I changed a chain at the weekend, over 1,200 miles on the electric bike, slipping and could no longer use the 10 tooth at the rear. (lasted twice the miles of last chain.)

New chain on but the same as the first 4 gears of the 10-42 tooth rear were gubbed, next 6 never been used.

New Sunrace Cassette Fitted.

So new chain and old chain which were same brand and were exactly the same length,  exactly, just the links were worn out.

Edited 18 July, 20187 yr by Offski

The length of the chain is irrelevant. The wear occurs on the pins and the chain gauges measure  the change in distance across a few links between the pins.

PS, 

New KMc Chain & Sunrace Cassette and worked great did about 60 miles on 2 runs, then used Muc-Off C3 ceramic lube

(free with 5 Mags for £5 along with cleaner and hand cleaner. DD will get cancelled after the 5th mag delivered.)

and it was slipping badly so reset the stops and indexed gears.

OK again.

Edited 18 July, 20187 yr by Offski

Happy to know.!

Well another 10 tooth ring bites the dust at under 250 mile.

That is the 3rd now, so back to it set at 1 x 9 instead of 1 x10 on my Specialised Levo Turbo Hardtail.

Too much torque going through it obviously end just gubs some teeth. 

(the recommended Praxis upgrade cassette is over £100 and since i do not need the 10 tooth at the rear not buying one.)

 

The bike has done 2,500 miles in under 12 months and been expensive not only purchase price but for the replaced brake pads, chains & cassettes.

Battery is showing 95% health now and the range has not reduced and it has been worth every penny for smiles per miles.

Edited 19 July, 20187 yr by Offski

On 05/06/2018 at 12:55, hwr1983 said:

Had you reset the indexing on the deraillieur (high/low limit screws etc) as using the "stretched" (or should I say "out of shape") chain would need different adjustment than a brand new one?  I would presume you have done this but worth asking

The high/low screws are only intended to stop the chain falling of either end of the cassette or block. Nothing to do with wear!

On 19/07/2018 at 11:44, Offski said:

Well another 10 tooth ring bites the dust at under 250 mile.

That is the 3rd now, so back to it set at 1 x 9 instead of 1 x10 on my Specialised Levo Turbo Hardtail.

Too much torque going through it obviously end just gubs some teeth. 

(the recommended Praxis upgrade cassette is over £100 and since i do not need the 10 tooth at the rear not buying one.)

 

The bike has done 2,500 miles in under 12 months and been expensive not only purchase price but for the replaced brake pads, chains & cassettes.

Battery is showing 95% health now and the range has not reduced and it has been worth every penny for smiles per miles.

Largish mileage. Ebikes put more torque through the system so wear chains more rapidly. When I was racing mountain bikes, my team leader would fit new chainset and sprockets at the beginning of the season with the cheapest compatible chain. Then replace the chain about every 6 weeks because he avoided wear to  the expensive components and never had to worry about chain failure in a race. Could be an answer to your issues?

Up to 90Nm of torque, and breaking a chain really is not something you want 20 miles from home when you can not walk. I have only one leg.

So i have a spare chain with me and 2 quick links.

Edited 28 July, 20187 yr by Offski

Had my Scott ESpark 720 since Nov 2017. Done 1831k, virtually all off road. Several mtb orienteering events during the winter had ice & snow. Gradually improved the firmware using Shimano updates. Tyres were upgraded to tubeless at purchase and have fitted my dropper seatpost. Spares - two sets brake pads (one because the second set became noisy despite being part worn) and replaced the chain (just) before too much wear. No sign of chain slip after the change despite a QOM blast on turbo up a steep off road climb. Otherwise only fault was crank bolts vibrating loose. I managed to lose a spring on the suspension control - was fixed in minutes without cost by the supplying shop. Sure they would have done so for anyone but I do know the mechanic through his racing and my role of British Cycling Commissaire.