Rain Tires for a CM Formula F?

[Jim Garry]

Hi All. For the FF autocrosser out there, what are you using for rain tires? Hoosier discontinued the bias ply Formula F rear rain and they have clearly stated that they will not do a small run. Are you using the spec radial rains? Another brand? Anything you feel comfortable sharing would be appreciated.

[Lynn]

I've been wondering that, myself

[Gary Godula]

Brandon and I tested both the Hoosier bias ply and radial spec rains at the test course at the Solo Nats in 2018. We opted for the radial rains based on the larger size of the front tires, but they were not needed at the event. We have not tested them on a real course at competition speed. I have a feeling that the radial tires would not offer much predictability or stability in quick offsets or slaloms. They will definitely drive differently.

[jdr17]

Early in my FF ownership, I tried R888R in 185f/205r.
In the dry, they stiffened the rear so much relative to the front, the car was basically undrivable. It was a big enough change that disconnecting the (fairly light) rear bar couldn't begin to correct the imbalance.
I never actually tested them in the rain.

I currently have a set of hand-grooved R25Bs that Greg and I made from a fairly low run count set a couple years ago in Lincoln. While I'd say they are more 'intermediates' vs wets, if it is too wet for them, the car probably isn't coming out anyway and I'll happily concede to whoever is better prepared :-)

[PDM075]

Hoarding and treating an older set of bias oky rains (will tell next Saturday how they still work at the race track ) but I opted to buy fresh Radial rains which are essentially A7 compound with tread block formed in the mold

They are a weirder size... 185 front and 205 rear and from touchy-feely gauge they don't feel as soft durometer wise as the bias rains.

For extra I also took a set of 2 year old soft autox compound slicks and hand cut my own intermediates last month. Have not tried them but this is now for road racing FWIW.

Simple tire iron and draw your own pattern and cut some grooves. May be an option for autoxers that rarely see rain.....

[Jim Garry]

I suppose it's good to know that others are struggling with this issue also. Thanks for the feedback.

P.S. I called Hoosier Tire East and asked about grooving a set of R25 slicks and was told, "you'll ruin the tires". I guess I won't be talking to them for information on tires anymore.

[bassracer]

Radial wets and send it

[chrisw52]

It's probably time to reach out to https://britainwestmotorsport.com and see if get the Avon A15. That's the only tire that I know of that can be cut to make a full rain tire.

It's really just a question of if the tire is made in our sizes, in a crossply construction, with the right compounds that we want.

[CM/FFdriver]

We all have very little option for Rain tires, I'm crossing my fingers that it doesn't rain. I wonder if rally tires have something soft to use as rain tires.

Ben

[mmi16]

I suppose it's good to know that others are struggling with this issue also. Thanks for the feedback.

P.S. I called Hoosier Tire East and asked about grooving a set of R25 slicks and was told, "you'll ruin the tires". I guess I won't be talking to them for information on tires anymore.

I am not a FF driver. Hoosier East about a decade ago hand cut some R25's for use as intermediates for me.

[Lynn]

Ben, Hoosier is the only company I've found that has wet tarmac rally tires in a 13" diameter. They recommend 7.0 and 7.5 inch width wheels.

[Lynn]

Ben, Hoosier is the only company I've found that has wet tarmac rally tires in a 13" diameter. They recommend 7.0 and 7.5 inch width wheels.

[EYERACE]

Get yourself a grooving tool and a set of rears that you feel like attacking.
"You'll ruin the tires" needs defining.
It can be argued the heat from the tool will influence the compound adjacent to the finished groove versus the rest of the tire surface....but really.....who would care about such a detail?
Years ago I spent hours at it but I grooved up a set of slicks - they worked - they were not ruined.
I used the traced pattern from a record album circumference overlapping in places as my pattern rather than straight lines