2012 Racer

[davidd]

Eugene,

This is the basic seat mold for the racing seat, which is made of fiberglass. I glue a 1/2" piece of foam on the base for heightened comfort. I have a few different molds for various seat modifications, like left and right exhaust and land speed rules.

These are all of the fiberglass parts used:

David

 

[greg brillus]

Hi David, As a bit of a side note........whilst working on the racer today, I happened to notice that the alloy sprocket carrier we made earlier in the project has cracks in 5 out of the 6 spokes that radiate from the hub out to the sprocket flange. This is evidence that removing metal from that center section was not a good idea. So I will make another one, and not machine any thing from that area. This was my own doing and no fault at all of your original drawing that you sent me. So I will leave the hub per the drawing, as it works very well...other than the cracks....................Cheers....Greg.

 

[vibrac]

not unusual, I had a hub on the Egli racer crack radially after a few seasons. Clever Trev made me a new one that's been Ok many a season

 

[greg brillus]

I wonder if it happens because of no cush drive in the system.......When I showed it to my machinist this morning, he could not believe it.

 

[davidd]

Greg,

That is interesting because it looks quite robust. Tim would have the experience on this issue. I assume this is the carrier and sprocket:

Do you know what material was used? I wonder if a change might cure it. It certainly looks stronger than the original Lightning set up. For those interested, the adapter I used was designed to fit a stock RM Suzuki 1/4" sprocket, so I could just order sprockets off the shelf that would work. This was done after a brake drum (Rapide) shattered. Here is a photo of the one I used on the 500:

I believe this is much thinner than yours, but it has worked well on the 500. It seems the twin needs a bit of help.

I must admit that I am more interested in cush drives now than when I first started racing.

David

 

[greg brillus]

David if you look at the picture you have above at the huck bolt in the one o'clock position...above that in that corner is where all the cracks are, and they start at that corner and head back towards the center at about a 45 degree angle. This on 5 of the 6 spokes.....I have another race meet in less than a month, so was not expecting to find this, but I have been rearranging the rearsets and seat stays to suit. So because I have been looking a lot at the surrounding area, I noticed black lines in the carrier which I thought was just grease and dirt from the chain, but they are definitely cracks. I do not want to take any risks, so I will make up another one without the spokes machined into it. I think from memory we made it from 6061. Cheers..........Greg.

 

[vibrac]

I expect I kept the cracked one I never throw anything away from the garage if so I will take a snap

 

[litnman]

This sprocket carrier was made in a school shop in 1955 for my drag bike. They used alloy 2024.

 

[TouringGodet]

John, what is the red coating inside the pipes? Or are they plugs?

 

[davidd]

John, what is the red coating inside the pipes? Or are they plugs?

Plugs. It is always a problem for racers with steel pipes. The cooling pipe draws moisture and then the interior diameter of the pipe gets coated with high drag rust! Stainless or an interior ceramic coating are the best solutions. It is still good to keep the mice out.

David