I've got a creak in my cranks!

[rog_london]

Originally Posted by Mussels

Deviating from topic slightly but that isn't so much the case anymore, the 09 models have the chainring much closer to the frame. It's close enough to stop the chain coming off every 100 miles or so anyway.

I think that modification took place a bit earlier than that - rather like the high/low power control. Mine is a late 08 model and the bottom bracket is symmetrical and about 3.5" wide. The chain clears the battery by barely 3/8" when in bottom gear and it has never come off.

I don't know for sure, but I think the longer Wisper BB was a bit troublesome. I base that opinion purely on the number of posts in here relating to problems with it. Anyway, it seems now to be fixed. As with most things to do with engineering, it's best not to buy the Mk 1 of anything, though sometimes it's hard to avoid if you really have to have a new model as soon as it appears.

Rog.

[Caph]

Fixed! Well almost.

I've deduced that the reason for the smaller hole in the drive crank is twofold. One is that the magnet disc will only slide up to the end of the square tapered section of the bottom bracket axle so the crank has to stop short of this, secondly I've got a three ring chainset on my front crank and the smallest inner ring sticks out thus requiring the crank to stop even further out from the BB.

I figured that if I got a longer BB (the one that comes with the bike is about 114mm) then I could use my Shimano Acera drive crank whilst still keeping the crank about the same distance out from the BB, so I bought the longest one I could find, a 127mm Shimano BB. I collected it today and it fitted like a dream. The crank now fits snug in almost exactly the same place as the old one did and leaves about 5mm between the inner chainring and the BB, just enough for the 3mm magnet disc. Perfect, or so I thought.

That was when I deduced the second reason for having a smaller hole in the original crank - to prevent it sliding all the way up the square taper. So although I have enough room for the magnet disc, it is on the larger untapered round section of the axle which is too thick for the magnet disc.

I've come too far now to give up on a fitting a standard drive crank but I'm off on holiday this weekend so I'll worry about fitting the magnet disc when I come back.

Oh, and the creak? After fitting my Shimano cranks to the old BB it was much better (I had definitely caused some damage to the original crank) but still there. Oh well, I thought, it must be the BB itself. Then I fitted the new BB with the Shimano cranks and it was still there! So I started looking for any other explanation. I eventually found it. My bike has rear suspension and one of the hinges (well more of a bolt which tightens with an Allen key) is about an inch back from the BB. I checked it and it was loose. I tightened it and the creak is gone. I should have twigged really because I only got the creak going uphill and that's when the rear suspension is working hardest.

Mussels, I wasn't ignoring you, I missed your post. My bike is the Powered Bicycles Galileo.