Best Hybrid---KX125 or Cr125 ???

[GS]

Considered this for some time and I have a 220R that isn't getting ridden much.....and I've always dreamed about a KDX-powered woods-weapon.
But, which chassis is best and what years work best???

Can some one enlighten me please? I have read many postings, so not completely in the dark....but not much feedback after the conversion.

Thanks!

[dfeckel]

The newer the KX chassis, the better, I'd say. '03-'05 KX 125 chassis are pretty easy in terms of getting the KDX motor to fit. Theyt have a rear had stay, so you have to cut off your front one. I built mine from an '03, and it was pretty easy. The CR 125 hybrids look pretty enticing, as well, but maybe technically a little more difficult, since the CR radiator coolant flow through the radiators is not the same as the Kawasaki flow. Also, at least one person had some clearance issues with the KIPS mechanism and the front of the CR frame, necessitating some creative grinding and welding. That said, an aluminum framed KDX hybrid is pretty neato...

I'd say if you can get a screaming deal on one or the other, then go for it. If a cheap CR comes up on CL, then go for the CR. If the KX comes up first, then go for that one.

[Tedh98]

I agree on going as new as you can find/afford. I would also try to ride a few different ones to see what bike fits you best.

[Julien D]

I very much prefer a steel frame to aluminum, so the KX gets my vote.

[SS109]

Juliend, I don't think I have ever heard you state exactly why you are against aluminum frames. Aluminum is used in the aerospace, automotive, and motorcycle industries with great success so it is hard for me to understand your aversion to it in DB frames. So, why do you not like aluminum frames so much?

[fuzzy]

There are lots who don't. For one they are more rigid then steel, and can pose more vibration problems.

[Tedh98]

Many think or assume there is a big weight advantage. I've never personally weighed the difference, but have read multiple threads were the weight difference between and AL and steel frame wasn't much. The thought was that you had to use a lot of AL to get the similar strength of steel.

I think the big desire for an AL frame is the cool factor and having the latest and greatest.

Unless you can weld AL or know someone that will do it for free, fabbing AL is going to be more expensive than working with steel.

The only advantage I can see of an AL frame is not having to worry about painting, PCing, chipping, etc.

[dfeckel]

The big disadvantage with an Al frame in my mind is access to the carburetor. This may be a moot point if your jetting is spot-on for all conditions, but if you like to fiddle with the carb, an aluminum frame makes it very difficult to do without raising the sub frame and possibly removing the shock.

Actual owners of CR/KDX hybrids correct me here if I'm wrong.

[Julien D]

Juliend, I don't think I have ever heard you state exactly why you are against aluminum frames. Aluminum is used in the aerospace, automotive, and motorcycle industries with great success so it is hard for me to understand your aversion to it in DB frames. So, why do you not like aluminum frames so much?

First, there must be so much aluminum used in an aluminum frame to provide equivalent strength to a steel version, that the frame becomes very large, and the mythical weight saving is not realized. Most ally frames are actually heavier than their steel counterparts. It is also much more rigid, so more feedback is felt by the rider in rough sections. The bulk of the frame also makes it more difficult to access/work on the engine without removing it from the bike.

That just about covers it, I think. Just another marketing ploy, basically. Japan was short on good steel, and was able to manufacture aluminum frames quite a bit cheaper. So they throw it out there as "new, IMPROVED, aluminum frame!" And people ate it up. So far as I can see, the only advantage is that aluminum doesn't rust....

[SS109]

Thanks for the info gentlemen. That is what I was wanting to know. I like the aluminum frames but I can see the maintenance/jetting issues.

Not that I'm saying AL frames are the best but, other than what I said above, I don't see them as a negative per se. More feedback isn't necessarily a bad thing and neither is being more rigid. One of the many reasons we go to the KX forks is to get the rigidity. As far as the weight goes, from what I found looking at the specs for KX250f models, steel vs. aluminum, the weight is virtually identical between them.

I think for some it is definitely for the bling/new factor but for others it might just work better for them. Different strokes for different folks and all!

[Julien D]

Rigidity is a good thing to a point, but generally for trail riding / enduro / HS, you want the bike to have a certain amount of "flex", as it helps with control. I recall when honda first put out the aluminum frames, everyone complained about how "stiff" the bike felt.

[Fletch]

Rigidity is a good thing to a point, but generally for trail riding / enduro / HS, you want the bike to have a certain amount of "flex", as it helps with control. I recall when honda first put out the aluminum frames, everyone complained about how "stiff" the bike felt.

True. My friend rides track days on an 06 r6 and it's so much stiffer than his old 04 r6 that his lap times are only now getting close to what they were. He and his riding buddy(who made the same switch at the same time) say it's so stiff that he can't get feedback from the frame before it starts to get loose, unlike his old bike.

We have an old saying in the MTB world. Steel is real, flexy that is....

[GS]

Thanks for the replies. It doesn't sound like one is decidedly better than the other, maybe just different?

defeckel: Does the bike you created live up to it's 'promise'?

I have a hard time finding much in the way of post-construction comments. And, I'm not looking for something just to keep me busy!!

I've owned a 2003 kx125 and liked the handling very much, but the power/delivery was all motocross, not the cut and thrust of single-track or trail riding that is such great r & r for the soul.

I love the look of the Al frames, but very good points have been made about the practicality.

Thanks to all!

[Tedh98]

GS - I remember reading many post construction reviews from hybrid owners (all positive by the way), I think they are just buried within other posts and difficult to find.

I really like my hybrid. I've had 125s, a 250 and a kdx and the hybrid really is the best of them all for me.

As I mentioned, I think your best bet is to ride a few different bikes to see what fits you best and which one handles the best for your ridng style. Putting a kdx motor in a bike isn't going to make it fit you better or make the suspension/handling better.

[SS109]

I had heard of the problem with the early Honda AL frames being too rigid but I have never heard that complaint with the AL framed KX 4T's. Also, in defense of the early Honda AL, just like anything new, it does take some time to figure out what works best. Just look how forks, shocks, brakes, power valves, etc. have evolved and improved over the years.

[dfeckel]

I love my '03/'90 KX/KDX hybrid. I set it up for hills and rocks, and it really excels. It's light, easy to flick, holds a line very well, and with the 18" rear wheel, trials tire, auto clutch and soft rocks valving, it'll plonk through anything. I gave up the stock KX whoops pounding ability with the rocks valving, but if I twist the clickers clockwise far enough, it's pretty good, and way better than a KDX. It's definitely a neat bike to own, especially since there's never another one like it at the enduros. The only real problem I have with it is that I used an E series motor, so I've had the wimpy KIPS valve issues. My first set of new valves lasted only about 30 hours. I'm using the Juliend Bigfoot reinforcement plate now, so I might get more time from my new set of valves, but I have an H motor ready to go in should they fail again. I definitely recommend an H motor for hybrid attempts.

Was it worth all the hassle and cost to build and modify for woods use to save 20 pounds? Probably not. I could have spent half the money to pimp out a nice H series KDX, and gotten 90% of the performance. But you'll never save that kind of weight on a KDX, and you'll still be stuck with the old-world ergonomics. Plus, I do kind of like riding a bike that I built all by me onesy, savvy?

I do think the aluminum frame hybrids are very cool, and if you avoid the first generation Honda frames, you'll be quite happy with the results should you decide to go that way. They are just a bit more difficult to build, and when you're done, they kind of look like a Honda.

Now if you build a hybrid using an aluminum KX 250f frame, well, you've achieved a whole new level of cool in my book...

[KarlP]

I have a '99 CR250/KDX 220 hybrid. It was not a terribly difficult build and is a great woods bike. I think the '99 CR frame is a first generation AL frame. I definately had to put a lot of time and money into getting the suspension to work. I raced it in Enduros for three years. It was and continues to be very picky. When it is right, it is REALLY good. When it is off a bit it is terrible. Little things like tire pressure, built up air pressure in the forks, slightly worn linkage bearings can make the thing really sucky.
If I was going to do another hybrid I'd use a much newer frame. Steel frames are easier on the fabrication side, apart from that I don't really have an opinion either way.

I've since bought an '08 KTM200 and really like it!

I've converted the CR hybrid into a trail maintenance machine with mounts for a chainsaw and other tools.

[zomby woof]

I'm surprised you guys are building MX hybrids for single track. I have an RM 125 and it can't touch the handling of my KDX in the woods. I understand the KDX weaknesses, but for single track, I love it.

[GS]

Thanks for all the response/discussion.

I like the idea of the lighter/lower weight of the KX/CR.....of course my most frequent mount these days is a DRZ400.....2-ton Mabel!

KarlP: YIKES....it's been relegated to tractor duties!! Guess that reflects the fondness you have for the KTM, eh?

So, guess I'll keep an eye out for one of these bikes, sans motor, and see what comes along.

THANKS!

PS...I've been more or less off the KDX and this site for a while and just read a little about the passing of Inda.......very sad. He has helped a whole lot of people, myself included and certainly deserved to have many great years ahead of him. Sometimes life can be so unfair.....RIP, Mr. Inda.

[frankenschwinn]

I'm surprised you guys are building MX hybrids for single track. I have an RM 125 and it can't touch the handling of my KDX in the woods. I understand the KDX weaknesses, but for single track, I love it.

My kx chassis handles so much better for me but I am not tall so the 125 chassis fits me better.