FL Front End

[tomo256]

Hi Guys.
I have posted a thread on the custom section of the forum regarding springer front ends. I have a problem in that i have a FL front end on my rigid frame which has a negative rake( by this i mean that the yolks pull the wheel closer to the bike ) and i want to fit an inline set of springers, but i do not know the negative rake in degrees so that i can adjust the length accordingly to compensate for it. Or do you think it will not make much difference. Hope somebody can help.

Regards

[bazereid]

What rigid frame have you got? Is it an 1940s big twin frame or an after market custom? If it is a factory big twin frame, springers should fit straight in and work fine. The head stock castings were the same from the rigid Panheads up to 1970s Shovels.

[kiwidave]

If the springer fork is the same length as the FL set-up, the front of the bike will sit lower obviously......I am guessing that will, like with my bike, far improve the way it looks as the bottom frame rails will finally be more parallel to the ground.

I just took off my FXWG some horrible FL trees that some idiot previous owner installed. I have fitted orig factory yokes (they came raked 3deg.....) AND 3deg raked bearing cups (these restore trail lost with the rake in the trees, so it's safe) ...... all to have the bike sitting low with bottom rails parallel to the ground. I am not expecting any handling issues ...... they don't move round despite some physics-based theories I have seen ....and it looks a HELL of a lot better.

If you fork out for a costly springer and then find you want the front end kicked out further still, the raked cups do the job. Do a search for Vulcan ... i recently posted a link on where to get them direct from makers.

[Kiwi]

its basic trigonometry, you need to work out what the trail is to see what effect the changes will make.

I could explain it properly on paper but in narative its a bit difficult

in short you are looking at the distance between centreline of the fork spindle hits the ground and the point vertically down from the centre of the axle

usually this is around 4", more = more high speed stability less = quicker handling and negative is a complete **** up

[tomo256]

OK Guys . I understand the raking cups and how they work. But has anybody got any experience of them and can you reverse the action of them or can they only be fitted one way, by this i mean use them to take out rake and make the trail of the bike shorter.

Regards

[Kiwi]

no problem just fit them back to front or upside down

[bazereid]

Check out the parrallel thread in the custom section. The photo and postings should help Tomo out with his question.