3+2 is fine but check with your local rules and make sure your not to wide if you are then 4+1 will be in order.

[450MEDIC]

Go with the 4+1 offset...less bump steer, your arms will thank you.

[jacobw]

Originally posted by 450MEDIC
Go with the 4+1 offset...less bump steer, your arms will thank you.

Do you know what you are talking about I think you are refering to leverage thier will be more leverage on the arms with 3+2 but bumpsteer has no bearing on how long the arms will last the reason that they use 4+1 is its closer to the balljoint and the arc that it toes in is smaller with the 4+1 wheels if you have to run 3+2 to get your width do so but if you have to run 4+1 to get your width down do so, I have ran both and cant tell you either offset is superior to the other.

[400exrider707]

wheel offsets dont effect bumpsteer...

Go with 4:1, best handling.

[BlaineKaiser450]

Originally posted by 400exrider707
wheel offsets dont effect bumpsteer...

Go with 4:1, best handling.

[rustyATV]

I believe the characteristic the wheel offset affects is "scrub radius", which has a bearing on steering effort.

Whether or not the scrub radius affects bump steer, I'd have to break open some dusty books, but I do recall that a benefit of a greater scrub radius is the steering will be a bit more "self centering".

[t29sab]

Originally posted by rustyATV
I believe the characteristic the wheel offset affects is "scrub radius", which has a bearing on steering effort.

Whether or not the scrub radius affects bump steer, I'd have to break open some dusty books, but I do recall that a benefit of a greater scrub radius is the steering will be a bit more "self centering". thanks you guys and happy quading

[400exrider707]

Originally posted by rustyATV
I believe the characteristic the wheel offset affects is "scrub radius", which has a bearing on steering effort.

Whether or not the scrub radius affects bump steer, I'd have to break open some dusty books, but I do recall that a benefit of a greater scrub radius is the steering will be a bit more "self centering".


Bumpsteer is simply the wheels steering from cycling of the suspension without input from the handlebars... how would scrub radius effect this?

[rustyATV]

Originally posted by 400exrider707
Bumpsteer is simply the wheels steering from cycling of the suspension without input from the handlebars... how would scrub radius effect this?

I guess I'm thinking more about the perceived effects of bump steer, which the scrub radius would contribute to by making the change in wheel angle more pronounced.

[400exrider707]

Originally posted by rustyATV
I guess I'm thinking more about the perceived effects of bump steer, which the scrub radius would contribute to by making the change in wheel angle more pronounced.

I believe what you're saying is true, but it isn't the cause of bumpsteer. Good point.

We all know stock atv's have some bumpsteer built into the frame design, so adding these offset rims will enhance that even more.

Good point.

[xsr_racing28c]

Most if not all control arm manufacturers will plain out tell you that there arms are designed to be used with 4:1 offset wheels.

Not much info to offer, but from my experience I believe that 4:1 wheels are by far the best setup and offer the best performance and strength to match.

Jay

[rustyATV]

Originally posted by 400exrider707
We all know stock atv's have some bumpsteer built into the frame design,

Off on this tangent; bumpsteer usually occurs in the steering linkages, not the frame. The frame mounts determine "roll center", which is probably one of the most important suspension characteristics there is.

The cause of bump steer has to do with the arc path the links follow in relation to the spindle's arc path; if the arc is greater or smaller in relation, you'll get bump steer.

The steering setup that yields the lowest (that I can think of off the top of my head) bump steer is "rack and pinion", in the proper location.

Polaris tried their link setup (forget the name) on the Predator when it came out (I don't know if they still do it), but most quads with their steering stems and ball joints are more compromising.

[400exrider707]

Originally posted by rustyATV
Off on this tangent; bumpsteer usually occurs in the steering linkages, not the frame. The frame mounts determine "roll center", which is probably one of the most important suspension characteristics there is.

The cause of bump steer has to do with the arc path the links follow in relation to the spindle's arc path; if the arc is greater or smaller in relation, you'll get bump steer.

The steering setup that yields the lowest (that I can think of off the top of my head) bump steer is "rack and pinion", in the proper location.

Polaris tried their link setup (forget the name) on the Predator when it came out (I don't know if they still do it), but most quads with their steering stems and ball joints are more compromising.

If the frame was narrower where the arms mount to it, there would be less bumpsteer. Most bumpsteer on quads is caused from the inner tie rod ends not pivoting in line with the a-arm mounts on the frame. That is where the bumpsteer is coming from. This is why Leager had their "narrow frames" they virtually eliminated bumpsteer and allowed for longer a-arms to keep the same width. Longer a-arms also offset track width change during suspension cycling as well.

[rustyATV]

Originally posted by 400exrider707
If the frame was narrower where the arms mount to it, there would be less bumpsteer. Most bumpsteer on quads is caused from the inner tie rod ends not pivoting in line with the a-arm mounts on the frame. That is where the bumpsteer is coming from. This is why Leager had their "narrow frames" they virtually eliminated bumpsteer and allowed for longer a-arms to keep the same width. Longer a-arms also offset track width change during suspension cycling as well.

Yes, that's right; the narrow frames make the arc paths of the a-arms similar to the tie rods. It's not a perfect solution, though, because the point where the tie rods mount move fore/aft and up/down slightly as the rider turns the handle bars, whereas a rack and pinion system keeps them moving along a linear path. But, of course, there's not much room in a quad for rack and pinion, so call it good enough. All vehicles are compromises.

[400exrider707]

Originally posted by rustyATV
Yes, that's right; the narrow frames make the arc paths of the a-arms similar to the tie rods. It's not a perfect solution, though, because the point where the tie rods mount move fore/aft and up/down slightly as the rider turns the handle bars, whereas a rack and pinion system keeps them moving along a linear path. But, of course, there's not much room in a quad for rack and pinion, so call it good enough. All vehicles are compromises.

well said:o

[havinnoj]

How much benefit would you see with 4x1 wheels (vs 3x2) on a protrax front end?

[400exrider707]

Originally posted by havinnoj
How much benefit would you see with 4x1 wheels (vs 3x2) on a protrax front end?

Pro trax front end shouldn't make a difference.... but.... 4:1 is better all around... You may not even notice it, but it is better and will make a difference. Some people notice things that others dont so its hard to say...

[t29sab]

Originally posted by 400exrider707
well said:o we are only talking about 20 mm wider though surely it would be impossible to notice 20mm

[matt250r21]

Originally posted by havinnoj
How much benefit would you see with 4x1 wheels (vs 3x2) on a protrax front end? You will lose an inch or so of over all front end width and there will be less stress on the spindle shaft. Also the tire contact patch will be more in line with the spindle pivots.

[400exrider707]

Originally posted by t29sab
we are only talking about 20 mm wider though surely it would be impossible to notice 20mm

25.4mm!!! haha.

In a long race every little bit helps. If I can make the ride just a little bit easier on my body, why not? It is the best handling wheel/tire combination.

When looking at overall design it does more than just make it easy to steer. Running a narrower rim like this and keeping it at a max of 50" width will now allow the use of longer arms, which means better suspension setups and less track width change when the suspension cycles. It will also allow the use of longer shocks (ie, longtravel) and allow you to tune shocks easier.