Author Topic: Anyone done a girder front fork?  (Read 13752 times)

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Offline Syscrush

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Re: Anyone done a girder front fork?
« Reply #25 on: March 10, 2010, 10:05:44 am »
I found a local fabricator who's interested in taking this on, so I thought I'd bump my own thread.

My tax refund comes in a few days, with that in hand I'll start talking money with this guy.

Thanks again for all of the info and advice that's come so far!
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Offline JS550

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Re: Anyone done a girder front fork?
« Reply #26 on: March 10, 2010, 02:42:55 pm »
Keep us posted! I would like to see what the cost & design would be.
jim
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Offline madmtnmotors

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Re: Anyone done a girder front fork?
« Reply #27 on: March 10, 2010, 06:22:26 pm »
Have you seen Jeri Springer? (NOT "Jerry")

http://www.jeris-springer.com/home.html
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Offline Syscrush

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Re: Anyone done a girder front fork?
« Reply #28 on: March 11, 2010, 07:00:21 am »
Have you seen Jeri Springer? (NOT "Jerry")

http://www.jeris-springer.com/home.html
Thanks for the pointer.  Springer and girder aren't quite the same thing, but I'm sure that some folks reading this thread will be interested to know about JS!

And of course I'm always interested in knowing what's out there. :)
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FWIW, I'm not a shill for Race Tech - I've just got a thing for good suspension and the RTCE's are the most cost-effective mod for these old damping rod front ends.

Online 754

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Re: Anyone done a girder front fork?
« Reply #29 on: March 11, 2010, 09:09:06 am »
I think there is a good market for a 2in to 6in over girders, with brake mounts.. keep that in mind..
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Offline Syscrush

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Re: Anyone done a girder front fork?
« Reply #30 on: April 14, 2010, 10:11:43 am »
Well, it looks like I just bought this:

Life is precious: wear your f'n helmet!
There's nothing more expensive than a free bike...
FWIW, I'm not a shill for Race Tech - I've just got a thing for good suspension and the RTCE's are the most cost-effective mod for these old damping rod front ends.

Online 754

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Re: Anyone done a girder front fork?
« Reply #31 on: April 14, 2010, 10:18:05 am »
P &P ......from I think Wall Lake ? MI?

 Cool find, looks in good shape..
Maker of the WELDLESS 750 Frame Kit
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Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Syscrush

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Re: Anyone done a girder front fork?
« Reply #32 on: April 14, 2010, 11:44:32 am »
P &P ......from I think Wall Lake ? MI?

 Cool find, looks in good shape..
All I know is that it was made for some kind of Harley but has an XS650 steering stem pressed in now.  It should be about the right length, but I'm expecting it will need some mods to work correctly with my 550 and maintain approximately stock geometry.  Rake should be easy, but I expect it will be hard to maintain trail.

It'll need some work to fit a front wheel, mount a caliper, and fit a new headlight mount anyhow so hopefully the other adjustments won't be too tricky to incorporate.

For the price I got, I'm willing to invest a bit in making it work correctly.
Life is precious: wear your f'n helmet!
There's nothing more expensive than a free bike...
FWIW, I'm not a shill for Race Tech - I've just got a thing for good suspension and the RTCE's are the most cost-effective mod for these old damping rod front ends.

Offline 1080

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Re: Anyone done a girder front fork?
« Reply #33 on: April 14, 2010, 04:40:45 pm »
Syscrush 
 On my P&P girder you change your rake by move the legs to the extra hole.
I could not make out if yours has that as well.

srook

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Re: Anyone done a girder front fork?
« Reply #34 on: April 14, 2010, 08:41:57 pm »
1080
Do you have any more info on that P&P Girder?  I have the same girder that came with a bunch of parts I bought a long time ago.  Are the bushings still available?  Do you know what the spring rate is?  Any info would help me.
Thanks
Scott

Offline Syscrush

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Re: Anyone done a girder front fork?
« Reply #35 on: April 14, 2010, 08:53:22 pm »
Syscrush 
 On my P&P girder you change your rake by move the legs to the extra hole.
I could not make out if yours has that as well.
Good to know.  I didn't take note when I checked it out, I'll see once I pick it up.

It would also be a very straightforward matter to change the lengths of those links - they're not a complicated part to machine by any means.
Life is precious: wear your f'n helmet!
There's nothing more expensive than a free bike...
FWIW, I'm not a shill for Race Tech - I've just got a thing for good suspension and the RTCE's are the most cost-effective mod for these old damping rod front ends.

Online 754

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Re: Anyone done a girder front fork?
« Reply #36 on: April 14, 2010, 08:56:58 pm »
They probably use oilite bushings, easy to find , if not get em made..

 The oddest thing happened to me today,
 got a call, guy said I finally found that springer I told you about.. its damaged.. get there, can see top half.. not a springer..its a nice girder  :o, but bent..


 Says he will dig it out soon and its mine.. free!!   ;D   ;D

.................................................................................

 WARNING... :o

 Beware of setting one up with unequal length links or links not parallel..
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Offline 1080

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Re: Anyone done a girder front fork?
« Reply #37 on: April 15, 2010, 11:16:38 am »
Srook
All I got is what was in the Jammer Handbook from 1981.
I think I had a assembling sheet. I will try to find, but I think it is a slim chance of finding.

srook

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Re: Anyone done a girder front fork?
« Reply #38 on: April 15, 2010, 09:51:09 pm »
1080,
Thanks for the pics.  Those are helpful.  I never knew the make of my girder until the other day when you posted it.  I had taken it apart in the late 1990s and had the trees, links, spacers, and shock parts re-chromed.  I always thought of getting new bushings made but never did.  I am considering getting them made and bringing this thing back to life.  I love it when a post re-kindles parts of a project.
Thanks
Scott

Offline 1080

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Re: Anyone done a girder front fork?
« Reply #39 on: April 16, 2010, 08:24:16 am »
srook

You are in luck, I found my girder instructions ;D
If you need a larger file I will e-mail them to you.

Offline Syscrush

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Re: Anyone done a girder front fork?
« Reply #40 on: April 19, 2010, 12:16:08 pm »
Beware of setting one up with unequal length links or links not parallel..
Understood 100%!!!  Don't want the front wheel kicking out or in when you go over any kind of bump.
Life is precious: wear your f'n helmet!
There's nothing more expensive than a free bike...
FWIW, I'm not a shill for Race Tech - I've just got a thing for good suspension and the RTCE's are the most cost-effective mod for these old damping rod front ends.

Offline Turbogrimace

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Re: Anyone done a girder front fork?
« Reply #41 on: May 03, 2010, 06:33:00 am »
The P and P's are good girders.  Simple to work on and adjustable.  The shocks are 12" long and can be replaced with a newer HD shock with minimal effort.  The HD shock, however, may be a bit more stiff than you'd like. 

The bushings are oilites (.5 id .625 od i believe).  They also used nylon washers between anything that wiggled. 

I dont know much about the stock bolts on the rocker studs, but I used an acorn nut and a jam nut on mine so I could adjust the force on the joints.  I did this because it's easy to tighten the crap out of them and lock up the front end from moving at all. 

The extra hole behind where the lower rocker mounts to the legs is 5* internal rake.  That will reduce your trial quite a bit.  Dont use it unless you're raking your bike out.  I believe the offset from the neck on the P and P is 5".  So that's already going to drop your trail if you keep stock rake in the neck. 

A lot of the P and P's were made with 7/8" sporty stems.  It's relatively simple to get a stem made that fits your neck and then use spacers between the bottom tree and the lower neck cup to make the rockers parallel.  The stem threads into the lower tree.

Online 754

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Re: Anyone done a girder front fork?
« Reply #42 on: May 03, 2010, 08:28:55 am »
I have a fairly complete Indian Leafspring girder kicking around that is fairly complete..  bars have been cut off the tree. I picked up a set of Chief Bars this weekend with internal controls, and stock switches! Also am suposed to get a cut off set which may graft on. If not I can make a top tree for risers, run Flanders style rubber mount risers up to the Chief bars!

 Anyway, was just thinking I have a buddies Amen frame sitting here the leafspring would look cool on there. May have to graft an inch or two into the girder. I have a rough rear leg assembly here I could use for that.

 I think it would look cool with a hanging gas/oil tank, and hinged back fender... ala 101 Scout..
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My next bike will be a ..ANFOB.....

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Offline Syscrush

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Re: Anyone done a girder front fork?
« Reply #43 on: August 04, 2010, 10:48:56 am »
Bumping my own thread again just to talk about the aesthetics, engineering, and philosophy of girders. :)

I'm still in the planning phase for my 550, but did buy that P&P pictured above.  It'll need some work to make everything fit, but it was a good deal and should serve as a good starting point.  I'll be replacing the shock with a unit custom-made for my application, and will do some tuning to the geometry to get it as close as possible to stock.

One thing I'm surprised at, though, is that people seem to assume that running a girder automatically makes the bike a chopper or a bobber.  I am planning to have the girder up front and a monoshock conversion on the rear (with a triangular brace on the swingarm and a linkless shock setup running to the frame's backbone - Vincent or 900SS style).  I expect that in addition to looking good, the girder should be stiffer and possibly lighter than the stock setup, and will definitely have better damping due to the modern shock sprung and valved for the bike.

In my mind, this will be a cafe build, and I don't see anything about going girder that makes the bike any less of a cafe racer...  One guy I was talking to said something about the front end being old-fashioned and a mono conversion being modern seems like an odd combo.  To me, the girder isn't particularly old-fashioned (Britten, Foale, and Cramp have amply demonstrated), and the linkless rear suspension I have planned isn't particularly modern.

The combo seems to have worked pretty well here:



So... Thoughts?  Can a girder setup work with the minimalist cafe look if it's done right?
Life is precious: wear your f'n helmet!
There's nothing more expensive than a free bike...
FWIW, I'm not a shill for Race Tech - I've just got a thing for good suspension and the RTCE's are the most cost-effective mod for these old damping rod front ends.

Offline scunny

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Re: Anyone done a girder front fork?
« Reply #44 on: August 04, 2010, 11:46:29 am »
can't get more cafe than the temple anzani
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Online 754

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Re: Anyone done a girder front fork?
« Reply #45 on: August 04, 2010, 08:50:11 pm »
That is a Harley J springer fork, or a copy thereof..
 The conniving Brits, copied it and called it a Castle fork..
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My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline scunny

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Re: Anyone done a girder front fork?
« Reply #46 on: August 04, 2010, 09:04:07 pm »
ooops, I'm off to read up on suspension types, in the meantime I'll see if I've got any decent pics of the Britten, pity I didn't have a camera when he was building it
past-cb100,ts250,cb500,cb500,gs1000,gs650g.phillips traveller
present-CB 650 retro
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Offline bradweingartner

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Re: Anyone done a girder front fork?
« Reply #47 on: August 04, 2010, 10:11:07 pm »

So... Thoughts?  Can a girder setup work with the minimalist cafe look if it's done right?

Yes. I'm loving it. A big fan of the Britten.

I think if it's done it needs to be something different from the chopper girders in design.

Either a frame like the choppers but 'skinned' so as to appear as one solid part.

A Billet Machined upright.

Or, a large diameter main tube.

To me, the skinny tubes on a typical chopper girder would look very out of place on the front of a modernized cafe-style bike.

But in concept, it's awesome. I'd love to experiment.

Offline Syscrush

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Re: Anyone done a girder front fork?
« Reply #48 on: August 05, 2010, 05:42:30 am »
To me, the skinny tubes on a typical chopper girder would look very out of place on the front of a modernized cafe-style bike.

But in concept, it's awesome. I'd love to experiment.
Here's what really got me thinking about it:

Life is precious: wear your f'n helmet!
There's nothing more expensive than a free bike...
FWIW, I'm not a shill for Race Tech - I've just got a thing for good suspension and the RTCE's are the most cost-effective mod for these old damping rod front ends.

Online 754

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Re: Anyone done a girder front fork?
« Reply #49 on: August 05, 2010, 08:22:47 am »
The main problem as I see it is decreasing friction on the moving elements & tightening clearances, to provide good rigidity.. which may mean needle bearings.

 Curious note, when HD re-introduced the springer. They ran in through their computer design equipment for analysis, to find ways to improve it, the only thing they came up with was changing pivot points to needle bearings. In other words it was already a very good design, still in use today. When they started making them again, they had less stiction than any other fork.

 Go for it.. Tele-forks, even upside down, have gotten too familiar..
Maker of the WELDLESS 750 Frame Kit
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Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

 

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