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.