TTAC reader Mockard writes:
As a web-savvy car enthusiast and budget autocrosser, I try to do a lot of reading before pulling the trigger on a big purchase. With a set of R-compounds now hitting the $800 mark, I want to make the most of my investment. The consensus seems to be that shaving tires can make them perform better and last longer, but I remain skeptical… The cynic in me suspects that shaving is just a way to reduce tire life and pad the shaver’s wallet to the tune of $10 a tire. Why couldn’t tire manufacturers just build tires “shaved” from the beginning, if there was a real advantage?
Sajeev responds:
Judging by the clearance pricing I (occasionally) see for certain sizes of specialty tires on Tirerack.com, I suspect that multiple tread depths of the same model is like selling the Toyota Venza with the Highlander and the Lexus RX: it’s a big risk. Economies of scale rule, so let the grassroots racing community take that financial burden, right?
In theory, shaving tires is a good idea: reduces tread squirm, puts a wider footprint on the pavement and minimizes rubber-degrading via overheating. But not all R-compound tires behave the same way on the same car. And some tracks eat more rubber than others: from my limited time in racing, purpose made asphalt tracks are friendlier to rubber than a coned-off concrete parking lot. It depends on what you want, and what you want to spend. Weekend autocrossers honing their driving skills don’t need the competitive “edge” of a shaved tire, and its opportunity cost. A hardcore Spec Miata racer might beg to differ.
But that’s only the opinion of one dude with limited track time. So now I am throwing the ball in your court. It’s time for the B&B to discuss shaved tires.
Everyone I autocross with says not to waste your money on shaving or heat cycling.
Another data point: I run shaved Toyo RA-1s on the track. I have not found them to last any longer than unshaved. But, its totally worth not having to drive them when they are full tread. The whole time you are just waiting for them to wear down enough to start sticking. Shaved, they are great right off the bat.
I think this would have a tremendous amount to do with your car and how it’s set up, and the courses you’re running. My RA-1s are always shaved, and on 911s, most of the guys I know do the same. As OffCamber said, they’re not so good at full tread. They actually get even better right before they give up completely.
Opinions seem split on whether shaving increases wear and life, but anectdotally, I’d say it does. Even when I was running Dunlop R compounds on a VW R32, I got nearly twice as much life out of my shaved Dunlops as another driver in a nearly identical R32 did on un-shaved Dunlops. Granted, you have to allow for driver variation, but it seemed to suggest shaving helps. I also know that in conversation with other Porsche racers that sometimes, some drivers report chunking on unshaved RA-1s on their first weekends out, which pretty severely compromises the life of the tire.
I say shave and don’t look back.
OffCamber said the real advantage. Most tires grip better when they are worn a bit. It saves you the time it takes wear them down to that point. I don’t see how it could increase tire life, when you are taking tread material off the tire. Maybe with an aggressive alignment it might benefit, but I’m still skeptical. If they are dedicated track tires, and you are looking for the absolute advantage, it might be worth it.
I got to addmit it took me a while to figure out the relation of the article and Brazil, specially because of the Interlagos picture.
I was wondering if Brazilian made Bridgestone would be somehow better (I don’t think we manufacture any here, though we do have Firestones made in Brazil). Or that Brazilians did something different to their tires.
Just after reading the article twice I realized Brazilians do something different, not with their tires, but with their shaving…
The claim to extended life due to shaving has to do w/ the excessive build up of heat that you can put into full tread tires when driving them to extremes on the track. This decreases tire life.
When at any local Club event I use whatever tires came the Rental Car that I happen to be Autocrossing in that day.
Go Team Avis!!
If you’re running autocross R-comps, there’s no need for shaving, as V710’s and A6’s don’t need shaving…and the other tires aren’t competitive.
I actually get my vintage Jaguar out and autocross it every summer. I do pretty good (5th continentally in my class last year) but I also realize that my equipment is NOT what is holding me back… it is ME. The spacer between the seat and steering wheel is the biggest variable and has the greatest room for improvement in the whole system. It is best to concentrate your efforts of fixing or improving yourself before you start picking nits like shaving tires.
–chuck
CR did some testing and found that on the road, shaving to make them absolutely round and “siping” I belive it’s called (diagional cuts in the tread) made no preceptable difference to the driver.
I believe they kept switching the tires to see if the driver could guess what was on the car and they could not.
They then ran them long-term and found no advantage except for the tire seller making an extra buck on a theoretical advantage.
The above is general road use. On a twisty track where you are having a problem coming out of turn 3A into 3B at speed, minimizing the tire squirm makes some sense.
There are a few things to understand here.
Benefits depends greatly on use and the specific tire.
Use:
If you are on the street, shaving is the least of you problems. Getting them up to temp is a much bigger obstacle.
In the wet, you generally would want an unshaved RA-1 for example to help with water dispersion.
On a dry track with any type of tire that could be shaved (r compound with treads) you will benefit to some degree by shaving. The entire benefit of shaving is to reduce tread flex and clumping as well as maximize contact patch. Many treaded r comps are designed to go almost full slick at a certain tread depth. This helps grip significantly and keeps you within the tire rules for a specific class.
Tire:
Every tire is different. An RA-1 for example has a deep tread to start. Great for rain, not great for maximum performance. So the end user can shave it to their desired performance compromised with tread life. The idea here is to make one tire that can be adjusted to fit a variety of uses
Now take a NT-01 or Pilot sport Cup. They both work quite well at full tread. Yes they get better as they wear down, but for those wanting more life they can leave it full and still do quite well.
Why don’t tire MFGS make shaved tires to start? They do…sort of. Full slicks or r comps like the Hoosiers (near slick) are similar to other tires that have been shaved from the start. There is still an advantage even with these to being heat cycled or scrubbed which are two things you generally would not want to do from the factory. Additionally, Tire MFGs mess with tire designs to get past competition rules while offering their customer a competitive advantage should they modify the tire.
CR did some testing and found that on the road, shaving to make them absolutely round and “siping” I belive it’s called (diagional cuts in the tread) made no preceptable difference to the driver.…
I would feel safe saying that the toaster testers at CR were way out of their league when they tried to venture into the world of performance. “Hey Bob, I just can’t seem to feel any difference with these tires on my Camry”…LOL
One thing to consider is that a number of people sell used race tires online. The hardcore guys often sell their tires after only a few heat cycles at a significant discount. I don’t have a link handy, but if you search you’ll be able to find them. Of course, most all of these will be shaved.
I think somewhere along the way someone confused shaving with siping. Siping is the real deal for extra grip but I don’t think it makes much difference on dry pavement.
Kumho V700s work just fine unshaven – and that’s on my 4350lb 400RWHP Impala.
Serious racers will choose either the Hoosier A6 or Kumho V710, and those tires don’t have any real “tread” to shave.
Anyone who wants to use a lower-class R-compound tire probably wants to get some street miles out of their rubber, and thus would likely be best-served by skipping the shaving process.
I think it really depends on what you are doing with your car. I know my philosophy seems to be different than other people I encounter at the track.
If you are driving to race and win and expense is a lesser consideration, then probably shaved tires are better, you get them to the proper depth for best traction. If you are to this level I trust you are logging your tire temps so you could figure out the best depth over a few sets of tires?
If you are just out to challenge yourself and be a better driver, I don’t even see the point in R compounds, unless you are looking to get experience with the tricker limits of race rubber. Myself I run Bridgestone RE-01Rs, they run great rain or shine, don’t chunk even on the hottest of days on the track, and last a whole season of street and track for me. They have plenty of stick, even when they are on the cooler side which would be useful for auto-x probably.
I give up a little I guess by not running street tires, and having track tires, but I don’t care if I am a little slower. I value durability over ultimate capability, I like showing up and practicing my skills, not worrying too much about my stuff.
Thanks everyone for the feedback.
This season is about a refresher for me, and an introduction to autocross for my co-driver. I wanted to give both of us some experience on R-compounds and also save my street tires.
I picked up a set of used Toyo RA-1s; they had been shaved and have only had a few cycles through them, and the price was about the same as one new Hoosier A6.