Tires are one of the biggest expenses with track days and racing. As the only piece of your car that touches the track (hopefully), they are also one of the most important parts.
If you are on a tight budget, a good deal on a set of used tires may allow you to be reasonably competitive at a fraction the cost of new. On the other side of that coin, a bad deal may leave you underwhelmed with expensive lawn ornaments. Whether you’re trying to race and win on a budget, or just want R-Compound tires to play in HPDE sessions this guide should help you navigate the market so you can maximize your chances of scoring with scrubs.
There are two words often said when buying Racing tires. Stickers and Scrubs. Stickers are new tires, named for the stickers and labels manufacturers put on before shipping them. Scrubs are used tires, and may be bought from individuals, race teams, wholesalers, etc.
I have always been a big fan of running scrubs, they are a large part of my regular tire rotation. I typically begin a season with one set of stickers, a moderately used set of scrubs, and last season’s (now very used) stickers. This leaves me shopping for a set of moderately used scrubs, the following 5 items are what I look for.
5) Date Codes:
Reading date codes: Almost Every tire related post on this blog has included checking tire date codes… because it is both easy to find and very important. Race Tires are not wine and should not be allowed to age as such. I Have head from both Maxxis and Toyo Tires that a fresh, unused tire will not have any degradation in performance for 1-2 years if it has not had it’s first heat cycle. However, once the tire has had it’s first heat cycle, I have seen performance drop-off if it is not used up within a year.
Once most racing tires begin to approach and get beyond 5 years of age, I would tread very carefully and have second thoughts about driving on them at speed. I certainly wouldn’t buy a set that is older than 5 years. Certain tires like Toyo RA1’s have a reputation of working for a very long time… I ran my Toyo RA1 tires for rain races until they were 9 years old, and they remained competitive until I retired them based on age alone. However these are the EXCEPTION, and only running in heavy rain keeps temps down… the heat from a single dry session could have destroyed them.
4) Heat Cycles
A heat cycle is when a tire goes from ambient temperature to operating temperature, and back to ambient. Each session on track counts as a new heat cycle to a tire. Different tires will have their own “useful life”. Typically, a tire is competitive for a short number of Heat Cycles. It is good for practice for some more heat cycles after that, then becomes useless after a few more (If it wasn’t already down to the cords by then). This is a big part of why you see more 200 treadwear ultra performance street tires for HPDE use. Most 200tw tires are good for quite a few more heat cycles than a R comp. You can burn up the “useful” life of R-compound tires in a HPDE weekend.
Tires like Toyo RR’s are known for being pretty competitive to and past 12 heat cycles, and have a reputation of being decent to practice on well beyond 20. Hoosier SM7’s are known for being competitive for about 7 Heat Cycles. Before choosing a tire, check how many heat cycles they can sustain.
Heat Cycles are the biggest concern when buying scrubs, as you are at the mercy of the seller’s honesty. There is no easy way to see how many heat cycles a tire really has. Many racers will add hash marks to a sidewall to identify Heat Cycles but it may not be accurate (I usually get lazy and stop marking around 15)
3) Reading wear
Make sure you thoroughly inspect any used tire before purchasing. Look carefully for flat spots (can typically be spotted as a spot when grooves in the tires disappear or get shallower). Flat spots don’t mean instant death for a tire, but can be a pain if they’re deep. Look for uneven wear, it’s very common for one shoulder of the tire to be much more worn than ther other. You can mount a tire opposite way, but if it’s very close to cording, you still may not get a lot of life from it. Just before a tire starts cording on the shoulder I usually see little areas beginning to look like they’re peeling.
Sometimes, Rain Tires will have patches of rubber that look like a shallow surface “peel”. These marks come from locking up the tires while braking in the rain. Despite their concerning appearance, in my experience these have been a nonissue.
Tire storage is similar to Heat Cycles, as you’re at the mercy of the previous owner. Race tires shouldn’t really see temps below freezing, especially if they are mounted to a vehicle. If a car on race tires is moved when temps are below freezing (Toyo says 15 degrees), the tires may crack and should be tossed. In the Best case scenario for any long term storage, tires should be placed in bags, aired down about 10 psi (if mounted on wheels), and kept from freezing. Keeping them mounted at full pressure, in your freezing garage, doesn’t mean they’ll explode, but they will lose some performance vs a set that was properly stored. When you’re fighting for 10ths on track, why not put in a bit of work for ideal off-season storage?
Most racing tires use the same tire sizing scale as your normal street tires (Some Non-DOT tires come in sizes measured in other ways). When choosing a tire size, know that race tire manufacturers are sometimes very conservative on their width markings. If your current street tire sizes (let’s say a 245/45) jjjust fit without rubbing, a Hoosier A7 245/45 with the same size stampings may end up being significantly wider.
If you are searching for scrub tires and are able to use a tire common in popular classes, you may have a MUCH better chance of finding an easy, cheap source of tires. 205/50/15 is used across many classes that run in my area (Spec Miata, Spec E30, Honda Challenge), so finding them is easy.
If you are racing and need R-Compound racing tires, scrubs may a great way to keep your running costs as low as possible. If you are looking for scrubs because you want to use them for HPDE and Track Days, know that the cost of running race tires may be a bit higher than the initial sticker price makes them seem. With limited heat-cycle lives R-Compounds (especially used ones) will need to be mounted and unmounted often, creating significant expense if you don’t have access to a tire mounting machine. Most Race Tires are slicks, so it is a good idea to bring an extra set of treaded tires for rain days, which could add more expense.