Adam Lea said:I also have a Birdy. I have found that I am limited to a speed of about
35mph above which it seems that any additional extra power applied to the
pedals does not result in a speed increase. The bike also seems to get less
stable when it reaches these speeds. Other riders on conventional road bikes
in the club I belong too can manage 40mph easily if they want to.
There are various different Birdies... what sort is yours, which bars
does it have, and what tyres is it running at what pressure, do you have
mudguards? There's a lot more to speed than wheel size.
Quoted message said:I asked at my LBS about how to get more speed out of my Birdy and was told
it was impossible because of the small wheels, they don't work, they can
only spin so fast and if I want to go fast I should get a racing bike.
Tossers. A faired Moulton holds a world speed record for an upright
bike, which it clearly couldn't do if it was "impossible because of the
small wheels", and Moultons have been used to get creditable results in
the RAAM. The reason small wheels never show up in UCI races is because
the UCI have banned them: they usually tend to ban things that help, not
things that hinder...
Quoted message said:cycling club seem to think that I would be faster on a proper road bike as
well. How truthful this is I don't really know but I guess there is
something in it if so many people with a lot more experience than I have are
saying it.
Again, what is the setup of your Birdy? If it's, say, the tour
(formerly "Blue"😉 model with mudguards, DualDrive and 38mm tyres then
of course you'd go quicker on a full-on road bike, but if you put a
heavier, less efficient gear system, air-catching mudguards and tough,
comfy but relatively high rolling resistance tyres on one of their bikes
then that would slow them down too.
To get something faster than a Birdy Tour, get a Birdy Speed with no
'guards and Stelvios and you'll probably find you can go faster (that's
why it's called the "Speed" (formerly "Black"😉).
Big wheels do better than /unsuspended/ small over rougher roads, but
the suspension on the Birdy is probably good enough to iron that out,
and may even make it /more/ efficient on really dodgy tarmac.
Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/