Check my feedback before buying from me
First time rider
Wow, was the fuel tank molded with an extension in it like that? I don't remember ever seeing anything like it. Mike, can you elaborate on the geometry of the ATC500R frame. I spoke over the phone with Marty a few years back. He mentioned some change in the rake of the steering stem. I'd love to know how the frames were modified.Originally Posted by CoeShow
Tundrawillie,
Honda took frame geometry numbers (rake) and went to a local shop that had fixturing capabilities. The shop then cut, rewelded and re- gusseted the steering stem of a production ATC250R frame into its new position. There were a number of other smaller alterations as well to accomodate the forward mounting of the fuel tank, radiators and other parts. Thats all I can recall about the frame changes. The work was professionally done and invisible to the eye under new paint and assembly. The fuel tank in the photo of Marty's racer is likely made of aluminum. It appears to be made to hold additional fuel volume over the std Honda optional plastic short course tanks and carries this fuel a little lower to find the space for the additional volume. I feel it was similar to what the works MX teams used to run on the bikes. While it may have looked "trick" and unique, I doubt there was any performance gain other than longer run time between re-fills. Perhaps there was a race with a long moto where the std. short course tank would not have allowed sufficient distance.
Last edited by CoeShow; 11-02-2010 at 10:05 PM.
Always finding new and exciting ways to not give a hoot in hell
Catch me if you can
Mike,
Its funny we're talking about the ATC500R again now, because we were just having a discussion a few weeks back. http://www.3wheelerworld.com/showthr...rail-of-Trikes It got a little heated, the debate between it and a new in the crate 250R that was on ebay recently. I guess I'm the skeptic (Not that they ever were, but that one or more survived and are still around). Would sure love to be proven wrong though!
Hey did anyone else notice on that picture Jez posted, the pipe is on the left hand side like the earlier model 250Rs, instead of around the right hand side? The panel under the short track tank almost looks like its a heat or knee guard of some type for flat tracking but its on the wrong side for left hand turns?
In the photo of Marty's race trike, the pipe had to be made on the left side to clear the custom low fuel tank. It seems to me it would have been better and likely easier to build the low tank on the left side allowing normal clearance for the pipe and kick-starter. That way all of the available current pipes could still be used for tuning. Maybe Marty will inform us if he remembers someday.
Last edited by CoeShow; 11-03-2010 at 09:23 PM.
Registered User
New to the board
Don't mean to hijack Coe's thread here so if it needs to be moved please do do.
Well it only took me 2 years to unearth my old pictures and not a ton from Porterville. Pre-digital didn't provide nearly as many.
Here are a couple.
The static one is me(105) with Charlie Shepard (126) next to me waiting for practice I believe.
Registered User
New to the board
Mike,
I remember racing the 2500cc Amateur class in Columbus, Ohio in ~1985. I remember seeing the modded ATC250R frame "works" bike you guys had at Honda there. Believe it was Marty's bike, like in the photo.
It was so easy to tell the frame had been modified by the rake of the forks. You could tell at 100 yards that frame was not stock.
AATVA allowed that back then? I thought there was a production rule to an extent or was it Honda's deep pockets that got it through cause I would bet dollars to donuts that Kawasaki would not stand for it!!!
Don't remember seeing it run much after that though.
I also remember when Honda disbanded the entire race program - was the end of 1987 or early 1988. We had desert support from Honda in '87 and had won the 250cc 4-Wheel class at the Baja 1000 that year.
Bruce O' called me up to say they were "liquidating" their supplies and to come on down. I was like a kid in a candy store. All pretty much stock stuff but got a truck load of parts. Only wish I had my Ohtsu desert tires in state as he was swapping any old tire out for the new ones. I know the Ohtsu tires for short course were junk but the desert ones were hands down better than anything else.
I wasn't privy to any actual machines at that time and I imagine you had to be further inside than I was. Likely got transferred from the dumpster to someones truck.
All this ATC reading/talk I think I'm going to have to find a way to get one back in my collection....
Ben,
I'll have to disagree with your comparison of how noticeable the frame changes were to the trikes. I also rode a race trike with the same frame mods as Marty, so we both raced them. Again, while you could tell differences between a stock and modified with trikes side by side if I were to point out all of the suttle differences. By itself, it wasn't that obvious. To me the biggest tell-tale was that the seat cushion was mounted (bolted instead of latched) noticeably forward of the plastic part of the rear fender. Besides, the changes WERE small. You can't alter the rake too much and still use the same triple clamps and forks without affecting the handling in a way that would hurt performance.
I can tell you from experience that the forward mounting of the tank, seat, radiators and other components influenced better performance than the slightly steepened rake. If I would be doing this today, I wouldn't even waste the time and effort it took to modify the steering stem. That part of the mod provided the least improvement IMHO. There were other frame mods that altered the engine mounting location and other elements of the entire trike, more than just the steering stem angle.
As far as the rules, I don't know. We had used complete custom one off chromemoly chassis' built by Nick Nicholson and my brother Sam. There were never any issues that I can recall. It was really all evolutionary on the ATC250R. The changes would have most likely been incorporated into following year production trikes had they continued to be manufactured. The Honda engineers were very sharp. The custom "works" cylinders were made from custom modified cylinders that we used to race with. (most of custom Paul Turner ones I had were SLOW) The production JAP cylinders were great right out of the box. These cylinders would also likely been incorporated into following year trikes as well. I believe that the works ATC200R style swingarm and axle design would have been introduced with a 1988 ATC250R version had the trikes not been discontinued.
Last edited by CoeShow; 11-03-2010 at 09:52 PM.
First Time Rider
Arm chair racerNew to the board
Hi Mike,
Went through a couple of my old magazines last night and found this picture of you on a late '84 model 250R that looks to be watercooled. Is this one of the bikes you mention earlier in this thread? It looks very trick! Can you shed any more light on it??
Thanks for spending the time to answer these threads. It's great to have you on the site.
Cheers,
Jez
First Time Rider
Arm chair racerNew to the board
Also found these:
Jez,
Wow, I had forgotten about those! Honda of Japan sent over left side covers equipped with water pumps along with quite a number of water cooled, nikasil plated cylinders and matching cylinder heads designed to fit the early air-cooled engines. I had a friend of mine who owned (still owns!) a radiator shop, custom make a half dozen or more radiators that would fit along the right side of the frame below the tank. with a simple hoop welded to the frame and a few rubber mounts and simple aluminum shroud and hoses, POOF, water-cooled ATC250R!! Everyone knows the benefit of water cooling. It enabled the engine to run harder, longer, while making more power without over-heating and slowing down. I designed all ofthe components myself and had my buddies and brother fabricate all of the necessary external parts. All of the engine components were bolt on items. No alterations to the engine were required to accept the water cooled parts. To be perfectlly honest, I liked the power delivery of the 70mm bore and 64mm stroke 250 engine better than the soon to be released 85 ATC250R's long 72mm stroke with 66mm bore engine design. DG Performance ported some VERY strong cylinders and we made some excellent working pipes as well. Again, these engines really ran well and IMHO were better suited for ATC racing.
The additional pictures are cool as well. The girl is my wife(ex now), Miss Parker and Miss AZ. runner-up, Samantha Roper. The pictures of the trikes are of Marty and me at Riverside 1985. A real battle royal. Well, not really. I would battle to pass Marty through the rough sections of the track, only to have him blow by me down the long "Thompsons Ridge" straightaway section of the course. I can remember getting into 6th gear down this straight, getting tucked in and Marty would go by me with at least 10 mph more speed and pull away by about 20 yds. before the end of the straight. The finish line was right around the turn following Thompsons Ridge, so Marty won both moto's. We went back and forth every lap. I would be leading coming onto Thompsons Ridge and Marty would pass me easily down that long straight, every time! Very dissapointing. It was so very clear who had the power. It made me sick and ANGRY, but I HAD TO RUN TURNER (junk) PARTS. Marty's trikes were always noticeably faster than mine during most of the 1985 season. This year at Riverside really turned into a race between Marty and me. We left everyone else quite a ways behind. If the finish line had been at a different location on the track, I would have won this race, no question. Thats the way it was in 1985.
Glamy,
I think it's great that you still have your 250R! When you mention, "Could it be the one" concerning the ATC500, it sounds as though you suspect it may be the original ATC500 that Marty rode. The answer is no. The trike you saw was a CR500 engine swap, no question. The factory ATC500 would not have to flip the seat up and out of the way to start it. It would have kicked forward like your 250R. You don't bore me! I hope you have other questions. Keep 'em coming.
Last edited by CoeShow; 11-06-2010 at 08:24 PM. Reason: typo's
Always finding new and exciting ways to not give a hoot in hell
Catch me if you can
Mike,
What do you see as probably one of the bigest areas of improvement that here we are even 20 years later still probably over looking on most machines? Suspension designs, weight bias forwards/backwards, lower center of gravity, more emphasis towards lighter weight, rotating mass reduction, etc?
Billy,
I don't really see anything that is being overlooked. Had the ATC stayed in production, I feel certain that evolutionary changes would have certainly been made in an effort to continually improve the product. It would have been the same as we see currently with the MX bikes. Until recently when Yamaha tilted the cylinder back, the changes to bikes have mainly been quite small overall, but improved none the less. 3 wheelers would have been the same. Especially if the other manufacturers were on board like with the quads.
Always finding new and exciting ways to not give a hoot in hell
Catch me if you can
Thats cool Mike. I just was curious. We are lucky to have a lot of very talented custom builders/fabricators and machinists here on the site. I love doing that type of stuff as well, and I think we all strive to try and keep improving and adding and making things better, trying to keep up with technology. Its fun to dream about the sort of changes the manufactures would have made with another 20 years. Would the trikes have been closer to 2 wheelers are as far as the level of evolution? Or quads which, arguably really haven't changed all THAT much. Certainly not as much as dirt bikes have.
Check my feedback before buying from me
First time rider
Mike, it's such an eye opener to hear about the politics involved, specifically back then, between Marty being the "golden boy" and at the same time, you being the superior rider fighting to win with inferior parts on your 250R's. As a kid, I imagined that all the Team ATC250Rs were mechanically identical. One thing I know...the magic of you guys in the old magazines will NEVER be topped by any sport or publications.
Reply With Quote