Chain skipping

[patrickj]

New derailleur or chain?

Hi, I have a mid drive ebike conversion that I installed and has been running great the past 3 years until recently.

I’ve been having issues with the chain, which sounds like it’s skipping when peddling hard or going uphill especially. When it skips, I cannot go faster with the throttle and my pedals are not effective either. It sounds like the gear is stuttering or hiccuping when this occurs.

What does seem to help is to switch into a higher gear and then the skipping goes away.

When I installed the mid drive motor i used a 48t sprocket, in retrospect maybe this was too big?

I noticed that the chain seemed like it was too short as you can tell looking at it, the derailleur is tilted forward even on 5th gear.. It also looks slightly bent which i will try to fix.

Would you recommend I get a new chain at the appropriate length or a new deraileur or sprocket? Something else?

Not sure what to do

[Retrorockit]

There are tools to measure chain stretch. I like Park CC2. There are also bike shop tools to check the derailleur hanger for alignment. But when the chain wears it can wear the cassette, and over longer time the chain ring as well. Something does look quite bent in the 2nd photo. To check the chain ring see if a new chain will lie down flat around it. If it bunches up the chain ring is worn too small.. Also hooked teeth are another sign. Some of us just replace chains and cassettes as a a pair. FWIW I run a 50t chainring on a 26" bike.

[patrickj]

Thank you, so from what youre saying are you thinking it might be a worn chain issue? Ive got almost 3500 miles on the odometer

[73Eldo]

Ya I too was thinking your derailleur looks like it got tweaked. It looks twisted. Maybe could be tweaked back but being a Tourney I think those can be had new for less than $20. Also you don't have a cassette, you will be looking for a freewheel. Changing a freewheel requires a special tool called a freewheel tool., most common one would be a Park FR-1.3 and they sell for around $10

Also can't help noticing your chain looks really rusty. When a chain gets stiff it can start doing wacky things so maybe try soaking it real good with some lube? Mine just last week was acting kinda like you described and I was starting to wonder if I had serious issues even though it all looked way way better than yours. Some chain lube and some lube on the shift cable got things back happy again so it may be worth a try.

Is the gear that seems to be slipping the one you use the most? It could just be worn if all the other gears are fine. If its more than one gear it still could be wear but the rust and tweaked derailleur sure are not helping things.

If you had not already got that many Km (and you list your location as usa?) out of it I would be concerned about your chain line and suggest using an offset chainring assuming there is clearance to try and improve it but thats like 1500 miles which is actually pretty good because you either don't lube your chain at all or take minimal care of it and expose the bike to really harsh conditions.

[Retrorockit]

I didn't zoom in on the chain photo.I thought it was one of the gold colored chains. I would say replace the whole mess and buy some chain lube and use it often. Every 50-60 miles. If the derailleur is bent the hanger might be also. I would go to the bike shop and get it aligned. You may even need a new one. Squirt drip wax is easy to use and stay s where you put it. There is better high end stuff out there, but I don't think that's your style.

[AZguy]

Yeah that's a mess, chain's all rusty

Me, I'd toss the chain, cogset and ring (that are almost certainly messed up if for no other reason than that horrid chain) and get fresh ones

[designerron]

I have to agree with this and in addition suggest a regular clean and lube schedule.