DM 28" uni speed review

I woke up on Saturday morning a little bit sick, but eager to go
offroading with the AUS crew in Canberra. As I walked out to get the
paper, I saw a very large box sitting conspicuously on the firewood.
Since I’d been expecting my new uni to arrive on Wednesday, I don’t
know how long it had been sitting there.

Anyway, building up my fire-engine-red 28" wheel would have to wait
until after a 2 hour off-road extravaganza with some pretty insane
downhill sections and lots of washed out gullies. Anybody who comes to
Canberra should definitely get in contact if they want some
sensational off-roading.

Anyways, I’ve commuted four times on the 28" now and it’s a lovely
ride. I’m a bit limited for speed by traffic lights and busy
intersections, but on the occasional open bikepath I’ve maxxed out at
21 km/hr and can average 14km/hr over a 4.5km trip with lots of forced
dismounts and walking to cross roads. I’ve only measured a ‘maximum
average’ once, but I averaged 16km/hr over 650m before I hit a red
traffic light.

At the moment there are three main things limiting my speed and
comfort. The first is, obviously, my route, which is restricted to
bumpy bike paths because of peak hour traffic. Secondly, I’m carrying
a backpack, which makes me slightly more unstable than usual (although
I did carry 10kg of shopping for 3km on the weekend). Thirdly, the
Fear of Falling. Because the bikepaths are generally pretty bumpy, I
don’t want to risk having to run out of a UPD at greater than 20km/hr.
Especially not since I’m sick at the moment and have a backpack on!

For those who care, my speedo (a Sigma BC1200 but without the cadence
kit hooked up) has been calibrated with a wheel circumference of 2200
mm and I’m using one magnet. The max speed must be maintained for over
2s to register, corresponding to about 3-4 magnet passes.

This weekend I’m going to find a nice flat open stretch of path and
see what kind of speeds I can hold for a kilometre. I anticipate being
able to maintain 20km/hr reasonably easily for about a kilometre.