Hi folks - just wondered if anyone has had this problem, or can tell me what it might be, as my LBS - and Velorution - have so far not been very helpful.
My bike is an Orbea Gain F40. It's been fantastic since I bought it in July - so good that I have used it for my 9-mile workday commute ever since. Just over 1,000 miles according to my bike app.
In the last 2-3 weeks though it has developed an infuriating tendency to cause the chain to come off the front chainset. What seems to happen is that when I have it on the smallest gear (9th) at the back and have been powering hard, with maximum boost, then slow down relatively quickly, the chain is kind of thrown forward, as though the rear cassette is failing to slow down at the same speed as the front chainset. I went out tonight to study this, so can confirm this is more or less what is happening.
My LBS glanced at it and said it might be the rather inadequate looking chain guard - a piece of plastic that is fixed to the seat tube and sits just above/inside the chain near the chainset. It did look to be out of line. He tightened this and moved it closer to the chain. However, on my usual commute today the same problem occurred. I have tried to check the chain for wear and tension, and the derailleur for alignment issues, but can't see anything obvious. Then again, I am not a bike mechanic. My fear is it is something to do with the way the hub, with the motor, is freewheeling. If it is still rotating with some speed and force and not slowing down with the rest of the chainline, this might explain it?
Anyway, views from more expert pedelecs would be much appreciated. The bike is still under warranty but when I pointed out to Velorution I had bought it on their recommendation, after trying one out in their shop, they said because I had bought it via mail order from a shop in the Lake District (because Velorution had sold out), I would have to take it back there!
My bike is an Orbea Gain F40. It's been fantastic since I bought it in July - so good that I have used it for my 9-mile workday commute ever since. Just over 1,000 miles according to my bike app.
In the last 2-3 weeks though it has developed an infuriating tendency to cause the chain to come off the front chainset. What seems to happen is that when I have it on the smallest gear (9th) at the back and have been powering hard, with maximum boost, then slow down relatively quickly, the chain is kind of thrown forward, as though the rear cassette is failing to slow down at the same speed as the front chainset. I went out tonight to study this, so can confirm this is more or less what is happening.
My LBS glanced at it and said it might be the rather inadequate looking chain guard - a piece of plastic that is fixed to the seat tube and sits just above/inside the chain near the chainset. It did look to be out of line. He tightened this and moved it closer to the chain. However, on my usual commute today the same problem occurred. I have tried to check the chain for wear and tension, and the derailleur for alignment issues, but can't see anything obvious. Then again, I am not a bike mechanic. My fear is it is something to do with the way the hub, with the motor, is freewheeling. If it is still rotating with some speed and force and not slowing down with the rest of the chainline, this might explain it?
Anyway, views from more expert pedelecs would be much appreciated. The bike is still under warranty but when I pointed out to Velorution I had bought it on their recommendation, after trying one out in their shop, they said because I had bought it via mail order from a shop in the Lake District (because Velorution had sold out), I would have to take it back there!
