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.
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.
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.
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.