Holy Tire Rub!

[brewsmith]

Posting for posterity, been fixing up bikes for a while now and this is a new one for me. I really don't understand how one could ride to this point without noticing anything. The frame is an early Litespeed.

https://i.postimg.cc/QCVXbCdw/0329190855a.jpg

https://i.postimg.cc/vHgYx4j6/0329190855.jpg

[MattTuck]

How does rubber wear down metal? That makes no sense. Must have been done with a file to get more clearance.

[AngryScientist]

How does rubber wear down metal? That makes no sense. Must have been done with a file to get more clearance.

you have heard of water eroding stone, no? same basic principal.

i have seen some pretty severe tire rub myself, but that is really quite bad. looks like a wheel that was out of true and rubbing on that one side every rotation.

[weisan]

A minimum of 80 watts increase once the rub is removed.

Best power boost ever!

I suspect that was filed down on purpose to accommodate wider tires.

[MattTuck]

you have heard of water eroding stone, no? same basic principal.

i have seen some pretty severe tire rub myself, but that is really quite bad. looks like a wheel that was out of true and rubbing on that one side every rotation.

You'd be going through tires at a pace of once per week :) Unless you got the diamond dust coated side walls, then you could saw through your chain stays in a matter of days!

I guess it is possible, but seems like willful negligence. There would be a lot of other clues that something was wrong.

[cribbit]

Any sort of sand or grit will speed it up greatly.

You'd be surprised at how long rubber on metal can hold up.

[berserk87]

Yeah. The smell of burning rubber would be a giveaway that there was a problem. Maybe he only rode this bike in and around a dragstrip and the burnouts masked the odor.

[572cv]

Yikes! Reminds me that back in the day (19th, early 20th century), there was a clever strategy for cutting large blocks of granite, like, 8 ft high, 12ft long and 20 ft deep, for example, into slabs. You set up a couple of 10 ft diameter wheels about 20ft apart, and strung a wire loop around them, reasonably taut. the wheels spun on vertical slides and were maneuvered over the granite then the wire was also set to run through a slurry of wet sand, and set in motion. The weight of the apparatus dragged the wire and sand slurry over the granite block, but was long enough for the wire to cool on every rev and pick up more moisture and sand. After a few weeks, the slab was sliced, and you moved the whole thing over for the next slab. Slick.

[Veloo]

So that's what happens when you force a 28 tire into a 90's frame.

[batman1425]

I'd check the alignment of the rear end given the bias in wear - presuming it is still rideable with a hole that big in the stay.

[nooneline]

You'd be going through tires at a pace of once per week :) Unless you got the diamond dust coated side walls, then you could saw through your chain stays in a matter of days!

I guess it is possible, but seems like willful negligence. There would be a lot of other clues that something was wrong.

You'd be surprised.

I have an old trainer, and there's a groove worn in the metal from where the tire contacts it.

And I've had an old bike with tire rub like that - though nowhere near as bad. The rubber gives; the metal doesn't, so it wears away.

[YoKev]

I saw the exact same hole/shape happen on a Cannondale. Incredible stuff...

[benb]

Remember we're not talking about a lot of metal there. Probably less than a millimeter thick, maybe a framebuilder can say.

I had tire rub take the paint off the stay of my MTB really quickly. I don't doubt it could have worn a hole.

Even that stay cracks the bike could still be pretty rideable. That's not a location that's catastrophic. I cracked the driveside stay on my first road bike and didn't notice for quite a while. It was a Trek, they covered it under the warranty. Just a fatigue crack.

[Butch]

Titanium has a lot of great characteristics but abrasion resistance is not one of them. Poor frame alignment, too big of a tire or an out of dish wheel can do some damage. Cable housing can do some wear and tear to a frame as well.

[charliedid]

I've seen it more than once.

Some people just don't have that sense of awareness to actions that affect them physically and they just keep riding along. You work in a shop long enough you will see it all. Saddles that appear like a torture device seem completely comfortable to the rider. Same with bar position, fit etc.

Looks like the rim did some work on that too.

Reminds me of this : https://www.nytimes.com/2019/03/28/health/woman-pain-anxiety.html

We are a complicated bunch.

[redir]

I did that in one mountain bike race. It didn't go all the way through but it was darn close. Stupidly of me I din't think it was a big deal after a crash that I could hear the tire hit the frame every cycle round. But heck I was winning the race and jsut kept going. I could not believe the damage done. It was an Aluminum frame. I guess the tire and the sand and grit acts like a file.

[Tony]

You'd be going through tires at a pace of once per week :) Unless you got the diamond dust coated side walls, then you could saw through your chain stays in a matter of days!

I guess it is possible, but seems like willful negligence. There would be a lot of other clues that something was wrong.

Inmates in California correctional facilities/prison can't have dental floss. It can be braided and with a bit of tooth paste and time cut through steel bars.

A tire can easily do this over time.

[benb]

I did that in one mountain bike race. It didn't go all the way through but it was darn close. Stupidly of me I din't think it was a big deal after a crash that I could hear the tire hit the frame every cycle round. But heck I was winning the race and jsut kept going. I could not believe the damage done. It was an Aluminum frame. I guess the tire and the sand and grit acts like a file.

This is what happened to me too.. MTB wheel went out of true in sandy wet conditions.

The tire will deform to get past the stay, the sand won't, and the stay won't, so the tire can act like a file/grinder pretty effectively.

[papa bless]

I'd bet the owner of this bike has some jacked legs from the pure resistance training.

[Spoker]

Titanium dropouts that are smooth (like the Litespeed) have very little resistance to slipping. Quality QR's are a must. You can wear a hole like that in a weeks time.

[bulgie]

http://bulgier.net/pics/bike/broken/Chainstay_perforated_by_Tire.jpg
Picture shows a circa '71 Raleigh Super Course, left c-stay perforated by the tire (or maybe the grit clinging to the tire).

-Mark