Fun Coker ride 5/27/07

What kind of 36ers? Airfoil? Coker or Radial TA tire? Crank length?

I have a wired cycle computer on my Radial which is calibrated very accurately compared to known-mileage routes which I’ve ridden. With it I know I’ve hit and slightly exceeded 17 mph a few times, but only momentarily, and only since I’ve installed 125mm cranks. My feet felt like they were flying and I was barely in control.

I’m not saying it’s impossible, but 17 mph is about 165 rpm on a 36er, that is nearly 3 whole revs per second. How long did you maintain such a pace? Unless your feet were moving in frenetically fast circles, I respectfully suggest that woman’s speedometer was wrong.

Get yourself a cheap, wired cycle computer, calibrate it carefully and check it out.

Caveat: I’ve only 3 years’ experience, so maybe you spin MUCH more smoothly than I do, but 17 mph is way fast and 165 rpm is maniacally fast pedaling.

Damn, Corbin - 17 MPH is right around where I start freaking out thinking if I fall, I’ll perish. And the idea of doing 100 miles on a 36er is frightning. Maybe I should stick with Muni . . . but we’re having to much fun doing our once-a-week Coker cruise.

JL

It is certainly possible to hold 17mph or more for quite long periods. On July 26 last year, Patrick rode 27.18km in an hour. That is just under 17mph. That’s for an uninterrupted hour! With 110mm cranks, even to a slow rider like me, 17mph no longer feels scary and wild. It is controllable, holdable and comfortable. Faster guys cruise at 18mph or even 20mph for minutes at a time. When I first started riding a Coker, over 8 years ago, every time I hit 17 or 18 mph I felt like I was cheating death. That was with 152mm cranks. Go short and you can go fast.

I remember riding one time in Norway with Christian. It was the end of the day and we were going down a slight descent into the town on a smooth road. 3 of us were cruising fast at 14 or 15mph. 2 bike guys go by and say something that sounds derisive, so Christian took off after them. In what seemed like 2 seconds, he was FAR down the road, cruising smoothly at 24mph (according to his carefully calibrated cyclometer), chasing down those guys. Ultimately he was unsuccessful, but it was awesome to watch. Actually there are quite a few people who have hit 24mph on Cokers, verified by cyclometer, not car speedometer. It’s just a matter of skill and experience (and ditching the long cranks).

—Nathan

Whoa.

WHOA!

Corbin, my apologies, and perhaps I spoke to quickly. And Nathan, thank you for the reality slap - I stand corrected.

I’m using 125s with no urge to go shorter. Maybe just experience will make the frenetic rpms feel less so.

Silly question

Okay, this is probably a silly question but I’m going to go ahead and show my ignorance.

Why has no one produced a super light carbon fiber uni with skinny road bike tires?

My road bike is very light and has skinny tires that are pumped up to 120 psi. It just seems that distance riding on a uni of a similar construction would make it easier to maintain speed. There must be a flaw in my thinking or someone would have already invented one.

Scot Cooper has one. It is nice! I’m sure it was uber expensive.

That’s the hard part. Apparently it is hard to get tires manufactured. Plus, a 36" rim really needs a pretty fat tire for durability.

corbin

  • Nimbus 36
  • Airfoil rim
  • thinner, stronger spokes
  • UDC wide hub
  • Coker tire
  • Ken Adelman wheel build
  • Magura steel braided brake (broken)*1
  • 125 mm steel cranks (bent)*2
  • Scott Wallis “road relief” seat + CF base
  • Scott Wallis “V-grip / death grip” CF handle (cracked/breaking)*3

I was cruising with them for probably 1/4 mile till we hit the hills and I left them behind :slight_smile:
They caught up to me about a 1/2 to 1 mile later (estimated).

This was on flat; I maintain much faster speeds downhill. I need to borrow Nathan’s GPS (or get one of my own) and see how fast I go, but I really book it down hills. It is easier for me to go fast than to use the brake.

I’ve been riding 3 years too (2 years on coker), but as Nathan said, it took me a while to get comfortable at fast speeds, and 125’s are essential.

So, regarding my *'s:

*1: While one footing on the coker, I broke my steel braided magura brake line – pushing my left foot on the nimbus frame puts it in a terrible spot right on the brake. IMHO, the frame’s brake location should be on the after fork member, and not the fore one. Hunter frames got it right, and put it on the aft member.

*2: I tend to bend the steel cranks. But then again, I ride down some rough stuff. I also like to hop up stairs on my coker, and that puts a lot of pressure on the cranks.

*3: My CF handle started cracking and bending too much. Possibly from hard crashes, or me putting too much downward pressure on it.

corbin

John – definitely bring your coker down for California Muni Weekend and ride one of the Coker-muni rides one day. It is a ton of fun!

corbin

Ti hit 18 mph on a coker with 152mm cranks, you’d be spinning like a madman!

The first time I went over 18mph with 152mm cranks I crashed hard. After a couple of weeks of recovery I started Cokering again, but never tried for increasing speed records. Years later, after I discovered the joys of shorter cranks, I built back up in speed and actually went over 20mph a few times without crashing. Nowadays, 18mph is unremarkable. Although holding it for any real length of time requires 110mm cranks for me. I am NOT a fast rider though, not even close.

—Nathan

Imo, 18 mph is fast, period. Especially w/152’s!

Going downhill, it´s not that hard.
On my ride yesterday my gps gave me a top speed of 35.4kph(21.4mph).
That might be a slight exaggeration, but not by much. I was really flying down some hills with my 152s.
I´ve only been cokering since March and have felt that I have been holding back while riding downhill. Yesterday all that changed. I just realised everything I had to do was push down hard on the handle and just “let go”, let the legs spin without me controlling them too much(if that makes sense). I guess it just took me a while to feel secure enough to let go.

Really, really looking forward to getting my 125s and T7 delivered now!

Training hasn´t been perfect yet, but I´m really starting to push it now. I will meet up with you in Siena, Nathan!

/Mikael

GPS is not really an accurate method to measure instantaneous speed. But going 21mph downhill is believable. It probably felt crazy though with those cranks! Zack Baldwin could accelerate up to 23mph on pretty much any downhill he wanted and that was without much training or practice. He was just a damn good rider. One one ride we did, he crashed twice, at 23 and 24mph, and still cranked out 80 more km to the finish. Crashing at speed like that can really hurt too.

–Nathan

I find that REALLY hard to believe with those long cranks, but if you say so, ok.

I agree that gps can be pretty unreliable. I do have it set so it averages the speed over the last 5 seconds, though. So the 34.5kph shouldn´t be a “spike”.
I could never get up to that speed on the flat, though. I just found some perfect downhills and let go, like i wrote. Really no pressure at all on the pedals. It´s funny just how much of a difference pushing down hard on the handle makes.

Nathan, if you consider yourself a slow rider, and can go 20 mph on a 36er, I’m like a total duffer.

My qustion–I have an old Coker, with the good airfoil rim but the rest is just the tin junk without the extra wide hub. I have an extra Wallis CB seat and can upgrade the rest (Nimbus frame, new wheel build et al) for about 350 bucks so I’m wondering if the advantages of the rig Corbin described are worth it over the old Coker/airfoil set up.

JL

I’m afraid it is true John, neither of us is at the cutting edge of speed on Coker. The fastest I know of someone riding is 29mph and there are a number who have gone over 24. Just spend some time riding with one of those guys and you’ll see what I mean. I don’t worry about this at all as it’s obvious that you can have an absolute blast on these cycles at way below world-class speed.

What you need to enjoy 36" unicycling is a great wheel build with a wide hub, brakes that work, and a seat that is as comfortable as possible. Without those things, it can be good, but not great. Really the wheel is the deal. The old stock Coker frame is probably fine as long as you weld on the Magura mounts. The Nimbus frame is perfect - much cheaper than other custom frames and quality is good enough. Is a $350 upgrade worth it? No if that $350 is needed for something in life. YES if you can afford it, yes for sure.

Actually there are some people like Ken who are so skilled that they don’t need a brake. I would say that most people would need a brake to get the most out of it though.

—Nathan

To go with what Nathan said – the best upgrade is probably the extra-wide hub + airfoil. If you could get someone to rebuild your wheel, you may be able to add the hub to your airfoil, weld on magura mounts to the frame, and you’ll be set for very little additional cost. I was going to go down the frame-welding route for my stock Coker, but I never got around to getting it done, and instead just got a new frame for $120 when I ordered Louise a new Nimbus 36’er. I used the old frame, sans brake, for quite a long time. I just bent it outwards by hand to accommodate the UDC extra-wide hub.

Scott Wallis’ seats are GREAT! But, the new KH ones are good too.

corbin

Nathan - was the 29mph documented in some way? Was it a geared 36? If ungeared, 29 mph is around at least 275 rpm or 4.5 complete revolutions per second. That’s just not believable.

Please tell me more about this inhuman feat.

Are you sure they weren’t just banging together two empty halves of coconuts?

It was done by Christian Hoverath and measured by cyclometer. I think it was actually 29.3 or so. If you knew him, you would know it’s believable. He expected to crash but didn’t and was very happy and I think he vowed never to again go so fast. I wasn’t there when he did it but he is trustworthy and told me personally about it.

There are lots of threads discussing this. See Fastest speed on unicycle or unicycle speed record

—Nathan