Now, now, stop laughing and pay attention. Forget about those podgy, post seventies, K-series CDs and go back a few years to 1967 when men were men and Honda CD175s were an altogether different kind of motorbike.
I have to admit a great deal of personal bias as regards early CD175s. It was a 1969 bike that allowed me to escape the shame, indignity and sheer danger of a three speed NSU Quickly (FS1Es did not yet exist in 1972). That CD was my first real motorcycle and one that was to take massive abuse and neglect for a year until I foolishly sold it to buy a Triton.
These earlier CDs have a similar basic layout to the newer, and much more common bikes, one that is very different in detail design. In the late sixties there was no sporting CB175 version available, so the CD had to serve both camps. It did this by having an engine that could be strung along on the minimum of throttle for those who insisted on using it strictly as a commuter, but it was also possible to rev the balls off the engine and get 90mph on the speedo. The exact revs that this equated to were not deducible as there was no rev counter, but the grinding vibration from the engine hinted that it must have been dangerously high.
The engine was a 360° vertical twln with a single carb, one cam operating two valves per pot, a four roller bearing crank that put British 500 twins to shame, and gear primary drive to a four speed box.
That gearbox was one of the minor problems of the bike - to keep up the momentum between second and third the thing had to be really caned, while changing up from first to second would often put the bike into neutral - itself impossible to find at a standstill. The gearchange movement was long and imprecise, but the clutch was light. From cold you had to shove on the front brake to stop the bike from stalling when first gear was engaged because of clutch drag.
The frame was pressed steel with no down tubes. It was a very strong affair, but let down by the usual toy town forks and shocks. It never went into a speed wobble but I had to hang off the seat to go round corners flat out otherwise it liked to go straight on. Sudden changes of direction left it very upset, unsure as whether it was going to sit down on the tarmac or just throw the rider off. Despite this, and taking quite outrageous youth inspired risks, i never fell off the bike at speed.
I did fall off going around some suburban street. A very tight, slow turn on the way to school, and the next thing I knew I was kissing the tarmac. Looked at bike, looked at road, couldn't see anything wrong. The next corner the same thing happened. Still couldn't see anything wrong, so decided it was fate telling me not to go to chemistry practical and went for a ride instead. No more falling off. Strange, huh?
Naturally, I modified the Honda by removing the baffles from the dangerously quiet silencers. Extending this easy breathing theory to removing the air filter produced a huge flat spot midway up the rev range, so that was quickly replaced. I didn't have the money to make any more mods to the Honda and, apart from the occasional oil change, didn't touch the engine.
Much to the annoyance of friends who insisted on buying Bantams and Tiger Cubs, the Honda could see off a tuned Bantam on top speed but was burned off from a standing start. But these British bikes were more often in bits so I didn't really worry.
I bought another one a few years later. This was a little slower and would oil the plug on one cylinder, but it never broke down despite similar neglect. A friend had one that broke its camchain, but it was soon repaired with no other damage. The tensioner is adjusted with a tiny screw that strips its thread - but can be repaired with Araldite... the clutch pushrod seal can be: messed up by the nearby chain sprocket but can be pulled out and replaced with a; new one... the carb leaks petrol but cleaning out the bowl or adjusting the float height solves that problem.
The engine really is much better made than later models, I don't know how or why but they are incredibly tough - these are the bikes that built Honda's reputation. Thrashed the bike returns just 40mpg, but it's quite easy to average 55mpg.
Later CD175s (K series) look, handle and perform in a vastly inferior manner, but they are very economical and cheap. They do snap their camchains quite frequently and wreck the head. OK if you're desperate and, short of the folding stuff.