Interesting ideas here, and yes, I’ve contemplated the same thing, more of a long channle slot running vertical along the pedal with a click-in mechanism with fixture points every so often, maybe with a spring to pull out and move. Anyhow just ideas…
However, you guys haven’t given many real answers to my concrete project. The only real answer being here:
Due to a shipping mishap, I actually do have both KH Spirit Dual 165/137 and KH Moment Dual 165/137 cranks (i have to send one back).
Prior to bouin-bouin’s comment and based on some other older threads where people drilled Moments (either to save weight or for multi-length crank options), I thought the Moment was the better (or rather only) choice as it’s stronger and easier to drill as it’s straight.
Can you really safely drill the Spirits? Or are they hollow somewhere? I’m wanting to use them for road and 36er Muni, no trials, but they still have to be pretty strong.
And I know it’s a lot of personal preference, but still looking for opinions at to which holes for cranks lengths and why?
Moments with 165/137/116/99 (21/17)
or
Spirits with 165/137/120/103 (17/17)
I just pulled out the Spirits and from about 20mm to 99mm (from the crank axle) it has a recessed area (on both front and back pedal sides). A hole at 103 will go down to about 95mm, so definitely into this recessed area. That doesn’t look good. So I think if I use the Spirits I can only drill one hole. If I did 165/137/117 then I could probably achieve my main goal, which is not having to switch cranks for my commute (currently on 127s) and offroad (currently 170s), as I could just switch the pedals from 117 to 165 (much easier than changing the cranks). But I won’t be able to play with really short (near 100mm) cranks as well (I have 100mm cranks but I don’t use them often, as if I’m tired then I become slow with many dismounts and so).
Pierrox, I would like Martin CHARRIER to present it here and to explain his concept, from next week we will be neighbor at office so I expect him to joint unicyclist.com
Tapping is not easy and requires specific tools for pedals (9/16"-20TPI), left and right are different … I got mine from WWW.RDGTOOLS.CO.UK (reference 1214 for right side, reference 1789 for left side)
I talked to today while picking up some tire levers said, “No way, wouldn’t do it.” He went it to how the cranks are reinforced where the holes are drilled and that they’re not made to have an additional set of holes.
While it is true that many cranks aren’t suitable for extra holes, it is not without exception. There are at least a couple of machine shops that custom drill and cut cranks to fit smaller riders on bikes. I had a set of cranks that were cut down to 140mm that i used on my Nightrider.
I had idea at least 7 years ago for “ratcheting” cranks, or something similar that could change length on the fly without tools or removing the pedals or cranks. I’ve seen many variations suggested since then but so far I haven’t seen anything commercially available for unicycles. The multi-hole cranks do the trick for me and takes all of maybe 60 seconds to switch pedal holes. But it would be very cool to have something like this:
Found a local machine shop (school) that will add a new set of holes to my Venture 2 - 150s — at no charge. I guess they use it as a learning tool…he promises a quality job.
When making multi hole cranks I would try to make the space between the holes as wide enough so that you can use quick release pedals on it. For the QRD II System you’ll need about 18mm of material between the holes.
In 2013 I wrote with Kris Holm about this. He had samples of both systems (QRD and QRD II) at this time and was testing them. The problem was, that on the existing dual hole cranks there is not enugh space between the holes to install two QRD adapters at the same time. He also sent me 2 photos, but I don’t know if I’m allowed to upload them here.
But if you drill new holes in the cranks, than I would choose lengths which allow to mount a QRD II adapter in every hole.
Thanks for the info and that looks like a reasonably priced option of something I had been thinking about. Looks like the pedals can be had for around €60 and an extra set of adaptors for less than €20.
So I have unfortunately been busy with way too many non-unicycling things (moving).
But I am probably going to drill the Spirits instead of the Moments. I’m not sure if 2 holes are possible and/or worth it.
So is there something special in the crank that only allows drilling at 110?
But then how does this translate to the 150/165 lengths?
Spirit Duals come in 150/127, 165/137, 137/117 and 127/110.
Does this mean there are two forging patterns?
165/137/117
150/127/100
Meaning that then I can only drill at 117 on the 165/137/117? What is the problem if you drill somewhere else, like at 118 and 100? Are there hollow spots?
So drilling options:
one hole at estimated “forging spot” per bouin-bouin:
165/137/117 (20/20)
or
165/137/110 (20/27)
or maybe still 2 extra holes:
165/137/118/100 (20/19/18)
(all these would work with QRD as at least 18mm distance)
I think something between 110 and 118 would be my ideal commuter crank length, as I’m getting really good with the 127s and I have great control and can definitely go shorter (today I had my fastest time of 52 minutes for 16km with 127s). Actually, I’m thinking 110s sound best, but it’s so hard to know without trying. I think I’ll put the 100s on again end of the week and try them for a few days.
OK, yeah, you said that but I missed it. Thanks for the clarification.
Although I don’t think that’s so bad, as with triple of quadruple holes, you can definitely do QRDs at 2 non-adjacent holes. In particular, I use 165 for Muni and something between 100-127 for my commute.
