Mick F wrote: ↑16 Apr 2021, 4:30pm
A few words in my defence.
My riding style is generally for higher gears but that doesn't stop me wanting lower gears. Hence my gearing choices for the Moulton.
The main issue I notice, is not efficiency of pedalling technique, but the lack of "go" that the bike has.
Heavy bikes - all else being equal - go faster downhill but more work going up them.
Trouble with my TSR, is that it's
slower going down the hills in the first place.
It's very very noticeable riding on the self same roads as I do, Mercian vs Moulton. It's not the "bobbing" of the suspension when I pedal, just the inefficiency of design. Aerodynamics of the frame coming down hills ........ besides the extra weight going up them ......... but the weight going down doesn't help and assist like it should.
Very very noticeable indeed, and when I ride round here, I'm doing on average 100ft of ascent per mile ridden. Often 120ft per mile.
No need for defence Mick, a chap who rides as often as you can ride however and whatever he likes!
I agree that the spaceframe is inherently unaerodynamic, although how much this affects speed is hard to know. It would be interesting to compare directly against the new Moulton Flyte which is essentially a Jubilee with a fatter-tubed Y-frame. FWIW I've long thought Moulton should offer a carbon monocoque frame -
the stiffest possible vehicle structure suspended from the wheels by a known and controlled amount, to paraphase Alex Moulton. Would reduce the weight somewhat too.
We know and accept that all things being equal a smaller wheel accelerates quicker, decelerates quicker and has higher rolling resistance than a larger wheel. Aerodynamics is more tricky though, and makes my brain hurt. The smaller wheel ought to move less air so be more aerodynamic, but will it create more turbulence because it spins faster?
But at any given speed the edge of the wheel is moving at the same speed no matter how big the wheel is...
You sometimes see disc wheel covers for 17" wheels but I've never seen any for 20". They would be an interesting experiment. Hopefully the smaller wheel would be less affected by gusting sidewinds than a bigger wheel. Or there are the deep-section carbon HED wheels in 369 or 406 if you have deep-section pockets.
For the spaceframe Moulton used to offer rather smart frame skins (which you could also keep things inside) that I imagine smoothed the airflow somewhat. Again would be an interesting experiment. Then, as discussed elsewhere on this forum before, there's always the Zzipper front fairing or a range of increasingly-serious full fairings which turned the AM into the upright bicycle 200m world record holder that I believe it still is today.
And finally small-wheeled bikes are quicker as part of a group ride than on their own, as the small front wheel allows closer drafting of the bike in front. So just go out with your chunky mate and sit on his wheel!
Big wheels good, small wheels better.
Two saddles best!