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Frame tube

PostPosted: Sat Jan 23, 2021 8:59 am
by gaz_powell
Can anyone give me the size of the frame tube where the forks go on a GP.
I've aquired a Spanish series 80 frame and want to reduce it to take GP forks
Thanks

Re: Frame tube

PostPosted: Sat Jan 23, 2021 10:10 am
by ULC Soulagent
Spanish is 40 inches
Gp is 37 inches

Re: Frame tube

PostPosted: Sat Jan 23, 2021 11:52 am
by gizmo
Last one I had done by Paul at Oiltek i think he took about 28 mm off fork tube but it was an Italian Li. He also cut it out of the middle and welded a tube inside. This for one reason retains the lip at the top to seat the fork bearing. Same with forks, taken out of middle. Good look. Think Knowledge did a post on this at some point.

Re: Frame tube

PostPosted: Sat Jan 23, 2021 3:16 pm
by Knowledge
ULC Soulagent wrote:Spanish is 40 inches
Gp is 37 inches


Do you mean centimetres rather than inches?

Re: Frame tube

PostPosted: Sat Jan 23, 2021 4:58 pm
by Warkton Tornado No.1
gizmo wrote:Last one I had done by Paul at Oiltek i think he took about 28 mm off fork tube but it was an Italian Li. He also cut it out of the middle and welded a tube inside. This for one reason retains the lip at the top to seat the fork bearing. Same with forks, taken out of middle. Good look. Think Knowledge did a post on this at some point.


Interesting method. As I have a TV200 frame to 'unreduce' it is something I would consider, though I have a complete donor frame so could substitute the whole fork tube. I suppose that if fine threaded taps & dies were available a fully threaded tube could be screwed inside. I'd trust that method if correctly Loctited in place as (I doubt you could ever get them apart!) if they came loose, you'd soon notice via the forks tightening up. Like a steering damper with no steering :lol:

The trouble is with either method is maintaining the "provenance" IMHO because 'matching' of the welds to the size & high quality of Innocenti.

As a consequence, to get fully back to subject :oops: my belief is that Innocenti Li III to Innocenti DL is 25 mm so the 28 mm mentioned would make sense.

Re: Frame tube

PostPosted: Sat Jan 23, 2021 6:00 pm
by ULC Soulagent
Knowledge wrote:
ULC Soulagent wrote:Spanish is 40 inches
Gp is 37 inches


Do you mean centimetres rather than inches?

:lol: yes Martin :D

Re: Frame tube

PostPosted: Sun Jan 24, 2021 1:28 pm
by gaz_powell
I've not got the frame yet, so nowhere near cutting anything yet.
Frame will be jigged, so will getting the cut done then and sort out the steering lock plate.
I ve got the GP forks, leggies and headset bottom.
Thanks for the comments todate.... I'll make sure I don't get me inches and centimeters mixed up... ;)
Another bitsa on the way

Re: Frame tube

PostPosted: Sun Jan 24, 2021 1:34 pm
by gizmo
gaz_powell wrote:I've not got the frame yet, so nowhere near cutting anything yet.
Frame will be jigged, so will getting the cut done then and sort out the steering lock plate.
I ve got the GP forks, leggies and headset bottom.
Thanks for the comments today..... I'll make sure I don't get me inches and centimeters mixed up... ;)
Another bitsa on the way
can't beat a bitsa. Probably most on the road are :lol:

Re: Frame tube

PostPosted: Tue Mar 30, 2021 5:00 pm
by tommy200184
Hi, everybody. Your post is interesting me. I have a li 3 frame converted in GP. I'd like to know if it has been well done.
37 cm is the lenght of the tube with our without the bearing tracks?

Re: Frame tube

PostPosted: Thu Apr 01, 2021 8:25 am
by tommy200184
DL150.jpg

I' ve put the legshield on the frame. I think the tube is too low...
Can anyone confirm?

Re: Frame tube

PostPosted: Thu Apr 01, 2021 11:55 am
by gizmo
Without bearing tracks

Re: Frame tube

PostPosted: Thu Apr 01, 2021 4:33 pm
by tommy200184
Ok thank you