Saturday, May 28, 2005
A day of forks!
There was an article in a recent issue of scootering about rebuilding Lambretta forks.
It mentioned a method of measuring inside the forks to make sure that the fork springs are evenly pre-loaded.
I borrowed the special tool used in the article (friend in high places! Not really - the article was written where I work).
I originally intended to do just one set of forks before I built them but I decided to check all the forks I have to hand while I was at it.
The first test was to see if a straight metal bar would fit straight through the holes in the forks for the fork link bolts. Out of the eight sets of forks I have three failed this test - which means they need repairing or replacing.
I spoke to Phil at Grand Prix scooters in Leicester who offer a fork straightening service. He charges between £5-£30 per fork to straighten them, depending of course on how bad they are. I think I may end up giving him all my forks to check!
The second test was to measure how deep inside the forks the internal stops are. The distances have to match as this means an even amount of pre-load is put on each spring. If the distance does not match then the springs are unevenly loaded which can affect handling. It was fairly easy to measure the fork stops using the tool from the article as it provides a fixed point to measure from. Out of the 8 forks only 3 matched which means I have to do some shimming as and when I get round to building each set.
I have kept a note of all the results for future reference.
The other job I did today was to start building the cutdown Lambretta I hope to get on the road for the summer.
I had sprayed everything matt black the other day so it was all ready to build. I fitted the twin tanks which was a bit of a pain. The paint got a bit scratched but of course with matt black you can just spray over it and carry on. I also fitted the rear mudguard. Next step is to fit the bar between the frame tube and the fork stem for the bike tank. I will get that done at work. I also need to fabricate some sort of bracket for the side stand I will fit.
I think with the bike tank and the twin tanks I will have nearly 25 litres capacity for fuel which will be very useful for touring!
It mentioned a method of measuring inside the forks to make sure that the fork springs are evenly pre-loaded.
I borrowed the special tool used in the article (friend in high places! Not really - the article was written where I work).
I originally intended to do just one set of forks before I built them but I decided to check all the forks I have to hand while I was at it.
The first test was to see if a straight metal bar would fit straight through the holes in the forks for the fork link bolts. Out of the eight sets of forks I have three failed this test - which means they need repairing or replacing.
I spoke to Phil at Grand Prix scooters in Leicester who offer a fork straightening service. He charges between £5-£30 per fork to straighten them, depending of course on how bad they are. I think I may end up giving him all my forks to check!
The second test was to measure how deep inside the forks the internal stops are. The distances have to match as this means an even amount of pre-load is put on each spring. If the distance does not match then the springs are unevenly loaded which can affect handling. It was fairly easy to measure the fork stops using the tool from the article as it provides a fixed point to measure from. Out of the 8 forks only 3 matched which means I have to do some shimming as and when I get round to building each set.
I have kept a note of all the results for future reference.
The other job I did today was to start building the cutdown Lambretta I hope to get on the road for the summer.
I had sprayed everything matt black the other day so it was all ready to build. I fitted the twin tanks which was a bit of a pain. The paint got a bit scratched but of course with matt black you can just spray over it and carry on. I also fitted the rear mudguard. Next step is to fit the bar between the frame tube and the fork stem for the bike tank. I will get that done at work. I also need to fabricate some sort of bracket for the side stand I will fit.
I think with the bike tank and the twin tanks I will have nearly 25 litres capacity for fuel which will be very useful for touring!
