TR750 frame

[busa1300]

Anyone out there attempted to build one of these frame kits from a donor GT750?
I'm considering this route over my preferred thought of a RZ500, since RZ's have a pretty high buy in price....and none are original or clean that are remotely affordable. ......provided I can get rid of my NSR soon
Could a GT750 put out compare able power to a good running tuned RZ.....

[aslsmm]

i am talking with dennis curtis, eric K and kris bernstien about my tr750 street bike build. so i can lend a hand as far as what i have been told and read on google.

basically modifying the gt750 frame is a no no because it is just too heavy. they are better to be made from super light weight steel. CMR racing has these kits in stock. you can buy a tr750 in a box minus the engine for about 10K. that includes gas tank, frame exhaust and all the nuts and bolts. axles can be made to your spec. so can fork bearings.

as far as performance goes, i am not too familiar with rz 500 performance but i know if you have the cash you get a tr 750 to flat out fly. some where in the 140hp to the wheel i believe is what i read. dont quote me on the number. you will need to get a tr750 crank built, tr750 cyl built and the 6 spd close ration tranny. all in all you may be looking at the 20K-ish price range to do a tr750 super bike build. hope that helps. i will be in mine about 15k and thats with an estimated 80RWHP. there is alot of custom machining needed to get the power of the daytona bikes.

[pearljam724]

PM sent.

[busa1300]

The CMR kit, is a bit expensive....but it is closer for shipping, than the PHW frame I have been checking into. I'm thinking 80-90RWHP is where I want to be with finished bike. Not for track days, but for making noise and having fun every now and then. A hard core cafe racer....with no fairing... If I were to spend over $10,000.00 either direction though, I think the RZ would be the choice then....it's always been the one that got away.

[tz375]

For a complete replica TR the investment would be huge and not very useful for most of us. The engine is the easy part. Mine makes 80 hp with relatively minor mods and 80-90 is very doable. Back in the day a TR750 reportedly made in the region of 100-115HP at the crank. Pipe and port designs were pretty good for the time, but modern software allows tuners to get more HP than the factory - that's the benefit of time and technology. For a full on race bike it is possible to get close to 150HP at the crank but it would be all but unrideable on the street.

For a street motor there are a couple of paths to 80-90hp and that involves minor modifications but takes quite a lot of time. Obviously the motor needs to be sound. They are incredibly heavy motors though. As I mentioned earlier, my street bike that I take to the drag strip makes around 80HP and getting another 10 to 20 HP is not too hard. And mine runs stock CV carbs. Round slide cabrs require some machining and welding to the block to tilt the carbs up so that they clear the motor or an adapter block, but that's less elegant. The more it has to look like a genuine TR, the more work is involved.

In the real world you don't need a $10k chrome moly CMR frame for a street bike. But I suppose, that in that same real world none of us actually "needs" a bike so that's arguable. A stock 750 frame is ungodly heavy for sure, but that shouldn't be a job stopper. It is relatively simple to make an early High Boy type replica that looks the part without a huge cost - but it does take time. The more you can do in house, the cheaper it is. Forks and wheels are not complicated and brakes can be updated if absolute TR originality isn't necessary.

Again, just as a point of reference, my bike with water, oil and half a tank of gas weighs in at around 445 pounds. A further 10 pounds wouldn't be too hard/expensive.

A later year low boy needs a completely new frame though. That said, check out the custom bike that Suzukidave created. His frame looks a lot like a Mk2 TR750 but with monoshock. You could easily make similar modifications to the main frame cradle and could replace the rear end with chrome moly tube to save a couple of pounds.

Or you could contact Framecrafters in Woodstock IL and talk to Randy or Kartsen. They can make a whole new frame and swingarm and tank at a reasonable cost.

You could also look at slipping a motor into say an FZR1000 chassis or maybe an early GSXR chassis or RF600R and start off with modern suspension and wheels a ton less weight.

It all comes down to how much you would do yourself and how close to original does it need to look. A tribute bike/hot rod is much easier and cheaper than a full on replica. Do you have a donor bike ready to sacrifice to the cause or does that need to be acquired too?

[busa1300]

The engine does not need to look like a replica....nor the completed bike in my case. I wanted the TR style frame, just to have a much better foundation for a period looking cafe racer. I have a bone stock GT750, and it's fine to ride around on,...... but I want a better performing GT motor, in a better chassis that matches the engine, to play harder.

One question I have wondered about on the upturned carb issue...for bigger carbs. Why couldn't a set of GS1100 intake boots be used on 73 up heads and bolt on a set of 34 round or flat slides?...just angle the boots up instead of to the side as they are on the GS......

I have a 72 frame from a parts bike, and just picked up a late 72 complete engine, which needs a total rebuild. But that is all I plan on using for the project from GT750 parts. After looking at the frame.....I really want a lowboy style over stock. I will do all work except machine work on bores and crank rebuild.

a few pics.....
http://www.rzrd500.com/phpBB3/download/file.php?id=377" onclick="window.open(this.href);return false;"

http://www.rzrd500.com/phpBB3/download/file.php?id=376" onclick="window.open(this.href);return false;"

[Suzukidave]

How did you get that engine into that trunk LOL but if you do decide to convert the stock GT frame to a TR style first thing you need to make is a jig to attach the stock frame to before you start sawing off the upper frame . We made a jig out of scrap I beam so i could solidly attach the frame at the neck and the swing arm pivot https://www.google.com/search?q=buildin ... =993&dpr=1" onclick="window.open(this.href);return false;

[busa1300]

How did you get that engine into that trunk LOL but if you do decide to convert the stock GT frame to a TR style first thing you need to make is a jig to attach the stock frame to before you start sawing off the upper frame . We made a jig out of scrap I beam so i could solidly attach the frame at the neck and the swing arm pivot https://www.google.com/search?q=buildin ... =993&dpr=1" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

Do you have a link to your SRAD framed bike?

[Suzukidave]

I think this is the only one viewtopic.php?f=21&t=776" onclick="window.open(this.href);return false; the rest is is a bunch of pictures stored on my computer

[Suzukidave]

Ah .. one more http://2stroker.createforumhosting.com/ ... t1246.html" onclick="window.open(this.href);return false;

[Suzukidave]

Been giving it any more thought on a frame ?

[busa1300]

I think with an engine of this vintage....I'll keep it a steel tube with 18 inch wheels. The thought of a newer sport bike aluminum frame that is easy to locate, as well as much better initial handling abilities, is a definite plus. But it's like a flat head ford in a mustang...coming from a automotive past (my dad had a speed shop in the 60's, so I was chewing on old spark plugs since birth)
The SRAD is a better platform to get the best of the engine, but I'm going the old school route, after thinking more on what I really will be expecting out of the bike. I do like the way you incorporated the old GT frame to adapt to the SRAD... Have you had a chance to ride it yet?
If I had say, a Kawasaki 800 twin jet ski engine, tied to a harley trans....the new sport bike aluminum frame route would be perfect for me.
I have e-mailed the guys that build the frame pictured above, numerous times the past week or so. With no response on shipping costs or a kit price...1000 sterling was the quote on the frame. That price would be hard to beat even if I welded the frame myself....which I still might do in some form, incorporating the original.
Thanks for a deeper look into other possibilities.

I do know I want the cross through exhaust....it's just too cool.

[Suzukidave]

The Suzuki Katana " steel " frames are another possible way and they are wide enough to fit in the GT engine but then wouldnt give you the classic look i think you are looking for .

[tz375]

Ron Moolenar (Sp?) built one with a little help from Cor Geraets http://2stroker.createforumhosting.com/ ... t6105.html" onclick="window.open(this.href);return false;

They started with a stock GT frame and essentially changed out the side rails and rear end and it looks very credible. Framecrafters could do something like that with your frame at a reasonable cost. There was some daram between Ragged Edge, Pete O'Dell and others on the UK supplied replica frame and I cannot recall who did what to whom and who owns the jigs etc.

Scroll through Ron's pictures through the links on NATS to imageshack and you will see a couple of the frame.

[busa1300]

The engine mounting lugs look like original GT....but the rest looks all new/TR style
I've seen this a few times before...very beautiful bike...the exhaust is a must.
I'm looking at something on this theme/period look....yet not as serious,but naked and street ridden..
Framecrafters is not that many miles from me.... I may e-mail them tomorrow on their possibilities, I'd at least save a little money on shipping in that case.