150mm isis crank arms

[Gringo]

Due to limited movement, I'm looking for 150mm crank arms for my Bosch motor (isis fitting) I thought I'd found the perfect thing at a unicycle shop 150mm, isis & only £25 but alas no offset.
I'd like to buy something off the shelf but at a push I could buy the taps and modify my original 175mm arms (or a secondhand pr)
There's plenty of 150mm square taper cranks out there but dose anyone know where to buy 150mm isis cranks ?
Thanks Carl

 

[Deleted member 4366]

Due to limited movement, I'm looking for 150mm crank arms for my Bosch motor (isis fitting) I thought I'd found the perfect thing at a unicycle shop 150mm, isis & only £25 but alas no offset.
I'd like to buy something off the shelf but at a push I could buy the taps and modify my original 175mm arms (or a secondhand pr)
There's plenty of 150mm square taper cranks out there but dose anyone know where to buy 150mm isis cranks ?
Thanks Carl

You can get various adapters that screw into the pedal hole. They provide additional inboard threaded holes for the pedal to change the crank length. I think that they're expensive for what they are. It would be much cheaper to drill and tap your existing crank arms.

http://www.getcycling.org.uk/details.php?id=460

 

[Gringo]

It would be much cheaper to drill and tap your existing crank arms.

£16 for a pr of taps is cheap enough, my only concern is the Bosch crank arms are cast with a hollow back making them thinner in the area I'd be tapping
making an adaptor plate is also an option and that would have the benefit of being adjustable, I could then find my own best length
Another option for adjustablility would be the flat unicycle cranks that would lend themselfs to an adaptor plate.
None of the above is quite as easy as buying an off the shelf crankset

 

[anotherkiwi]

£170! Each! Before VAT!!! "manufactured in Germany to the very highest standard" I hope they are...