I know the 400f is commanding some high prices. I heard that there is someone, possibly in the UK, that is buying them up. http://www.ttr400.com makes some really nice aftermarket items for them. I am not sure if he is available at this time as I believe he is out of the country on a vacation maybe.
His name is Kevin Bidgood and he lives in South Africa. He's a great guy, but most of his parts are bespoke, so they take a while to get in. Used to, another Kevin ran the 400fourstore.com. He moved to Japan at the end of last year, and he was the supplier for TTR's parts. Now you order and wait. The 400f was only made for 3 years. The 350f was a good bike, but was anemic in comparison to the 400f. The 400 got a different transmission and an overbore which made a huge difference. I own 3 of them (two are rough) and they are great little bikes. They are hard to come by because people are buying them again, and the market got drowned. The last 2 I bought I had shipped down from Michigan to Alabama. The 550f is a better bike than the 500f much like the 400f trumps the 350f. Here's a magazine article I saved that compares the 2.1973 Cycle World: CB550K1 Road Test
Hardly anybody had much bad to say about the Honda 500 Four. So why did Honda enlarge its bores by 2.5 millimeters to make a 550? There are several reasons. First, and probably the least important, is the presence of Suzuki's 550 - Honda doesn't want to lose any sales over a piffling 50ccs. Second, the consumer will be more likely to absorb the price increase to $1,600 without squawking if he's digging deeper for a different motorcyck--not the same old 500. Third, the extra displacement-tiny volume that it is (a guppy could barely turn around in a 50ce fishbowl)-actually adds a noticeable amount of mid-range power and torque. Finally, it is likely that Honda increased displacement as a marketing trick to insure that several other subtle, but costly, improvements would not go unnoticed. Magazines will rush to test a bigger Honda, and in so doing will discover and explain the other new features and improvements. Without the extra displacement first to motivate the magazines and then entice the people into reading the road tests (or factory brochures or advertisements), thousands of motorcycle riders would think the 500 is still the same machine.
It is far from being the same. Solutions to two major problems on the 500 and a few other smaller improvements make the 550 a considerably better motorcycle. Fixing the 500's two big flaws-an ill-shifting transmission and a clutch sometimes prone to slipping-makes the biggest difference in the 550 aside from a bit more mid-range urge.
The old transmission used to clunk noisily, hang up in false neutrals between gears and generally offer a disagreeable action and feel. It was a lousy gearbox. Honda completely redesigned the drum and shifting mechanism so the 550 now has short-throw, knife-sharp action that selects gears with a barely discernible snick. Even at speeds when boots often deal clumsily with the gear lever, the new transmission in the Honda 550 doesn't miss at all.
Correcting occasional clutch-slipping problems involved another total redesign and all new tooling. Since one of Honda's proud points has always been light lever pull, stiffer springs were not considered as the solitary solution to slipping problems. Slightly stiffer springs, improved friction material on the plates and a change in throw-out rod leverage all help toughen the clutch. A further precaution in the form of a reduced primary ratio (3.246 on the 500 to 3.063 on the 550) maintains an equivalent amount of torque multiplication at the clutch despite a torque increase in the engine due to bigger displacement. A parallel benefit of the faster-spinning clutch is longer, more efficient operation of the Morse Hy- Vo primary chain since it likes the larger sprockets necessary for the new primary ratio better than the smaller ones on the 500. The new clutch fits inside a diecast sidecover which also incorporates an external cable buttress and rod-play adjuster so the clutch may be tuned from one side of the bike without removing any covers or plates. The opposite, or left, sidecover is now free of the clutch plumbing which cluttered that side of the 500. All of these clutch modifications are almost an over-reaction to a fairly uncommon problem, but the result gives the 550 a smoother, wider friction point than most Hondas and absolutely flawless operation.
Results of the displacement increase aren't quite so dramatic. Cycle tested a 1973 500 Four (August '73) which turned 14.31 seconds, 94.43 mph in the quarter-mile. The 550 recorded a nearly identical ET of 14.27 seconds and a slower 91.55 mph trap speed. Part of the decrease in speed is due to slightly taller overall gear ratios in the 550-high gear, for instance, is 6.00:1 compared to 5.81:1 for the 500. Also our particular test bike was surging through the traps, either from improper float levels or tired plugs. It had arrived with 72 miles on the odometer and drag testing was conducted after 1,400 additional miles with only a points and timing check in between. Furthermore, the 550 weighs nine pounds more than the 500 and the bikes ran at different drag strips.
Though stronger, the 550 is still a bike of medium engine displacement. It is capable of touring across continents, even around the world, but headwinds, high altitude, uphills and passengers will fizzle power at anything below 7,000 revs. Bear this in mind when trying to decide between a 550 and 750. Two side effects of the extra 50ccs are an increase in sound level from 79 dB(A) on the 500 (the lowest level ever recorded by Cycle) to 81 decibels on the 550; and vibration on the 550 blurs mirrors and tingles feet a bit more than the smaller bike. But again, few motorcycles are smoother than either.
Further changes in the 550 include a pressure oil feed to both sides of the two transmission shafts, whereas before two ends were splash- fed. Forks have been changed from piston-valve to free-valve type to reduce the wear factor. A unique electric starter safety interlock controlled by a microswitch in series with the neutral light prevents the starter from working with the bike in gear unless the clutch is pulled. No more accidently leaving the bike in gear, hitting the starter button and lurching forward. Five-fifties now have CB-750 instruments (the best in motorcycling) and a centralized fuse box with three spares snuggling in the lid. Honda now includes a document compartment under the locking seat for safe, dry storage of papers relating to the motorcycle. New handlebar controls have improved turn signal and high/low beam switches which include the audible beeper to remind people to turn off their directional signals. Also, the turn signals bum continually with the headlight on-a safety feature which will distinguish a motorcycle from a one-eyed car. Good idea.
Other than 550 stamped on the sidecovers, its appearance matches that of the 500. So does handling, which is positively inspired for a 458-pound pleasure cushion aimed at a conservative clientele. The 500 was always good and the 550 still is. Its suspension moves on freeway seams, it tracks straight and steady on rain grooves, it doesn't sink or dive in turns and it doesn't wiggle until a really fast rider goes to work in some really fast turns. Its single most detrimental handling problem is ground clearance, on the left side. The sidestand will touch with your grandmother riding, and after it is removed or ground away, the centerstand arm drags. The danger here is that the rear wheel will lift and lose traction. Clearance on the right is perfect: the peg brushes the pavement and folds up without offering resistance to further leaning. At those angles, however, the Bridgestone tires are approaching their limits, so the scraping peg should be heeded.
Braking, of course, cannot be faulted in front because of the Honda disc. Less sensitive linings in back reduce the chattering and instant lock-up that has plagued big Hondas for years. Softer linings which wear faster may be why Honda provides a visual wear indicator consisting of a red line on the backing plate and a red arrow on the brakecam arm. When the arrow points at the line, it's time for new rear brakes.
Riding the Honda a long distance eventually leads to an almost reverent respect for its consistency. You can expect, and get, instant starting, even idle, tireless revs, cleanliness, good manners, reliability, 38 mpg riding easy, 34 mpg riding hard and suitability to both city and highway. Even its bad points, such as a stiff throttle and a lurch in the drive train, are there with consistency.
Should present 500 owners trade up? Not really-especially if you've learned to live with the old transmission. The 550 engine just isn't that much stronger, and besides, downshifting the 500 is equivalent to a lot more than 50 extra cubic centimeters.
Should 750 owners trade down? Only if the weight and ominous feel of the bigger Four consistently unnerves you. Otherwise you'll feel naked without all that 750 power.
Should a new rider buy a 550 Four? You bet. And you'll love it.