Breaking chain.

Simon Lloyd

New Member
Jun 21, 2020
4
0
Burntwood
Hi.. I have an orbea fs2020.. 2 chains in.. Just wondering if anyone has any ideas why the chain snaps.. First one was replaced after several repairs.. Fitted new chain (the correct one) steady ride and guess what.. It snapped.. Please help
Simon
 

Fingerpuk

Member
Apr 8, 2020
250
197
Kent
You cleaning and lubing it? Not changing in extreme climbs? Has the rest of the drive chain been checked? Alignment good? Not using super cheap chains?
 

Simon Lloyd

New Member
Jun 21, 2020
4
0
Burntwood
Thanks for the reply.. Always cleaned and lubed.. The new chain was a shimano cn-m7. The correct one and pretty expensive.. Gears are all trued up. This time it snapped on a fairly level path.. Nothing extreme
 

GrahamPaul

E*POWAH Elite World Champion
Nov 6, 2019
1,127
1,088
Andalucía
Have you checked the chain length? Chain on biggest rear sprocket, rear suspension emptied of air and right down on its stop limit. There should still be a bit of movement possible in the derailleur arm.
 

Simon Lloyd

New Member
Jun 21, 2020
4
0
Burntwood
To be honest.. It was all set up at Tredz.. Followed all instructions etc.. Looks like its going to an 11 speed because there is no straightforward answer
 

Fingerpuk

Member
Apr 8, 2020
250
197
Kent
I think it’s nature’s way of saying you need to buy an additional bike for when this one needs another chain.

Or nuke it from orbit, it’s the only way to be sure.
 

Kaelidoz

E*POWAH Master
Patreon
Apr 29, 2018
312
304
Belgium
2 chains in 3 months... with multiple repairs on the first one!? Both time a cn-m7100?

I found 2 reviews in the last 30 days that complained about this chain snapping although it is almost brand new (on non-e bikes).




Pour le 12 vitesses, j'ai re-testé une chaîne Shimano, depuis longtemps je ne voulais plus en entendre parler, je ne faisais que confiance à KMC.
Verdict, même pas 400km et elle casse, ces chaînes Shimano sont toujours d'une qualité très bas de gamme ou alors il faut certainement y mettre beaucoup plus cher.

0 out of 5 stars. I am 6 ft tall 180 lbs, and broke this chain on my second ride (Less that 3 hours total on this chain) The chain came stock on a Giant Trance 2 enduro bike I just bought and broke on a steep climb in the Waterloo Hydrocut trail I was riding. I expect much more from a stock chain on a $3400 bike.
 

urastus

⚡The Whippet⚡
May 4, 2020
1,548
995
Tasmania
It looks as though Kaelidoz has found the most logical answer. It wouldn't hurt to just eyeball the alignment of the chain - look along the chain from the rear while it is in different gears. You might see something glaringly wrong like a poorly mounted motor which has the chainring alignment out. I'm running 7100 chains (I alternate between two every 500kms or so). I'm in steep country that must be close to the limit of climbability considering the loose rock etc. Every ride is technical climbing. Admittedly only 850km between the two chains. I take chain off and clean every 80 - 100km and re wax generally using the same joining link. I've replaced joining link on both chains once due to what I considered stress when the links weren't properly locked and I tried to pull them shut. Also, did chains break at joining links? Either way, it's easy to eyeball the chainline. I'd also try putting bike upside down and doing the same thing, but with someone turning the cranks, just to see if there are any outrageous buckles in the chainring or cluster.
 

RazorBlade

Member
Jun 6, 2020
98
65
UK
My guess is your changing gear before the motor has disengaged, you need to stop pedaling and wait briefly then shift, before resuming.
 
Last edited:

steve_sordy

Wedding Crasher
Nov 5, 2018
9,033
9,481
Lincolnshire, UK
All the advise above is worth pursuing, but I would double check the chain length. Deflate the shock and push it fully down to simulate max depression on the rear suspension. Then put the chain in the largest rear gear, will it even go there? Is the angle of the mech arm at 45 degrees to the horizontal or is it stretched out towards the horizontal? If your chain is too short and you do a big G out on the bigger gears you may snap the chain, or maybe rip the mech clean off.
 

Intermtb

Member
Jan 5, 2020
87
74
USA
try to spin more than mashing. spinning is easier on the drivertrain, motor, and knees.
I learn to spin more on emtb than on my reg mtb, trying to be somewhat easy on my drivetrain for durability, and more range on battery.
I know some people like to mash, putting a lot of torque using higher gear plus torque from motor, like standing up on steep climb, that put a lot of force on the chain. especially for heavy rider.

and 12 speed chain would not help either, if you keep snapping chain, I suggest go to 10 speed or even 9 speed drivetrain, thicker and stronger chain. I have box component 9 speed 11-46t, easier to adjust than 11 speed, because of wider space between gears, better tolerance for adjustment, also stronger chain overall.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
9,033
9,481
Lincolnshire, UK
................and 12 speed chain would not help either, if you keep snapping chain, I suggest go to 10 speed or even 9 speed drivetrain, thicker and stronger chain. I have box component 9 speed 11-46t, easier to adjust than 11 speed, because of wider space between gears, better tolerance for adjustment, also stronger chain overall.
You make a good case for lower speed drives. I was convinced until I rode one with the latest high tech EX1 8-speed. It was on the highest spec Cube emtb that I was testing. I just could not find a gear I liked and found myself changing gear much more frequently than I would have expected. I then swapped that test bike for the next spec down which had a 10-speed and I was immediately more comfortable. No doubt I would have got used to the 8=speed, but I didn't want to spend over £6k and then spend time getting used to it.
 

Gemini2k

Member
Sep 9, 2019
66
28
Normal
try to spin more than mashing. spinning is easier on the drivertrain, motor, and knees.
I learn to spin more on emtb than on my reg mtb, trying to be somewhat easy on my drivetrain for durability, and more range on battery.
I know some people like to mash, putting a lot of torque using higher gear plus torque from motor, like standing up on steep climb, that put a lot of force on the chain. especially for heavy rider.

and 12 speed chain would not help either, if you keep snapping chain, I suggest go to 10 speed or even 9 speed drivetrain, thicker and stronger chain. I have box component 9 speed 11-46t, easier to adjust than 11 speed, because of wider space between gears, better tolerance for adjustment, also stronger chain overall.
Lower speed chains are not stronger. That’s a common misconception. 12 speed chains are typically stronger, but tensile strength isn’t the issue here anyways (it never is). You can hang a small car from a 12 speed chain. The issue is shifting under load or otherwise unnecessary wear and tear.
 

Mooree

New Member
Jan 18, 2022
11
0
USA
Specially designed bike repair equipment is really convenient, but there will be times when all of a sudden you need to repair or replace your bike chain without special tools. Disconnecting the main link without special tools can be very complicated. To do this, you can use any substitute to master the link pliers as long as they can reach between the chainplates and pull or tighten both links until they disconnect.
 

urastus

⚡The Whippet⚡
May 4, 2020
1,548
995
Tasmania
Specially designed bike repair equipment is really convenient, but there will be times when all of a sudden you need to repair or replace your bike chain without special tools. Disconnecting the main link without special tools can be very complicated. To do this, you can use any substitute to master the link pliers as long as they can reach between the chainplates and pull or tighten both links until they disconnect.
yes, I used the shoelace technique once on track; I ended up having to use a stick as handle to the each end of the lace, then it was easy.
 

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