Cranks have been one of the tougher nuts to crack on the 2 kids/youth (tween) bikes I have put together for my 2 boys, but things are definitely getting easier. Seeing XS complete bikes come with 170mm or even 175mm cranks is maddening.
My boys have used the SJS cranks from the link below with a Sq Taper BB and a 4 bolt NW ring. They have been absolutely fine for them, no issues at all. They are a cheaper and (more to the point recently) in stock option.
The eldest also used Canfield cranks on a long term loaner Orange 5 and they seemed very very nice but they aren't cheap.
Hope Tech make short cranks for their Hope Academy Rental Bikes but don't seem to sell them to the public but it might be worth an international phone call.
Link Dump:
[https://kidsracing.co.uk/collections/short-cranksets-kids-cranks-lengths-narrow-q-factors](https://kidsracing.co.uk/collections/short-cranksets-kids-cranks-lengths-narrow-q-factors)
[https://canfieldbikes.com/products/canfield-bikes-am-dh-cranks](https://canfieldbikes.com/products/canfield-bikes-am-dh-cranks)
[https://www.sjscycles.co.uk/cranks/150-thorn-10464-pcd-triple-crankset-mk2-black/](https://www.sjscycles.co.uk/cranks/150-thorn-10464-pcd-triple-crankset-mk2-black/)
[https://www.vpace.de/produktkategorie/kinderbike-komponenten/](https://www.vpace.de/produktkategorie/kinderbike-komponenten/)
May 10, 2021, 5:08 a.m. - Dan Lees
Cranks have been one of the tougher nuts to crack on the 2 kids/youth (tween) bikes I have put together for my 2 boys, but things are definitely getting easier. Seeing XS complete bikes come with 170mm or even 175mm cranks is maddening. My boys have used the SJS cranks from the link below with a Sq Taper BB and a 4 bolt NW ring. They have been absolutely fine for them, no issues at all. They are a cheaper and (more to the point recently) in stock option. The eldest also used Canfield cranks on a long term loaner Orange 5 and they seemed very very nice but they aren't cheap. Hope Tech make short cranks for their Hope Academy Rental Bikes but don't seem to sell them to the public but it might be worth an international phone call. Link Dump: [https://kidsracing.co.uk/collections/short-cranksets-kids-cranks-lengths-narrow-q-factors](https://kidsracing.co.uk/collections/short-cranksets-kids-cranks-lengths-narrow-q-factors) [https://canfieldbikes.com/products/canfield-bikes-am-dh-cranks](https://canfieldbikes.com/products/canfield-bikes-am-dh-cranks) [https://www.sjscycles.co.uk/cranks/150-thorn-10464-pcd-triple-crankset-mk2-black/](https://www.sjscycles.co.uk/cranks/150-thorn-10464-pcd-triple-crankset-mk2-black/) [https://www.vpace.de/produktkategorie/kinderbike-komponenten/](https://www.vpace.de/produktkategorie/kinderbike-komponenten/)