It's Speed Week again on Bonneville Salt Flats in Utah. They are not having a lot of fun, it has rained a lot but the wind is rapidly drying the salt & if it keeps up, things might be better after the weekend.
Anyway, Max Lambky is out there again with his 3 litre twin engined Vincent powered streamliner, after the LSR for wheel driven motorcycles. Entirely funded by gifts from around the world, Max is flying the flag for British bikes & has the Vincent logo emblazoned on the sides of the bright red 'liner.
I came across this bit of minutia & thought I'd share it - the lengths they go to ......
"The last time Boris Murray was at the house the conversation was about streamliners. Surprise. Surprise. Anyway we were talking about his two rides in streamliners built by Dennis Manning, one being a double engine Triumph powered machine, I believe it was the same machine but the second was backed by the Norton Works. It had two Norton Commando engines.
He told his story in quite detail as to his experience in riding streamliners. The cockpit was apparently larger than the cockpit in the Vincent streamliner. He said that at speeds above 200 MPH he could move his knees, which were in 90 degree bend, from side to side and steer the liner by this action.
My ears perked up when I heard this. It was apparent that balance is critical in the handling of streamliners. In the past, the balance of all my streamliners has been like such: Get the front wheel as straight as you can. Try to find the balance point as best you can by visual, then add weights to either side to achieve a somewhat close balance.
Balancing the 2004 streamliner will be accomplished in a precise manner. As very high speeds are anticipated and I want to give every advantage to the rider to aid him in riding the thing.
Now that the fibreglass work has been completed, the balancing of the streamliner is possible. The reason I had to wait for the body to be completed is that the body is of a hand laid up method. It's impossible to achieve consistency in the thickness of the fibreglass , for sure one side of the body is heavier than the other. Many things were taken into consideration while addressing the balance of the streamliner. I'll mention a couple to show my thought process:
The two parachute tethers are of different lengths, one is mounted on one side the other is mounted on the other side. A small and probably insignificant amount of weight, nevertheless the parachutes will be in place when the balance of the streamliner is determined. The fuel, which is in various sizes of lines, goes from one side of the streamliner to the other, here again, minute this weight differential when the fuel lines are full but there would still be a weight difference. So all fuel lines and fuel tank will be full when the balance factor is determined. There are other things to consider, but I think you get the point. The liner will be precisely balanced.
The balancing of the streamliner will be undertaken in this manner: A bar will be manufactured approximately 6' in length and will be attached just aft of the cockpit where there is a threaded hole in the frame used normally for a lifting eye; this hole is on the centre line of the motorcycle. The 6' bar will extend out on either side of the streamliner an equal distance from the lifting eye hole. From the lifting eye hole, a hole approximately 3' from the lifting eye hole will be drilled. This hole will be a precise measurement, as well as the hole drilled in the other extended portion of the bar on the other side. Two pipes with pins the size of the hole will be manufactured approximately 2' long with jacking screws placed in the opposite end of the pins. The pipes will become legs extending downward to a pair of bathroom scales. A plumb bob will be hung from the ceiling for vertical assessment of the front wheel. Pressure will be applied to the scales by the jacking screws, achieving a vertical position of the front wheel. The scales will be read to ascertain which side needs weight.
When building the new frame I made provisions for weights to be added as low as possible to help the centre of gravity. This provision for mounting weights is underneath the rider's seat. When I achieve a one pound weight differential between the scales, that will be just about as good as you can get it.
Now that I've told you everything you never wanted to know about balancing a streamliner but were afraid to ask ... I guess I'll shut up. Max"
Regards,
J. Kim Siddorn,