There is no doubt that having the right bike for the task at hand is wise and I have been on a mission to make a fast trail bike. The trail in question is a 7.5mile circuit that follows the coast of a small local lake. Its more or less flat.
The total climb is less than 100ft but it is made up of five short, steep climbs that come in the first two miles. After that the rest is a cruise!
Not quite; if you are going to get a good time round this little loop you have to pedal non stop, you will discover there is no where to rest, its relentless and if its not presenting you with a short killer hill its another of the 20+ hairpins!
To get round here quickly you have to keep the power down, keep it flowing through the hairpins and attack the climbs. This means you need grip, lots of it. You dont need [much] suspension. you need strong legs and you need to be able to accelerate, lots. Breaking it down there is less than a minute between each significant effort.
When the body isnt enough to close the gap I start looking at the gear. What am I riding?
This bike is an Easton tubed hard tail street trials frame with a 1 x 9 drivetrain using XTR parts for the back wheel and shifters and RaceFace for the cranks and chain wheel. Its got RockShox Silver forks that have seen better days and need replacing up front. Untill recently I have been running Easton XC One wheels with appropriately chosen tyres for the prevailing conditions. The bike feels fast and in general has been.
What has been clear as the trails dry out and the tyres get slicker and harder is the bike reaches its limits very quickly, violently breaking traction at any opportunity! Hard cornering and powering up those short climbs the back end is skipping round but then half the circuit is smooth, flat and fast so the low rolling resistance is a distinct benefit. What needed tackling was the lack of traction without compromising the fast rolling tyres.
I decided to run an experiment; I got in touch with Mike at Onza for some Reggie and Ronnie drilled trials rims built on to some Tension Aerosilk hubs. They arrived yesterday!
I was so excited I didnt even bother weighing them [I’ll do it next week]. To insure I could make a fair comparison I swapped not only the cassette and disk from the Eastons but the tyres and tubes as well for the new wheels. I normally run these tyres at about 40psi on the Easton rims but in this case I went strait in at 20psi front and rear and went for a ride!
Two early morning runs, one in each direction were immediately impressive, the bike felt fast but dead! It was a lot more comfortable and the power transfer was amazing! Normally I would be standing in the pedals for most of the run but I found myself seated for 80% of the circuit and noticing the saddle was to low!
I had to go to work so uploaded the runs to Strava and got on with the day, thinking all the time. By the end of the day I had reached the conclusion I needed a little more air in the tyres to make it feel a little more lively and I need to put the saddle up a little so I could get the power down while seated. This done I headed out for another evening run.
I had increased the tyre pressures by 5psi and I think that was a bit much, Ill drop them to about 24 front and 22 rear. The seat can still go up a little but the main thing is a stack of PR’s. I got my fastest time ever on the circuit!
Whats the benefit?
- 26″ wheels accelerate faster than any of the new 650b, 27.5 or 29″ wheels.
- The wide rims from Onza allow us to increase the air volume of the tyre without increasing the size of the tyre and as such we can run a lower pressure.
- Lower pressure tyres conform better to the ground so power transfer to the trail is improved.
- Larger volume tyres absorb minor trail bumps better so the bike doesnt skip about.
So 26″+ bikes rock in Suffolk!
If you want to know more or have a ride get in touch!