Chain guide for 42 to 44t ?

[quadfather]

hey, i have an enduro ebike and the chain keeps falling off!

its really frustrating when i pass evryone then have to pull over to put my chain back on. On a short ride today (15 miles) i had to put the chain on no less than 5 times!!

i have bought this chain guide

but its pretty useless.

i've also shortened my chain by as much as possible and adjusted my rear de-railer (the spring screw is so tight it's almost rounded) so im stuck.

looking online, theres not much that's available as everything seems geared towards 30 odd tooth chainrings. also with the shape of my frame, the only one that would work would be something underneath, not on top of the chainring if that makes sense ?

do you e-bikers have the same problems ? it seems to be when i hit some bumps at speeds too fast to peddle at. if the chain is under tension (me pedalling) its fine.

maybe theres an e-bike manufacturer that produces something ? im not sure any help / links would be appreciated.

peace

 

[nutnspecial]

Do you have a round chainring 'bash guard' on there? Because I also lost the ability to use the front deraileur, I installed one on each side of my chainring and it fixed drops due to the chain bumping off the first tooth or two under bumpy conditions of coasting. They have many sizes on aliexpress and ebay- just give mounting size and tooth range.

The other option is similar to what you have there, but even on DH bikes I think they are typically integrated with bash guard and use a pulley on chain return, not on top.
If something more is needed than bash guards or what you bought, I'm sure something can be done. If you post a pic here of that area on your bike it could help!

 

[paracidium]

I run a 53t chaining and also had a lot of trouble with the chain dropping off, I tried all sorts of chain devices that I had modified to fit but none of them were reliable enough. As a last resort I fitted an aluminium chain guard to the crank. It worked perfectly, no more getting off every 10 mins to refit the chain! Here's what I bought, comes with the correct spacers and longer bolts to fit to the crank(assuming your crank is 104mm BCD): http://m.ebay.co.uk/itm/Driveline-Alloy-Chain-Guard-44T-BCD-104mm-Black-/190878652295?nav=SEARCH

 

[Chalo]

If what you're talking about is an approximately normal bicycle, you can simply use a front derailleur as a chain keeper. Set it down low so it overlaps the chain a bit, and drive in the limit screws to hold it in the desired position. There's no need to have a cable or shifter connected to it.

 

[snellemin]

A while back I found a 46T capable chainguide.

 

[eVelbike]

Have you tried to use narrow-wide chainring and 9sp chain?

 

[ccmdr]

Use this derailer on both vector frames. Off the top of my head it's a 33T up front and 22T rear on cro and 18/20T on hs3540 rear. You can adjust the spring tension easily by simply rotating and holding it in position whilst tightening the mount bolt. You have to make sure the 'guide' is in the right place, it's simple but has worked fine for 100's of miles on both bikes.

Edit* - This gives a better view of the spring .