Shih Fa

Does anybody know what causes almost new gumwall tires to split so quickly. Replaced them less than six months ago. I wish I could attach a photo. But the forum says I’m not allowed until i write more than 10 posts.

cb400bill

Pic Assist - https://www.bikeforums.net/g/picture/21514614

Chuck M 

I put tires just like those on an old Takara about a year ago. I haven't put many miles on them but they look like the day I put them on (about 100 miles give or take). Just a guess, maybe these were older tires when you bought them. I would think that even under inflated they would hold up better. But what are you inflating them to?

Edit: And I would contact where I bought them to see if they will stand behind them.

canklecat

Try another tire. I've never had that problem with Continental Grand Prix Classic or Soma Supple Vitesse skinwalls. Those aren't too expensive either for good quality tires. Excellent ride quality too.

That tread pattern on the pictured tire vaguely resembles the Conti GP Classic, but the genuine Continental tire has reddish brown sidewalls. They're translucent, not gumwalls stuck to the sides. Remarkably tough too, although I avoid gravel on those tires.

Sy Reene

Don't know the cause, but it appears that the fact that the tires are gumwalls is irrelevant.

indyfabz

IKR. The sidewall looks better that the rest of the tire.

Looking at that photo I get the sense that it's a cheap tire. I am guessing an on-line, the-price-was-too-good-to-pass-up special.

CliffordK

It looks like you've put a fair number of miles on those tires.

But, as far as the cracks, those look like they may have been NOS tires.

Are they 27"? Perhaps they tend to sit on the shelf for a few years at a time.

The only things I can think of that would cause damage like that would be a LOT of direct sunlight, or perhaps parking on a hot air vent.

PeteHski

What tyres are those? They could just be ancient stock or some cheap junk.

njkayaker

Looks like the tires are really old. That’s why they split.

Ive never seen tires do that. Even ones with thousands of miles on them.

terrymorse 

Rubber cracks are caused by three things: heat, UV light, and ozone.

If a tire cracks when almost new, it was probably exposed to one or more of these causes before it was installed.

big john

I have Vittoria Rubino Pro tires doing that. I usually buy them on-line and I think two of them must have sat around because I had to take one off because it was splitting so bad and the other is starting to get the same way.

popeye

What pressure are you running? Hot garage?

Iride01 

I don't have any need for gum wall tires. But I've not bought a pair this century at all. So maybe the tech is better. But the tech has also gotten so much better with modern tire compounds that the benefits of gum walls today aren't anything other than cosmetic.

In the 70's, they'd look like that or worse pretty quick from UV damage. Maybe if that is a cheaper brand of tire, there isn't much UV protection for any of the material whether the gum wall or tread.


Might be the camera angle, but the tire looks like the bead might be at the witness line in the area where the cords are showing in the tread. Is this a 27" tire? Last 27" tire I bought had to be a cheapo tire and I had trouble getting it to seat properly on the rim. That was on my old Varsity that I pretty much gave away for the cost of the chain and a few other things I had just put on it.

shelbyfv

Is that one of the Rene Herse tires?

Psimet2001 

That's a really inexpensive tire. It probably had been sitting around for a long time before you got it. Sorry.

Ogsarg

Tire looks old. Check the date code to see when they were made.

ThermionicScott 

You're kidding right? Of course it's not one of those. It's a cheapo CST that's falling apart.

HTupolev

No. They actually look quite different. RH slicks have a strip of flat tread between the herringbone section and the sidewalls, which is apparent in the image you posted.

RH slicks also generally have either a bald or ribbed center, not the diagonal cuts seen in the OP.

Apologies for backwards tire:

PeteHski

They actually look like non-branded tyres from the 80s that you typically got on mail order catalogue bikes! I like how the black "tread" section is just painted (really badly) onto the casing.

HTupolev

It's not painted. The tread rubber on almost any tire is a separate rubber from what's on the sidewalls.

The reason it looks sloppy is that the tread rubber wasn't well-aligned with the tread patterning in the vulcanizing mold.

PeteHski

Yes, I was kind of joking. This tyre is so badly made it doesn't really surprise me it that it fell to pieces.

Shih Fa

i’ve been inflating them to 90 psi which is the max pressure allowed. And it has probably been almost a year, so I will check with the bike shop to see if they’ll stand by them.

Shih Fa

Bought it at an LBS, but it was the cheapest tires they had available.

Kimmo 

It's no big deal - the rubber doesn't provide the strength, the casing does that. As long as the splits aren't so big that the exposed casing is vulnerable to cuts you should be fine.

PeteHski

I would be prepared to spend a little more next time if you intend to ride regularly. Tyres are about the most important component on your entire bike. These are not fit for purpose.