Chain Stretch or Failure on Mid-Drive Bike

[Alaskan]

Just an informal survey here.

Has anyone who rides a mid drive bike experienced excessive chain stretch or failure?

I have three bikes with Bosch mid-drive, 2 CX and 1 HS all have well over 1,000 miles with no measurable chain stretch (I have the park tool for measuring chain stretch). One of the CX bikes has an eleven speed rear derailleur with the thinner more delicate chain. The other is a gates belt drive so it doesn't count.

 

[jazz]

I've had mid drives for years I have never had this issue.

 

[JimFMB]

No issues

 

[Saratoga Dave]

I replaced the chain and cassette on my Trek xm700+ at around 3000 miles last fall when the measurement tool showed the chain had stretched and you could feel it in the shifting. I’ll check it again this fall when it gets around 6000. At 5000 now the shifting is still pretty good.

 

[rich c]

Over 2,100 miles on one, almost 2,300 miles on a second. No problems.

 

[PDoz]

My kmc e chain was showing 0.5 wear by 350 km ,( and starting to tinkle) , but I'll accept resonsibility for that - I hadn't read the the posts re shifting with the cranks at 12/6 oclock , plus the posts on adjusting the rear derailier...this pace is an awesome resource.

Ps that's 350 km of rocks , mud, jumps and berms

 

[batmick1]

I didn’t pay attention and missed checking my chain until about 3000 miles on it. It wasn’t slipping but when I replaced the chain I found that I had to swap sprocket and cassette too. Park tool shows well over 0.75 wear on the old chain. 11spd Bosch drivetrain on a Haibike XDuro Trekking RX.

 

[rich c]

I didn’t pay attention and missed checking my chain until about 3000 miles on it. It wasn’t slipping but when I replaced the chain I found that I had to swap sprocket and cassette too. Park tool shows well over 0.75 wear on the old chain. 11spd Bosch drivetrain on a Haibike XDuro Trekking RX.

.75 what?

 

[PDoz]

.75 what?

Percent wear.

This is the tool he refers to

https://www.parktool.com/product/chain-checker-cc-2

 

[Mr. Coffee]

.75 what?

Usually chain wear is measured as a percentage of the original length. So a chain measures at 0.75 has stretched 0.75 percent.

It is recommended to replace your chain when it has stretched 0.5 percent or more, and you'll probably have to replace your cassette if your chain has stretched much more than 0.5 percent.

 

[BikeMike]

Percent wear.

This is the tool he refers to

https://www.parktool.com/product/chain-checker-cc-2

I use Caliber 2 https://www.rohloff.de/en/products/tools/

 

[rich c]

Usually chain wear is measured as a percentage of the original length. So a chain measures at 0.75 has stretched 0.75 percent.

It is recommended to replace your chain when it has stretched 0.5 percent or more, and you'll probably have to replace your cassette if your chain has stretched much more than 0.5 percent.

Do you know what that is in a linear measurement? I have engineer scales and digital calipers.

 

[BikeMike]

I always carry a spare link and tool to repair the chain.

 

[PDoz]

Do you know what that is in a linear measurement? I have engineer scales and digital calipers.

Here you go

https://www.bikeradar.com/au/road/gear/article/bicycle-chain-wear-explained-46015/