LBS had a specialised roller pro 2.5 tyre which is as light as a feather, and some generic platforms. I welded a handle on, ready for the brake lever, then common sense got in the way. Might be safer for him to get used to it a bit before adding brakes. I tried a few bmx calipers, and one or two seem to fit round the tyre no problem, so that will be less hassle than setting up v-brake mounts.
It’s just such a shame that I’ll have to go out riding at least twice as often now
That looks like a mini Coker. At one of the USA conventions I remember a little kid doing a freestyle routine on a 24" unicycle with the seat just above the crown. With the size of the wheel, the size of the rider, and the height of the seat, it had all the proportions of someone doing a freestyle routine on a Coker.
The frame is made by cutting the seat tube off flush with the top of the fork tubes,and putting a 1.5" long seatpost in, then welding round top and bottom. The handle is welded straight to what remains of the seat tube.
The first bit of growing room comes from shimming the seat up, then when needed I’ll cut the legs and make them telescopic as per Unicycle.com’s shortie coker frame. I liked the clean lines of it too much to chop the legs straight away, and there’s no point carrying the extra weight for nothing.
The handle is on straight forwards, 'cos I like them that way. It’s easy to make a ‘clamp on’ handle out of an mtb bar end if he wants an angled / T bar handle.
Cranks are 152’s, for torque. It will go to 125’s or shorter in time, but it’s best to start safe.