Alba Rd. hurts me - 29er vs. 36er content

[phlegm]

I don't intend this thread to be an extensive pros/cons listing of 29ers vs. 36ers. I'm well aware of the differences, but I'm still a bit perplexed about them.

Earlier this year I rode up about the first 2.5 miles of it for the first time. You can see the profile here--just select Alba. It's an average of 10% grade, and there are definitely much steeper sections.

So, the first few times I had N36 fever, and I rode my N36 with 140s. My best ride required five dismounts (from sheer exhaustion) to go the 2.5 miles.

Today I decided to take my KH29 with 150s up it. Supposedly, according to various maps I've examined, there are trails that should connect to it, but there is also a lot of private property. So I never found the trails I was looking for.

Anyway, I also rode about 2.5 miles up it, but it took enough more dismounts that I lost track. I haven't been riding quite as obsessively, but I don't think I'm in that terrible of shape right now.

I don't get it. It seems that really steep stuff should be easier on the 29er with longer cranks, but based on all my dismounts it didn't seem so. Has anyone else had a similar 29er vs. 36er experience? I've definitely ridden more road mileage on my 36er, but I've also done a fair share of grueling 29er climbs too.

[tholub]

I certainly haven't seen any evidence that Coker riders are working less than I am on steep climbs on my 29er. I expect it's just a question of familiarity.

[phlegm]

Originally Posted by tholub

I certainly haven't seen any evidence that Coker riders are working less than I am on steep climbs on my 29er.

I actually expect that Coker riders have to work harder on really steep stuff because those 36er wheels are so heavy.

Maybe I'll have to try it several more times on the 29er to see if I get better. That is, after I ride the trails backwards out to Alba Rd. and find out where I need to trespass.

[tholub]

Originally Posted by phlegm

I actually expect that Coker riders have to work harder on really steep stuff because those 36er wheels are so heavy.

Maybe I'll have to try it several more times on the 29er to see if I get better. That is, after I ride the trails backwards out to Alba Rd. and find out where I need to trespass.

There are some scary mountain folk up there; be careful where you walk.

One thing I've noticed when riding in packs with Cokers is that the specific angle can make a difference; there are some slopes which are faster on the 29er, and some which are faster on the Coker. You can keep spinning the 29er on slopes which are steeper than where the Coker goes into funky-chicken mode, so the 29er gets faster, but when they're both in funky-chicken mode, the Cokers speed up again.

[phlegm]

Originally Posted by tholub

funky-chicken mode

[steveyo]

In my experience, Whiteface Mtn, with 8% avg grade for 8 miles, is pretty tough with KH29/150s and not bad with KH29/165s, in fact I did it without a dismount this year. Then Mt. Equinox, avg 12% for 5.2 miles, was quite tough with my KH29/165s and almost as tough with Rolandisimo on his KH24/150s. We were both in borderline "funky-chicken" mode on that one.

Interested in Aspenmike and Ben's ideas about Mt. Washington with 12% avg, 7.6 miles.

Re: cokering these climbs, ask Max about the Coker/170s experience on Whiteface. It would be insane on the 12% stuff.

[Mikefule]

A bicycle typically has 165mm cranks or 170mm cranks. 36" on a bicycle is a fairly low gear. As unicyclists, we think of 36" as big, but bicyclists would think of it as fairly small.

I used to have a Coker, and found that it would cruise up some hills surprisingly well. I think it was something to do with the smoothness arising from having a big wheel. On a smaller wheel, you can make slow progress in a series of short "steps", never getting any momentum up.

Some of it is psychological, too.

[tomblackwood]

Originally Posted by phlegm

So, the first few times I had N36 fever, and I rode my N36 with 140s. My best ride required five dismounts (from sheer exhaustion) to go the 2.5 miles. Today I decided to take my KH29 with 150s up it. Anyway, I also rode about 2.5 miles up it, but it took enough more dismounts that I lost track. I don't get it. It seems that really steep stuff should be easier on the 29er with longer cranks, but based on all my dismounts it didn't seem so. Has anyone else had a similar 29er vs. 36er experience?

I finally have both a 36 touring setup, and a 29 road setup with big apple tire. I'm also actively training for an upcoming Long Distance Charity Ride, so I've been mixing long rides on the 36 with shorter, more intense rides on the 29 with lots of climbing. I've absolutely found the 29-er to be the superior climber. There is one big hill near my house that's about 200 vertical feet bottom to top. It's steep enough that I've only made it once on my coker, and that was extremely difficult. On my 29-er, I can crank up and down it four times quick, and next week I'll go for five rounds of climbing. What will you guys be doing?

[GizmoDuck]

I find the 29'er/150mm combination to be quite a low gear, and tends to be pretty choppy compared to the Coker. On the road, it would be have to be well over 10% gradient for me to feel like I'm getting much advantage on the 29'er.

On the other hand, I've been riding my 29'er/150mm unicycle exclusively for the last few months, and I'm loving it...but you have to learn how to spin smoothly for it to work well. I'm thinking of using my 29'er for next years Uninam tour.

[abridged]

First off, I haven't completed my 36er project, so having never ridden a 36-inch wheel, I can't compare.

But, until new rims become available that fit the coker tire, I've been experimenting with shorter cranks on my Nimbus 29er. I started with 127 mm, then dropped to 114s. It's taken a lot of training, but I feel pretty comfortable with most hills. In the next couple of weeks, I'll order some 102 mm cranks. I feel pretty certain that it'll climb just fine.

I do wonder if 24 and 36 inch wheels represent something of a "sweet-spot" with unicycling. The 29er is not as stable. My only evidence for this is that shoulder-lean/body twisting seems so much more prevalent (in these posts) on a 29er than on the 24s or the 36s. I haven't heard much about 20 inchers or smaller, though, so I could be way off.

Any physics geeks out there that could shed some insight?

Bottom line: Mathmatically with most popular crank sizes, the 29er is easier to climb, but there may be other rolling forces that contribute to the stability of the ride.

[tholub]

Originally Posted by abridged

I do wonder if 24 and 36 inch wheels represent something of a "sweet-spot" with unicycling. The 29er is not as stable. My only evidence for this is that shoulder-lean/body twisting seems so much more prevalent (in these posts) on a 29er than on the 24s or the 36s. I haven't heard much about 20 inchers or smaller, though, so I could be way off.

I don't think this is likely; I think wheel size performance is pretty much linear. However, the equipment available at different wheel sizes makes a difference; there isn't a large selection of 29er tires, and there's an even smaller selection of 36" tires and rims, so the way those few selections behave impacts the overall experience of those wheel sizes.