Another kids build. I saw the price of a 20″ islabike and thought, nope, can’t afford that, how hard can it be? Turns out Isla bikes are good value, it’s been a saga. If you thought building a 24″ was an issue…

Cranks were the trickiest thing. There just isn’t anything properly short around. I wasn’t prepared to go long, really wanted 135mm cranks so ended up with what you see here.

Frame was a few quid on eBay from an early alu hotrock that had been left out in the rain. Forks are trials forks, roughly the same A-C as the junk suspension the bike comes with. Wheels and tyres from Germany, some shed parts and liberal use of eBay.

Overall, I’d say, buy don’t build! The boy and I spent a lot of time in the shed ‘working’ on bits together but ultimately, spending ages sorting a chainline isn’t top of a 5yr old’s fun list.

Here it is, grass is long, shed needs painting etc.

Looks good! I’m sure he’ll enjoy riding it.

Nice, I’m picking on up next week for a similar project. What cranks are they?

Nice bike. I had the same issues getting short cranks so I got a nice light set of solid (ie, not hollow arms) cranks, cut them down, then drilled and tapped them.

Absolutely love it. Much more fun when you build your own.
Just about to start my daughter’s 24er.

Nice, I’m picking on up next week for a similar project. What cranks are they?

Sinz 135mm BMX cranks, I don’t think even these are made any more. Trouble is that the smallest ring you can get on them is 32. If I had the skills I’d have preferred to shorten a set of MTB cranks to give better options on ring size and go N/W.

Bit late now but FWIW Evans sell the cranks that are fitted to the Hoy bikes, which are half the price of the Sinz cranks and include the chainring.

They do, that’s a fantastic option, shorter too, shame it wasn’t available 6 months ago (or I didn’t see it…)

I might swap as that is 114mm.

Good tip Bez. 🙂

Here’s the full selection:

https://www.evanscycles.com/search?text=hoy%20chainset

Chainsets from the 14″, 20″, 24″ and 26″ bikes, plus the road double that comes in 155/160mm options which looks ideal for short adults.

I’m still on the lookout for a well-priced 155~160ish chainset that’ll take an MTB granny ring, though.

Can confirm the Evans chain sets are good value. However, I bought one to replace a knackered chainset on an isla beinn 20. Same square taper type, same bb but the chain line is well off, anyone have an idea why? I also fitted a new square taper chainset to my daughter’s 24 and that was off in a similar fashion which makes me think I’m missing something about fitting square taper cranks!!

Probably designed for different length axles (square tapers come in anything from 103-127mm, though 110-118 is the normal range these days). Hunt down a cheap BB? Can often get square tapers for a tenner.

I bought some of those Evans cranks, they’re spot on. Will keep the 135mm for the next bike.

Today was the first shakedown ride, boy loved it, so much easier over the bumps than his 14″. He was seeking out rocks and bumps after a while.

Perfect day for it 8)

Looking forward to a first summer of rides now. (Introduced him to the concept of pub and crisps post ride too…)

Your thread inspired me to undertake the same project for my daughters next bike

So I picked this up for £26 in the week with a view to strip, paint & build using a set of those Hoy cranks and some nicer bits (forks!!)

The best bit was telling her that I’d got it & now she wants to build it with me!

Awesome. Good luck with the build, keep us updated!

8)