Help - unwell ebike

[PennyFarthing]

Hello,

Sorry to not post for a while then pop in when I'm having a crises - so I hope you'll forgive me.

The day I've been dreading has come - my beloved Gepida Reptilla 1000 is misbehaving. Its a crank driven Hungarian made bike.

There is a noise coming from the crank but it sounds like the chain and not the motor. The motor is thankfully behaving but the chain is very noisy.

The chain vibrates/judders in the crank area (noisily) creating a clanking/knocking noise I think caused by the small cog just underneath the chain guard cover. I can see the little cog is knocking against a bolt or a nut. I haven't braved taking the casing/guard cover off yet, so before I do I thought I'd ask if anyone had an idea what might be causing it. It did start intermittently on one ride but by the next ride it started after about 2 minutes and didn't stop. I also sometimes get the feeling the chain is slipping when its clanking/knocking but only now and then - ie its not always when its clanking.

I've lifted it up (with assistance - its a very heavy bike) and pushed the pedals around with my hand which is when I can see the small cog banging/vibrating.

Any ideas? If you do have any ideas please be as basic as possible, as unfortunately I'm not very technical.

So frustrating as its prime cycling weather at the moment.

Many thanks in advance.

Penny

 

[Deleted member 4366]

There was a lot of discussion on this a while back in relation to Kalkhoffs. It should be nothing serious. It sounds like you need a new chain and sprocket (small cog). Some said it was OK with a new chain and the sprocket flipped over. There was also discussion about the best sprocket and chain. Perhaps Flecc or Tilson can give a bit more details.

 

[PennyFarthing]

Hi d8veh, hope you are well?

Many thanks for replying so promptly. I will do a search for the previous discussions - so thanks for the heads up.

Should I take it back to my dealer (E-bikes in Sussex) which is quite a way to travel or just go to a more local e-bike repair place?

Many thanks, I feel a bit less forlorn having read your reply.

Penny

 

[Deleted member 4366]

Wait 'til the others verify what I'm saying. If it's right, you have to order the sprocket from somewhere - probably German Ebay:
http://www.ebay.de/sch/i.html?_odkw=panasonic+kettenrad&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR2.TRC1.A0.H0.Xpanasonic+ritzel&_nkw=panasonic+ritzel&_sacat=0

Any bike shop should be able to fit it.

 

[flecc]

I'm not familiar with the Yamaha unit it uses, but know it's similar to the Panasonic one. It may well be that the idler arm that keeps the chain on the small motor drive sprocket is coming adrift, judging from your saying there seems to be some knocking against a bolt. The Panasonic unit has had this happen on occasions. You'll only know once you get the covers off.

 

[tillson]

Hi Penny,

I can't really help because I know very little about the Yamaha motor, and I don't want to mislead you with incorrect advice.

flecc and d8veh are probably not too wide of the mark with their suggestions. I'd probably lean toward something working loose given the way you describe the fault developing. If you haven't already done so, it might be best not to use the bike until it's fixed. You run the risk of causing further damage.

 

[D8ve]

The bike shops in Bristol have a wide range of experience and a mechanical fault of this type should be easy for them
Good luck

 

[PennyFarthing]

Hello lovely helpful people,

I just wanted to thank you all for your suggestions. Two days after I posted this I flew to Holland and I was in amazed at the cycling provision, not just in Amsterdam but across the entire country! Now I'm back I'm going to have a look at my poor ebike. Thank you so so much - I really appreciate it. Fingers crossed!

 

[PennyFarthing]

Its fixed!! Mr non-technical pennyfarthing followed the links/instructions above (thanks SO much!) and in the end it was a combination of oil and discovering the chain had worked its way loose. Nothing looks worn out yet - phew, but now we have a basic understanding of what goes on in there.

Massive relief and a big sigh.

I have another smaller technical question but I'll save that for when I'm not in a hurry. I just wanted to pop in and thank you ALL for your advice and links.