Topic: Cut/modify frame to remove top end ?

[CR750]

Who of you guys - racing a cb750 - have modified their frame, or cut it ( and put a Gordon frame kit or such in ) in order to be able to acces the top end / remove it, without removing the engine ?

I myself am leaning towards a dohc750 style frame mod for the lower two tubes from the top of the frame, as it 'feels' better in terms of rigidity compared to the Gordon thing... something along the lines found below.


Yes, I need to use a modified tank(-bottom) I am aware.. I can bend, Tig/Mig weld in-house,  and also have a lathe and mill etc for inserts. So that can all be sorted.

But before I commit to that plan....any thoughts, tips, opinions, first hand experiences ?

[754]

 I at first was building a die to bend tubing, to do something similar to what you show.
 But to be able to sell them, and have to modify your tank to use, cuts most people out of  going that way.
 But you have the means, so go for it. If you can find a heavily damaged Auto tank, you may be able to salvage the tank tunnel.
 If you want more fuel capacity, Auto tank may be the way to go..

[turboguzzi]

riccardo races his 750 with the straight tubes / removable bolted kit, doesnt seem to slow him much according to his lap times. dont know how crazy he is with the latest events here, will tell him to drop in for details.

[Medyo Bastos]

I at first was building a die to bend tubing, to do something similar to what you show.
 But to be able to sell them, and have to modify your tank to use, cuts most people out of  going that way.
 But you have the means, so go for it. If you can find a heavily damaged Auto tank, you may be able to salvage the tank tunnel.
 If you want more fuel capacity, Auto tank may be the way to go..

The matic frame allows easy top end removal, but finding an appealing tank is tough. I took an F Tank skin and put onto a Matic tunnel. Fits like a glove!





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[livefast_dieold]

riccardo races his 750 with the straight tubes / removable bolted kit, doesnt seem to slow him much according to his lap times. dont know how crazy he is with the latest events here, will tell him to drop in for details.

Hey Yoss, I'm actually using a dohc style bended tubes :-)

There's enough space to add to downtubes to stiffen the whole area

Btw the mod was done using the original tubes bent upward

[CR750]

Good info guys, thanks for the pics.
Confirmed my plans; some grinding and welding coming up !

@ ric that rear wheel looks familiar 

[turboguzzi]

ok, bad memory..... was going to add "if i remember right" but then thought, damn, im not that senile.... well, looks like I am!

[CR750]