Suzuki GT750

Discussion in 'WERA Vintage' started by r47sniffer, Jul 31, 2009.

  1. r47sniffer

    r47sniffer Member

    Hey guys, I wondered if anyone has any experience of running a GT750 in Formula 2 stroke or V5? I'm still getting through the rules before I start modding anything. maybe someone could let me know what can and can't be done for these classes? For formula 2 stroke can you use a purpose built frame and modern suspension/brakes? I'll be putting something together for the smaller classes first and this is a longer term plan along with a Harris GSX1100.

    Any help appreciated!

  2. footwork

    footwork Honda Research Analyst

    Brad Morrison runs a Seely(i think) GT750 at Summit Point on occasion.... who knows more about this?
  3. r47sniffer

    r47sniffer Member

    Thanks Buff, there has to be someone running GT750s. I'm just starting my 350 V1 Honda too so I expect I'll be in touch quite a bit. I haven't raced since '03 and it was 25 years before that!

  4. hinshaw929

    hinshaw929 Well-Known Member

    Build the bike to F2Stroke rules and it can legally bump up to V5. You can use a custom or specialty tube frame but twin spar aluminum frames are prohibited. USD front forks up to 43mm are allowed with conventional 4 piston brake calipers and monoshock rear suspension is allowed. 17" wheels 3.5" front and 5.5" rear are allowed along with slicks.

    Since it is a Formula class you can use items such as magnesium wheels and TI fasteners if you like.

    A GT750 will need to go on a serious diet to run at the front. :D You might want to do a little research about the factory race version from back in the day - the TR750 - to give you some ideas.
    Last edited: Aug 1, 2009
    Rich Graver likes this.
  5. charles

    charles The Transporter

    About 12 yrs ago, I had a Barton Motors-prepared TR750 (on loan from a friend in the U.K.), the real deal, and I took one lap around at Summit Point during practice and promptly parked it...hats off to those who mastered it...much much too heavy, but power was there, not a screamer, just a good strong steady'll have a difficult time trying to duplicate the Barton specs (motor, gearbox, clutch, etc). Info on the Barton spec machine is readily available on 'Google.'

    Why not go the Kawi triple route like Jim, or...try something different and build yourself a Yam triple, either air-cooled or water-cooled? I've got some details around here somewhere...
  6. r47sniffer

    r47sniffer Member

    Thanks Jim, I well remember the TRs racing with the Heron Suzuki Team back in the 70s, I know the H2Rs continued a little longer and were further developed and I have seen quite a few GTs with modern style frames used on the road. I thought that V5 allowed stock frames only and was wondering if that included the swingarm? I have one I am working on with a GPZ550 front and rear suspension though it would run narrower wheels at 18". At least I can run this on the road legally to get a decent motor tested.

    The way to go is with a clean page with the mods you mention. Anyway, it'll be an interesting concoction that should work in theory!:eek: I may never get close to you quick boys but it'll be fun trying!

  7. hinshaw929

    hinshaw929 Well-Known Member

    Forgot about your Barton adventure.

    V5 is the "bump up" class for F2Stroke so any bike legal for F2Stroke is legal for V5. You can use an aftermarket swingarm in either class.

    Charles has pictures of the Barton TR750 if you want to pursue that.

    In your part of the world the man to beat most weekends will be Tommy D on a reed valved Kawi H2. Most of the other bikes in the class will be Yamaha RZs and TZs.

    I will warn you in advance that everyone else in WERA vintage considers the triples guys complete nutters. :D
    Last edited: Aug 1, 2009
  8. r47sniffer

    r47sniffer Member

    Hi Charles, was the TR you used in the 74/75 Team Suzuki colours? It may have recently turned up in the UK and is being rebuilt. I could have a bash at the GT380 like the Sparton though I reckon the 750 offers more options since I have a few kicking around ( I bought a load of cheap runners/non runners, I'm working on a CB350 and a DS7/TD3 right now) An RZ with Banshee motor would be what I'd build with unlimited funds for the Formula class........hmmmmmm;)

    I just want to make the right decisions before spending time and money and ending up with a white elephant so all comments and any advice is really great.

    Thanks, David
  9. r47sniffer

    r47sniffer Member

    Looking at this would you say it's legal for F2 stroke as it's a tube frame isn't it? (Not mine I hasten to add!!!!) If the forks are 43mm with 4 pots then this is legal?

  10. eightforty

    eightforty Member

    look halfway down

    I've seen the bike Denis is building, with custom chambers and aluminum tank. Nice set up! Ask him for updated photos...

  11. hinshaw929

    hinshaw929 Well-Known Member

    The forks are designed for radial mount calipers which are not legal in vintage.

    I think the frame would be legal as Spondon built that style in the 1980s. To my knowledge no one built any swingarms like that in the 1980s so my guess is it would be protested. Strictly my personal opinion.

    As a rule of thumb if you don't have documentation of what you want to do dated 1985 or earlier then you're taking a chance.
  12. charles

    charles The Transporter


    A proper approach...consider a Yam RD 350/400 and be advised you can build a substantial RZ350 without the Banshee stuff...mainly, have something that is reliable and allows you maximum track time. And remember: if you do decide on a Twisted Triple, yes, people will think you're a nutter and a maniac, much like the Ol' Georgia Dawg.
  13. r47sniffer

    r47sniffer Member


    I think the Cagiva 500 and the Heron Suzuki TSR05 had similar arms to this, just braced underneath on the Suzuki, plus a number of endurance racers probably did.They definitely used fully floating systems then. Anyway, it's not that I can build something so exotic, just finding out what can be done! The operating priciple is the same as the Full Floater and the arm is an alloy design which existed then? There were also a few single siders about then so using RC30 stuff may be OK too? I'll ask the rules peeps to see what they say.

    Thanks ,David
  14. WERA33

    WERA33 Well-Known Member

    the frame may get a protest as i dont believe spondon made the frames like that in the day. not sure it would qualify as perimeter type epecially with the beefy allloy rear portion.

    No need to start an arms race and make the class out of reach of too many people.

    that particular frame of course would be pretty pricey..thousands new.
    if you look at a spondon tz you'll see the diff.
    i believe bob may have one. i think kris bernstein has one also as well as a seeley framed gt750.
  15. r47sniffer

    r47sniffer Member

    I'm happy riding something of the period design (I don't think the standard frame is up to the job) though I wanted a monoshock and fitting 17 inch wheels with decent brakes in order to be competitive in the class. Spending stupid amounts of money isn't possible nor in keeping with the whole thing for me anyway. I looked at Seeley style frames and Moto Martin amongst others which should be a lot better. I'll be coming along to one of the meets where they are run to take a look as there were none at Mid-Ohio.

    I doubt I'll be quick enough to warrant any protests!

  16. r47sniffer

    r47sniffer Member

    I decided on a GT750 in a GPZ900 frame in the end to get something that should work and doesn't cost a fortune. I think that's within the rules isn't it? The GPZ is a 1984.

  17. PaulMB

    PaulMB Catman

    Is it this one?

  18. Chumbucket

    Chumbucket Well-Known Member

    OK, that's cool...
  19. mgmark

    mgmark George Tirebiter for President

    Denis Curtis is making a TR750 replica frame, very nice work.


    Mark Badger
    Last edited: Jan 17, 2010
  20. yam rookie

    yam rookie Member

    The GT750 motor fits real nice in a Katana chassis, with mono shock.

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