Mountain Bike Reviews Forum banner
1 - 20 of 37 Posts

· Registered
Joined
·
408 Posts
Discussion Starter · #1 ·
Tore down my 2020 Topfuel frame to clean and service pivots and whatnot and found a crack down by the bottom bracket. Lbs submitted it to trek for warranty evaluation. Here’s hoping trek takes care of me. Now if you’ll excuse me, I’m gonna go have a drink.
Land vehicle Hand Bicycle part Automotive tire Finger

Automotive tire Automotive design Grey Rim Automotive exterior
 

· Ridin' dirty!
Joined
·
2,308 Posts
Looks like impact damage to me….
Maybe they’ll do a crash replacement.
Good luck with the claim.
Keep us posted.


Sent from my iPhone using Tapatalk
 

· Registered
Joined
·
408 Posts
Discussion Starter · #5 ·
Given that it was behind the chainring (which was why I never saw it before today) I’d say impact is highly unlikely if not impossible. Also the crack follows a natural line of the gusset. Seems like a flaw.
 

· EAT MORE GRIME
(ノಠ益ಠ)ノ彡┻━┻
Joined
·
8,488 Posts
something got wedged in there and crunch

looks like operator damage not frame flaw
[explain the gouges that could never have happened if only a frame flaw]

let trek review I reckon...
 

· Elitest thrill junkie
Joined
·
42,025 Posts
Although there are some scratches, they don't even go down to the white epoxy primer, which should be the layer beneath the paint, and there are no CF fibers present, which seems to indicate to me that it's not likely that something was jammed in there. Scratches are a normal part of riding, but scratches from impact damage are much more prominent IME. I transported a fat-bike once and the wheel was situated so the cassette rested against the downtube and scratched the hell out of it. Although I don't think I damaged the underlying CF, the scratches were prominent and unmistakable. Very different from this photo. I've also done some CF repairs on my turner, sanding down to the bare CF. There's a good bit of clear coat, paint and sealing epoxy that should be showing if you are really getting down to CF. Surely there would be scars going deep if this was all the case, but it doesn't look so to me.

Cracks show white, but not the scratches and the scratches don't seem to be correlative with the cracks (as in, leading into a crack). Two types of failures you are going to see are tension and compression failures. Tension will be snapping CF fibers. Compression will be mainly cracks without the visible busted CFs.

Although cracks can also indicate point impact damage, there appears to be a lack of scaring/scratching that I'd expect to see with such an impact.
 

· Registered
Joined
·
82 Posts
Tap it with a penny and see if it sound different than when you tap the rest of the frame, it makes a completely different sound if its cracked. Its like dragging a chain on concrete vs carpet, very noticeable. If its not noticeable or barely, its probably just cracked clear coat/paint. I thought I had cracked my remedy frame, submitted for warranty, the bike shop did the test and found it was just cracked paint. Sanded the paint off for my own curiosity and sure enough, it was fine.
 

· Registered
Joined
·
408 Posts
Discussion Starter · #13 ·

· Registered
Joined
·
408 Posts
Discussion Starter · #15 ·
I have two friends with similar damage on their Top Fuels and both were replaced under warranty this year.
That's interesting.
 

· Community Manager at Trek
Joined
·
616 Posts
So many folks trying to guess - best to let it be evaluated by the pros (aka our warranty team)!

As long as you're the original owner with proof of purchase, we'll definitely take a look at it and take care of you (y)
 

· Registered
Joined
·
408 Posts
Discussion Starter · #17 ·
Update. Trek sent a new front triangle. Frame should be ready Monday. :)
 
1 - 20 of 37 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top