Chain damage after each ride
 

Hello guys, I picked up a new Giant Roam 2 about 3 months ago, i've only put 200 miles on it. For the past 3 rides I been having an issue with my chain, it gets like a chew spot and I have to fix with a chain break tool and some sanding orherwise the chainink would get stuck. After fixing, the bike shifts okay but I cannot find what is causing this. Please see attached photos.

I don't think you can post pics until you've reached 10 posts as far as I know.
If by "new" you mean brand new from the shop, why don't you take it to the shop where you bought it and have them take a look at ? I'm going to assume it's still covered by warranty and stuff like this shouldn't be happening.

It's hard to figure what you are doing but I'd be surprised if you have fixed anything. More likely you have ruined your chain. Take it to a shop, please:thumb:

Okay. So this ^ statement is ambiguous. Did you purchase a brand new bike from a bike store? Had the chain been replaced before you took possession? Is the gearing the standard 2 x 9 speed Shimano stuff? These are important questions.

I also don't know what a "chew spot" is...

Hi Everyone, I wish I can show you a picture but the page does not allow it until I reach 10 posts. The shop is about 45 minutes drive from here and this is why I been hesitant of taking the bike back there. The gearing is shimano 2 x 9, the bike uses a kmz chain with a missing link, I already bought a replacement chain just in case. What I am trying to describe is basically a smash mark in the chain like if one of the teeth of the crank or the cassette smash it hard on it, I get those every time I go for a long ride (20 miles). The way I been fixing it is by taking out the link and sanding a bit the part where its been smashed then assembly it back. If I don't "fix" it the chain link will get stuck and the chain will start skipping, I keep the chain well lubed so the issue is not lubrication that causes the stick links, the issue are smashed marks in between the links.

My last resort would be taking it back to the shop, so I figure I could ask here to see if anyone experienced something similar.

I've never heard of a chain needing to be "fixed" as you describe. Taking the bike back to the shop needs to be upgraded to your first choice. Your only going to cause more expensive damage if you continue to ride this bike. Take it back to the shop straight away.

I uploaded the picture to my google photos for you guys to see it since I cannot post it here yet.

photos.google.com/share/AF1QipO2Qnrvlj51AXOEzPCMPtFRrIFIRB7Qh7pkrmXAYA9QMdY70lt8H3WIrUQ-WIpgaw?key=d2g5c2dEcGxEQzNYLUFEWFk1UFQ4aUVGWGVkX3RR

Does the damage to the chain occur with the chain on both the big ring and small ring, or only on one of the rings, say the big ring. I'm thinking there is a bent tooth somewhere.

The bike shop is a bit far for me, If I can figure it out myself I would def give it a try.

I checked all the tooth on the cassette and the crank and they look fine, what I think is doing it is the shifting, sometimes I shift uphill and i can hear the chaing taking the gear very hard. But the shifts are well calibrated and smooth but uphill is a different story if i drop to a lighter gear too fast.

I had a look at your photo and while it shows the damage it gives us nothing in regards to trying to diagnose the problem.
I have NEVER seen such chain damage in a lifetime of riding bicycles. Something somewhere is out of alignment and your just going to have to take it to some bicycle mechanic somewhere to have a look at it. Bicycles aren't the most complicated machines yet there are any number of proprietary tools that are needed to work on bicycles and my bet is that one of these proprietary bicycle tools is going to be needed to fix your problem.
I doubt your going to fix it with an allen key. Do you even have allen keys?

Photo assist.

https://cimg5.ibsrv.net/gimg/bikefor...1faabe64e8.jpg

From the picture DrIsotope posted it looks like that chain is needs some oil on it; try that first and see if it helps.

I'm wondering if the chain is correct for the drive train - maybe a single-speed chain so its not fitting correctly on the 9-speed cassette? Check the teeth on the cassette gears you use the most and see if they show unusual wear and damage from a wrong size chain.

If neither of those work its probably best to go to a bike shop and have a mechanic look at it.

Go with the "last resort" you mentioned . Take it to the shop. You have a problem much out of the ordinary. I hope your shop is understanding of how far you travel and try to get it fixed without a long return trip.

If you bought it new and are having problems, there is no better solution than to take it back to the shop. Disassembling the chain, and fooling around with it after each ride, should not be necessary - and has likely reduced your chances of getting the shop to fix this at their own expense, which would be standard practice on a two-month old bike. (I mean, if you bought a new car, and the transmission wasn't shifting properly, would you tear it apart yourself, or take it to the dealer for warranty service?)

Yea it really looks like a 5-8 speed chain. Also sounds like the OP could be shifting under load while climbing, not good.

Don't listen to the haters, chain lube is completely a scam and you can get by just fine with some good old fashioned 110 grit garnet paper

:popcorn

Album is empty. :<(

Cheers

a 45 minute drive is nothing and it shouldn't hold you from taking the bike back to the shop. You would've saved yourself some headache and even money. And, assuming the bike was bought brand new, you shouldn't be missing with it yourself at this point.

I found the issue myself, the cassette seems to be lose. I'm taking it back to the shop.

You should probably ask for a new chain, too, since you've been messing with it. But they may not want to do gratis warranty work precisely because you were messing with it. (And by "messing," I mean doing things that you should not have been doing.)

As an aside: last year I bought an expensive new bike from the nearest good shop, which is 80 miles away. It basically kills 1/2 day or even a whole day for me to take the bike in for work, since they will often do things while I hang around in the area. But that's how I've done all but the most minor work. When the bike was a year old, they found a tiny issue with the RD that I had never noticed - I really didn't know there was anything wrong, but the lead mechanic noticed it. End result was a brand new Ultegra Di2 RD (not a cheap part) at no cost, installed and everything. I think they (and Shimano) were willing to do that, in part, because they knew I hadn't messed with it. (I had apparently only ridden it into the ground!)

I'm gonna give it a try next Saturday, hopefully I can get away with the chain thing, I can blame the cassette causing the chain damage... Next time I get a new bike I would look for a closer shop loll.

If you've taken the chain apart and then pushed a rivet back in, get a new chain for sure as a 9-speed chain rivet is flush with the outside plates and pushing one partway out with a chain tool and then pushing the rivet back in with a chain tool makes for a VERY WEAK joint there. 9-speed chains should be joined either with the special Shimano pin (if a Shimano chain) or much better in my opinion, with a quick-link.

A chain that breaks under load can cause a nasty spill and you don't want that to happen in traffic or in an intersection.

Cheers