Tire Grooving Question

I just got a set of Maxxis Goldspeed slicks. I want to groove them for the dirt but don't know how deep to set the cutter. I've never grooved slicks before, only DT tires. Any ideas? BTW, who's gonna be at El Cajon tomarrow? I still would like to meet some of you all. All help is appreciated. :)

I'll be there tomorrow (427), I think I'm just going to bring the truck and a canopy so I can setup "inside" instead of the outside treatment you get when you bring a trailer. Definitely stop by and say hi.

I'll be doing some grooving experiments tonight on DOTs. We'll see how it turns out tomorrow :) Worse-case scenario, I buy tires. :D

As far as how deep to set the groover, I'm not really sure. I don't set it too deep, whatever looks good I guess (definitely less than 1/2 way). I'm pretty new to grooving, but I don't think you can really go too wrong. Standard "blade" (?) is #4, right? I've just used that one.

Hopefully someone with more info can help you out a bit more.


Groove the rear all the way to the cords, just till you can see them. Since rear slicks only last about a days worth of hard riding it's fairly common practice.

This will give you better "hook up" in the dirt. Every tire manufacture has different tread depth, so you'll need to experiment with what ever you have. The Avon Supermoto slicks have 6mm on the rears and 4mm on the fronts for your reference.

I'll be there too.

Gee, it'll be like Team Thumper Talk. :)

You need the TT stickers to go really fast.


DONT go all the way to the cords....

set your depth just a tiny bit deeper than the "wear" holes in the tire. a flat bottom blade works better than a round bottom blade. You will have to experiment with patterns.......its a secret :D ....shhhhh! :)

I've only used the round bottom blades - do you modify one of those to make it flat? Guess that'd be pretty easy...


Nope you can order the flat bottom blades also. I have always used the #4 round blades, but wont argue with the flat blade idea...just never used them.

I thought those "wear" holes were actually "heat dispersion" holes? they do serve as a pretty good indicator of wear but I think the purpose is is heat dispersion? yes no?

No, the little holes are just for tread depth indication. If they were for heat dispersion, Mladin's tires would look like swiss cheese!?! :):D :D

Well I guess they do it different than sprint car tires then, i was always told that the holes were for heat dispersion to prevent the tire from blistering, in fact here is a quote from a sprint car site:

Unlike siping in which you should go no deeper than 1/2 the depth of the tread block, grooving can and generally is the full depth of the tread block. Also, the "hole" in the tread block(s) is called a "heat dispersion vent" which serves to reduce the chances of blistering.

this quote can be found HERE about 3/4 down the page.

Still I could be wrong...

I don't remember looking at the sprint car tires that closely, but they have a lot of tread and it's interesting they need vents too, but they do smok'em pretty good sometimes! The holes in the slicks are in sets of 3 or 4 and run from the center to the edge at only a few places around the tire. If they were vents, I would think they would be more evenly spaced around the tire.

Listen to pete, the Michelin guy told me to use a tire depth gauge to check the hole depth, or a nail, then set your tire grooving tool to that depth, I would assume he would know.

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