What year is my bike?
One of the most common questions is, "what year is this thing?" The most common error I see is CT-90s and 110s mis-identified, particularly the older bikes.
This page and the pictures in the picture gallery should help you identify almost any 1966-1986 CT-90 or CT-110 sold in the United States.
Numbers
For every CT-90 sold after around 1968 or 1969, you can (and should) just look at the plate on the fork tube on the front of the motorcycle. It will tell you the year and month the bike was made, in keeping with common model-year designations. Thus, a bike built in 12/69 is a 1970 model, a bike built in 10/70 is a 1971 model.
On early bikes, this plate may not be present or may not disclose the date of manufacture. You also may have a bike where the plate is missing or was deliberately removed (boo). That's when you look at other clues.
An important point: your serial number doesn't necessarily indicate the year in which it was built. It
does
indicate its "K-series," which is useful for buying parts. In a rough sense, a K2 has a serial number starting with CT90-3xxxxx. And most K2s were 1970 models. But not all. Most bikes with a serial lower than 200000 were pre-1969 bikes, and they built around 30,000 per year. Do the math. If you don't know where your serial number is, check this page.
Big differences
There are four or five major design changes you can look for in the CT-series. First thing to look at is the engine displacement. For the very early bikes, about which I have little information, the engine is roughly 50cc. These are Trail 50s or 55s, and if you have one so designated, it dates from 1962 to sometime in 1964 or 1965. You should be able to see the engine displacement cast into the metal of the cylinder head. On a "50," that's 49cc. On a "90," it's 89cc. For a "110," it's 105cc. 1966-1979 bikes are 90s, and 1980-1986 bikes are 110s. In Australia, 110s were built later on, well into the 1990s, but those should all have plates on the forks.
The next major feature change was the trail gearing. On the early bikes, up until about 1967, the CT-series had a dual rear sprocket. That's right, two actual sprockets on the rear wheel. If your bike has this, it's older than 1967. No bike after 1968 has it unless the owner deliberately replaced the rear wheel with an older unit. Sometime during 1967, Honda added the "Posi-Torque" subtransmission, which is identified by a small extra cover just above your left heel as you're sitting on the bike. There's a lever underneath to switch between direct drive and a 2:1 underdrive. However, 1980 CT-110s for some reason do not have this device. I don't know why... they just don't. For this reason, 1980 CT-110s are somewhat rare and easy to spot.
Another major change was trailing-link front suspension. All bikes prior to 1969 have trailing-link front suspension with forks made of steel sheetmetal stampings. All bikes 1970 and newer have modern telescopic forks. The front fender on the old bikes was bolted to the fork and did not move up and down with the wheel... the later fenders were attached to the moving portion of the telescopic forks and much closer to the front wheel.
The "weird" bikes were a transitional model made during 1969, often referred to as a "K1b." These bikes have telescoping front shocks and full "saddle" plastic frame covers, but the air cleaner cover ends abruptly under your left butt-cheek and does not extend up into the rear rack. The K1bs are rather uncommon but a surprising number of them still exist. For frame and mechanical parts, treat them like 1970 models.
Harder things to spot
If you can't figure it out with these clues, you have to go on obscure differences between years. The following list is not complete and not 100% accurate, but between this and the picture gallery, you should be able to figure out what your CT is.
1969
Last year for old-style forks and "box" air cleaner on frame downtube, though partway through production telescoping forks and left-side-mount air cleaner was introduced as K1b model.
Colors were red and yellow
Speedo is D-shaped, not teardrop and not round
Main muffler guard has horizontal slots
1970
First full year for telescopic forks
Rear rack has four large apertures that run front-to-back, and has raised rear butt-rail
Frame cover is now saddle-shaped, full-size gray-metallic plastic. Logo on side is 4" long by 1" high, with round Honda logo at front and silver-white block HONDA
Left handgrip has a rear brake lever
Main muffler guard now has only vertical slots and was originally all chrome
Carburetor has high-altitude pullout
Logo on air cleaner is same lettering as HONDA logo and is small-caps
Colors are red and yellow, some orange
1971
Nearly identical to 1970, except that fenders have flaps riveted on
Logo on frame cover is now black and white and consists of a "racing stripe" that extends up and over to the other side, and HONDA across the stripe.
Logo on air cleaner box is now a sort of funky "Star Trek" typeface and is not like the Honda logo
Muffler changed over to black metal instead of chrome sometime during production run
Buddy seat now has a slight bump at the rear edge
1972
Very similar to 1971, but logo is again different
1973
Seat is now different... no white piping and more saddle-shaped
Turn signals now standard equipment in US
Logo on frame cover is now HONDA with stripes running parallel to the words
Logo on air cleaner is "Old West" style type
Rear brake lever on left handlebar dropped
High-altitude pullout on carburetor dropped
Rubber cover added for clutch adjustment nut on right side
1974
Mudflaps dropped
Rubber rub-rail added on front fender to keep cables from abrading paint
Otherwise identical to the 1973
1975
"Always on" headlight... switch has no "off" position
1976
Last year for polished metal hubs
1977
Hubs are black from here on out
1978
1979
Last year for CT-90 model
Subtransmission cover is black enamel
1980
Only model made without dual-range gearbox.
First year of 105cc engine
No buddy seat available
Squared-off turn signals
1981
Dual-range gearbox restored... first year for 110 with it.
1984
CDI ignition installed... left side point over says "CDI" on it in casting
1986
Sale in USA ends, last model year. Production and sale continues elsewhere
1987-2000
Large market for CT-110 in Australia. Model used for Australian Post Office does not have dual-range gearbox. Other appearance differences
Last updated:
09/29/2001