Bent Crank?

[Goggs]

Indeed, and the kicker is it's not my bike. My boss owns the bike but I get to use it as my own whenever he's not in the country, which is a lot. The payback is that I maintain it for him. It's a good deal, current situation notwithstanding.

 

[Tim Hall]

Will the fact it's electric make a difference? Surely I just need a big allen key?

Edit* I can take the nut off but I'm unsure how to get the actual crank off.

A picture of it with the nut off will help at this point.

 

[Ajax Bay]

https://www.ebay.co.uk/itm/Sram-Hus...905487?hash=item2138aee00f:g:TakAAOSw~o5abHS0
But do the spirit level check first to confirm it's the crank that bent. Could be some failure in the ISIS spline/crank interface.

 

[Goggs]

A picture of it with the nut off will help at this point.

Good idea. Here you go...

 

[Goggs]

I had a brainwave! I thought it might be a good idea to swap a crank off my own bike (Cube Hyde) to see if it really is thecrank that's at fault. I can take my own cranks off with an old crank removal tool I have but the Giant demands a different tool. No point in buying one either as the cranks are obviously not interchangeable.

I'm going to have to give up & take it to my LBS, which is shut today. He should at least have enough bits & bobs lying around to be able to diagnose the problem.

Boss comes back on Thursday. Tick tock...

 

[Ajax Bay]

Spirit level test

I thought it might be a good idea to swap a crank off my own bike (Cube Hyde) to see if it really is thecrank that's at fault. I can take my own cranks off with an old crank removal tool I have but the Giant demands a different tool.

Pretty sure your Cube has a square taper BB, not ISIS (like the Giant). But this video shows one how to remove an ISIS crank using a 'normal' crank puller (AKA "old crank removal tool").
http://www.trials-forum.co.uk/topic/90497-how-to-remove-isis-cranks/

 

[KneesUp]

I reckon it will be a bent crank - I remember as a kid my mum compalining that her knee had begun to hurt when she rode her bike, and it turned out to be a bent crank. She had never fallen off, and put it down to the bike gettting blown over in the wind as it had done a few times while she was at work (obviously locked up with a long thin cable - those were the days!) If a 15kg Raleigh Shopper can bend a crank falling over, then I'm sure a crash could do it.

That looks like an ISIS crankset - it will come off like a square taper one.

https://www.parktool.com/blog/repai...nd-installation-three-piece#article-section-1

 

[Profpointy]

You don’t say what type the axle is. If it’s a solid square taper it won’t bend, if it’s a hollow two piece type it may well do. Remove it and check. if the drive side took the hit and it’s the two piece type the crank could have bent the hollow spindle. If bent you’ll need a new crankset, if you try to straighten it you can’t guarantee the structural integrity of the unit.

Not so. On my old bike the chainrings had a wobble which was regularly throwing the chain. Took it all to bits and it was quite obvious that the solid square taper axle had a bend in it. I was astonished to be honest as I couldn't recall crashing the bike nor am I an ultra strong tour de France pro - but bent it was

 

[Ajax Bay]

the solid square taper axle had a bend in it.

I would be pretty surprised too, but as you say (and evidence) not impossible. However even more unlikely with a modern sealed bearing square taper. and even more so on the (shorter) left side.

 

[Goggs]

Spirit level test

Pretty sure your Cube has a square taper BB, not ISIS (like the Giant). But this video shows one how to remove an ISIS crank using a 'normal' crank puller (AKA "old crank removal tool").
http://www.trials-forum.co.uk/topic/90497-how-to-remove-isis-cranks/

That's a clever trick, thanks for the link. Trouble is I can't use my Cube crank on the ISIS BB so it's kinda pointless. I'll keep the link for future reference though.

I reckon it will be a bent crank - I remember as a kid my mum compalining that her knee had begun to hurt when she rode her bike, and it turned out to be a bent crank. She had never fallen off, and put it down to the bike gettting blown over in the wind as it had done a few times while she was at work (obviously locked up with a long thin cable - those were the days!) If a 15kg Raleigh Shopper can bend a crank falling over, then I'm sure a crash could do it.

That looks like an ISIS crankset - it will come off like a square taper one.

https://www.parktool.com/blog/repai...nd-installation-three-piece#article-section-1

I've seen bent cranks too back in the day. The thing is the pedal spindle is definitely bent and the next thing in line is the crank so it makes sense that that should be the problem.

 

[Goggs]

Whilst I don't doubt that a BB spindle can bend I doubt it would happen before the crank gave way. I may be wrong.

 

[Goggs]

I took the bike to my LBS yesterday. As I rode there I was beginning to think I was imagining things but just before arriving I did notice the slight wobble again. Anyway, despite my very poor French the shop-owner did understand what I was saying and told me to come back on Thursday. I got the impression he wasn't unfamiliar with the problem so we'll see. He does seem to be a Giant dealer as he has plenty of new models on display so hopefully he can supply a replacement crank. He has the correct Giant pedals too so I bought them and he'll fit them for me. A replacement identical saddle will be here next week then I can give it back to the boss and walk away knowing I've done my best to undo the damage I caused.

Oh, one more thing; I got some nail varnish & it's worked pretty well. You can see it if you really look for it but it's invisible from a casual glance.

 

[Levo-Lon]

Just make sure your nails match your outfit or you look cheap and easy

 

[Goggs]

Just make sure your nails match your outfit or you look cheap and easy

Is it possible for black nails to ever look classy?

 

[Goggs]

Job done! New Giant pedals and identical replacement crank fitted for €77. Bike rides perfectly.

Thanks to all for their input & understanding.