I have heard from numerous posts on this forumn as well as from other racers that the 1986 TRX250R frame is stronger (and consequently a little heavier) than the '87,'88, and '89 frames. Does anyone know if this is true or not? I know that the '86 was considered to be the fastest R because it's a long rod motor but this info about the frame is new to me. Any help is appreciated. Thanks!

 

seems like i heard that somewhere too. I dont really have any substantiating proof, but it wouldnt suprise me b/c when companies redesign stuff, they also try to figure out how to make them (in their minds) more efficient and may have changed the frame to cut costs.

yes the 86 was the fastest year. it was the short rod engine and it revs faster than the 87-89 models. 6th gear was also a little taller than later years'. mine has left quite a few newer ones with more mods (not like a 310R or anything) sitting there.

 

The '86 (I believe '87 as well) frames have extra gusseting. It is pretty obvious if you have an '86 or '87 beside an '88 or '89. The other weight difference would be the swingarm is steel in the '86/'87 and aluminum in the '88/'89

 

See I thought that the '86 was a long rod motor because it has a smaller bore but a longer stroke. I heard that the '88-'89 motors were the short rod motors and that they revved higher and produced less vibrations but were less powerful than the '86-'87. Maybe I just have my years crossed up.

 

Kennyroo now that you mention it I have noticed my frame has more gussets around the shock mounts and on some lower parts of the frame. The mounts attached to the frame that hold the front motor mounts also appear to be a little beefier.

 

The 1987 and later TRX 250R's come equipped with a crankshaft that has a connecting rod that is 5 mm longer (center to center) than their earlier model cousins (1985 & 1986 ATC250R & 1986 TRX250R & the 1984 thru current model CR 250R). The piston of the long rod version engine has its wrist pin located 5 mm higher to offset it.

The 86 engine has a slightly more definite hit to it when the powerband comes on. In 1987, they were attempting to change this and create that electric feel.

 

DAMN! And I thought I knew my stuff! So whats your favorite year? Obviously mine is the '86 because I have one plus from what you've told me its quicker and stronger. I have an aftermarket aluminum swing-arm that is stock length so its as light as an '88-'89 but has the stability of an '86. Actually it's a little lighter because of all the aluminum parts and chromoly a-arms I've added. Thanks for the info. Now I feel good about that '89 I passed up for mine!

 

For years I have been trying to clear up a misunderstanding about the CC displacement of the TRX250R.

In stock trim, all years have the same bore and stroke. They are all 246cc.

The 86 was the only year of the short rod.

By increasing the length of the rod for 87-89 models, they moved the wrist pin up higher in the piston (and used a much different piston than the 86). This keeps the top of the piston in the very same location as the 86 model.

You can stick any year cylinder on any year bottom end (provided you're using oem parts) and it'll run just fine. You can stick an 86 jug right onto an 89 and go.

Now, I'm sure you've seen some people using spacer plates on the bottom of their cylinder. The only time you need to do that is when you use an 87-89 crank and stick in an 86 piston. This still will not increase your bore/stroke.

Anyway, I have an 86 and my wife has an 87, both are freshly rebuilt and still run great! At this time, we still don't have frame cracks on either of them.

And they run right along with any of the 88-89s through the dunes!

 

Not to **** anyone off, but the 88-89 250r is much better the the 86-87 models in my opinion. I owned an 87 which I loved, but my brother's 88 handled slightly better. You can not swap thing such as a-arms from 86/87 with 88/89. They changed various things from the 86/87 model to the 88/89 model.. My favorite year is the 88, I think that is the year that Honda had everything going right for them. 86-87's used different swing arms and the bikes are about an 1" longer then 88/89. The swingarms sucked and some have cracked in the past, the newer prolink design is much better. In all, the 250r frame is the model after which all other frames copy. I now ride a 450r and I still like the way the 250r fly's better then every quad I ahve ever riden (z400's and yfz450's included)

 

The 88/89 R is definetely a better MXer because of the shorter swing arm and higher revving motor. However, I race XC and the only thing stock on my bike is the frame so at this point when most R's are so higly modified a 250R is mostly judged by the amount of aftermarket parts it has. My swing arm even though it is aftermarket is the stock 86 length because I like the extra stability it adds and how it keeps the front end down. In the end though a 250R is a 250R no matter what year and in my opinion they are still king.