1960's spaceliner springer forks

srdavo

Well-Known Member
Joined
Nov 4, 2006
Messages
3,161
ok...gearheads....here's some q's for ya:

here are some pics of my sears spaceliner bike, with my trike in the backgound.....exact same forks.



now...notice on the spaceline, I've flip-flopped the rocker plates, so the upper legs of the springer do not cross anymore. this has lowered the frame 2+ inches & moved the front wheel forward 5 inches.



now, guys....will my fork function properly like this ? or am I looking at problems? Handling? Dangers? weakness?



talk to me, you gearheads.

tia,
davo

ps. Yes....I flipped the handlebars over for that board track-ish look. :LOL:

looks cool, but isn't comfortable for an old guy who likes to sit upright.
 


D

DougC

Guest
The handling will be dangerous.
The bike probably only had about two inches of trail to begin with, and you have eliminated that. The front wheel will no longer be automatically self-centering like it should.
http://en.wikipedia.org/wiki/Bicycle_and_motorcycle_geometry

The angle of the head tube and the fork's rake are inter-related to produce the proper amount of trail, so that the head-tube's axis intersects the ground a couple inches ahead of the center of the tire's contact patch. This is what makes the front wheel naturally self-centering. If you really wanted to run the forks that way, you'd need to modify the frame to lean the head tube angle back few degrees more.

The RANS Fusion for one uses a fork with about twice the normal amount of rake (the forks are "bent forward" more than normal) but the head tube angle is more laid back--so for that bike it's proper:
http://www.ransbikes.com/Fusion07.htm
(below is a link to a picture of a "normal" bicycle, for comparison)
http://www.sunbicycles.com/sun/bicycles/cruiserBikes/retroCruiser/retroCruiser.htm
~
 

srdavo

Well-Known Member
Joined
Nov 4, 2006
Messages
3,161
Thanks DougC, for explaining this to me & the wikipedia link.

(Old Dogs can learn new tricks! :LOL: )


I'm taking the spaceliner apart to prep for paint. The chrome is too far gone. When I reassemble, I will put the springer back to it's normal form.

thanks again.
 
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