Tweet
Both bikes have seen pretty much the end of their production cycles, with the Katana's last year being a small batch of 2007 models for certain markets (Brazil, possibly New Zealand), while the TZ's final batch was a miniscule 18 units produced for 2008! Both use 17" wheels with a 120 width in the front. Both take over 5 US gallons of fuel in their tanks when filled all the way. They both have fairly low compression ratios (the TZ has even lower compression than the Kat). Both use Mikuni carbs in the 36 to 38 mm range, one per cylinder. Both have six-speed transmissions and dual 300mm front brake rotors and a single rear brake rotor.
Both effectively started their lives in the three decades earlier and morphed over the years from there, growing more aerodynamic fairings and having big changes in the '96-'98 time frame.
In the left corner, ladies and gentlemen, producing 39 ft-lbs of torque and 79 HP, I am proud to introduce the Yamaha TZ! In the right corner, producing 42 ft-lbs of torque and 71 HP, is the challenger, the Suzuki GSX600F, known as the Katana 600!
Not incomparable numbers, right?
Ah, wrong.
The TZ clocks in at a flyweight 227 lbs dry and only has 250 cubic centimeters of displacement in a racing two-stroke form. Geared for the NorthWest 200 (an Irish race), it tops out at 168 miles per hour in the real world on real-world roads.
The Katana flattens the scales at 468 lbs dry and uses 2.4 times as much displacement (599 cc). It tops out more than 30 mph slower than the TZ.
OK, if Yamaha can engineer the TZ to produce those kind of figures (neigh-on-80-HP, 39 ft-lbs of torque, 227 lbs dry), where's the catch and why aren't we all zipping around on TZ250's?
Well, first of all, that kind of power out of a 250, even out of a two-stroke, means that the replacement intervals suffer -- massively. In standard form, the TZ would make it 300 miles between replacing pistons; in this hyper-tuned '08 race form, it only makes it 140 miles between piston replacements. The crank on the TZ also goes from a 700-mile life-expectancy down to only 450 miles before it's due for replacement. Can you imagine yourself down in the garage replacing the pistons and crank on the Katana because you went for a weekend rip around the hills with the boys?
The Katana will roll through 100,000 miles without a hick-up with daily use and minimal servicing (oil & filter every 3500 miles, valve adjustments every 7500 miles, air filter every 11k miles).
Then there's the carbs. To wring that kind of power out of the TZ250, you better be a wiz at changing jets, carb nozzles, float heights and settings every time the weather changes (looks overcast, humidity will be up, need this configuration instead). The Kat's CV carbs will simply get the job done without fuss.
Naturally, all this ignores the fact that the US (and virtually every other first world country) has made two-stroke road bikes over 125 cc's illegal because some people really don't like their entire world coated with a microscopic layer of oil and unburnt fuel
And there you have it: you can engineer for reliability and longevity or you can engineer for supreme power. You just can't have both -- there's always a trade-off in there somewhere.
Cheers,
=-= The CyberPoet
______________________
CyberPoet's KR Specials
SuzukiStratosphere.com - 6 Cylinders, wet dreams...
The Best Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.
Both effectively started their lives in the three decades earlier and morphed over the years from there, growing more aerodynamic fairings and having big changes in the '96-'98 time frame.
In the left corner, ladies and gentlemen, producing 39 ft-lbs of torque and 79 HP, I am proud to introduce the Yamaha TZ! In the right corner, producing 42 ft-lbs of torque and 71 HP, is the challenger, the Suzuki GSX600F, known as the Katana 600!
Not incomparable numbers, right?
Ah, wrong.
The TZ clocks in at a flyweight 227 lbs dry and only has 250 cubic centimeters of displacement in a racing two-stroke form. Geared for the NorthWest 200 (an Irish race), it tops out at 168 miles per hour in the real world on real-world roads.
The Katana flattens the scales at 468 lbs dry and uses 2.4 times as much displacement (599 cc). It tops out more than 30 mph slower than the TZ.
OK, if Yamaha can engineer the TZ to produce those kind of figures (neigh-on-80-HP, 39 ft-lbs of torque, 227 lbs dry), where's the catch and why aren't we all zipping around on TZ250's?
Well, first of all, that kind of power out of a 250, even out of a two-stroke, means that the replacement intervals suffer -- massively. In standard form, the TZ would make it 300 miles between replacing pistons; in this hyper-tuned '08 race form, it only makes it 140 miles between piston replacements. The crank on the TZ also goes from a 700-mile life-expectancy down to only 450 miles before it's due for replacement. Can you imagine yourself down in the garage replacing the pistons and crank on the Katana because you went for a weekend rip around the hills with the boys?
The Katana will roll through 100,000 miles without a hick-up with daily use and minimal servicing (oil & filter every 3500 miles, valve adjustments every 7500 miles, air filter every 11k miles).
Then there's the carbs. To wring that kind of power out of the TZ250, you better be a wiz at changing jets, carb nozzles, float heights and settings every time the weather changes (looks overcast, humidity will be up, need this configuration instead). The Kat's CV carbs will simply get the job done without fuss.
Naturally, all this ignores the fact that the US (and virtually every other first world country) has made two-stroke road bikes over 125 cc's illegal because some people really don't like their entire world coated with a microscopic layer of oil and unburnt fuel
And there you have it: you can engineer for reliability and longevity or you can engineer for supreme power. You just can't have both -- there's always a trade-off in there somewhere.
Cheers,
=-= The CyberPoet
______________________
CyberPoet's KR Specials SuzukiStratosphere.com - 6 Cylinders, wet dreams... The Best Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.
so many roads so little time 
Comment