It's just a bit smaller in diameter. Gives a tick more top-end. I actually really like that rotor in 2s TC and been running it in 1/12th too.

My understanding is that the stock (large) rotor is good for blinky whilst the smaller rotor is used for boosted. Cheers!

I don't know. In 13.5 boosted I stuck a 1s rotor in and went about .1 faster. Of course that was an old stock rotor vs. a nearly new 1s rotor so that might be the reason.

Let's talk about front tires.

Jaco vs CRC. The Jacos have a 37mm wheel while the CRCs have a 38mm. I have noticed that a lot of people are running very small tires... ie: ~40mm. With the Jacos, this leaves a decent amount of usable rubber... but with the CRC wheels, this translates into 1 or two run tires since they are so small.

Granted, for club racing, larger tires are fine. But for big races, I see most running very small.

Which brand of tires do you guys prefer and why? And what sizes do you normally run?

History and results show that larger diameter rims (not tires) tend to be an advantage in both real and scale racing. Going back many years when Yokomo surprised many other teams at the offroad worlds with 2.2 in rim (standard was 2")", it was a huge advantage prompting some teams to scramble to make rims larger during the event. In most racing applications, you will find that the wheels are built to the max specs allowed by the rules.

Also, the overall diameter of of the tire is really not the key, we believe that the sidewall size is more important than the overall diameter. For most grip conditions experienced in road racing, small sidewalls give the car a solid planted feel that a large rubber-to-wheel ratio (tall sidewall) will not give. We feel that a 40 mm tire on a 38 mm wheel will out perform a 40 mm tire on a 37 or 35 mm wheel. IMO, the 40 mm size mentioned is not the key or the target, it is the tire size relative to the wheel.

Obviously, both sizes have won many races, so this is more grey than black and white, but if small wheels are as good as large wheels, why aren't we using the old 1.4 (35 mm) rims from the old days? The reason... bigger is better. (pun intended) :-)

My good friend and racing teammate, Terry Rott has been bugging me to make a 1.2" wheel for many years. He enjoys harassing me about it every chance he gets in a joking manner. I suppose there are some occasions when the small wheel would be better, but history shows big wheels and small sidewalls make fast lap times. That is why we designed CRC rims to the max dimensions of the rules.

Sizes we normally run...
Speaking for the Rome, NY based drivers, Brian Wynn and I usually start at 1.63 (~41.4) fronts and 1.67 (~42.4) rears. Most of the time at large events, by the 2nd or 3rd round we end up running about 1 mm smaller. Tom Firsching has had some excellent results with larger tires, 1.65 front, 1.70 rear. Similar to Tom, John Firsching and Mark Calandra tend to run larger tires as well.


Frank @ CRC

Thank you for the detailed response. It is much appreciated!

I ask because I did back to back sessions with Jaco and CRC fronts a few days ago. I made sure to shim the front axles appropriately so that the width remained the same. Both the Jaco and CRC fronts were at 40.5mm, and I preferred the feel of the CRCs. There was no difference in my fastest lap times and since I was just practicing, I did not have a print-out to compare average lap times... but the CRCs felt more consistent, especially at turn-in.

Ran the Enneti Yellow 30 last night and they worked great. 2 thumbs up!!

something also to take note is the hardness of the rims and the flex each brand provides.... My personal experince at this one trackwhich is a smaller low to med bite track i race at is that i ran back to back also with the same prep and rutine as i do and making sure the width is the same between jaco/parm and crc tires i was instantly .2 to 3 tenth slower a lap with crc and the car felt i dunno hard to explain like it was still fast but "ontop of the carpet" compared to jac/parma but like i said it is just at this one track im thinking cause gthe track is smaller the flex and give of the jaco/parma gives it that little bit of extra i needed...

But on other tracks dont have a prob....

Def like the way the front bearings firin the crc though..

Does anyone use the xceed tires?

Also did you true them down a bit before you ran them, I got some sets to try but when i mounted the the i had a hard time of them rubbing on the inside of the body.

You will typically want to true down any and all tires you purchase, no matter the brand. When millimeters can make such a big difference in 12th, it makes sense to make sure you are always starting from the same point when testing new parts. I personally true down all of my tires to 1.7" straight out of the box, but that is for club racing, so you will likely want to go smaller for higher level events. The other thing is that if you aren't paying attention to tire diameter but are making different setup changes (springs, camber, whatever), as your gear ratio and rolling speed change you could find yourself lapping slower or faster completely independent of the setup changes you are making.

In regards to the xceed tires themselves. I bought a couple different pairs to mess around with. I normally use CRC Blacks/Greylows, so I was trying to find a combo of the xceed tires that might drive similarly but be cheaper $. I was able to get pretty close with Hard/Soft and playing with dope width. I did have poor experience with the xceeds chunking a lot more than I was used to with CRC tires though.

Hi all, I'm looking to get in to 1/12 scale. I currently have a 1/10 CRC genx10le so I would like to stay with CRC. I'm just not sure between the XL or Xi. What is the difference and is the Xi that much better or as a newb to onroad would I not really notice? I will be running on carpet,13.5 blinky.

If you're buying new, I'd go Xi with the shorty pack battery. At our track a friend of mine switched from XL to Xi and went quite a bit faster. If there is a good used XL around, it's still a good car. Take it easy, ask a lot of questions and don't get discouraged if it takes a while to get up to speed

I would not go with the shorty pack for 13.5. But then, I run boosted not blinky but I can dump a 5200 pack in 13.5 boosted.

FWIW for comparison, I can take anywhere from 2500mah to 3100mah (max timing) out of a pack using 13.5 blinky in eight minutes on a fairly large track (104ft). So for stock racing the shorty should work. But wont have as much punch left at end of race as the larger mah packs will.

It's starting to get serious in 1/12 at Competition Hobbies in Tucson, I may find myself doing a lot more work on my car than I used to I found a setup that it likes but I keep deviating from it and needing to go back, or I have to change tires and no two sets are exactly the same. Standard stuff, never quite satisfied.

I love the competition, but its strange, as I'm used to being the slow guy in all of my offroad classes I had somebody tell me that I am their benchmark and their goal to shoot for, and people even ask me (at 23, with less than 1 year of 1/12 scale under my belt) for advice! I'm not used to being the fast guy at my class.