Lowered Center Wheel for 6 wheel drive

[Guy Chriqui]

Our first year of lowering our center wheel we dropped it down 3/16, too much rocking for us. Last year we dropped it to 3/32 i believe and it worked alot better. Keep your CG low as possibly for the best handling when you do that. Also the rocking could be productive if you can drive it but its difficult.
-Guy

[Peter Matteson]

We did .200" this year because we weren't sure if warpage would be an issue when we welded the frame. I would be comfortable decreasing it a bit but there are other factors beyond just the amount of rock to account for when we do our final drive train layout.

[Joe Johnson]

I have used 1/4" over the years, but I now think 1/8" is enough. Actually, the more rigid your frame and wheels, the less offset you need.

Also, if you use pneumatic wheels, you can play with inflation levels of the center wheels to get more or less rock. In general, lower inflated wheels grip better so there are limits to what you want to do here, but it does give you some freedom.

Joe J.

[Pat McCarthy]

For the 2006 HOTBOT, we had the four corner wheels with rough top tread and the center two with wedge top tread. This made the center slightly higher than the outer wheels just with the tread difference. On top of that, we offset the outer wheels 5/16" or 3/8" (I can't remember which anymore). This worked extremely well for us.

[RogerR]

in 2004 and 2006, 1369 dropped the center wheels by .100". in 04, we used beadlok wheels, and in 06, we used roughtop tread. both years, we had excellent maneuverability.

[lukevanoort]

Last year I believe our center wheel was lowered 3/16" and for wheels we used six of the KOP 8" wheels ground flat with SBR Roughtop attached using small wood screws. We were very happy with this setup, it turned easily, and pushed hard, although it was rather heavy. (Mostly due to twelve 54 tooth sprockets)

[Paul Copioli]

2005 - 3 mm (just under 1/8")

2006 - 2 mm (just under 3/32")

In 2005 we had a bit more rock than we wanted. In 2006 we used 30% more current to turn than in 2005. We found that the closer your CG is to the center, the less the center wheel has to be lowered. We had a very stiff sheet metal chassis.

We will probably go with 3m this year.

[Josh Murphy]

we have used 6 wheel drive on 2 of our last 3 and I know that this year it was lowered 1/8 and in 04' I am pretty sure it was the same.

[Mark McLeod]

Originally Posted by Paul Copioli

We will probably go with 3m this year.

3 meters seems a bit extreme

[Josh Murphy]

Originally Posted by Mark McLeod

3 meters seems a bit extreme

I am sure that he ment 3mm if you read the post. .

[Lil' Lavery]

Originally Posted by Paul Copioli

We will probably go with 3m this year.

I take it you have the inside scoop that the height restriction is going to be quite tall in 2007?

[Andrew Blair]

Originally Posted by Lil' Lavery

I take it you have the inside scoop that the height restriction is going to be quite tall in 2007?

No, he's talking about new tread material... I guess FIRST is lifting the "No Adhesives" ban... ;-)

[Wayne C.]

you don't lower the middle wheel-

you use progressively larger tires from front to back

[Billfred]

Originally Posted by Wayne C.

you don't lower the middle wheel-

you use progressively larger tires from front to back

<offtopic>Can someone explain in businessmajorese how this would work effectively? It sounds interesting.</offtopic>

[Madison]

Originally Posted by Billfred

<offtopic>Can someone explain in businessmajorese how this would work effectively? It sounds interesting.</offtopic>

I've thought about this for a bit and, operating under the assumption that all the wheels remain on the ground all the time, I can't understand either how such an arrangement is helpful.