I think climbing speed is more important than downhill. Riding muni, I think my top speed was a little faster with my 27.5x3.0 145mm crank combo than with the 24x2.8 148mm, but I know for a fact that I could climb better on the 24", and if you’re having a UPD, walking up a hill and then remounting, well that is going to slow your overall trip time down way more than the extra mph that shorter cranks might deliver on the downhill or the flats. Maybe if you live in Florida or the Netherlands that’s not an issue though.
Also, I think that just like there being a point where shorter cranks stop being a speed advantage, there’s also a point where longer cranks stop being a climbing advantage. I think that point is probably around 160mm for most wheels and maybe 170mm for a 36er.
Before I got a 29er I rode everywhere on my Club 24 with 125mm cranks. I could average around 6-7 mph for 10-20 miles, could sprint two and a half miles at an average speed of a little over 10mph, and could approach light speed rpm and hit 17.5mph once on a nice section of flat, smooth road. 24” is a do everything kind of size, but I feel the same about 29” now that I have one. The 29er just does it all little faster and isn’t the best for hopping up things. Back on topic though, I used to run 75mm cranks on a 20” freewheel but switched to 125mm at some point since I was more used to that size and thought it might help but it feels about the same anyways. I also had those cranks on the 24 at some point and that was interesting, trying to slow down I immediately just got launched off and it took a bit to figure out how to stay planted while slowing down. I also put them on a friends 26 and that was pretty similar to the 24. 40mm on 36 must be crazy, I can hardly fathom what that would be like!
Nice speeds @unigoof, particularly for 125mm on a 24! I could not do that and since you can I think you should go shorter for such a small uni.
I looked back at some of my rides on a 26" with 89mm cranks last year. I see one in the lower end of the range of distances you mentioned, where I cycled 16.82km (10.45 miles) with 347m (1138 feet) of elevation and multiple road crossings. I did it in just under an hour, meaning I averaged 17.1km/h (10.6mph), despite all the hills and for 20 minutes I even managed to average 19km/h (11.8mph). If I can do this, I have a feeling you could do better, with the right (shorter) setup.
P.S. In terms of strength and stamina I feel I could probably go faster but the real problem is applying it on a small wheel with short cranks, while remaining stable. So this is probably about as fast as I can realistically go over a course like that, with such a setup.
I really can’t get on with short cranks! I run 125s on 20” , 145s on 26”& 27.5” and 165” on my hatchet. I tried 125s on my 26” and found it slower and I just didn’t get on with at all.
I don’t know how long you tried for but it can take a while to get used to them and actually get quicker. Initially when I started trying shorter cranks I think I was slower (at least over longer distances). Now short cranks feel great for cruising along.
75mmm is the smallest standard size we can get… sometimes! They seam to go in and out of production. You can get in bike shops 50mm that are for kids bikes. I have scrounged some off scrapped kids bike for myself as well.
Speaking of scrounging off of kids bikes… I noticed my nieces bike has these Trek dialed two hole cranks on them. I’ll be scrounging them to try as soon as she outgrows the bike. I need to measure them and see what Length the holes are at and check if the chain ring is easily removable
If they are like these ones, then 127mm and 152mm. Which pretty much the same as SHW dual holed cotterless cranks (but for those you do not need to remove the chain ring).
UDC UK is out of the SHW cranks for the time being but you could buy from SHW directly:
https://www.standardhighwheels.se/?page_id=2248 (actually the dual holed ones are not listed here still but you can email Per-Olof and ask for them. They are €32 last I checked. The product code is “3133”.)
I remember you posting those and was hoping UDC would restock them so i could grab a set. The dialed cranks you linked have a slightly different shape to them so I’m curious if the spacing is the same on the silver version
In theory they are cheaper direct from SHW but of course if you are buying multiple things at the same time (or were UK based) a UDC purchase can be cheaper because of shipping. I have several sets, with the last ones bought from UDC. I shouldn’t ever need more but perhaps UDC should try and stock them again… just in case.
Ah yes… you are right. I had another look just now and did not see any silver ones but I did find a different black set that not only look visually closer, the ages on the crank holes match (I now see they did not before). So I expect these are the correct ones. In that case they are 120mm/140mm.
The best way, to buy two pieces left side bicycle Alu cranks, to make holes, so many, as you want and to cut extra ends.
I’m always doing it. Chipest, lightess, available.
