Zaskar

Saturday was one of the worst rides - that didn't involve a crash - I've had. It was supposed to be a 75-mile ride. Three of us made it 42 miles before my chain dropped between the spider and frame. I was soooo proud of my recent derailleur whispering - big/big and small/small with no rubbing and no trim on a 52/11... until the chain dropped. Yeah, gotta adjust the limit. I had to loosen the left crank, push the spindle to free up the chain. Seemed quicker than breaking the chain. Side note: three small allen wrenches held together makes a passable wrench for the preload cap.

12 miles later: BOOM! At about 25 mph the rear tire went from 85 psi to 0 psi in .0001 seconds. Yeah - fortunately the rear. I first looked at the tire. Definitely the biggest cut I've had. Just a bit more than the sealant could handle.



Then I looked at the frame. The seatstays are chunked right where the tire passes. Clearly the tire caught something, brought it around and it smacked the frame. We couldn't find whatever it was - likely flew once it popped free. The chips are through the clear and paint and just barely into the first layer of carbon.





... still 20+ miles from home, I had to make the call of shame. I don't think the frame is at risk of failing. I think the only fix I'll do is gently smoothing the edges and hiding the divots with black or yellow tape. I'm not selling it... just don't want to have to look at it every time I ride that bike.

datlas 

Bummer, but I agree it does NOT look structural. You may want to use some matte black touch-up paint or even nail polish just to protect the exposed part of the frame.

tempocyclist

That's one hell of a slash in the tyre! Did you run over a medieval battle axe?!?! 😨

tomato coupe

That's one of the big advantages of a gravel bike -- they usually have enough clearance for a battle axe.

LarrySellerz

TBH this is what you get for cross chaining that badly. Hope the bike isn’t dead op goodluck

Canker

Go to an autoparts store and buy a touch up pen
https://www.amazon.com/ACDelco-19328...785460&sr=8-10

79pmooney

I think this thread jinxed me. Took out new wheels today for a spin on new tubulars. Rear wheel is my first ever deep V rim. Coming home I ran over something and immediately flatted completely, felt impact metal to metal and then a hard object in the tire. Roofing nail. Through the tread, tube twice and back out of the inside of the tire, then through the rim bed. I had a full 1/2" of nail inside the rim. (God thing it was a deep rim and the nail no had nothing more it could reach.) Pulling the tire off, I had to disengage both the valve and the nail (which I left in so finding the repair will be really easy!)

So this brand new to me wheel now has another hole in the rim bed. It had 31 already so I'm not concerned. (28 spoke holes, the valve and three at the joint - weight balancing?

str8jakett

I had a sheet metal screw go into the tread of my rear tire and into the rim bed last year and the head made a few rounds of shredding my seat tube paint layers. Looks like yours, nothing structural, but it ain't pretty.

Chuck M 

Did you read the part about this not being after the chain drop but after the flat?

indyfabz

That damage would not have happened to a steel frame.

Kai Winters

It would have caused the same superficial damage and would become the entry point for corrosion and possible frame failure if left unattended long enough.
Sand the area smooth, build up layer by layer with primer then paint...if no clear coat...then when a bit higher than the area sand smooth to level and buff to match...good off season project...while waiting for off season, if you wait, cover with tape as you mention.
Small, small is a great way to derail your chain...lucky you didn't damage the paint at the bottom bracket shell.

indyfabz

You think a layer of steel would have cracked off like that? I don't. Maybe some paint abrasion at most.

Zaskar

To be clear, I wasn't riding (and don't ride) in small-small. When I install/adjust mech front derailleurs, the goal is to be rub-free big-big and small-small. The later being less important... but easier to do. I was in the small ring (36t) and toward the middle of the cassette. I back pedaled as I approached a light. That did it. The recent adjustment was the issue.

And yeah - non of ^that^ had anything to do with the flat ;-)

Kai Winters

The carbon layup didn't "crack off"...barely touched
Possibly the steel would have a nice dent
The repair method would basically be the same as the frame material is barely touched...sand smooth, build up layers of primer/paint...sand smooth and buff to blend.

indyfabz

Barely touched? Are we looking at the same photo? I would hate to see what would have happened if it had been moderately touched.

Zaskar

The carbon was barely touched. The frame definitely took a shot. All of the clear coat and paint are gone - exposing the naked carbon. It looks like a tiny bit of the top layer got nicked enough to damage a few strands. If that renders the tube compromised... I'm getting rid of all my carbon bikes ;-)
(it didn't and I'm not)

Kabuki12

I picked up a dry wall screw in the side of my rear tire and it made at least three revolutions hitting the chain stay on my vintage steel bike. It was loud and I stopped as quickly as I could. It just removed the paint but no damage to the chain stay.

eduskator

Yeah, a color matched nail polish will do the job! Doesn't seem structural, but we never know. It may be worth a checkup.