750 GT SEAT PRONGS

W

whitedog

Full member
Evenin' all
I'm completing a restoration of a 750 GT (1969) and would like an opinion on the seat prongs on the
Frame. I either have the wrong seat pan or the prongs that would hold the front of the seat in place have been amended in the past. Attached pic.
 
very early twins did not have seat "spade lugs" but a drop on arrangement perhaps that is the problem, if you have a drop on seat it is probably worth more than the whole bike.
CLEM
 
Hi Clem,
Thanks for the information.
Having trouble resizing photo. Just downloaded an app to resize photo
So will post shortly.
My seat has two rubber bushes inside two metal cylinders at front of seat.
But bear no resemblance to the two spear shaped lugs on the frame
My picture will explain all (hopefully)  :D
 
To go along with what Clem said, the early pans were also longer than the standard SF. My SF is an early one that has the longer seat base too. And like Rob said those tangs are suppose to be down near the frame so the seat can slide into them.

Clay
 
Not sure David, my serial number is 4334 and from what I can tell it is like all the later SF's except for some different brackets welded in different places. There are some on here that know a whole lot more about the 750's and the little things done that made each a little unique. But those seat tabs being bent up like that I have never seen anywhere in any picture. I have been researching and restoring (trying to at least) my SF back to factory original and am using pictures of Gert and Bertrand's machines to see what was suppose to be where. I just bought a manual for an American Eagle 750 that might show some of the fittings and such for yours unless there is a big difference between it and a GT.

Clem, do you know when the seats switched to the spaded ones like I have?

Clay

 
American eagle handbook is a good idea. Will have a look for one
I think the early GTs (like the eagle) have seat tubes that are 22.5 cms
As opposed to the later ones (I think including the SFs) which were 20cms.
But I'm no expert either. When you finish your restoration, I will be interested in
Seeing the results. I was hoping to have mine ready for the Laverda weekend in
September but it seems unlikely now. Will post some pics once finished
Good luck with the restoration and research
Regards
David
 
Hi the change was between 1968-1969 when the spades came and the bike called GT ,first it was just 750 and the seat on GT are wider and longer than the rest of the 750:s.
 
Very early wide frame GTs had seat prongs made of round bar (8 or 10mm dia.?).  The seat pan had appropriate (round) fixtures.  This was altered to the flat prongs used till the hinged seats were introduced.  Not sure if the round prongs were kept till the frame width was altered.

These early GTs also had the rear of the tank held down with 2 hooked springs, as opposed to the later rubber band.

piet
 
How are the prongs supposed to work please, are the supposed to slide behind the fibreglass?
My seat has prong shaped holes, a bit of metal screwed to the back makes it secure.

 
Olly,

Your seat is fucked, and has been "repaired". ::)

The prongs are normally parallel to the frame, about 10-12mm clear of the top rail.  The seat should have only a slot to the front of a lowered part in the fiberglass, this slips over the prongs.  The seat is only loosely located by the prongs, rubbers in the seat base afford secure seating on the rails and the rearward bracket bolts to the frame.

Might post a piccie of an intact seat when I return from my evening stint... :D

piet
 
Oi!  :'( I made that temporary repair.  It works an absolute treat, nice and snug under the prongs.
It'll be a right pain to fix it up with fibreglass I imagine.
I do need mix some up though as the back is bit cracked where the hump's horizontal meets the vertical at the back.

Interested to see what it should look like though...thanks
 
If the prongs aren't low and parallel with the frame, I would worry about them pointing upwards through the seat foam and piercing something precious !!

Cheers,

Rob
 
Dellortoman said:
You might be able to make that metal bar work better with the seat prongs if you crank the ends down a bit so the (horizontal) seat prongs can hook behind it.
Click to expand...

I put the bar on because even with the seat bolts done up pretty tight, if you pressed hard on the back of the seat the front would pivot round the bolts and pop up.

You're right,if the bar went a bit in the holes left by the prongs then it would be tighter but as it is now there's very little movement.  I haven't got a mill so neatly thinning the middle but would be tricky.
 
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