Chain broke at 7400 miles....not bad.

[Sefutau2020]

Yesterday, just after hitting 7,400 miles on my trusty Trek 8s, the original chain finally gave out and broke. Fortunately, I was only about 5 miles from home, so I was able to coast most of the way back, taking full advantage of every downhill stretch.

Now, I fully admit, I probably should’ve replaced that chain around the 5,000-mile mark. But life got busy, and I kept pushing it, still running on the original cassette as well. Honestly, though, that just speaks volumes about the rock-solid durability of the Trek 8s series. These bikes are built like vaults.

My first Trek 8s delivered an incredible 4,500 miles without a single issue; zero. That level of reliability alone is impressive, but the performance of my current 8s has taken it even further. Aside from one early hiccup related to charging (which Trek resolved immediately by replacing the battery free of charge; talk about standing by your product!), this bike has been a true workhorse.

Trek’s engineering and customer support continue to impress me. The craftsmanship, reliability, and thoughtful design built into their bikes are a huge part of why I remain such a loyal fan of the brand. I’m not sure how long the motor will ultimately last, but with performance like this, I’m confident it’ll keep rolling strong.

Today, I’ll be heading into the shop for my annual tune-up and to finally swap out that chain. Here’s to many more miles on this incredible machine. Trek, you’ve got a fan for life.

 

[fooferdoggie]

Yesterday, just after hitting 7,400 miles on my trusty Trek 8s, the original chain finally gave out and broke. Fortunately, I was only about 5 miles from home, so I was able to coast most of the way back, taking full advantage of every downhill stretch.

Man, I bet you toasted your drive train. I get 2500 miles from a chain or 3500 from an e-chain. however, I replace them at .5 wear. cassettes, I get maybe 6000 miles before one of the cogs starts skipping. I think I wore out the original chainring in 8000 miles the replacement was 42t and steel, so it will last far longer. my older bosch bike with the Gen Two motor, I got 14,000 miles from the cassette.

 

[DaveMatthews]

That's excellent!
I'm at around 6500kms on my original chain/cassette on a Giant Stance E+2.
I suspect I might get 1000km more (maybe).
Nicely done!

 

[Stefan Mikes]

I totally agree with foofer. The cassette must be heavily worn. Sefutau, you will see what happens when you install a new chain...

 

[fooferdoggie]

I totally agree with foofer. The cassette must be heavily worn. Sefutau, you will see what happens when you install a new chain...

the difference in wear between the Gen Two bosch and the Gen Four was pretty big for me. the gearing is about the same, although the Trek has bigger tires, so it takes more to get it going. not sure if that accounted for it, but I bet it did, as it took more torque to spin the bike up.

 

[Jeremy McCreary]

Yesterday, just after hitting 7,400 miles on my trusty Trek 8s, the original chain finally gave out and broke. Fortunately, I was only about 5 miles from home, so I was able to coast most of the way back, taking full advantage of every downhill stretch.

Curious as to how bike chains actually break. It's only happened to me once, and in that case, a side-plate pulled off one pin. What failed on yours?

My break happened on a 70 lb hub-drive with throttle. Not sayin' how far I pushed it before realizing that I could just throttle it home.

 

[Stefan Mikes]

Curious as to how bike chains actually break. It's only happened to me once, and in that case, a side-plate pulled off one pin. What failed on yours?

My break happened on a 70 lb hub-drive with throttle. Not sayin' how far I pushed it before realizing that I could just throttle it home.

I broke the chain only once, on a brand new Lovelec hub-drive e-bike. Of course I pedalled the e-bike to the nearest train station as the PAS was working PAS is a leg activated throttle.

 

[carl06]

Yesterday, just after hitting 7,400 miles on my trusty Trek 8s, the original chain finally gave out and broke. Fortunately, I was only about 5 miles from home, so I was able to coast most of the way back, taking full advantage of every downhill stretch.

Now, I fully admit, I probably should’ve replaced that chain around the 5,000-mile mark. But life got busy, and I kept pushing it, still running on the original cassette as well. Honestly, though, that just speaks volumes about the rock-solid durability of the Trek 8s series. These bikes are built like vaults.

My first Trek 8s delivered an incredible 4,500 miles without a single issue; zero. That level of reliability alone is impressive, but the performance of my current 8s has taken it even further. Aside from one early hiccup related to charging (which Trek resolved immediately by replacing the battery free of charge; talk about standing by your product!), this bike has been a true workhorse.

Trek’s engineering and customer support continue to impress me. The craftsmanship, reliability, and thoughtful design built into their bikes are a huge part of why I remain such a loyal fan of the brand. I’m not sure how long the motor will ultimately last, but with performance like this, I’m confident it’ll keep rolling strong.

Today, I’ll be heading into the shop for my annual tune-up and to finally swap out that chain. Here’s to many more miles on this incredible machine. Trek, you’ve got a fan for life.

If the drivetrain is adjusted and maintained properly, a broken chain should not happen very often. My last broken chain was caused by a stick that got caught in the rear derailleur. Probably the most common cause assuming the drivetrain is properly adjusted is chain suck caused by a dirty drivetrain or a worn out drivetrain.

 

[Base]

Funny story, when i stil was chef at a lbs workshop we had a customer in with a wholesale e-bike. Complaints where that the gear shifting was broken and the battery mileage was very short compared to new.

After houding the bike in the air and opening the closed chain case we had a laugh because the trusted and broken chain was inside the lower part of the chain case. It was there for a while and it took a serious shake ti get it out.


Was indeed also a rotation sensor e-bike which has been ridden just on the front wheel motor. Shifting was ok and with an actual chain the milage was ok again

 

[Gionnirocket]

I hate to burst your Trek bubble... But I doubt very much that the chain is manufactured by Trek.
It's most likely a Shimano or KMC so not sure how that relates to Trek quality.
A new chain will probably be problematic as your cassette and chainring are most likely heavily worn.
But if you're happy... I'm happy... Keep rolliń!

 

[Jeremy McCreary]

I broke the chain only once, on a brand new Lovelec hub-drive e-bike. Of course I pedalled the e-bike to the nearest train station as the PAS was working PAS is a leg activated throttle.

Good point. Pedaling without the chain didn't activate the motor in my case — a torque-sensing hub-drive with its torque sensor on the rear dropout and its crank rotation detector actually watching the cassette.

 

[smorgasbord]

I can’t imagine being happy about a chain breaking. Especially if you’ve been checking for wear (elongation) and it wasn’t well past 1% stretch.

 

[Stefan Mikes]

Especially if you’ve been checking for wear (elongation) and it wasn’t well past 1% stretch.

1% stretch means the drivetrain has been already ruined. 0.75% indicates wear to the smallest cogs could have been already done.
I don't want to make @Sefutau2020 more worried but what I think is replacing the chain will result in the chain skipping on the 5 smallest cogs, and he can count himself lucky if the chain wouldn't fall from the chainring soon.

Four new smallest cogs installed on a serviceable Shimano cassette. It was necessary only after several chain replacements past 0.5% stretch. A new expensive cassette would be the alternative.

 

[smorgasbord]

1% stretch means the drivetrain has been already ruined. 0.75% indicates wear to the smallest cogs could have been already done.

I agree, but we're talking about chains actually breaking, and yet people being happy. Makes no sense to me.

 

[Stefan Mikes]

I agree, but we're talking about chains actually breaking, and yet people being happy. Makes no sense to me.

He was happy to save several chains He thinks the chain should be replaced after 5,000 miles. Not. The inspection shall occur past 1,000 miles (with 2,000 indicating negligence).

I had to replace the cassette after this. A total negligence on my side! (This is kilometres not miles!)

Proper chain inspection and maintenance.