Post by Pardee on Jun 25, 2014 13:14:34 GMT -5
YAMAHA TX750 STREET MACHINE
Yamaha bucks the multi trend with an all-around good twin
Cycle Guide, June 1973
When I first learned of Yamaha's plans to introduce the TX750 into their lineup, my inevitable reaction was one of puzzlement. Why a 750 twin? All the other manufacturers seemed to think the multis were the hot setup, and judging by their sales figures, they were right. Sure, the big Yamaha had a few new gadgets like "omni-phase balancing." and an exotic looking exhaust manifold, but it was still a twin. A bone-jarring, nut loosening, finger numbing, shake-apart vertical twin. Right? Wrong. To understand Yamaha's thinking on the 750, examine the current crop of 650 and 750 "superbikes."
The three and four cylinder motorcycles come in two and four stroke versions. Some are lightning quick, but leave much to be desired as touring machines or for city driving. Others are smooth, excellent tourers, but because of their weight and width, they aren't a lot of fun to ride in town or down twisty back roads.
Some of the twins provide neat handling characteristics, but because of the vibration they produce, a whole day of riding puts your hands and feet to sleep. Besides, these twins are inherently unreliable, because that same vibration makes various parts of the motorcycle break, fall off, or wear out prematurely.
What if someone built a motorcycle as fast as the superbikes; as smooth and comfortable as the multis; as narrow as the twins; and as easy to ride in town and on back roads as a good 250 or 350? Sounds like quite a concept, but maybe that was the thinking of the Yamaha designers who conceived the TX750. If so, and if they were successful, then a 750 vertical twin wouldn't sound so stupid after all.
The first unusual feature I noticed on our test bike was the finned aluminum balance manifold that connects the two exhaust ports. Its function is to equalize the exhaust impulses for smoother, cooler running. It also makes the exhaust note a bit quieter, since each impulse has two mufflers available to deaden the noise. It's been done before, but never with as much style as the TX750.
Most of the 750's novel features are internal, like the omni-phase balancers. These are two counter-rotating weights located in the transmission area, chain driven from the crankshaft. Their purpose is to produce a vibration whose force is equal and whose direction is opposite to the vibration set up by the crankshaft. If phased properly, the two vibrations should cancel each other out. Later on, we'll see how well they work.
The outer engine covers are highly polished, fit nicely--and get this--they are fastened to the crankcase with Allen head screws. Actually, the whole engine and all its fittings are held together either with Allen screws or hex head bolts. Some accessory manufacturers have been selling replacement Allen Screws for a long time. I guess Yamaha got the message. It would be nice if they used Allen screws on all their models.
Outide the engine area, the TX750 incorporates a few electrical innovations like a "back-up" lighting system. No, it isn't something that lights up when you go backwards. Here's how it works: If either beam of the headlight burns out, the remaining beam turns on automatically, and a warning light on the instrument panel tells you.
The rear lighting has a similar setup. Whenever the brakes are applied, a red light on the dash panel comes on simultaneously with the rear brake light. This lets the rider know that the brake light is functioning. If the brake light filament burns out, the dash light won't come on. If the taillight filament burns out, the brake light filament lights up at a decreased intensity, and the red warning light will come on and stay on. It's definitely a gadget, but a useful one.
Speaking of gadgets, the TX750 has another one that blows the minds of all who see it for the first time; a brake lining indicator light that comes on when the rear brake lining wears down to a thickness of 2 millimeters. It stays on, too, until the brake lining is replaced. It's a neat idea that some cars have started using.
The Yamaha is a flashy looking machine. The paint is candy orange metalflake, with gold and black accent trim on the gas tank. Chrome fenders are fitted to both ends of the bike, and the upswept mufflers are shaped like giant reverse-cone megaphones. Aside from emitting a quiet but healthy exhaust tone, they look neat.
Louvers must be "in" this year in Tokyo; most Japanese bikes have them, and the Yamaha is no exception. At least they're functional on the TX750; the right side panel has plastic bolt-on louvers in front to allow air to circulate around the oil tank, and real louvers are punched around the top and rear of the panel to permit that air to escape. The left side panel covering the battery has only dummy plastic louvers to balance the styling.
The quality and appearance of the motorcycle is very good. All the pieces fit together very well, and the bike's styling is consistent; it looks like it was designed by a group of people who were working together, instead of each part being conceived by total strangers. A lot of motorcycles fall short on this "togetherness."
Although the paint on the test bike has a slight orange peel effect, the finish is very glossy and durable, so the orange peel does not detract from the appearance of the machine. Overall, it is a very attractive package if you're into flashy bikes.
Starting the 750 is relatively easy--if you use the electric starter. Although the engine does not posess a high compression ration, the kick starter requires a healthy stab or two to turn the engine over fast enough to start. Once it has warmed up, though, the engine generally comes to life on the first kick.
Using the electric starter simplifies matters quite a bit. To start the engine when cold, open both petcocks, (one on each side of the tank) depress the enriching lever mounted on the left carburetor, and turn on the dash-mounted ignition switch. Leave the throttle closed and push the starter button on the right grip. The TX will fire into action almost immediately, even after sitting several days in a cool, camp place. The engine is a bit cold-natured, so you have to run it a couple of minutes before you will get the proper throttle response. At this point, the enricher can be flipped off, and you're ready to go.
Starting when warm is slightly different. Open the throttle about 1/8 to 1/4 turn, and push the starter button; the enricher is not needed. A touch of the button brings instant life to the engine.
I found the TX750 to be an extremely easy motorcycle to get used to. The handlebars fit me (6'1", 37" sleeve) just right. A friend, (5'10" 33" sleeve) liked them too. The footrests seem to be in the right place in relation to the rest of the bike; the seat is wide and feels fairly comfortable.
The shift pattern is the conventional one down-four up, with neutral between first and second. Starting off is quick and easy. The clutch engages smoothly, and there is no sweat about stalling the engine unless you are starting on an upgrade, or have a passenger aboard. Gear-changing is effortless and positive. Unfortunately, the test bike developed a shifting problem with fourth gear. If I lifted the shift lever firmly going up from third, the gearbox ended up in a false neutral between fourth and fifth gear. I am sure that this is a characteristic peculiar to the test bike, because we checked with various mechanic friends in Yamaha shops around the country, and they said the TX750 gearboxes weren't giving them any trouble.
The gearbox ratios are very close from second through fifth with first gear being quite a bit lower to aid in starting off. Even so, the bike will run 40 mph in first at the 7000 rpm redline. The engine has a wide, flexible powerband, and, when coupled with these close ratio gears, accelerates the motorcycle from 30 mph exceptionally well in second, third, fourth, and even fifth gear. Sometimes it is difficult to know what gear you're in. This is not a complaint; it's just a blow to my ego to ride a motorcycle as much as I did this one, and not know what gear it's in. I guess it doesn't matter, 'cause it goes pretty fast in all of them. Actually, this characteristic, in combination with the 750's surprisingly nimble handling, make it a blast to ride around the city, as well as on the highway.
Going around street corners, or maneuvering in and out of traffic is easy. The front-end steering geometry, although essentially the same as Yamaha's TX650 (see May '73 CG test) feels right on. Maybe the weight is distributed differently, or the center of gravity is changed, but the TX750 goes where you want it to, whereas the 650 sometimes doesn't.
The sidestand will scrape if the bike is heeled over real hard to the left, but nothing drastic (except noise) happens. I never succeeded in dragging anything around right handers.
The bike will run down to about 5 to 7 mph in first gear with the clutch still engaged, so inching along in heavy traffic won't require much clutch manipulation. Low speed handling and control is great; I could come to a complete stop before putting my foot down. As soon as the bike moved forward the slightest bit, I could return both feet to the pegs. Even while turning around at full steering lock, I never felt any need to put a foot down.
My only complaint about the low speed operation of this bike is due to the jerkiness encountered when accelerating and decelerating in first gear. The TX750, like most Japanese motorcycles, has a lot of slack in the gearbox, especially in first gear. This slack makes it difficult to be smooth when applying the throttle in first. If the bike were leaned over quite a bit in a slow, sharp turn, a little too much throttle would cause the rear wheel to break loose. Whether or not the bike fell down would depend only on the ability of the rider. A small, but aggravating point.
Once out on the highway, the big difference between this 750 and other large displacement twins was quickly felt. It's not a screamer, but it's fast--sneaky fast. You are accelerated smoothly, effortlessly, with only the barest trace of vibration. The omniphase trickery works. This motorcycle fools you; if you don't watch the speedometer, you end up going faster than intended.
I liked the way the TX handled the freeway entrances. Riding a motorcycle on the Southern California freeway system can be scary. When entering the freeway, it's desirable to have a reserve of power, so that you can take advantage of an opening in traffic, which is moving along at 70 mph, damn near bumper to bumper. With the Yamaha, second or third or fourth gear usually provided enough acceleration to get into an open slot and move with the fast flow of traffic.
The infamous freeway rain grooves did not bother the 750 very much. Occasionally, a gusting crosswind would move the bike over an inch or two, but otherwise, the course you selected was the course the bike took. Cruising at 70 or 75 was a snap, with plenty of power left to make passing a simple, safe process.
The brakes are excellent or adequate, depending on which end of the motorcycle you are speaking of. The front brake is a super stopper; it whoa'd the 471 pound scooter to a halt as fast and straight as any I've ever used. It was consistent, too; repeated panic stops and continued downhill braking didn't faze it a bit.
The rear brake is usually adequate. I say usually because repeated use will make it fade to a point where nothing short of standing on the pedal will slow the motorcycle down. If the rear brake does lock up, quite a bit of wheel hop occurs. This is due in part to the rear shocks; they don't dampen very well and allow the wheel to bounce up and down too easily. I also don't like Yamaha's decision to mount the brake pedal above the right muffler. If the play in the rear brake linkage becomes too great, the pedal will strike the top of the muffler, preventing further movement of the pedal; thus, no rear brakes. It happened to me twice while making repeated hard stops. Of course, the immediate solution is to adjust the rear brake. However, there is one prerequisite for adjusting the brake; you have to stop in order to do it. Think about it.
Riding the 750 Yamaha on the freeways and in town was as much fun as a bike can be under those circumstances, so I headed out into the sticks to find out how it reacted to back roads. I ended up on notorious Topanga Canyon Boulevard in the Santa Monica Mountains. Not only does this road give you an opportunity to ride 10 miles of continuous turns, but some of its side roads are incredible. Like Old Topanga Canyon road; sharp, twisting uphills and downhills, switchbacks and corkscrews. Neat. There are a couple of places where the warning signs say "10 mph." If you're driving a two-ply-tired standard Detroit iron, the sign means what it says; if you're on a good handling motorcycle, well ...
The TX750 was more fun on these roads than most other big bikes I've ridden. It handles predictably and well. Because of the extra wide, smooth powerband and the close ratios, it doesn't make too much difference if you are one gear too high or one gear too low when shooting a corner; the bike still accelerates quickly when exiting. Occasionally, the sidestand would drag, but it never caused the Yamaha to alter its course around the corner.
Because of the wide, flat power curve, many successive corners could be encountered without changing. (That is the one drawback to most small, agile motorcycles--they have a narrow power range and make the rider continually shift. Sometimes in the middle of a corner.) There are probably a few big twins that handle as well as the TX750; maybe better. But the Yammie is smooth, and forgiving because it has power where you need it. Everywhere. It is hard to compare it with other similar motorcycles because it does everything so easily.
It's not a perfect machine, either. Like everything else, perfection is a goal that few ever attain. For instance, you won't want to spend a lot of time on dirt roads with this unit. A tour along unpaved, gravelly Mulholland Drive was not the high point of the test. After a few early tank slapping speed wobbles, I decided to slow down and enjoy the scenery. That wasn't a bad idea, since the scenery included a rather neat lookin' chick riding a horse bareback and topless. (The horse was bareback-the chick was topless.) But, the 750 wasn't built for cow-trailing, so I wasn't too disappointed at its inability to go fast on this type of terrain.
Another minor complaint can be registered about the sidestand, and the centerstand. You see, one day I rode down to San Juan Capistrano to check out the annual parade and celebration hailing the return of the swallows. Somehow, I unwittingly got mixed up in the parade. After a short while, I decided that I didn't want to be there anymore, but the local Barney Fife told me that I couldn't start the bike--I might scare the horses in the parade. They would allow me to leave the area if I pushed the motorcycle to the end of the parade route--about a mile and a half. So I pushed. And I discovered that if I didn't walk far enough away from the side of the bike, I would rap my shins on the protrusions sticking out from the sidestand and centerstand. I pushed for a while, but soon my shins couldn't take any more, so I just sat and watched until the parade was over.
The rear tire is a 400x18 Yokohama. It seemed to be sufficient on dry roads, but in the rain, it was very easy to break loose while accelerating and stopping. This is due to the fact that there is virtually no cross siping (grooves or slits) in the center of the tire tread. I really wasn't too happy with the way the tire held on wet corners, either.
The Yamaha speedometer and tachometer are big and easy to read. At night, they glow with a soft, green light, making them as easy to see as in the daytime. The speedometer error however, is a whopping 9%. At an estimated 60, the true speed is 54.72 mph.
A trip to Orange County International Raceway proved to be an interesting one. The TX750 turned in a respectable quarter-mile performance; its best elapsed time was 13.668 seconds, with a terminal speed of 96.03 mph. Part of the reason for the fairly quick E-Ts was the way the bike came out of the hole. Run it up to about 4500 rpm and turn it loose. It usually tracks off the line straight as an arrow, without ever bogging. All those low end horses keep it churning. The TX never does anything spectacular while covering the quarter. It just pulls steadily, smoothly. The quarter mile times could have been bettered a wee bit; because of the aforementioned shifting problem, I was forced to let off the throttle completely, and make the third to fourth shift slowly. It cost valuable time.
It took me a long time to assess the suspension of the Yamaha. I finally determined that the front forks were OK. They could use a set of slightly stiffer springs for riding two up, or solo, if the rider is my size. But, hey dampen pretty well, so, overall they do a good job.
The rear shocks don't seem to dampen much at all. Also, if I left the springs in their softest position, the shocks would bottom on just about every bump. At their firmest setting, they wouldn't bottom, but were too stiff to give a decent ride. I finally settled for the middle position (there are five), which seemed to be the best compromise. A better damping rate would have made the rear wheel behave better on hard braking, also.
Speaking of two-up riding, the Yamaha does that very well. I traveled 50 or 60 miles of winding road with a 160 pound passenger. That made a total of 385 pounds. The additional weight hardly fazed the big twin, both in performance and handling. Don't let anyone tell you this isn't a touring bike.
I really liked the TX750. I think yamaha has come within 95% of their design goals. The bike is almost as fast as the best superbikes, but it's easier and more forgiving to ride at slower speeds; it's almost as smooth as the super tourers, but is more fun to ride in the city or on twisting roads; it handles almost as well as the European hybrids, but in most cases is smoother. What it doesn't do is insignificant when compared with what it does do. The TX750 definitely has a place in the 1973 motorcycling Scheme. It can have a place in my garage anytime. Paul Dean
Yamaha bucks the multi trend with an all-around good twin
Cycle Guide, June 1973
When I first learned of Yamaha's plans to introduce the TX750 into their lineup, my inevitable reaction was one of puzzlement. Why a 750 twin? All the other manufacturers seemed to think the multis were the hot setup, and judging by their sales figures, they were right. Sure, the big Yamaha had a few new gadgets like "omni-phase balancing." and an exotic looking exhaust manifold, but it was still a twin. A bone-jarring, nut loosening, finger numbing, shake-apart vertical twin. Right? Wrong. To understand Yamaha's thinking on the 750, examine the current crop of 650 and 750 "superbikes."
The three and four cylinder motorcycles come in two and four stroke versions. Some are lightning quick, but leave much to be desired as touring machines or for city driving. Others are smooth, excellent tourers, but because of their weight and width, they aren't a lot of fun to ride in town or down twisty back roads.
Some of the twins provide neat handling characteristics, but because of the vibration they produce, a whole day of riding puts your hands and feet to sleep. Besides, these twins are inherently unreliable, because that same vibration makes various parts of the motorcycle break, fall off, or wear out prematurely.
What if someone built a motorcycle as fast as the superbikes; as smooth and comfortable as the multis; as narrow as the twins; and as easy to ride in town and on back roads as a good 250 or 350? Sounds like quite a concept, but maybe that was the thinking of the Yamaha designers who conceived the TX750. If so, and if they were successful, then a 750 vertical twin wouldn't sound so stupid after all.
The first unusual feature I noticed on our test bike was the finned aluminum balance manifold that connects the two exhaust ports. Its function is to equalize the exhaust impulses for smoother, cooler running. It also makes the exhaust note a bit quieter, since each impulse has two mufflers available to deaden the noise. It's been done before, but never with as much style as the TX750.
Most of the 750's novel features are internal, like the omni-phase balancers. These are two counter-rotating weights located in the transmission area, chain driven from the crankshaft. Their purpose is to produce a vibration whose force is equal and whose direction is opposite to the vibration set up by the crankshaft. If phased properly, the two vibrations should cancel each other out. Later on, we'll see how well they work.
The outer engine covers are highly polished, fit nicely--and get this--they are fastened to the crankcase with Allen head screws. Actually, the whole engine and all its fittings are held together either with Allen screws or hex head bolts. Some accessory manufacturers have been selling replacement Allen Screws for a long time. I guess Yamaha got the message. It would be nice if they used Allen screws on all their models.
Outide the engine area, the TX750 incorporates a few electrical innovations like a "back-up" lighting system. No, it isn't something that lights up when you go backwards. Here's how it works: If either beam of the headlight burns out, the remaining beam turns on automatically, and a warning light on the instrument panel tells you.
The rear lighting has a similar setup. Whenever the brakes are applied, a red light on the dash panel comes on simultaneously with the rear brake light. This lets the rider know that the brake light is functioning. If the brake light filament burns out, the dash light won't come on. If the taillight filament burns out, the brake light filament lights up at a decreased intensity, and the red warning light will come on and stay on. It's definitely a gadget, but a useful one.
Speaking of gadgets, the TX750 has another one that blows the minds of all who see it for the first time; a brake lining indicator light that comes on when the rear brake lining wears down to a thickness of 2 millimeters. It stays on, too, until the brake lining is replaced. It's a neat idea that some cars have started using.
The Yamaha is a flashy looking machine. The paint is candy orange metalflake, with gold and black accent trim on the gas tank. Chrome fenders are fitted to both ends of the bike, and the upswept mufflers are shaped like giant reverse-cone megaphones. Aside from emitting a quiet but healthy exhaust tone, they look neat.
Louvers must be "in" this year in Tokyo; most Japanese bikes have them, and the Yamaha is no exception. At least they're functional on the TX750; the right side panel has plastic bolt-on louvers in front to allow air to circulate around the oil tank, and real louvers are punched around the top and rear of the panel to permit that air to escape. The left side panel covering the battery has only dummy plastic louvers to balance the styling.
The quality and appearance of the motorcycle is very good. All the pieces fit together very well, and the bike's styling is consistent; it looks like it was designed by a group of people who were working together, instead of each part being conceived by total strangers. A lot of motorcycles fall short on this "togetherness."
Although the paint on the test bike has a slight orange peel effect, the finish is very glossy and durable, so the orange peel does not detract from the appearance of the machine. Overall, it is a very attractive package if you're into flashy bikes.
Starting the 750 is relatively easy--if you use the electric starter. Although the engine does not posess a high compression ration, the kick starter requires a healthy stab or two to turn the engine over fast enough to start. Once it has warmed up, though, the engine generally comes to life on the first kick.
Using the electric starter simplifies matters quite a bit. To start the engine when cold, open both petcocks, (one on each side of the tank) depress the enriching lever mounted on the left carburetor, and turn on the dash-mounted ignition switch. Leave the throttle closed and push the starter button on the right grip. The TX will fire into action almost immediately, even after sitting several days in a cool, camp place. The engine is a bit cold-natured, so you have to run it a couple of minutes before you will get the proper throttle response. At this point, the enricher can be flipped off, and you're ready to go.
Starting when warm is slightly different. Open the throttle about 1/8 to 1/4 turn, and push the starter button; the enricher is not needed. A touch of the button brings instant life to the engine.
I found the TX750 to be an extremely easy motorcycle to get used to. The handlebars fit me (6'1", 37" sleeve) just right. A friend, (5'10" 33" sleeve) liked them too. The footrests seem to be in the right place in relation to the rest of the bike; the seat is wide and feels fairly comfortable.
The shift pattern is the conventional one down-four up, with neutral between first and second. Starting off is quick and easy. The clutch engages smoothly, and there is no sweat about stalling the engine unless you are starting on an upgrade, or have a passenger aboard. Gear-changing is effortless and positive. Unfortunately, the test bike developed a shifting problem with fourth gear. If I lifted the shift lever firmly going up from third, the gearbox ended up in a false neutral between fourth and fifth gear. I am sure that this is a characteristic peculiar to the test bike, because we checked with various mechanic friends in Yamaha shops around the country, and they said the TX750 gearboxes weren't giving them any trouble.
The gearbox ratios are very close from second through fifth with first gear being quite a bit lower to aid in starting off. Even so, the bike will run 40 mph in first at the 7000 rpm redline. The engine has a wide, flexible powerband, and, when coupled with these close ratio gears, accelerates the motorcycle from 30 mph exceptionally well in second, third, fourth, and even fifth gear. Sometimes it is difficult to know what gear you're in. This is not a complaint; it's just a blow to my ego to ride a motorcycle as much as I did this one, and not know what gear it's in. I guess it doesn't matter, 'cause it goes pretty fast in all of them. Actually, this characteristic, in combination with the 750's surprisingly nimble handling, make it a blast to ride around the city, as well as on the highway.
Going around street corners, or maneuvering in and out of traffic is easy. The front-end steering geometry, although essentially the same as Yamaha's TX650 (see May '73 CG test) feels right on. Maybe the weight is distributed differently, or the center of gravity is changed, but the TX750 goes where you want it to, whereas the 650 sometimes doesn't.
The sidestand will scrape if the bike is heeled over real hard to the left, but nothing drastic (except noise) happens. I never succeeded in dragging anything around right handers.
The bike will run down to about 5 to 7 mph in first gear with the clutch still engaged, so inching along in heavy traffic won't require much clutch manipulation. Low speed handling and control is great; I could come to a complete stop before putting my foot down. As soon as the bike moved forward the slightest bit, I could return both feet to the pegs. Even while turning around at full steering lock, I never felt any need to put a foot down.
My only complaint about the low speed operation of this bike is due to the jerkiness encountered when accelerating and decelerating in first gear. The TX750, like most Japanese motorcycles, has a lot of slack in the gearbox, especially in first gear. This slack makes it difficult to be smooth when applying the throttle in first. If the bike were leaned over quite a bit in a slow, sharp turn, a little too much throttle would cause the rear wheel to break loose. Whether or not the bike fell down would depend only on the ability of the rider. A small, but aggravating point.
Once out on the highway, the big difference between this 750 and other large displacement twins was quickly felt. It's not a screamer, but it's fast--sneaky fast. You are accelerated smoothly, effortlessly, with only the barest trace of vibration. The omniphase trickery works. This motorcycle fools you; if you don't watch the speedometer, you end up going faster than intended.
I liked the way the TX handled the freeway entrances. Riding a motorcycle on the Southern California freeway system can be scary. When entering the freeway, it's desirable to have a reserve of power, so that you can take advantage of an opening in traffic, which is moving along at 70 mph, damn near bumper to bumper. With the Yamaha, second or third or fourth gear usually provided enough acceleration to get into an open slot and move with the fast flow of traffic.
The infamous freeway rain grooves did not bother the 750 very much. Occasionally, a gusting crosswind would move the bike over an inch or two, but otherwise, the course you selected was the course the bike took. Cruising at 70 or 75 was a snap, with plenty of power left to make passing a simple, safe process.
The brakes are excellent or adequate, depending on which end of the motorcycle you are speaking of. The front brake is a super stopper; it whoa'd the 471 pound scooter to a halt as fast and straight as any I've ever used. It was consistent, too; repeated panic stops and continued downhill braking didn't faze it a bit.
The rear brake is usually adequate. I say usually because repeated use will make it fade to a point where nothing short of standing on the pedal will slow the motorcycle down. If the rear brake does lock up, quite a bit of wheel hop occurs. This is due in part to the rear shocks; they don't dampen very well and allow the wheel to bounce up and down too easily. I also don't like Yamaha's decision to mount the brake pedal above the right muffler. If the play in the rear brake linkage becomes too great, the pedal will strike the top of the muffler, preventing further movement of the pedal; thus, no rear brakes. It happened to me twice while making repeated hard stops. Of course, the immediate solution is to adjust the rear brake. However, there is one prerequisite for adjusting the brake; you have to stop in order to do it. Think about it.
Riding the 750 Yamaha on the freeways and in town was as much fun as a bike can be under those circumstances, so I headed out into the sticks to find out how it reacted to back roads. I ended up on notorious Topanga Canyon Boulevard in the Santa Monica Mountains. Not only does this road give you an opportunity to ride 10 miles of continuous turns, but some of its side roads are incredible. Like Old Topanga Canyon road; sharp, twisting uphills and downhills, switchbacks and corkscrews. Neat. There are a couple of places where the warning signs say "10 mph." If you're driving a two-ply-tired standard Detroit iron, the sign means what it says; if you're on a good handling motorcycle, well ...
The TX750 was more fun on these roads than most other big bikes I've ridden. It handles predictably and well. Because of the extra wide, smooth powerband and the close ratios, it doesn't make too much difference if you are one gear too high or one gear too low when shooting a corner; the bike still accelerates quickly when exiting. Occasionally, the sidestand would drag, but it never caused the Yamaha to alter its course around the corner.
Because of the wide, flat power curve, many successive corners could be encountered without changing. (That is the one drawback to most small, agile motorcycles--they have a narrow power range and make the rider continually shift. Sometimes in the middle of a corner.) There are probably a few big twins that handle as well as the TX750; maybe better. But the Yammie is smooth, and forgiving because it has power where you need it. Everywhere. It is hard to compare it with other similar motorcycles because it does everything so easily.
It's not a perfect machine, either. Like everything else, perfection is a goal that few ever attain. For instance, you won't want to spend a lot of time on dirt roads with this unit. A tour along unpaved, gravelly Mulholland Drive was not the high point of the test. After a few early tank slapping speed wobbles, I decided to slow down and enjoy the scenery. That wasn't a bad idea, since the scenery included a rather neat lookin' chick riding a horse bareback and topless. (The horse was bareback-the chick was topless.) But, the 750 wasn't built for cow-trailing, so I wasn't too disappointed at its inability to go fast on this type of terrain.
Another minor complaint can be registered about the sidestand, and the centerstand. You see, one day I rode down to San Juan Capistrano to check out the annual parade and celebration hailing the return of the swallows. Somehow, I unwittingly got mixed up in the parade. After a short while, I decided that I didn't want to be there anymore, but the local Barney Fife told me that I couldn't start the bike--I might scare the horses in the parade. They would allow me to leave the area if I pushed the motorcycle to the end of the parade route--about a mile and a half. So I pushed. And I discovered that if I didn't walk far enough away from the side of the bike, I would rap my shins on the protrusions sticking out from the sidestand and centerstand. I pushed for a while, but soon my shins couldn't take any more, so I just sat and watched until the parade was over.
The rear tire is a 400x18 Yokohama. It seemed to be sufficient on dry roads, but in the rain, it was very easy to break loose while accelerating and stopping. This is due to the fact that there is virtually no cross siping (grooves or slits) in the center of the tire tread. I really wasn't too happy with the way the tire held on wet corners, either.
The Yamaha speedometer and tachometer are big and easy to read. At night, they glow with a soft, green light, making them as easy to see as in the daytime. The speedometer error however, is a whopping 9%. At an estimated 60, the true speed is 54.72 mph.
A trip to Orange County International Raceway proved to be an interesting one. The TX750 turned in a respectable quarter-mile performance; its best elapsed time was 13.668 seconds, with a terminal speed of 96.03 mph. Part of the reason for the fairly quick E-Ts was the way the bike came out of the hole. Run it up to about 4500 rpm and turn it loose. It usually tracks off the line straight as an arrow, without ever bogging. All those low end horses keep it churning. The TX never does anything spectacular while covering the quarter. It just pulls steadily, smoothly. The quarter mile times could have been bettered a wee bit; because of the aforementioned shifting problem, I was forced to let off the throttle completely, and make the third to fourth shift slowly. It cost valuable time.
It took me a long time to assess the suspension of the Yamaha. I finally determined that the front forks were OK. They could use a set of slightly stiffer springs for riding two up, or solo, if the rider is my size. But, hey dampen pretty well, so, overall they do a good job.
The rear shocks don't seem to dampen much at all. Also, if I left the springs in their softest position, the shocks would bottom on just about every bump. At their firmest setting, they wouldn't bottom, but were too stiff to give a decent ride. I finally settled for the middle position (there are five), which seemed to be the best compromise. A better damping rate would have made the rear wheel behave better on hard braking, also.
Speaking of two-up riding, the Yamaha does that very well. I traveled 50 or 60 miles of winding road with a 160 pound passenger. That made a total of 385 pounds. The additional weight hardly fazed the big twin, both in performance and handling. Don't let anyone tell you this isn't a touring bike.
I really liked the TX750. I think yamaha has come within 95% of their design goals. The bike is almost as fast as the best superbikes, but it's easier and more forgiving to ride at slower speeds; it's almost as smooth as the super tourers, but is more fun to ride in the city or on twisting roads; it handles almost as well as the European hybrids, but in most cases is smoother. What it doesn't do is insignificant when compared with what it does do. The TX750 definitely has a place in the 1973 motorcycling Scheme. It can have a place in my garage anytime. Paul Dean