rgr555

Not sure why my trainer did this to my tire today. Tire was pretty new and haven't used trainer in 6 months. Tire pressure was 95

The bike was properly mounted and the rear wheel was set with the proper 2 clicks.

Do I have to replace this tire or is it safe to ride on the street?

colnago62

You need to buy a trainer tire. I have trainer tires on some old wheels. Tainers tend to eat up non trainer tires.

redlude97

When did you notice this? Possibly the roller overheated and melted the tire when you stopped on 1 spot. Not uncommon with trainers with small mass rollers that dissipate heat poorly. Tire is probably okay to ride on the real although you might have a lump when rolling.

WhyFi

That's weird, but I wouldn't necessarily say that it's ruined; if you look at the wear indicator dot towards the lower right corner, that patch doesn't look any deeper. I would probably take it out for a ride and see if the patch is noticeable/bothersome.

noodle soup

it's also possible that the brakes were applied while the roller was overheated.

caloso

He has a trainer tire now. That one.

Now he needs to buy a new tire for outside.

redlude97

Yea or a tire slip when sprinting etc.

datlas 

Should buff right off....

TimothyH

I wouldn't ride a tire with that kind of damage.

redlude97

On the rear? Its not even as deep as the wear indicators on tread. I've ridden GP4000s until the casing is showing which this tire isn't.

firebird854

I don't mess with things that could cause horrible injury. I'd buy a new tire immediately.

MinnMan

I wouldn't generally use a tire on a trainer and then ride it on the road. Apart from he seeming damage to your tire, with time, the trainer wears a severe flattening into most tires. Some people buy trainer-specific tires. I just use old tires that are no longer road-worthy.

To make it easier to swap back and forth between the trainer and outdoors, I use an old rear wheel for the trainer, so all I have to do is swap wheels. The only real expense was buying an extra cassette for that wheel.

Psimet2001 

I have lost count of the number of GP4000's I have seen have heat issues on the trainers here in the training center. It's a really crappy trainer tire.

Seattle Forrest

I wouldn't either. It'll probably roll lumpy, and it's probably safe but might not be. And for context, I'm lucky to have my job, and the $ for one tire is worth the ride quality and peace of mind to me. I can understand how other people can weigh things differently though.

Psimet2001 

I don't have the $ but can get tires at wholesale and OEM pricing... but still I would simply replace it and be done with it.

i understand everyone's situation is different but for me life is too short to ride on crappy tires.

noodle soup

+1

That tire costs about $40. If it causes a crash, how much time away from work might that be?

canklecat

I use Conti Ultra Sport II on my road bikes, including on the Cycleops trainer. No problems, even with intervals and sprints that cause a little dragging on the rollers if I don't build up speed gradually enough. Good, tough, grippy enough for my purposes, reasonably low rolling resistance and cheap. Different rubber compound than the GP4ks tho', so maybe that's a factor.

Racing Dan

Its not the rubber holding the tire together, its the casing. - > Imo, the tire is fine unless the "injury" is all the way through the rubber thread. It may be a bit bumpy tho. Im betting it happened because you used the brake.

TimothyH

How are these things made?

I think it was @Doge who said to never use a tire with glued tread on a trainer and used Corsa as an example.

Are the treads glued to the casing on higher end tires?


-Tim-

gregf83 

I'm curious what type of trainer you are using and the diameter of the roller contacting the tire. I've always used GP4000s on a KK trainer and have never observed any tire damage. The reports of tire-eating trainers I've seen usually indicate a small diameter tire roller.

Doge

Tires treas and real cheap tires are molded with the tire. The put the casing in then mold the rubber around. These are not as supple (higher CRR) but hold together well. Tufo does their own weird thing and I think the tread is molded on. As Tufos will run near 200PSI - they are like riding on cardboard. Some have a similar two stage process where the tread is heat vulcanized onto the case. I believe most the Contis are this way. The tread holds pretty well. The hand made cottons and silks - FMB etc. have the tread as a strip. The tread often bought from Italian owned Vittoria, made in Thailand glued on in France then sidewalls coated. These are generally the best rolling tires, the best feel.

Trainer have rollers that cause the tire to deform quite a bit more than normal flat road riding. If riding on rollers the deformation is part of the resistance. Anyway keep bending a glued on case back and forth and the tread will be more prone to come off. A GP4000 - eh, don't know. That is a great clincher, and as a pure trainer tire, I wouldn't use it, but for warming up and periodic use seems fine. My wife used a GP4000 on her rear solely for about 2-3 hours/week on a 2.5" roller. The tire came apart about a decade after first use. That is not so bad.

rgr555

cyclops fluid 2
i haven't used my trainer in 6 months so I'm not sure what went wrong. I don't remember using the brakes but i don't see what else could have caused this.

woodcraft

It looks like a skid patch to me.

Maybe it was there & the trainer buffed it up to be more noticeable.

Man, chicken little is alive and well around here!

noodle soup

It's a $40 part.

If the OP has questions/doubts about continuing to use it, I'd replace it.