Did a bit of fine tuning and a few modifications. Had a long hard look at the front end set up and couldn’t work out why it’s pulling slightly to the left.
Made some adjustments to the drivetrain which should make pedalling easier.
Replaced the spring rod in the rear end with a set up that’s a kilo lighter.
After stashing it for seven years, in January 2022 I dragged the Pospedal out of retirement and made some adjustments.
First off the mark was changing the front wheels from 16” to 20”, to reduce rolling resistance.
The smaller wheels had been laced up single crossing front and two crossings behind (see above). The rims had also been offset inwards to get zero offset on the kingpin alignment. This made the steering a bit twitchy and unstable, probably more to do with the tiny contact patch than anything.
I laced up the new rims with two crossings both sides. I also offset the rims to the outside of the hubs instead of the inside. This gave the wheels a positive scrub radius in order to make the steering self-centering and stable.
The new wheels fitted. The effect of the Ackerman angle is clearly visible.
A new stiffening brace was fitted to the rear of the chassis. Made partly from a tapered bicycle chain stay.
A 16mm spring steel rod was fitted to the rear swing arms to increase the stiffness of the suspension. The air shocks were returned to their original positions and reset to 170lbs/sq” (same as the front). I hope to replace this rod with a lighter option in the future.
I checked the wheel alignment and found an excessive amount of toe-in that I apparently hadn’t picked up originally. It was corrected to 0.5mm. The old mangled fairing off a previous model was bashed into rough shape and fitted to cut down on drag.
Took it for a short test run (I need to get fitter) and all the adjustments seem to have had the desired effect. Steering stable and self-centering, chassis nice and rigid, suspension working well. Topped out at 32 km/h, only halfway through the gears.
