Short BMX cranks and fixed gear
 

My new frameset has a fair amount of toeverlap, and pedal strike is about at the same angle as on my last rig (which is to say that it does happen once in a while). I'd been planning to eventually switch over to 165mm Sugino 75s, but 5mm isn't going to make a huge difference in either of these things. Since last night, I've been thinking about BMX cranks, which you can get pretty damned short. I think a 155mm or 160mm crank would put me in the range of negligable toeverlap and pedal strike (both of these things have caused issues in the past). I've got short legs, too, so I think it would help me with a smoother spin, as sometimes my 170s feel too long when I'm really doing high RPMs. I know Turd has some short Bulletproof cranks on her ride - anyone else use short BMX cranks? Potential issues? Please no comments about the heresy of putting BMX cranks on a Keirin frame.

your bottom bracket asplode

just kidding.

good call going with bulletproof shorties. i mean, if you don't like em, you're only down thirty bucks...

i went from 170 sugino to 165 bmx style cranks.

I noticed no real improvement with pedal strike, and it just made it harder for me to spin the cranks from a stand still...

I did notice a slight improvement in spinability. =)

The Profile "Mini Magnutanium" cranks are available in lengths starting at 145mm. They're also farily light. You also get the coolness factor of running a crank called "MAGNUTANIUM"

http://profileracing.com/loader.php?...&productid=138

The suggestions for products in this thread just jumped from $30-$350 in 4 posts

Until they're made from unobtainium they're not worth mentioning.

I like 170s, but if I was looking for 160s, I think I'd be inclined to go with the Suntour Cyclone 7000 set at Harris http://sheldonbrown.com/harris/cranks.html

You should be careful what short BMX cranks you are buying. BMX racing age classes start at 4 years. I've been out of the BMX scene for a while, but back in my day 175s and 180s were the standard length for teenages and adults. The short cranks were used by 4-7 year old kids who ride around on tiny featherweight "mini" frames with weight limits of 75. If you get short BMX cranks, make sure they are built for adults, not kiddies. The Profile "Mini Mag.." cranks are undoubtedly for little kids. Any BMX stuff with the word "mini" in it is for very young age classes. Also most adult BMX stuff is Chromo and Alu...other fancy metals are used in "mini" size BMX bikes for kids.

Above, I meant to say weight limits of 75 pounds...somehow I left out the word pounds.

i use 150mm bulletproof cranks and they work fine, tho finding chainrings can be a b!tch.. i have to use rocket chainrings. the only issue i can foresee for you is how it affects your overal stroke circumference & cadence. you may have to change up your normal gear ratio.

You can use snap chainrings http://www.snapbmxproducts.com/ or go to http://loosescrews.com/ and get chainrings (Sugino, Suntour or Vuelta) with 110 BCD that will work with Bulletproof cranks.

There is some kid-specific BMX stuff out there, but most of it is pretty beefy -- if you look at bulletproof or snap cranks, the design doesn't really vary with the length.

If you want to know more about short cranks, you might want to go stir up the ghouls over in the recumbent forum, lots of those guys run short cranks.