Author Topic: Aftermarket frame - group purchase  (Read 27603 times)

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Offline Tintop

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Re: Aftermarket frame - group purchase
« Reply #175 on: June 28, 2020, 05:53:32 pm »
I'm taking simon#42's comment to mean - changing rake from the back also introduces changes to many other variables, so if you want to change rake do it at the front (triples?).  It's the old adage, 'only make 1 change at a time".
1977 CB550/4 Cafe - Speed Warrior / BOTM 03/11
1980 CB750F (project)
Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
1976 CB400 SS - stock / BOTM 04/11 (SOLD)
1973 CB750 K - basket case (SOLD)
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Offline livefast_dieold

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Re: Aftermarket frame - group purchase
« Reply #176 on: June 29, 2020, 01:58:34 am »
I'm taking simon#42's comment to mean - changing rake from the back also introduces changes to many other variables, so if you want to change rake do it at the front (triples?).  It's the old adage, 'only make 1 change at a time".

In that sense I agree, any change in rake needs to be balanced with a change in trail as well, if this was the sense of his comment

Offline simon#42

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Re: Aftermarket frame - group purchase
« Reply #177 on: June 29, 2020, 09:44:01 am »
tintop has understood me perfectly .  if you raise the rear of the bike to alter the rake it will have other effects . first it will raise the centre of gravity which will make the bike harder to roll ( lean from side to side )  it will also make the bike pitch more  ( dive under braking and squat under acceleration )  second it will alter the wheelbase ( very slightly shorter ) thirdly you will raise the swinging arm pivot which will cause the bike to squat more under acceleration ( which will alter the rake and soak up power as the engine works against the suspension ) . some riders will notice this and some wont but it will be happening regardless .

Offline westfieldandy

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Re: Aftermarket frame - group purchase
« Reply #178 on: February 06, 2024, 06:07:11 am »
At www.good-bits.co.uk we have been quietly working on new chassis for the smith honda F750 race bike. The new chassis is awaiting final approval for UK championship status etc, and we intend to have complete bike ready for some races next year.

The frame is available to order now. if anybody would like one. we have jigs already manufactured

For F750 rules the frame has to look the similar to original road frame, so it is twin shock etc, but the tubing used is lighter and more rigid and slightly larger in dia. we also took the opportunity to change the geometry of the chassis, and use a period looking box section swing arm in conjunction with new magnesium front and rear hubs to get rid of as much weight as possible.  This will be the best way forward to create a competitive machine, the std chassis/running gear is just not good enough to cut it with the rob north framed triples fully developed in todays championships

The frames are made here in uk by an established race frame manufacturer and are a real thing of beauty.

Frame and swing arm kit is £3600

I would love to get some out there running in f750 classic racing. and would consider some kind of support package if a good rider commits to a full championship.

andy

Andy,

Nice to hear about your frame project.  I’d love to see pictures of your work at some point.

George