Front crank for a whoosh big bear.

[Garrydog]

Just baught used whoosh big bear , I want to increase the size of the front crank on the bike to keep in contact with the gears to stop spinning out.
Has anyone done this ?can anyone recommend a suitable crank ? I was thinking of increasing to 48teeth will this be ok. Also been looking at a sturmey archer single crank on eBay ,will this be ok with a Shimano set-up as on the bike?
Thanks.

 

[Nealh]

Measure the BCD and bolt on a replacement, you may have to put in an extra chain link to lengthen chain.
For correct chain length remove chain form derailleur and put in on front & rear largest gear/chain ring and the ends should meet with a one link overlap.

 

[Woosh]

as an alternative, DNP 11T-28T 7-speed freewheel.
The smallest cog on the Big Bear has 14T.

https://www.ebay.co.uk/itm/DNP-Epoch-Freewheel-7-Speed-11-28T-Nickel-Plated-ebike-electric-bike-rear-cog-/153009092119

 

[Benjahmin]

I did it on the wifes bike.
Think we went 46, fitted new crank and arms. You will need a new chainguard though. Chain length was fine.
Here's my thresd, but it's mostly about cassettes.
I think just about any square taper set should fit.