wearing out a lot of sidewalls these days on bigger tires

[bicycletricycle]

for years I rode mostly 700x28 tires, with something like 75-90 psi. toping them up when they get down to 50-60psi.

In the last 2 or 3 years I have been mainly riding 700x35 tires on my main commuter bicycle, usually at around 60-65psi. I am not really good at keeping up with tire pressure and usually only top them up when they get in danger of pinch flatting (35-40psi).

For the first year or so I ran panaracer T serv 700x35 tires, I have now switched to Schwalbe Marathon supremes 700x35 tires.

I have worn through the sidewall on 3 panaracers and 1 schwalbe, all 4 have been on the rear.

I have never persistently worn out sidewalls before the tread on tires. These failures don't seem to be from debris cuts but just from becoming threadbare. When they finally go I can see lots of other places on the sidewall that are close to wearing through as well. I have run 700x28 T servs for a decade or so, almost always ran them down to the cord without sidewall failure.

Has anyone else had problems with wearing sidewalls out before the tread?

I guess it is from running them low a lot, all that extra flexing in those bigger sidewalls?

What do you guys think?

[Ken Robb]

What are the sidewalls rubbing on?

[bicycletricycle]

themselves I guess

[AngryScientist]

very interesting.

for sure, it is common knowledge that if you ride your car around on well underinflated tires, they will fail with a sidewall blowout; so it does make sense that the same could happen with bike tires, which have obviously much thinner sidewalls.

i would try and be more diligent about keeping the psi pumped up and see if that reduces the instances of worn out sidewalls.

[donevwil]

Narrow rims, bulging wide tires making canti pads rub ?

I've not had sidewall wear issues, but on my commuter I'm running 19mm rims and 37mm tires. While adjusting the canti brakes a while ago I was surprised how close the old-school fat pads came to rubbing the tire sidewall about 1/4 way through the path of the brake arm, maybe 1mm clearance.

Long shot, but maybe ?

[cachagua]

Canti brakes out of adjustment, yes, but that would produce wear in a very narrow slice, is that what you're seeing?

Or the sidewall flex is getting to the threads of the casing, and/or the protective layer on top of it? I'll admit, I've commuted pretty much the way you described (put in a bunch of air, then ignore for half a year)... and actually, thinking back, I retired fewer tires from worn out tread than from deteriorated sidewalls. And tires are meant to be lighter and have more flexible sidewalls these days, as well as having tread that lasts forever... at least if we believe the manufacturers.

Used to paint sewups with liquid latex, back in the Paleozoic -- it was the story of coating Dugasts with Aquaseal that reminded me of it. Maybe periodically putting a new layer of something on a tire's sides would increase its life?

[bicycletricycle]

I would kick my own ass if I let an out of adjustment brake pad slice a sidewall.

I think the extra distortion from running them at lower pressures is just chewing them up.

The worn spots happen at a sort of diagonal, if you push your bike down to deform the tire you will see little pleats happen at a diagonal in the sidewall, mine are failing along those lines.

I just never had it happen to me before, at first i thought it was the big panaracer T servs but now that the same thing has happen to the Scwalbe I think it is the way I am using/abusing them.


I guess i got to stay more on top of things.



people used to brush latex onto their tubulars?

[sitzmark]

Think you've answered your own question. My money would be on wear due to "low" inflation. More distortion, flex, and friction of sidewall materials. If you crank up to any significant speed, downhills, etc. some heat is also a likely byproduct of the extra flexing/friction.

Vehicle analogy is spot on.

[stephenmarklay]

Funny enough I was just changing out my tires. I have such a flat spot in the middle I wondered if running them lower pressure would reduce this tendency.

[bicycletricycle]

Think you've answered your own question. My money would be on wear due to "low" inflation. More distortion, flex, and friction of sidewall materials. If you crank up to any significant speed, downhills, etc. some heat is also a likely byproduct of the extra flexing/friction.

Vehicle analogy is spot on.

Ya, I Guess I was wondering if anyone else is having these kind of problems.


I have a fancy bike with 650x42 lightweights on it now, I guess ill stay on top of the pressure on those more to keep this from happening, those tires are expensive.

or maybe the thinner casing will actually be more durable because it flexes easier?

[MaraudingWalrus]

Low inflation. We see it regularly on cruiser tires and comfort bikes people ride around and don't know they need to inflate.

I also had it happen on my first set of tires for my gravel bike when I was trying to get away with too low of a pressure for a couple weeks...

[weightshift]

With the Panaracer Paselas, I always run into this issue. I don't seem to have this problem with Rivendell's Panaracer-made tires though, so I'm not sure if it's just lower price point=lower durability.

And: it always happens on the rear.

With this talk of lower inflated pressure though, it does make me agree that this could be a valid cause —*the bike that runs the Paselas doesn't see as much use compared to my other bikes, so it gets low often before I take it out for a camping run, or commuting. Coupled with the Paselas "lower"-quality (again, comparatively to Compass or Rivendell) perhaps, this might indeed be it.

[bicycletricycle]

makes me wonder if tires don't need a min. as well as a max. pressure rating.

[Joxster]

very interesting.

for sure, it is common knowledge that if you ride your car around on well underinflated tires, they will fail with a sidewall blowout; so it does make sense that the same could happen with bike tires, which have obviously much thinner sidewalls.

i would try and be more diligent about keeping the psi pumped up and see if that reduces the instances of worn out sidewalls.

Didn't I mention this on another thread but this isn't a problem????

[MaraudingWalrus]

makes me wonder if tires don't need a min. as well as a max. pressure rating.

many of them do have this.

[Mark McM]

makes me wonder if tires don't need a min. as well as a max. pressure rating.

But wouldn't they need a table, not just a simple fixed number? A pressure that might be perfectly fine for a 100 lb. rider using a wide rim might be far too low for a 250 lb. rider using a narrow rim.

If you look at automobile tires, you'll see that they have maximum pressure ratings, maximum load ratings, and even maximum speed ratings, but they don't have minimum pressure ratings.

[staggerwing]

Ahh, what about the Firestone/Explorer fiasco, where too low recommended inflation pressure, resulted in too much internal friction, heat build up, and eventually, catastrophic tire disintegration.

Not suggesting anything that dramatic on a bicycle tire, although, I can see where too low a pressure, particularly with a larger rider, like myself, would result in sidewall wear.

With a nice pump, it isn't terribly difficult to get pressures right, just prior to riding.

[smontanaro]

My regular commuter, a Trek 520 (Dia-Compe cantis), converted from 27-inch to 700C has been a wall hanger for a couple months after a series of sidewall tears. After the third one, I just hung the bike up until I get some time to look carefully at the problem (I have plenty of other bikes to choose from), but I suspect that the slight change in pad angle with the rim size reduction and running slightly wider tires (700x32c or 35c) at lowish pressures (60-70psi rear) are major contributors to my problem.

[fiamme red]

I just noticed that the Panaracer T-Serv 32mm front tire on my commuter has developed some sidewall fraying. After reading this thread, I'm wondering if it's because I ride it under-inflated. I usually only re-inflate it when I feel it getting soft.

[scho74]

I would kick my own ass if I let an out of adjustment brake pad slice a sidewall.

I think the extra distortion from running them at lower pressures is just chewing them up.

The worn spots happen at a sort of diagonal, if you push your bike down to deform the tire you will see little pleats happen at a diagonal in the sidewall, mine are failing along those lines.

I just never had it happen to me before, at first i thought it was the big panaracer T servs but now that the same thing has happen to the Scwalbe I think it is the way I am using/abusing them.


I guess i got to stay more on top of things.



people used to brush latex onto their tubulars?

your rear tire must look just like this: https://www.youtube.com/watch?v=F6PiKcAJmYk

[bicycletricycle]

many of them do have this.

I remember mountain bike tires having inflation ranges, but not too many road size tires,but to be honest, I don't really check tires for inflation pressures anymore, woops.

[bicycletricycle]

Ya, might be hard to fit a graph on the side of the tire, perhaps the box could have a sweet graph on it.




But wouldn't they need a table, not just a simple fixed number? A pressure that might be perfectly fine for a 100 lb. rider using a wide rim might be far too low for a 250 lb. rider using a narrow rim.

If you look at automobile tires, you'll see that they have maximum pressure ratings, maximum load ratings, and even maximum speed ratings, but they don't have minimum pressure ratings.

[steamer]

Keep in mind that the casing of the tire is what is actually taking the load (the weight of the bike and rider). Too much load can cause casing failure.

And, if the casing deflects too much, that has to speed up the process. (deflection dependent on a combination of load vs. inflation pressure).

I seem to recall Schwalbe publishing both max loads (lbs.) and minimum inflation pressures (psi) for their tires. Respecting both of these is what allows the casing to hold up.

This is normally a hotter topic for tandem riders.

[benb]

Michelin DID put graphs on the box for their tires for quite some time, maybe they still do.

65-70psi is not exactly a "low" pressure for a 35c tire though unless you are well into Clydesdale territory. 65psi sounds rock hard to me for a 35c tire. I'd probably start around 50psi on the rear. I run my 38c rear at 45psi.

[KidWok]

I've had this happen with Panaracers Paselas before. A few days ago, it happened with a 25mm T-serv. Sidewall blowout JST (Just Sitting There) after I have pumped up the tire before I was going out for a group ride. That tire was a bit older, but still had 25% tread left.

I've known this about Panaracers, but have used them nonetheless because they ride nice for the price. Looked at my 32mm Paselas on my all-arounder last night and saw some fraying on the sidewalls and decided enough was enough...Took them off and threw on some Schwalbe Marathon Supremes waiting in the wings. At this point, I have one more 25mm T-Serv in my fleet that looks like it's in good condition, but I'm probably done with Panaracers.

FWIW...I've had a set of Marathon Supremes on my commuter for ages and they have not shown signs of sidewall fatigue...and those are the ones I tend to run low all the time. Paselas do have a min tire pressure on the side and I was running the 32's on my all-arounder regularly below that, so I'm guessing they just aren't designed for that.

Tai

[559Rando]

Sounds like you need a little more air or lighten up the motor a bit (no offense intended--I'm working on this myself!).

[bicycletricycle]

Sounds like you need a little more air or lighten up the motor a bit (no offense intended--I'm working on this myself!).

ya, more pressure will help for sure. I could also stand to loose some pounds.

[bshell]

I've had this happen to a handful of 26" cross country MTB tires (with tubes) and I don't think it had anything to do with under inflation. I have no theory as to *why* it did happen (just disappointed at the $ loss) but I'm 180# and ride 'em at 40-45 lbs of air on old style, narrow rims...