The four inch wheels are nice. We like em so much we used 8 of them.
The one thing I would have changed this year is the tread its done fine on traction but we have had to change them every regional due to them wearing down. But I was just wondering what the speeds of that tranny are. Nice Job too. Good luck
Just coincidence. We used 4" wheels this year because it acted like another gear reduction to go in tandem with our custom transmission this year. I would even venture to say that this is the same reason why 114, 254, and 968 had 4" wheels this year.
yup… 4" wheels=much smaller initial reduction needed for the same speed=smaller gearbox=less weight.
Woah… did you test to verify that?
Nitrile isn’t as grippy as the SBR roughtop, as far as I can remember. In fact, there is a noticeable different upon inspecting both of them.
Yup. While the 4 inch wheels may have been a disadvantage when ramping, we felt that the weight gained by needing to reduce let was worth it.
The gearbox was an excellent, lightweight design. Next year, it will be even better, as Outback has talked to us about sponsorship. Issues this year will be worked out - one side worked perfectly, the other side shifted less reliably, resulting in the shift button acting as a right turn button.
With the aid of higher quality manufacturing - these issues should be taken care of.
As for Nitrile vs Rubber - Doing a few tests myself, rubber definitely seems more grippy. However, it is important to note, that on carpet, that much of the friction probably comes more from the little “bumps” on the roughtop locking themselves into the carpet, so the difference in COF may be considerably smaller then Nitrile vs Roughtop on a smooth surface.
Nitrile also seems far more durable, and longer lasting then rubber.
Yeah, what he said. The one downside of custom wheels is cost. They are not cheap at all, because you have to make them out of a sold block for this design. However, I love them to death, and wouldn’t trade them for any other kind of wheel. (however, we will be trading them for tank treads)
The Cost isn’t that bad.
We can make 11 wheels out of a 12" piece (they are 1" wide) of 6" AL 6061 Rod ($145 at onlinemetals, similarly priced at a local metal supplier near us. In the end the material was donated anyway).
This comes out to less than $14.50 per wheel. That’s not bad at all.
And since you have 4" wheels, it’s even cheaper.
I can’t wait to see the treads & shifter combo for real though.
The real cost comes from the machine time required to do this kind of wheel. With our design (which we’ve never had any issues with) it’s a two op process. For our older 6 inch version, it was a 45 minute op. These wheels ain’t cheap.
[EDIT] I’ve submitted a render of this system to be uploaded, highlighting our tensioner system. I highly suggest it to anyone thinking of doing a powerful 6 wheel next year, as it greatly decreases necessary maintenance.