I have a '97 CR250 frame, modifications minor compared to other AF's?

[RM_Rider14]

I want to start compiling parts for the conversion and I was just given this frame, is it worth using it or should I go with a different frame?

  Thank you much-

[PowerFiend]

If you are doing a CR500 conversion it is supposed to be fairly easy, but that frame was too stiff and didn't handle well. Every year since Honda has introduced more flex into the Al frame.

[Motorrad]

One of the worse frames I ever rode.  Made Jeremy mcgrath leave Honda it was so bad. 
IMO Honda didn't sort the AL frame out till 2001 2002 ish

[ShadeTreeFab]

i talked to a guy that did a '99, he said the kx5 fit better and was easier to do then the cr5. '97 to '99 is basically the same

[RM_Rider14]

Thank you all for the replies, I appreciate it...

[kritter811]

02 or newer CR250 frame is your best bet

[dave916]

02 or newer CR250 frame is your best bet

  the 00 on frames required a lot more work to fit the cr5 engines than the 98-99 frames, i assume it going to be similar with the kx, i have got a couple of cr5 97-99 supermoto fitted with crf frontend and differ shocks, good stiff chassis for supermoto, i think the 97 was a stand alone year suspension wise as the 98on changeed alot

[dubious01]

97 was the stiffest year, 98 had subframe and linkage changes, 99 had swingarm pivot changes to the frame to allow for more flex, but that was the wrong end to reduce stiffness.
I found my 99 CR500af still cornered really well, but unforgiving in that the front would push and slide out from under the bike if ridden real hard, and there was no warning when it was at the limits of adhesion... poor feedback from the front suspension due to chasis stiffness.

00 up the changes were increased flex around the steering head

[RM_Rider14]

Ok, I have a '01 CR 250 complete bike now in mint condition.  Would this be better suited for the K5 AF conversion?  If not it's getting sold also....

  TIA-

[81cr450]

I did a kx500 in a 02 cr 250 . Literally the best bike I ever have rode only short coming was I didnt get an oversized tank & ran out of fuel like 4 times. I sold it & am doing a 01 right now. The frame is stiffer on it but I like the idea, aluminum flexing sounds bad, as it will only take so much bending before it breaks. The hardest part of the cr250 swap is where you have to end mill the back of the case & drill out the swingarm bolt size through the case. PM me if you want & I can send pics of what I'm saying. You dont have to cut & raise the Y with the kx 500 either in the 02 frame, & it looks like I wont have to with the 01 but I'm not that far yet, should know tonight though. You drop the front mounts enough to clear the Y , but you have to watch the kick starter as the frame is tight around it in the forged area where it pivots, I'm hoping the 01 will be better here as well. As for pipe I did the kx500 to cr500 but I split it at the center line of the tire. I dont feel the power of the cr pipe is right for the kx motor & am going to try all kx500 pipe this time with a bunch of cut & rotate. Eventually I'd like to have CPI custom make one , as I live in Utah & could just drop it off for a couple weeks, but $$$ will prevent that now. Also I had to shim the radiators out because I dindnt have the bung welded shut I just capped it but it worked. coolant routing was all in the right all out the left & never got hot.  If someone could send me a link to a sticky on how to post pics I would, I just dont know how on this site   

[81cr450]

Oh crap what a pain. The 2002 is easier to do, due to a smaller diameter swingarm pivot area. I got it & the pipe will clear with out raising the Y ,so far anyway, I havent checked kick start interferance yet which will be the tell all. I'd like to have a 02-07 swingarm to look at to see if it is diameter or width, cause if it's just diameter you could pick one up on ebay & not have to diegrind a bunch on the swinger & just use the one for the newer bike.  One other comment on using your 97 vs 00 or newer. The 2000 & newer had a newer design of front fork that I feel would be a waste not to use. Anyway just my 10 cents, if I can help feel free to ask.

[RM_Rider14]

Thanks, I am starting the process this coming weekend.  I picked up a '00 K5 motor so I don't have to take my K5 apart now   I'll be coming to you with some questions if that's ok?

  TIA-

[81cr450]

Certainly, got her in the kitchen  workin on motor mounts. Great photo op time where its at in the conversion process