Got behind with progress blogging

 I have worked out a rear brake and also a reverse system...all of which is work in progress. I have reduced my cockpit buck a bit.

Rear bodywork - shrink and stretch

 I have made my back-top panel, which will support the sides. The folded (or rather slapped-down sides have been shrunk so as to form the radius of the boat-back, using my treadle shrinker. Incidentally, I made the treadle system during lock-down.

I formed two right-angle sectioned stringers which have been edge-shrunk to the same profile as the side of the back-top panel. I know that sounds complicated, but all will become clear.

These right-angular stringers will make the body-sides hold their shape, parallel to the slapped top panel edges.

Grandfather rights

Well, that is good news! I have just heard from Stefan, the Chair of Cyclekarts GB,  that the committee has just approved my variation to the rules regarding wheelbases, which were formally promulgated just after I started my build. Ordinarily under the Cyclekart GB rules, the centre-to centre wheelbase can't be longer than 66", and a car should be scaled to fit that. 

I wrote to Stefan back when the rules were being formalised, pointing out that the Bédélia, pro-rata with its width, had been unusually long, so that when scaled down, in order to look like what it pretended to be, with wheels in proportion to our 17" ones, a cyclekart would need a 72" base. He took my point and reassured me, back then, that he didn't think it would be a problem.

We car builders were recently invited to apply to the committee, justifying any design features which were at variance with the rules, if we had started our builds before the club rules were formalised. I knew the application was being considered, so I was a bit concerned. It could have been disallowed. That would have been unfortunate because, if you can't race with the club, there are currently no other race options for this class. And of course, you can't drive them on the roads.

In law, "Grandfather rights is a provision in a new law that allows old rules to apply; as such it provides exemption from having to follow new legislation".

Being given grandfather rights in the year I turn 60 seems somehow appropriate.

Many thanks to Stefan and the Cyclekarts GB Committee.

Pitch perfect

One of the things I really love about building this cyclekart is that I learn about things which I start out knowing nothing about at all, and today it is the naming of the parts of my main drive chain. And for that I consulted a site recommended by Stefan Nahajski, the Chair of Cyclekarts GB: the Cut Price Racing Guide.

picture from Renold.com

picture from hammerinhandcycles.com

This afternoon I measured the circuit my chain will travel round - when stretched around the driving and driven sprocket - in mm. Then, you just divide this by the pitch of your chain, which in the case of my 420H chain will be 12.7mm and that gives a total number of 92 links, which is what I need to order, bearing in mind that one of them will be a joining link.

Quick reminder of where this project started

Follow these links:

The concept car 

The mocking up

A chance to see a real Bédélia in action

The faux driver: Monsieur Bourbeau

My work-in-progress on its first outing

Drop-in engine frame

 I have constructed an engine frame which can be pulled out of the engine bay with the engine mounted on it. This makes it possible to keep the engine alignment if ever the engine needs work and access is tight.

engine bay with brackets to hold blue frame

blue frame dropped in 

The engine plate, which is welded to the frame, is slotted so that the engine can be slid back in it, if ever I need to take up slack in the chain.

To brace the engine against sliding towards the drive sprocket (and to assist with alignment) I have welded some nuts at the rear of the frame, so that tightening bolts can bear against the engine base. This last innovation is not my own. Another cyclekarter shared the idea on Facebook recently.

align and brace

alignment checked

engine in

skates

An algorithm read my mind and offered me these three wheeled casters. I got some and made skates for slipping under my kart so that it can be moved around easily, as I have little room to work in.