Powabyke/Shimano Chain wheel change

[averhamdave]

Hi the chainwhel on my Powabyke Euro is only 36T and I would like to change this to one with approx 48T.

The shimano bottom bracket is of octagonal form or put another way a sort of 8 point spline. You remove the pedal arm and then slide off the chain wheel so quite easy to change.

My question is - where do I obtain a chainwheel with the greater number of teeth? Can't see anything on e-bay.

Thanks
Dave

 

[flecc]

Older Powabykes are a bit of a problem in this respect since they use a whole chainwheel instead of the much easier to change chainrings mounted on a spider. David Henshaw of A to B magazine was faced with this problem when his brother's fiance wanted a change on her Powabyke and he came up with a simple solution, adding a chainring to the existing chainwheel by drilling and bolting it alongside. You need a 5 spoke 48 tooth chainring to do this if your chainwheel is a five spoke. Below you'll see a photo of this originally published in an early A to B issue:

 

[averhamdave]

Thats excellent and thanks very much Flecc. I had sat looking at it all thinking along those lines so that's what I'll do!

Dave

 

[plebas]

Did it!

Thanks from me too! Encouraged by the previous post, I bought a "48 TOOTH 94BCD GEBHARDT 3/32 CHAINRING" from Ebay, and have today fitted it to my old Powabyke Euro.

I didn't even have to take the pedals off, as the chainring just fitted over (and behind) the existing chainring. All I had to do was remove the plastic chainring guard, and then the new chainring could be bolted onto the old one. No drilling necessary.

What a difference too! I can now use the 6-speed gears fully (previously I had to have it on setting 6 the whole time, as the others were too low) and I don't have to pedal like mad when cycling along a flat road.

Thanks again,
Philip

 

[averhamdave]

Yes, I should have followed up by posting that I have done mine now.

Bought a s/hand shimano chain ring off e-bay for less than a fiver (46T, 105mm BCD for my old 5 speeder) and fitted it. Used the plastic guard holes as well. Drilled them out to 6mm.

New chain fitted. Grand job!