Maxxis RC-1 Tire Review
Maxxis RC-1 is a dry R compound tire with an emphasis on durability.
RC-1 is not as grippy as Toyo RR but is more grippy than Toyo RA-1, Toyo R888 and Nitto NT-01. My subjective feeling is that a 225 width Toyo RR is quicker than a 245 width RC-1 when both are new. My impression is that RRs retain grip better than RC-1s as the tires age, hence a 225 RR will be always quicker than a 245 RC-1. That said, when RC-1s are new they are not that far off the grip level of Toyo RRs, certainly new RC-1- are much closer to new RRs than RA-1/R888/NT-01s. As RC-1s age they move closer to RA-1/R888/NT-01s of the same heat cycle count.
I found RC-1s to have high, consistent and predictable lateral grip but be relatively easy to lock up under braking. RC-1s also seem to have trouble sticking under acceleration as the tires get older.
Being a hard compound slick, RC-1s do not stick that well in rain. I would rate RC-1s average in wet grip.
In my experience RC-1s are very sensitive to tire pressures when it comes to wear. The first set of RC-1s I ran in the 30-40 hot psi range; these tires all corded on both edges with maybe half of the tread still remaining in the middle. I found 43.5 psi to be the minimum and the ideal tire pressure - any less and the tires are worn on the edges, any more and the tires get greasy. This was for 245/40-15 RC-1s on 9" wide wheels.
With the tire pressure situation figured out I still had a hard time wearing the tires evenly. My 245s wore more on the outside half of the tread than the inside half, suggesting that more front camber is needed. As I already have -3.2 degrees of front camber running more camber would wear out other tires I run on the inside which is also not ideal.
With the outside half of the tires worn down, the tires lost lateral grip as they approached the end of their tread life, which in turn made the car hopelessly understeer in sweepers and go into wheelspin on hard corner exits, ruining the fun. RC-1s seem to lack grip at zero tread depth, unlike e.g. RRs which retain enough grip at zero tread depth to be useful.
The following recommendations are for the pre-production 245/40-15 size which is narrower than production 245/40-15, on 9" wheels.
RC-1s seem to want more camber than Hoosiers and Toyo tires, on both front and rear. I would say -3.5 to -3.6 degrees of front camber on a Miata would be a good starting point, with -3.0 degrees in the rear.
RC-1s also want higher inflation pressures than Hoosiers and Toyos. I ran RC-1s at a minimum of 43.5 psi hot whereas my target for Hoosier R6/SM6/SM7 and Toyo RR is 39 psi hot.