Mtracer

Do new tires break in and get softer and therefore develop a softer ride after say a few hundred miles?

Here's the reason for my question. I recently swapped out some Pirelli P Zero Race TLR, 30 mm tires for some GP 5000 28 mm on my Domane. With the Pirelli tires, the ride is exceptionally smooth. Though, while the Perilli's are good tires as far as rolling resistance, they still don't roll as well as the GP 5000's. So since I had some of those, I wanted to give them a try.

Of course they are a bit smaller tire and that alone should account for a stiffer ride. But, after a few hundred miles, the GP 5000's seem to be feeling softer. So, I'm wondering if tires in fact do develop a softer ride after some miles. I'm sure to some degree I've simply gotten used to the stiffer ride, but I'm still thinking the tires themselves have gotten softer.

Thoughts?

jolly_codger

Interesting question and the answer is No. By "softness" I am assuming you mean "suppleness". The suppleness of a tire is a factor of the threads per inch (TPI) of the casing and it is impossible to increase the value, i.e. you can't make a silk purse (120TPI tire) from a pig's ear (30TPI tire). If anything, the older the tire, no matter the TPI, the harder it will become due to the aging effects of sunlight and ozone (I am pretty sure it's ozone, but I admit that I could be wrong).
John

Jklotz

I recently tried some Vitorria N.ext's, tubeless. I'm not in love with the tires, but I have noticed, around the 200 mile mark, they seem to be feeling a bit more supple. I don't have any scientific data or specific methodology to back up my claims, I'm just suggesting there may be some truth to what you say.

SoSmellyAir

I am not sure if tires get more supple, which (as jolly_codger said) is mainly a function of thread count (just like your sheets!), but every road bike tire I have used have stretched and increased slightly in width after multiple cycles of inflation, riding, and (slowly) losing pressure. I suspect this may be felt as softer. I suspect my gravel tires go through the same process but they are very wide and quite soft already.

Troul 

if you rolled on Gatorskins you'd never have to worry about a ride quality change. Cement filled garden hoses don't give any.

Mtracer

I agree that over a long period of time, I would expect the rubber to stiffen as it ages and dries, but I think it's generally accepted that tires do stretch a bit initially. I think most find them easier to get on and off after they have been used. Of course, stretching doesn't necessarily mean the become more pliable. But it does point to something relaxing a bit. Which, just like a balloon, it's easier to blow up again after it has been stretched out.

I've certainly seen tire width expand a bit from brand new to used. Makes sense (see above comment). My thinking is that the new rubber is a bit stiff to start and after it gets worked a bit, it can add to the springiness of the tire.

But again, it's just a thought. Just looking for others thoughts on this to see if there is some consensus.

jolly_codger

Yes, I agree that tires stretch ever so slightly after being mounted, but the stretch is to the bead, which will not affect the ride quality. The casing will vary in size as rubber is worn away through use, yes, though I doubt to the extent that humans can kinetically discern that. Heat can affect grip for sure, hence race cars zig zagging before a start or drag racers doing burn-outs before lining up. Shift to another context: do your car's tires ride noticeable better as the put on miles? Given the mileage that can be put on car tires I would not be happy if I had a performance car and bought some super deflection-resistant tires for cornering performance, but they became more supple with use.
Good discussion, thank you for making us think,
John

PeteHski

Swapping back to the Pirellis might help to answer your question. I presume you are checking your tyre pressures regularly? Just to rule that out as a possible factor.

Bald Paul

I think it's more of a "getting used to the ride quality" than a "tire is getting supple" thing.

PeteHski

I think so too. But even if the casing did soften up a bit (not saying it would) I’m sure it would only be the equivalent of a minor change in tyre pressure.

wheelreason

They do break in somewhat, they do not become more supple. Performance tires tend to ride as they will right out of the box, where utility tires do seem to ride best as they approach mid life, this is separate from the few miles it takes to get rid of the slickness of the tread when new. I'm thinking what the OP if feeling is from the different widths and inflation.

veganbikes

I mean my Challenge Open Tubulars did stretch a tiny bit and shape up but they ship flat and the ride quality didn't change. As others have said it is probably more of a getting used to the tire than anything else. Probably they will develop their shape but it won't become a softer ride unless material wears out which is not good. However you might see a slight change with temperature and maybe a warmer climate will give a slightly softer feel but it won't be significant enough to really change things that greatly.

KerryIrons

Perfect summary. As others have noted, tires do stretch just a tiny bit as they are under pressure with time and that means the tire is just a bit wider, but unless pressures are dropped it's hard to see how this would make a tire more supple. The only other thing that could conceivably make a tire "softer" with age is that as tread rubber wears away, there is less tire to flex. What is really missing from this discussion is the question of whether any of us really has the "rider sensitivity" to detect any such change. If we had a dollar for every perceived (but false) effect people report from their riding experiences with tires, we could buy a few sets of tires ourselves.

Jughed

There is a not to be named (7 time TDF champ!!) that used to have his tires stored in a basement in France for years before he would ride them. Claimed they were more supple, better puncture resistance, better grip.

Saw a video of where they were stored and the old man that took care of them. Regularly rotating the tires to different parts of the basement.

Jumpski

I too ride Continental GP 5000 28mm on an endurance bike. Adjusting the tire air pressure can definitely change the ride quality. I add air before each ride and couldn’t be happier. Have fun and stay safe.