125-200cc Is there a slow movement back to smaller cc bikes?

[fitness2go]

That was great...I've been there done that!

Sorry Shane. Gotta post it.
http://vimeo.com/14556360

 

[firffighter]

There is very little corralation between size of a bikes regarding deflection

Boy, gonna have to disagree with you here.

I have sent almost all of my bikes off to reputable suspension folks as this is one of the most important additions to your bike.

That being said, there is no doubt that given two bikes of significant weight difference ridden over the same obstacle laiden terrain will react differently. Lighter bike tend to defect off of obstacles rather than track through them.

That is not to say that those same two bikes cant make the same time over the same terrain, they just do it in differnet ways.

Riding a 450 thumper vs. a 250 2-stroke over the same terrain will yeild much differnt results in terms of how they react to the rocks, roots, corners, etc. Much of this is due to weight and how that weight is distributed and carried by the bikes.

My KTM 200 exc's with full suspension revalve and setup reacted much differently than my WR450f and even my WR250f over the same terrain. The little 200's deflect off of roots and rocks like Shane mentioned compared to the 450 & 250 thumpers which tend to plow through the rocks and roots.

I think Shane said it best though that if you get used to the little bike reacting that way, it can fly through the nasties.

 

[NWRider]

I doubt that it is the slightly lighter weight of the small bores that make them deflect and bounce around more. I think it might have a lot more to do with the reduced gyroscopic effect of the lighter motor parts.

I bet a Husky WR250 weighs more than most MX 450s but the 450s have a lot more motor weight in motion and in turn probably plow through rocks better but take more energy to turn.

The lack of gyroscopic force is why small bores turn with so little effort. A big bike just wants to go straight which makes them very stable but also requires a lot more effort when you want them to not go straight and turn. I don’t think you can have both rock solid stability and effortless turning.

But a WR125 does not bounce around like a KTM 200, at least not in my experience. I think Huskys are just inherently stable, while KTMs are inherently sucky handling, so even the 125 is not awful through rocks. I have also found the WR125 to have a lot less wheel spin then the KTM 200 for some reason so I don’t know if that bike is a good comparison for anything other than static weight.

 

[speedkills]

My feelings are in between the other guys, I think weight makes a difference in deflection, but not nearly the difference of chassis design. So given the same frame I would expect a Husky 125t to deflect more than a 450f, but I know my GasGas and KDX two strokes were much, much, (have I mentioned MUCH?) heavier than my WR125 yet they both deflect a lot more.

I also don't think you can get the suspension to feel as compliant on a lighter bike due to the ratio of sprung to unsprung weight but it's not night and day to me, we're talking 10-20% but you'll notice it.

 

[Motosportz]

IMHO lighter bikes like the 125 deflect more than heavier bikes. Regardless of suspension setup the sprung to unsprung weight ratio goes up on heavier bikes. My ATK 490 (300 pounds) with ohlins and Paolis (SOFT) go through rocks amazingly well. It takes a lot more hit to move 300 pounds than it does 220.

 

[rockdancer]

I had a YZ 125 for a while and I found the forks terrible and it threw me around a lot -came off big time - 4 sale .. gone .. good riddance
motocrossers not really meant to soak up the small bumps as well

 

[LawnDartMike]

IMHO lighter bikes like the 125 deflect more than heavier bikes. Regardless of suspension setup the sprung to unsprung weight ratio goes up on heavier bikes. My ATK 490 (300 pounds) with ohlins and Paolis (SOFT) go through rocks amazingly well. It takes a lot more hit to move 300 pounds than it does 220.

Comming off my softly sprung and valved KX250 I had to get comfortable again letting the 125 dance under you. Of course with my weight it doesn't dance as much as it should. (I'm sure it would choose a lighter dance partner if it could! )

 

[ajaxauto]

Suspention set up is key.Once i got my CR 125 dialed in it would and could run with the open class. Then i got a WR 250 and tryed to race it i just could not make it work for me i even came in last place a few times THEN i had Zip Ty do the suspention and last weeken i won first place over 50 A Plus i was also the first Husky to cross the finish line
over 200 on the line and i finish 37 over all against a field of younger racers So once again get the suspention dialed in and hold on

 

[wallybean]

I agree with ajaxauto and all the others that have talked about suspension set up as key. After Les did my front forks all trail trash just seemed to disappear. No fuss no muss just absorb and run without thinking. They aren't on the soft side as I tend to run my suspension and I have yet to get them to bottom completely even on a few cased gilly humps onto flat road. Now like lawndart, I carry a lot of potential energy around my waist that tends to limit deflection but it is still a hoot to ride something that just works and darts where you look.

Walt

 

[firffighter]

Just wanted to say thanks for all of the insight on the 125. This thread along with the 125 sticky has been very insightful and I am sure leaning toward the little woods weapon because of all of your great input. Even dropped 10 lbs. over the past several weeks in anticipation.

One last question. If you were to compare the motor to another bike, what would be a good or close comparison?

Having owned both the KDX200 and KTM200 would anyone say they are close to these?

 

[wallybean]

Come on over to the Husky gathering in Bend and there will by many husky 125's/144's/167's to ride and see what you think.

Walt

 

[Kevin_TE250]

Come on over to the Husky gathering in Bend and there will by many husky 125's/144's/167's to ride and see what you think.

Walt

Hopefully 2 167's

 

[dfeckel]

I ride a CR 125 converted for woods and a KX 125 with a KDX 200 motor in it regularly. I have also ridden my buddy's KTM 200 XCW many times. Here's my take.

The Husky 125 is either a slow-going low-end chugger or a top-end ripper. The bottom end is tractable and smooth, but not a lot of power. That said, it will lug on the bottom end and surprise you with how well it climbs. It just doesn't climb fast on the bottom end. The top end is a ripping good time, and when she's singing, you really don't want for more power. If you can keep it on the pipe, there's plenty of power for anything. The trick is transitioning from a slow chug up the hill to a powerful rip up the hill. You just can't do it. It's one or the other. If you try, you'll end up having to slip the clutch til Tuesday or you'll just have climb-killing wheelspin. I have an EFM autoclutch in my 125, and I love it in the tight going. It also saves my butt on a regular basis in technical situations. In flowing single track, you can open er up when the trail allows, and then just SLAM on the brakes entering a sharp turn without worrying about stalling the motor. Mmm...good times.

The KTM 200 in its stock form had a very abrupt bottom-end hit that was very difficult to control, but I think this was jetting related. It was so fat on the pilot that it would just blubber along making no power until you cracked the throttle. Just a little throttle, and then the bars wanted to jerk out of your hands. Very difficult to modulate in tight stuff and very frustrating. My buddy did the JD kit and put in a less-aggressive throttle cam, and now the thing is just a pussycat. Progressive build-up of power that's very controllable, and almost boring. It's a-nice. And QUIET, too. If I envy anything about his bike, it's the low sound level. And there's nothing special about the setup--FMF Fatty pipe and the KTM accessories spark arrestor, which is just a relabelled FMF TC II. I think KTM's airbox design has more to do with this than anything.

Now, I'm not a big fan of KTMs. Not that I think they're ruining the Earth or anything, I just like to be different. That's why I got the CR 125 to race in the 200 class. But after having some difficulty with hill climbs in the rock runs of PA and NY, I thought having the extra 75cc might help me out a little. That's why I built the KX-DX hybrid bike. It's a 2003 KX 125 with a 1990 KDX 200 motor in it. I had the suspension revalved by Drew at WER for rocks, and I put an IMS 3.2 gallon tank, an 18-inch rear wheel with trials tire, and my Scotts damper on it. Motor-wise, I had Ron Black of RB designs shape the squish in the head and bore out the stock 35mm carb and do his magic on it (Ron is a KDX guru, and dozens of guys have done this exact mod with brilliant results--Ron can do it with his eyes closed). This motor is a low-to-mid rocket ship. It's hard to believe all this motivation comes from only 200cc. I routinely run a gear higher than what the CR would run, and I get smooth power from 12 rpm all the way up. The heavy KDX flywheel and the extra-low first gear let the motor lug down to impossibly low rpm when you're in really tough, technical situations, and you hardly have to touch the clutch. The RB motor will then smoothly pull from the lowest rpm with just a crack of the throttle. All other woodsy situations, second through fourth are great. In fact, I usually start out in second. Fifth isn't terribly tall, but it gets me down the transfer roads well enough (I'm running 13-51, where I think the stock KDX is 13-47?) But where this motor is truly magical is on hills. The meaty low-to-mid lets you do whatever you want. Chug up the hill slowly on the bottom end? Check. Rip up the hill on the pipe with the ample mid-to-top? Check. Start with a lug and gradually increase speed up the hill? Check. There is no flat spot between the low and the top like with the 125. The transition between the rev ranges is so smooth that you can start slow and just add throttle to go faster. It makes hill climbing a no-brain process. The 125 you have to think ahead and stay committed to your plan. The KX-DX is at your command. Slow or fast or both, it'll just motor right up.

With all that said, I'm not getting rid of the 125. I like it in the sandy flats of S. Jersey. It still rides lighter than the KX-DX in the ultra-tight Jersey stick farms (although I think the weights are very close), and that top-end rush is just intoxicating. Plus, it's a lot better in sand whoops than the rocks-valved KX. I just put a new ring in it (after probably 80 race hours), and I replaced the dented stock pipe with a Fatty, and I'm love with the thing all over again. I think a factory 144 kit is in my future, as well.

So I say get a new WR 150. It has an acceptably sized tank, or get a leftover and an IMS. Fiddle with the suspenders. Get one of Kelly's Kehin carbs. You're going to love it. If you ride hills more than anything, well, maybe consider a 200. (I wonder if KDX motor would fit in the new 125 frame??...)

Photo from the 2010 Husky Gathering, where the 125 brigade was well represented.

 

[speedkills]

Just wanted to say thanks for all of the insight on the 125. This thread along with the 125 sticky has been very insightful and I am sure leaning toward the little woods weapon because of all of your great input. Even dropped 10 lbs. over the past several weeks in anticipation.

One last question. If you were to compare the motor to another bike, what would be a good or close comparison?

Having owned both the KDX200 and KTM200 would anyone say they are close to these?

I would not say there is any chance you would mistake a 125/144 for a 200. A good running 144 probably makes as much power as a stock kdx200 as they weren't known for being rocketships but it makes the power very differently. The little motors just don't have that low end torque. It's like comparing a 250 to a 500, in many situations the 250 is just as fast or faster, but nobody would say a 250 feels like a 500 and I don't think many folks would confuse a 144 for a 200 either. It's actually shocking how much different a few CCs makes at that size, a 144 feels very (to me anyway) different from a 125 and better in every way. I really think around 150-200cc is the sweet spot for the type of riding I do but even in that range there is quite a bit of variation in how the bike runs. For what I'm riding right now a 144 is working out great but I definitely believe there are places a 200 would work better and wouldn't try to talk anyone out of a 200 if that is the size bike you have found works best for you. Worth a ride anyway, but compared to a kdx200 anyway there is really no comparison in any way other than they both have two wheels.

 

[rasputin]

i haven't read everything here, but...

here are two links to the most inspiring article i have read in a long time. actually, i cannot recall how often i have read it...

part 1
http://www.dirt-bike-tips-and-pics.com/future-of-two-strokes.html

part 2
http://www.dirt-bike-tips-and-pics.com/the-experimental-motorcycle-association.html

enjoy.

r

 

[speedkills]

That's funny, I have read those same things a few times myself. Seems like those articles pop back up every few months and I always enjoy giving them a read. Reminds me of some of the great work Bombardier does with two strokes, I remember the first time I put one of their snowmobiles into reverse the admiration I had for their engineers. Such a simple concept, but such great execution. You hit the reverse button and the engine dies, then just before it stops spinning the timing changes radically and it refires off, backwards. There you have it, reverse without adding a pound to the machine.

Those guys are really thinking.

 

[letitsnow]

That's funny, I have read those same things a few times myself. Seems like those articles pop back up every few months and I always enjoy giving them a read. Reminds me of some of the great work Bombardier does with two strokes, I remember the first time I put one of their snowmobiles into reverse the admiration I had for their engineers. Such a simple concept, but such great execution. You hit the reverse button and the engine dies, then just before it stops spinning the timing changes radically and it refires off, backwards. There you have it, reverse without adding a pound to the machine.

Those guys are really thinking.

^^^

 

[rasputin]

Reminds me of some of the great work Bombardier does with two strokes

not bombardier. rotax.

r

 

[Norman Foley]

not bombardier. rotax.

r

Doesn't Bombardier Recreational Products (BRP) own Rotax?

 

[wallybean]

Rasputin,

Give us a hint on the '12 two stroke engines. FI? DI? At least the 250/300 in the new frame with E start?

Enquiring minds want to know.