Confusion over wheel offset

[rdibley]

I just recently bought a TA-05 used. It has drift tires on it, and I'd like to switch over to some 24mm tires, with the eventual goal of racing it in the TRC. In looking for new wheels, I'm a bit confused over the wheel offset. From what I've read, the wheel offset is how far off the center of the width of the tread the mount point is. That might not be the best explanation, so feel free to correct me.

On the tires that came with the car, the front tires are labeled "3mm" inside the hub, and the rear are labeled "9mm". The rear tires stick out wider than the front. Here are my questions:

1. What do these measurements on my drift wheels mean? I have measured the distance (in the direction of tire width) from the base of the center where the hex pattern is to the edge of the tire, and the difference between the two is 9mm. With one wheel at 3mm, and the other at 9mm, I'm not sure why that's the case. The front and rear wheels are the same width, by the way.

2. Most of the official Tamiya wheels only come in small offsets such as +2, the highest I've seen is +4. Why is this? Is it only the drift tires that go out to the larger offsets?

3. I've been looking online (nobody seems to carry 24mm spoke wheels in my area), and on one web site, they reference the offset in "Deg". Do you think they mean "mm", or is this some other way of measuring offset?

4. There is no mention about wheel offset in the TRC rules. Are there any limitations or restrictions?

5. Aside from matching a particular body style, is there a performance reason for going with different offset wheels?

6. For a person new to the TA-05, what do you recommend as a starting point for wheel offset?

Thanks!

Ryan

[akuntze]

Offset does not have an effect on the width of the wheel, just on how far the wheel sticks out from the hub, or how much the wheel is "offset" from the hub. This will give you a wider car. This can be does for styling reasons, but also for performance reasons. A wider car typically is more stable and less responsive. In drifting, finding a balance between how responsive the car is, and reacting just slow enough to be able to pull off good slides is key.

I am not familiar with the TRC series so I cannot tell you about their rules.

Tamiya has not gotten into drifting very heavily at this point, so the offset wheels they do make are more to get the scale look to their cars than anything.

Best is to start with what you have and go from there. I am not experienced enough in drifting to tell you what is good and not, but +2 seems to be a good point.

[rdibley]

I think I've spread my confusion to you. :oops: Thanks for your comments, though.

Understood that offset doesn't affect the wheel width. When I was describing my wheels with the 3mm and 9mm, I was trying to see if that had any correlation to the offset of the wheels, that is, I assumed that the 3mm offset wheel should be out 3mm from where a zero offset wheel would be, and the 9mm should likewise be out 9mm, and the difference between the two should be 6mm. When measuring them a couple ways, the difference between the two wheel was 9mm. (I took into account that the axles themselves might be offset a little) It didn't make sense to me.

A second point of confusion to clear up: I bought the car already set up for drifting. I'm hoping to convert it back to a regular street racer. Looking back at my post now, I didn't explain that very well.

"A wider car typically is more stable and less responsive." -- Thanks. That was what I was looking for.

[akuntze]

Ok after reading that, and re-reading your original post, I see where I went wrong. See if this images helps at all.

Also, if you would like to convert the car to on-road, where is it I can help? I guess it would be good to know what chassis you had as well.

[rdibley]

Thanks. It helps. Between the picture and the explanation of the wider/narrower tradeoff, you answered the important questions.

As for the drifting wheels I have, I guess it really doesn't matter. I bought some wheels with an offset of 0 for now, and I might experiment with something close to that at some point, but I think I'll be good with the 0 offset tires.

As for setting up the car, I'm going to go based off of the settings in the manual, and maybe go with one of the setup sheets posted on another thread of this forum. If you happened to have a good setup sheet for a TA-05 planning to run the GT3 setup, that would help.

Thanks for your help.

[akuntze]

Well I can give you a good starting point of yellow springs and sway bars all around. 400wt Tamiya shock oil all around (comparable to 40wt by other companies). 1B - 1A toe blocks in the front suspension and 1XA - 1D in the rear, with - 1.5 degrees of camber. Ride height 5mm in the front and 5.5mm in the rear. This should at least give you a good starting point.