How old or rare is that US90 or that ATC110

[oldcodger]

Hi, I have a Aquarius blue US90 and a red 1979 ATC110 honda that I am trying to gather information on.

I originally purchased the two ATC's a few years back from an estate sale with the intention of preparing one for my grandson and maybe using the other to repair a step thru CT90 that has been languishing in my yard. I have since become interested in finding out more about them. I have been on the internet for many hours during the past two years trying to learn as much as I can about them and feel it is time to ask for a little help.

The serial No.s (in the 103600 range), on the US90, would seem to put this one in the very early production runs, The serial No.s and the frame tag on the ATC110 (in the 2059000 range) says it's a 1979. Details on the US90 like a take apart rear axle without a provision for a spacer on the left side, no provision (no screw holes) for a tool box where I would expect it to be, a two position kill switch, folding foot pegs with some sort of a trigger mechanism, an original type front wheel (although now junk), hub adapters on the rear axles (although tires are also junk), a steel front fender, fiberglass rear fender, chrome foot peddle ends, tank badges, and a slightly different grab bar construction all seem to point to a very early model. The details by them selves might not be that interesting but in talking with an individual who appeared to be a ranch hand or relative at the estate sale site (in the country) mentioned riding the blue US90 unit up till the time they got the ATC110. He said they used them first to handle the cattle on the ranch and them to manage the grape vines that have since replaced the cattle. Sort of sounded like they had them from new! I am in my mid seventies and would have guessed that individual was somewhere between late fifties to early seventies. At the time none of that much interested me, I was just interested in getting a play thing for one of my grandsons and I didn't pay to much attention to the conversation as I loaded them. I now wished I had been listening better.

Since then I have come to realize that both units are in very stock condition although I would imagine both have seen many hours of work. Both units had their air filter assemblies and all the covers I know about in place. Like I said the blue unit had an original front tire on it at the time of purchase and some replacement wheels and adaptors on the rear. , The ATC110 had what I would guess were the original large tires on it. Two held air while the third was leaking. Both units have/had head lights at one time. The US90 had a post brazed onto the lock handle for the bars, that mounted the headlight and it is still complete. But, the light on the 110 is missing the bulb, lens, and mounting ring. The front steel fender on the US90 has some rust but no dents or splits, The fiberglas rear deck has some stress cracks but no splits and has no repair patches. the rear deck still has the front rubber edging in modest condition. The whole bike has plenty of scuffs and rust, but nothing out of line for a work machine. The paint looks original although badly worn with surface rust in some areas. The tank looks sound, but has light to modest rust inside and some dents. One gas tank had a gas cap with the on/off lever that I believe was used when a person carried the unit around in his/her trunk so the gas wouldn't spill out.

The ATC110 has the plastic front fender and the moulded rear fender. The front is sound but the rear might be missing some edge material. It has had some work done to the mounting system to clear the tires. In my initial enthusiasm I purchased some smaller, stiffer, tires and wheels but am unsure just how to proceed since we have since concluded that neither ATC is suitable for my grandson, we will be sticking to a two wheeler. The gas tank on the 110 appears to be repainted, but seems free of dents unless their under the paint. It has modest rust on the inside but appears sound. The 110 has the tool box on the right rear of the frame.

Some of the chrome items are in pretty good shape considering their age, like the handle bars, foot levers, and gas caps; but the grab rails have plenty of rust. The exhaust system on the 110 has had some welding done on it and is missing the spark arrestor. The US90 spark arrestor is all but missing except for a small piece held in place by the mounting bolt.
Both units have running, shifting, engines and neither smoke. I have disassembled and ultrasonically cleaned both carburetors. Both required modest modification to the fuel valve levers (Removing the rivets and replacing with screws in order to access the chambers).

At this point I might add that I have worked on many honda and yamaha motorcycles with my children, as a hobby, and still have a few Triumph motorcycles that I ride and work on.

The help that I am looking for is encouragement and information that might confirm my belief that one or both of these units is/are very collectable and what further details might separate these from the "run of the mill". I have followed many advertisements that claim their units to be early but rarely do they give the frame and engine numbers, or comments about details except that they have original type tires that could date from a period 10 years later! I am troubled by the idea that a unit is rare or not rare by the presence or lack of a totally replaceable item like a tire! To me it's like someone saying I have the first Corvette because of the tires. If you want to collect tires, more power to you! But I'm thinking an early US90 has got to be more than just the tires, and that's what I'm asking help with. There must be some differences in the original carburetors, frames, trim or engine details. Maybe something in the frame welds, the cover stampings, or the axle forging? What is k0 and k1 and what do they actually mean? Why not put on your thinking caps and pull out all the stops. Just because a shop or someone "restores" a beautiful unit doesn't make it correct unless it actually is. I can appreciate that every one believes what they have is the best, the rarest, and the most valuable. It's probably what keeps most of us going, but of course it isn't true most of the time. Details from your collection of trikes should help shed some valuable insight on what is actually an early US90 and an early ATC110 instead of just saying it is, and give us something to measure by. Thanks in advance for any help.

[Mr_Gixxer]

They're worthless.

You should just ship them to me so they can be properly disposed of...

[jakep53]

can you please post some pics??

[ps2fixer]

Why can't people on craigslist be this descriptive??



The US90 I'd say is uncommon to rare. I bought one for parts a while back, the OEM tires are about the hardest thing to find good. I did get an "oem like" tire off a 110 with the same bolt patter. For the year, I think they where made somewhere around 1970-73, then at 1974 the model changed to ATC90, and in 1975 they change the tires to the standard rim+tire setup.

As for the atc110s, I think they are much more common vs the US90. I have two I parted out, but I think they were 81-82 and the 79-80 had a lot of parts that were different based on what I can remember.

I attached photos of the tire and the US90 I picked up. I think it was a 1972.

Overall, I'd say post up some photos and I'm sure there are people here with the parts to fix them up.

[oldcodger]

OK, I'm out to get some pictures! but I'm going to try and post one to see if I can do it now. Thanks for the interest.

[ps2fixer]

It looks like it is very complete (unlike the one I had lol). I'm going to guess the rear hubs were swapped, or maybe they had different sized bolt patterns throughout the years. The one I had used the same bolt pattern in the front as the rears (the super small one). Should be a pretty easy job to get it up to being a ridable machine, just cost a bit for tires and such. The front tire I posted would work on it if you are interested in it, if not I'd say swap the front hub system out to a newer style ATC90 and get a rim+tire setup unless you are trying to go for an oem restore. I'm pretty sure the swap is a direct bolt on, but I'm not much of an expert on the hard tails (atc70-200s)

[oldcodger]

OK, here are some more pictures. I grouped them in an effort to save space. Anyone asking can have a full photo if they had a need!

[ps2fixer]

Wow, looks like they either cleaned up quite nicely, or your camera is really misleading.

I'm no expert, but I think the rear rack on the 110 is an aftermarket item and looks to be in good shape.

[oldcodger]

Thanks for the input ps2fixer! I have worked to clean up the blue US90 unit, but haven't got past the first wash job on the red ATC110. I started out just trying to get both running to see if they might be useful for my purpose, bought the rigid tires and moved them around as I pondered. Like you said, I did move the large front tire from the ATC over to the US90 at one point so I could move things around, seen in one picture. The tire/wheel that your showing, is that a Honda piece? Looks like it was intended to retro fit a machine that had the one piece wheels, not aware such a wheel existed! I'm assuming thats a wheel and a separate rim? You are correct in observing that the rear wheels on the US90 have some sort of hub adapter, in that they were made originally for the small three hole pattern. No doubt allowing the use of a later style wheel and tube instead of the one piece unit. Everything always looks better in a photo, but they are pretty clean aren't they, considering their age?

[ps2fixer]

I don't really have a story on the front tire/rim, but it is a standard rim with the correct tiny bolt pattern. Not really sure where the tire is from, I couldn't find any info on it. My guess is that it was intended for a 6x6 or 8x8, but I think they had 20 inch tires.

I'm pretty sure I have an extra atc110 front end if you're looking to convert it over. I should also have some oem split rims with the 110 bolt pattern, just would need to be repainted (spray bombed).

[oldcodger]

Thanks again ps2fixer, mentioning that you have some useful parts is very nice of you indeed, but at this point I am more interested in the information you have to give. I would still like to know if that was an actual honda rim, don't care much about the tire except that someone could find it useful. What year was a rim like that first used? better yet what year did Honda first start using a rim and tire? If it was on the AT110 in 79, didn't they use the larger bolt pattern? Sorry about the time it takes me to get back on the computer, but it may take days at times! No one has mentioned the foot peg mechanism, the left one is definitely broken but is the right one complete or is it missing an "end". It does seem to work OK the way it is! When I read my own message it occurs to me that maybe the bolt pattern on your wheel "is" the big pattern, not the small one like I may have mistakenly understood?

[oldcodger]

Darn it, saw the words "tiny bolt pattern" as I pushed the post button! Also saw that you had already told me that 1975 was the first year of the separate tire and wheel! Getting old is a bummer!

[ps2fixer]

Haha, I'm about 80% sure the rim isn't from honda, the front hub setup matched my US90 exactly, so my thoughts is someone had it laying around. I don't see why someone would go though the effort to get that setup on a 110 since it never came with that style of rim or bolt pattern.

I'm not a super expert on these machines, but I'm pretty sure the first year Honda used the larger bolt pattern was in 1975 on the ATC90 when they went from the 1 piece tire/rim to split rims with a tubeless tire.

I like to use partzilla to confirm interchange of parts and check what was oem factory. For example the link below is for a 1979 ATC110, it came with the split rim and a tire. Sadly, the furthest they go back is 1976, so nothing on the US90s.

http://www.partzilla.com/parts/searc...EEL/parts.html
Reply times are no problem, I'm sure no one here expects you to reply to your own thread within a limited amount of time .

[oldcodger]

Hi again, grouped a few more pictures and have attached them. In the meantime have been trying to do more reading. My impression is that of the posts I'm reading so far, most are riders not collectors. Any one have any suggestions on how to get the collectors to talk about details?

[ps2fixer]

Just noticed your fuel lines, one looks to run to the tank, the other isn't hooked up? Both lines should be going to the thank, one is for on, and the other is reserve.

I think this is one of the only machines I haven't be able to find a service manual on, but here is a site you can get more of a generic atc90 manual, just to have a good reference since the engine didn't change much over the years. Here is a good site owned by kb0nly - http://www.atcmanuals.info/

For the most part, people here want to ride their machine, so there isn't a lot of collectors here that only build a machine to look at (proper full restore with 100% OEM parts etc), but if you direct us a question someone that knows your machine will probably reply, like those rear hub adapters, I don't know if that is aftermarket, or home made.

Also noticed that the chain cover is missing the rubber plug for the oiling hole at the top rear. Kind of looks like the dust cover for that side might be missing too, here is my poor shaped one:

http://atcfixer.com/bmz_cache/6/6471...ge.733x550.jpg
http://atcfixer.com/bmz_cache/8/8b56...ge.733x550.jpg


I re read you first post some and here are some of the major differences off the top of my head of the US90 vs the later production ATC90s (75 and up).

Axle is completely different, the spines used for the hubs are also very different (newer ones are like quads today, the US90 ones are squared off and are large sized per "spine"
The front end is very different too, metal front fender, the removable handle bars and of course the front hub assembly as well as the 1 tires.
Talking about tires, that is the other huge difference. I'm not sure if an axle/hub swap is possible with the later model ATC90, so the tires/hubs/axle might be a 100% indication of what it is (unless the entire carrier is changed, I think they are all the same, bearing sizes might differ though).
The rear fenders are different as well as the rubber edge to them, the later models ended up having mud flaps that stuck out (like your atc110).
I don't think the US90 came with a headlight factory, but according to some past research, the wiring should be there to add it yet.
Also the foot pegs break away (fold in) for easy transport in a car or wagon.

The special thing about the US90s with their special tires is the fact the pressure on the ground from driving the machine is less than a human, so they float easy, and does not sink in sand/mud like other machines.

Here is a fun read.

http://www.3wheelerworld.com/Brochur...e/70atc90.html