Gettin' More Outa Ya Bullet: Weight reduction

Mission Statement

This blog has been set up as a record of my attempt to build a cool Bobber style bike out of the Royal Enfield Bullet. With the cost of genuine early British and American bikes and parts spiralling upwards in the face of the current global economic climate, building a retro style custom is rapidly becoming cost prohibitive. Initially, there will be a period of accruing parts and information as the bike I intend to re-create is my daily rider.

I have heard so many horror stories about the Indian made Bullet from people who's mate used to have one, that I have lost count. All I can say is that I have covered over 20,000 miles on mine in the last three and a half years, and feel happy that it is quite capable of doing another 20.

So if you like the idea or just curious, you are welcome to come along for the ride.

Sunday, 24 October 2010

Weight reduction

As the Bullet is only of the 350 persuasion, weight of components is a bit of an issue. Pretty much everything that can be made of aluminium will be. In "Tuning for Speed" they even go as far as discussing drilling the centre out of the bolts on the bike to reduce even more weight.

A not inconsiderable saving in weight can be effected by waisting the bolts down to a diameter equal to bottom diameter of the threads, leaving a short parallel at each end to centralize the bolt or act as a register for the engine plates if required; alternatively, if the bolts have solid heads they can be drilled down the centre, as shown in the diagram, the hole (which must be accurately concentric with the outside) extending very nearly to the beginning of the thread. Far from weakening the bolts, this treatment actually makes them less prone to fatigue-failure and, if carried out consistently throughout the whole machine, a perceptible mass of excess metal will be eliminated.