are small "22" wheels slow on hills

inaperfectworld

I took a "22 wheeled bike to do some Alps last summer. I found that I was having to push on the pedals at a low cadence despite having a triple and being in bottom gear, and was struggling and I noted people passing me had a higher cadence. They were on light road bikes but I don't think the folder I've got is particularly heavy. I am nearly 60 but think I am fitter than my performance in the summer seemed to be. I do 2 to 3 century rides a year without difficulty and go to weekly training sessions for lactate work etc.
Maybe i just need to lower the gears but I also wonder if small wheels have an inherent disadvantage: If i consider the wheel spun by hand freely off the ground it will be easier to start moving than a big wheel, so acceleration will be easier but the small wheel will have less momentum and will slow down more quickly and stop sooner. Imagine spinning a cd against a cartwheel for example.
Whether this difference is significant on the road , and whether the potential advantage or disadvantage becomes greater when on these very long climbs, I wonder if anybody has any idea?

MichaelW

Small wheels have higher rolling resistance but less air resistance and they are lighter. Its a bit swings and rounderbouts but on an uphill, you shouldn't be at a big disadvantage. A speed record was set using a Moulton.
If you are stalling on a hill in a low gear, your gears are not low enough.

thescouselander

MichaelW wrote:

Small wheels have higher rolling resistance but less air resistance and they are lighter. Its a bit swings and rounderbouts but on an uphill, you shouldn't be at a big disadvantage. A speed record was set using a Moulton.
If you are stalling on a hill in a low gear, your gears are not low enough.

Is that true? I'm not saying it isn't true but I cant imagine why smaller wheels would have significantly higher rolling resistance. What's the theory behind this?

malcolmfrost

There's an article on Wikipedia about it, http://en.wikipedia.org/wiki/Rolling_resistance but i think the gist of the argument is that a smaller tyre deforms more when rotating, due to the smaller radius, so the losses are greater. having said that I've never noticed it with my Airnimal. If anything it feels faster due to the quicker acceleration.

careful

I use an Airnimal with 24" wheels each year in the Alps and other mountains. The bike is a bit heavier than my regular carbon and Ti bikes and I have the same triple and casette sizes. The smaller wheels give me lower ratios in each gear therefore my cadence would be higher if I used the same front & rear gears. I rarely need the granny ring.
I find the bike climbs very well and seems to accelerate better than my other bikes (supporting the theory of reduced inertia). I'm no great climber but I have occasionally noticed a look of horror on the faces of young guys on high end carbon bikes being overtaken by a 65 year old on a folding bike. Descending is another story as the small wheels make steering at speed a bit twitchy.