My ultimate cotterless muni cranks

I’ve recently perfected some uber cranks for my cotterless muni. Cotterless uber cranks These are adapted for the particular uses I’m interested in:

  • Double drilled for pedal holes - 150mm and 127mm
  • Self extracting crank bolts (remove and fit cranks using only a 6mm hex key)
  • Lightweight alloy to be easily carried when not in use

The drilling / tapping was done by an engineer friend of the LBS. The job cost £20, but that included modifications to accommodate a calliper brake on my frame. The self extracting crank bolts were made by Specialities TA and cost £10 (note: out of a number of pairs, I had one faulty set which I obtained some Shimano replacement parts for, so the bolts shown do not use the original TA top washer or dustcap).

The self extractor makes it fairly easy to swap these cranks off entirely, either before leaving home or whilst out on a ride. I have several sets of self extracting bolts. Right now I have some 90mm cranks on my 29er, but I can swap the muni cranks back on using a 6mm hex key, plus a spanner to move the pedals across.

Overall I’m hoping the ability to change pedal holes, and change to short length road cranks, will make for an ideal long range muni machine for rides too difficult or muddy to take the 36er. I’m particularly pleased with the self extracting bolts, since I didn’t know these were available for tapered axles until I recently saw them mentioned in a forum post here…


cool, splinned next?

adjustable cotterless cranks

Do you ever catch your heel or toe with on the end when your set for the short crank distance??

Not whilst riding, so far. Whilst mounting I guess you could, but I haven’t noticed it beyond my usual “sorting out foot position whilst riding” start :slight_smile: With a 150mm / 127mm set up there’s actually very little crank exposed beyond the pedal. That said, it’s probably even more important to tuck your laces in - wouldn’t want those getting caught on the end!

For really short settings I’m using single length 90mm cranks, and swapping them using the self extraction mechanism, so I can get a really high speed setting without having loads of excess crank sticking out.

Soooo…i suppose you aren’t doing any drops too big…

These are really for distance riding - an XC 29er or a 36" - so big drops aren’t what they get used for anyhow. That said, it’s a UDC wide hub - they’re pretty strong so it can probably stand up to decent sized drops. Fairly few people have actually broken these hubs.

I’ll probably get a splined setup at some point but that’ll either be a) a street / trials uni or b) I’d change the 29er to a splined hub if the wear caused to the tapers by repeated crank changes proves too much.

They look similar to my bike cranks, but those are specialized, and made from cast steel.

I posted it because, these cranks have been ridden by the worst hard landing biker in my city, my long time friend Nate, it’s the only part on his bike that he didn’t break… I’m just saying, my cranks are REALLY strong, and yours are a similar design, but I believe they’re aluminum? Either way, it’s a good crank design.