Header image header image 2  
Cycling Club
  || HOME ||


The Time Trial Bike

19th August 2013

My road bike is off the road at the moment so if I was to compete in the Time Trial series I was going to have to convert my single-speed mountain bike into a time trial machine.

Simple enough: For speed

  1. put slicks on
  2. raise the gearing
For aerodynamics:
  1. take the mudguards off
  2. give it a wash

Single Speed MTB, Knobblies, 32 x 18


Both wheels have slick filled inner tubes so are puncture free, that is until the tyres come off and all the thorns are discovered; two in the front and one in the back. Three patches later and I'm ready for the slicks to go on.

The mtb tubes are too fat for the slicks but rooting about in the cellar I find a slightly smaller diameter tube and that goes in the front. Sadly, the valve is very short and I cannot get more than 50 psi in it without the track pump slipping off.

I can only find one "thinner" 26 inch tube so the big fat slime is going to have to go in at the rear. It won't. The slicks say 1.6, the tube says 1.75 to 2.25. I manage to get it in with a bit of a squash but that means it kinks so that the wheel has a heavy spot and it makes the bike lift and fall when it spins. At least it has a long valve and gets 80 psi.

Changing the gearing should be simple. Leave the 32 tooth ring on the front, take the 18 off at the back and put on an 11 that I've found from an old cassette. As it's the end sprocket it is wider than the standard size and the lock ring won't fit back on, so a 13 has to go on instead.

Speed testing gives a comfortable (not spinning wildly) top speed of 19 mph. It'll have to do.

I was toying with the idea of putting tri-bars on but didn't as it was getting too close to the time I had to leave to get the start in Chelford I didn't bother.

After signing on, the whole of the Stockport Clarion contingent; Dave, Sarah and me, went for a good warm up to Alderley Edge and back. After riding off road at 10 mph for the last few months, this feels like a speed machine!

As we got back to the car park and were about to leave for the start the rear brake went "ping" as the spring broke and started to rub on the disc. Can I make it any harder for myself?

At least the weather was helping: a still night, nice and warm. The ride itself felt like any other TT I've done...pedal fast and try and keep your head down and out of the wind.

To the turn that was fairly easy and felt comfortable but on the way back therer was a head wind. Where did that come from?

I was quite plesed with my time of 30.59 an came 46th from a field of 51.

I'll have to do it on this bike again next year just to see if I can beat my time... not.

Single Speed Time Trial Machine, Slicks, 32 x 13


  Report by Martin Pigott