Alternative to building a junior crankset
 

I've been trying to find rings and crank arms in order to build a decent crankset for my young daughter's first road bike. Plenty of Sinz or Origin 8 crankarms out there, but it looks like by the time I buy some 145-150mm arms, and then a couple of chain rings to fill out the build, I've still dropped some decent coin. Australia and GB seem to have no shortage of junior cranks available for purchase that don't break the bank. Am I just missing all of the US suppliers? Google has let me down so far...

$40 for the crankarms, then buy a cheap old MTB crankset and use the 110 mm BCD chainrings. The "single speed" Origin 8 cranksets will accept double chainrings, using the right chainring bolts and spacers. Or you can go for the "triple" Origin 8 cranksets.

Or, to save $40, just buy the cheap used MTB crankset, cut the cranks shorter, drill and tap holes for pedal.

There are usually plenty of BMX crank arms on eBay in the lengths you want. Make sure you can find chainrings in the sizes you want for whatever BCD the arms have. You may need to play around with the bottom bracket (i.e. use a longer axle since BMX is usually a single ring) to get clearance for multiple rings, if that's your plan.

maybe I found a good deal? I just bought a Lasco commuter crankset on eBay for $35 shipped, new. I was encouraged that it had 44 / 36 rings and 152 millimeter crank arms, square taper. The only downside is that the bike I am working on is aluminum and I was trying to keep things light.I figure this new crankset will be pretty heavy since it has steel arms and rings. Still, for $35.00 I thought it was worth a shot, especially for a bike for a child to learn on. What do you think?

Soma came out with a new kid's road bike, which lists as part of a build package a 140mm 44x34 crank with a part number, but a search of the site isn't bringing up the cranks. Maybe email Soma?

If you are converting a bike from big chainrings to smaller chainrings just be sure that the front derailleur can be lowered enough. The FD needs to be really close to the biggest chainring. Many frames offered in today's market have braze-on type FD hangers that cannot be adjusted low enough. Or if the seat tube is not perfectly round a clamp-on type FD may not fit the seat tube in the position needed.

I know you want something nice for your daughter, and I would too, but frankly an additional pound or two is not going to make or break anything. I never had what I would now consider "nice" bikes when I was a kid and at the time I didn't know any better. The crank you mention sounds just fine. Arm length, appropriate gearing, and a not-absurd Q-factor are going to be far more important than steel vs. aluminum. But it sounds like you have those things covered.

Build a bike that fits her well, rides nicely, and she'll like it. Or maybe she'll hate it. I remember my dad trying to get me into softball when I was a kid. I didn't like it and to this day can't imagine anything enjoyable about playing or watching baseball/softball.

Unless you make your living pursuing record attempts, making light weight your primary criterion for selecting components doesn't make sense. A child won't know or care that the crank is a few ounces heavier than a fully aluminum version, and once he or she has become an experienced rider, and doubtless grown some, you can concentrate on making their bike lighter.

Thanks everyone. I'm sure you are dead on about the weight. I know that I let my racing mindset creep in where it shouldn't at times. She is only 9, but has really bee wanting a real road bike. Well see how much she likes it once she gives it a go!