tire wear midmotor, Evans set up ?

[Moose]

I think I read about the problem long ago but I didnt find the answer using forum search and google.

I run my midmotor 22 close to the Bloomfield setup but with less bump steer.
I have a lot of rear tire wear with no weight in the car.

Which setup did Evans use for the carpet EOS race? havent found it yet.

[jcb]

Can't help with Evans' set-up, but I have found that if I run the diff a little tighter than I have done on other cars it has helped to reduce tire wear as it has reduced the diffing out. It also helps to square the car up when you apply the power as there is less diff action.

[Robby]

Originally Posted by jcb

Can't help with Evans' set-up, but I have found that if I run the diff a little tighter than I have done on other cars it has helped to reduce tire wear as it has reduced the diffing out. It also helps to square the car up when you apply the power as there is less diff action.

What? Diffing-out doesn't increase tire wear, but running a tight diff sure does as it increases wheelspin.

[TKG26]

Looser slipper and lighter trigger finger can reduce tire wear....

[jcb]

Originally Posted by Robby

What? Diffing-out doesn't increase tire wear, but running a tight diff sure does as it increases wheelspin.

My understanding of diffing out is where a wheel spins excessively when not under as much load. As unloaded wheel then hits the ground spinning faster than car is moving additional wear will occur.
Wheelspin in my opinion is caused by a too tight slipper or a heavy throttle finger or thumb.

It's just my experience and may not solve a similar problem for someone else, like one set-up won't always suite another driver.

[Moose]

thx guys! My slipper is already loose. I have the most wear on the sides I guess it is not from spinning wheels. I use the dBoots multibyte for our track. For winter/ carpet I will run minipins and they wear even with other cars a lot so that is my basic fear.
Or is it just normal to have much more side wear on the midmotor than on the rear motor?

[Robby]

Originally Posted by jcb

My understanding of diffing out is where a wheel spins excessively when not under as much load. As unloaded wheel then hits the ground spinning faster than car is moving additional wear will occur.

Diffing out occurs when the inside tyre becomes unweighted during cornering - and because of the balldiff either being too loose or not thick enough lube in the geardiff (it's that terrible squaling sound some cars make)- because the power isn't so much transferred to the inside tyre, but since the inside tyre is unweighted it's not wearing and instead merely spinning in the air while the outside tyre isn't able to keep up. It touching ground again doesn't really result in wear because the diff's so loose it can't.

Again, tyre wear more often happens from the diff being too tight - being as the outside tyre will try to keep pace with the inside tyre because the car's diff isn't being used as much which results in the outside tyre wearing heavier on each corner as a result of it traveling farther and spinning more.

[Robby]

Originally Posted by Moose

thx guys! My slipper is already loose. I have the most wear on the sides I guess it is not from spinning wheels. I use the dBoots multibyte for our track. For winter/ carpet I will run minipins and they wear even with other cars a lot so that is my basic fear.
Or is it just normal to have much more side wear on the midmotor than on the rear motor?

I still tend to think your wear problem is from spinning wheels, diff being too tight - but at the same time wondering why kind of motor you're running, being as the faster the motor the more resultant wheelspin happens.
I'd also be comparing your tyre wear to others running the same tyre.
Again though, a heavy throttle finger and a lot of power always seems to wear out tyres faster.

I ran this chaps set-up last year mid-motor with minipins, and I got nearly a season out of tyres indoor on carpet. http://www.petitrc.com/setup/losi/se...023/index.html

[Moose]

thx for the set up I will definitaly try it.
I want to try the shorter rear turnbuckle first.
You didnt write where you put the shims for the front turnbuckle. I am 1mm outsindeon hub 2mm on the inside, 1.5mm bumpsteer.

Diff is tight (1/16 loosened), but with ceramic balls so still not what I would call too tight, I use quite a bit grease (Losi grease) and the wheels stil spin more than one turn when spinned against each other. Compared to some youtube vids (Matt TLR diff vid) I think it is looser than his diff.
Motor is the old LRP x11 6.5. Without any boost or turbo.
Hope weather is good enough to try two sets new tire with rear and midmotor to compare.

[Robby]

Originally Posted by Moose

t
You didnt write where you put the shims for the front turnbuckle. I am 1mm outsindeon hub 2mm on the inside, 1.5mm bumpsteer.

zero or 0.5mm outside, 2.0mm inside

Originally Posted by Moose

Diff is tight (1/16 loosened), but with ceramic balls so still not what I would call too tight, I use quite a bit grease (Losi grease) and the wheels stil spin more than one turn when spinned against each other. Compared to some youtube vids (Matt TLR diff vid) I think it is looser than his diff.
Motor is the old LRP x11 6.5. Without any boost or turbo.
Hope weather is good enough to try two sets new tire with rear and midmotor to compare.

Keep in mind those ceramic balls are going to perform/behave looser than tungsten ones would with the same setting.
That is a lot of motor, IMHO, unless you're running on a huge (1/8th scale size) layout - and personally, even on big tracks I don't run more than 8.5, and usually a 10.5 (on 1/10th track). Indoors on carpet, I'm running 13.5 or 17.5 and it's plenty (even without boost).