TR 750 or modern aftermarket crankshaft information

[Amboyy]

Hi, name is Steve. Live on the West Coast.

Got a technical historical/possibly modern day question. Were TR750 crankshafts built differently than Water Buffalos? By that I mean was the crankwheel/pin construction different or were they simply uprated with better rods and bearings?

Are any new parts being made for performance?

Thanks.

Steve

[tz375]

As far as we can tell, none of the above. They are different to a street crank in that they run a straight cut primary gear and the right end is machined off.

Good question as to whether or not the big end bearings were different with lighter cages or silver plating. I don't have the answer to that. They do not use the oil linger arrangement of the street motors.

Crank wheels are fully machined but I think they are the same as the GT.

Main bearings are different and look more like GT/TR500 with seals inside a steel "tube"

[Amboyy]

Hmmm. Are the wheels integral pin or pressed pin?

Thanks.

Steve

[Craig380]

I have an article which covers this, which I will try and scan, but what Richard said is correct.

Apparently the TRs used the GT conrods and crank wheels, but the TR main bearings had the seals built in as part of a unit, so the combined bearing/seal units were wider than the stock GT seals. Unfortunately it doesn't state if the big-end and wrist pin bearings were different from the GT.

As an aside, the article does mention that the TR crank, like the stock GT item, was a massively heavy piece of kit. Apparently the factory did experiment with much lighter cranks in an attempt to get the motors to rev quicker, but then the engine lacked torque and "wouldn't pull up the banking at Daytona."

Another anecdote does say that when Barry Sheene was campaigning the TR in Europe, he did use a lightened crank on the faster, more flowing circuits at which good drive from corners was less of an issue.

[tz375]

Hmmm. Are the wheels integral pin or pressed pin?

Thanks.

Steve

Pressed in. It's not a Honda...

[old racer]

TR500 cranks had integral pins,
So it's not to say they didn't try it in the 750.

[old racer]

Amendment to the above,
I should have said some TR500 cranks have integeral pins.