Post by: Uniflow on December 08, 2012, 10:56:43 PM
Another point, this fourstroke changes direction much easier than it should, why? It turns in much better than my 250T, same weight. Are the frames that much different? Or is it the fact that the fourstroke has a counter rotating balance shaft helping negate flywheel mass?
Anyway I won't be trading my 250T any time soon but I did like this YZF. The bike I was riding is the YZF I bought to use the frame as a twostroke project bike. It does seem a pity to take this engine out, probably change my mind when it need's it's next piston and I'm so over oil changes!
Post by: Stusmoke on December 08, 2012, 11:09:54 PM
I confess I rode a fourstroke 250, and liked it! But before I get tossed out of this forum let's have a little look at what I rode. I like my 250T, love to ride it and will never sell it, but was surprised, no shocked, at how well this little fourstroke went. Tight, bumpy, slippery track where power was not needed in fact was a disadvantage. Hook up was the key, many twostrokes were there and most of the time sideways. This little fourstroke would just hook up and drive, like it was stuck to the dirt. The key to future twostroke development is to make them perform the same but less weight and more power. It needs to be under control! I think it's going to take more than just changing the frame on twostrokes to modern fourstroke design frames , whats needed is a form of traction control. I can see there will be howls of outrage ( no electronics ) but that is whats letting the twostroke down! In their favor they are much cheaper to run ( twostrokes ).
Another point, this fourstroke changes direction much easier than it should, why? It turns in much better than my 250T, same weight. Are the frames that much different? Or is it the fact that the fourstroke has a counter rotating balance shaft helping negate flywheel mass?
Anyway I won't be trading my 250T any time soon but I did like this YZF. The bike I was riding is the YZF I bought to use the frame as a twostroke project bike. It does seem a pity to take this engine out, probably change my mind when it need's it's next piston and I'm so over oil changes!
Traction control... For real? Why don't we go ahead and throw in a jake brake, automatic transmission and abs brakes. Its a stupid idea no matter what stroke of the bike. Motocross is what? An extreme sport. This extreme sport was already made a hell of a lot easier when four strokes became dominant why on earth would you make it even easier? It used to be you were racing on sundays and gyming every day of the week just to pull a 7 lap moto on a smoker. Now local riders are smothered in puppy fat.
This sport is designed to be extremely difficult and demanding. To the point that it takes a proper dose of dedication to go far. Now its just getting easier and easier. Instead of traction control, why don't people just learn how to ride properly?
Post by: cnrcpla on December 08, 2012, 11:42:01 PM
Quote
This sport is designed to be extremely difficult and demanding. To the point that it takes a proper dose of dedication to go far. Now its just getting easier and easier. Instead of traction control, why don't people just learn how to ride properly?Well put. Motocross is dangerous, but with people seeing these bikes that are so easy to ride, throwing a leg over them and ripping is easy, until you loose control and then you have like 250 lbs hurdling out of control with a rider on it. MX isn't what it used to be, whats next pods that are crash proof that can do 200 mph though a track by itself with someone sitting inside? That's where I see it going, the less skill going into something, the less interesting I see it personally.
Anyways, four strokes are good for that, easily being ridden. I'm sure I could have a fair amount of fun on a 250f in the woods, but I would never want to miss the hit of my power band. Though I disagree with traction control and whatnot, I see your point. It would make riding easy. A little to easy though
Post by: Jeram on December 09, 2012, 12:18:47 AM
Post by: ford832 on December 09, 2012, 12:32:47 AM
Post by: Stusmoke on December 09, 2012, 01:25:17 AM
When it's all about going as fast as you can consistently,it's hard to beat a fourstroke for the average guy.I do my fastest laps on a 250F-even when I'm not used to it.These days,I don't care,I just want to have fun-so it's a two stroke for me.If I wanted the best finish possible......
I don't find it thus. But thats just me and the vast majority of people find a four stonk easier to ride. My hack and slash, attack the track, aggressive and steer from the rear attitude make pulling the bulk of a fooper around insanely tiring and frustrating cos it just doesn't do what I want it to.
Post by: ford832 on December 09, 2012, 01:40:30 AM
Post by: Uniflow on December 09, 2012, 01:49:05 AM
Back in the day, when a TS90 was desirable ( some would say never ) I had the occasion to find a TS90 in a fertilizer bin on a farm, I was probably 13. Saved and saved ( $60 ) and bought said TS90 from the farmer. As I was loading it up on Mum's trailer to take it home the farmer bought over a box of stuff, a " hot up kit ". I spent many hours at the local Suzuki shop researching the parts book to see what was missing. Eventually got it all together and running with the hot kit fitted. My dad told us to run it in and don't rev, it so my friends and I spent the day running it around our track keeping the revs low. We knew that a hot kit must make more power but the consensus was " it's gutless" until one of us hit the power by accident down a hill, we were astonished. We had no idea what a powerband was until that moment! There was a fight over who was going to ride it next. It got run in alright, at full throttle after that. It made an SL 100 look like what it was, a slug! I've hated fourstrokes ever since. ( until yesterday ).
Post by: SachsGS on December 09, 2012, 02:52:37 AM
Post by: twosmoke595 on December 09, 2012, 04:03:25 AM
I confess I rode a fourstroke 250, and liked it! But before I get tossed out of this forum let's have a little look at what I rode. I like my 250T, love to ride it and will never sell it, but was surprised, no shocked, at how well this little fourstroke went. Tight, bumpy, slippery track where power was not needed in fact was a disadvantage. Hook up was the key, many twostrokes were there and most of the time sideways. This little fourstroke would just hook up and drive, like it was stuck to the dirt. The key to future twostroke development is to make them perform the same but less weight and more power. It needs to be under control! I think it's going to take more than just changing the frame on twostrokes to modern fourstroke design frames , whats needed is a form of traction control. I can see there will be howls of outrage ( no electronics ) but that is whats letting the twostroke down! In their favor they are much cheaper to run ( twostrokes ).
Another point, this fourstroke changes direction much easier than it should, why? It turns in much better than my 250T, same weight. Are the frames that much different? Or is it the fact that the fourstroke has a counter rotating balance shaft helping negate flywheel mass?
Anyway I won't be trading my 250T any time soon but I did like this YZF. The bike I was riding is the YZF I bought to use the frame as a twostroke project bike. It does seem a pity to take this engine out, probably change my mind when it need's it's next piston and I'm so over oil changes!
you my friend are saying what many of us say.
the 4 strokes are great motorcycles, its the consequences that go along with them that we dont' like.one thing that does make the 4 strokes ride the way they do, is the weigh bias on the front wheel, they turn with the front wheel, whereas 2 strokes turn with the back wheel. that's why they feel so planted is because a lot of weight is on the front wheel
a 2 stroke is pretty easy to tune to make it less 2 strokey, but you will always have the tendencies to lift the wheel and spin a little. a flywheel and sprocket changes that dramatically
Post by: Stusmoke on December 09, 2012, 07:12:26 AM
I confess I rode a fourstroke 250, and liked it! But before I get tossed out of this forum let's have a little look at what I rode. I like my 250T, love to ride it and will never sell it, but was surprised, no shocked, at how well this little fourstroke went. Tight, bumpy, slippery track where power was not needed in fact was a disadvantage. Hook up was the key, many twostrokes were there and most of the time sideways. This little fourstroke would just hook up and drive, like it was stuck to the dirt. The key to future twostroke development is to make them perform the same but less weight and more power. It needs to be under control! I think it's going to take more than just changing the frame on twostrokes to modern fourstroke design frames , whats needed is a form of traction control. I can see there will be howls of outrage ( no electronics ) but that is whats letting the twostroke down! In their favor they are much cheaper to run ( twostrokes ).
Another point, this fourstroke changes direction much easier than it should, why? It turns in much better than my 250T, same weight. Are the frames that much different? Or is it the fact that the fourstroke has a counter rotating balance shaft helping negate flywheel mass?
Anyway I won't be trading my 250T any time soon but I did like this YZF. The bike I was riding is the YZF I bought to use the frame as a twostroke project bike. It does seem a pity to take this engine out, probably change my mind when it need's it's next piston and I'm so over oil changes!
you my friend are saying what many of us say.
Assuming you're talking about four stroke motocrossers and motocrossers only, I disagree. Strongly. They've caused costs to sky rocket, they've driven up the injuries hugely, they couldn't build your skills properly if you rode them 24/7, they teach you bad habits, they handle like a boxing kangaroo that just had it tail chopped off, they're crazy expensive, kick starting them is like trying to bring someone back to life, they force tracks to close because of the noise, they're boring and unrewarding as balls to ride and you've got to be constantly changing their oil. In comparison to a two stroke that is the opposite of just about every point there, how are they considered to be even remotely okay? They are useless and have only gotten as far as they have now because of rule changes.
Post by: 2T Institute on December 09, 2012, 08:23:23 AM
I confess I rode a fourstroke 250, and liked it! But before I get tossed out of this forum let's have a little look at what I rode. I like my 250T, love to ride it and will never sell it, but was surprised, no shocked, at how well this little fourstroke went. Tight, bumpy, slippery track where power was not needed in fact was a disadvantage. Hook up was the key, many twostrokes were there and most of the time sideways. This little fourstroke would just hook up and drive, like it was stuck to the dirt. The key to future twostroke development is to make them perform the same but less weight and more power. It needs to be under control! I think it's going to take more than just changing the frame on twostrokes to modern fourstroke design frames , whats needed is a form of traction control. I can see there will be howls of outrage ( no electronics ) but that is whats letting the twostroke down! In their favor they are much cheaper to run ( twostrokes ).Said the same a few times, flattening and widening the torque curve, then doing everything to gain traction. I think the balance shaft will have something to do with negating crankshaft inertia. This goes hand in hand, added crank inertia will help keep RPM up, gains traction and allows you to get on the power earlier every corner. At the expense of side to side flickablity which is where the balance shaft come in.
Another point, this fourstroke changes direction much easier than it should, why? It turns in much better than my 250T, same weight. Are the frames that much different? Or is it the fact that the fourstroke has a counter rotating balance shaft helping negate flywheel mass?
Anyway I won't be trading my 250T any time soon but I did like this YZF. The bike I was riding is the YZF I bought to use the frame as a twostroke project bike. It does seem a pity to take this engine out, probably change my mind when it need's it's next piston and I'm so over oil changes!
Broadening the torque curve helps when you do spin the tyre and is a bit of insurance with 'no surprises' in what will happen if you nail it out of a slippery corner. Easy for the tyre to get overwhealmed when you have a power pulse every revolution.
Things like a variable size stinger and ignition linked to a 3 axis accelerometer will help as well.
Post by: VintageBlueSmoke on December 09, 2012, 10:47:45 AM
Traction control... For real? Why don't we go ahead and throw in a jake brake, automatic transmission and abs brakes. Its a stupid idea no matter what stroke of the bike. Motocross is what? An extreme sport. This extreme sport was already made a hell of a lot easier when four strokes became dominant why on earth would you make it even easier? It used to be you were racing on sundays and gyming every day of the week just to pull a 7 lap moto on a smoker. Now local riders are smothered in puppy fat.
This sport is designed to be extremely difficult and demanding. To the point that it takes a proper dose of dedication to go far. Now its just getting easier and easier. Instead of traction control, why don't people just learn how to ride properly?
A little closed minded, aren't we Stu? First of all, Terry Cunningham won the National Enduro series in America on an automaic Husqvarna. Not once, but twice. I've known lots of guys who swear by them. In addition, one of the hottest new upgrades to any bike these days is the Rekluse clutch. Guys have been winning everything from Erzberg to Glenn Helen with it. Part of the popularity of the 4$ was that it was easier to ride - fast. ABS has been toyed with at various times.
It is call technology and unless it gets expressly banned by the rules (i.e. minumim weight limits, "production" rules, spec series, etc), technology will march on. Can you imagine motocross today if those engineers said "well enough alone" in 1976? we'd all be riding 360 Husqvarna's!
Oh waite...I am!
Post by: Stusmoke on December 09, 2012, 12:21:12 PM
Traction control... For real? Why don't we go ahead and throw in a jake brake, automatic transmission and abs brakes. Its a stupid idea no matter what stroke of the bike. Motocross is what? An extreme sport. This extreme sport was already made a hell of a lot easier when four strokes became dominant why on earth would you make it even easier? It used to be you were racing on sundays and gyming every day of the week just to pull a 7 lap moto on a smoker. Now local riders are smothered in puppy fat.
This sport is designed to be extremely difficult and demanding. To the point that it takes a proper dose of dedication to go far. Now its just getting easier and easier. Instead of traction control, why don't people just learn how to ride properly?
A little closed minded, aren't we Stu? First of all, Terry Cunningham won the National Enduro series in America on an automaic Husqvarna. Not once, but twice. I've known lots of guys who swear by them. In addition, one of the hottest new upgrades to any bike these days is the Rekluse clutch. Guys have been winning everything from Erzberg to Glenn Helen with it. Part of the popularity of the 4$ was that it was easier to ride - fast. ABS has been toyed with at various times.
It is call technology and unless it gets expressly banned by the rules (i.e. minumim weight limits, "production" rules, spec series, etc), technology will march on. Can you imagine motocross today if those engineers said "well enough alone" in 1976? we'd all be riding 360 Husqvarna's!
Oh waite...I am!
I'm not disputing the usefulness of technology such as ABS, traction control, DI/FI automatic transmission at all. Quite the contrary, for a farmer to be able to putt around checking the fences without clutching is useful. For a dual purpose bike, why the hell wouldn't you want ABS? Anything that goes on bitchimun should, in my honest opinion be outfitted with ABS by law cos the second those wheels lock up, you're steering nowhere fast. And its undeniable that most peoples first reaction to a suprise on the road is to jam the brakes resulting in a skid. Again, traction control should be compulsory cos it gives you that little edge that might save your life. DI/FI, I've already thrown my support in for that on two strokes on two conditions: Its ultra reliable and doesn't need new fuses and throttle bodies every 20 seconds and it doesn't make the two stroke into a four stonk on the power curve.
I may favor the "lets make everything easier and safer for ourselves" attitude on the road for everyday users, but it doesn't belong in an extreme sport. Enduro, motocross, supermoto, motogp, all extreme sports. Why the geezus would you want to make it easier? Thats the whole point of an extreme sport: Making sure only those with a healthy dose of dedication and talent can properly run it. Without traction control, all you've got to do is cover the clutch a little to keep your rear from getting out of line. Thats it. Its not hard and for the extra tricky bits you exert yourself LESS by not giving it as much gas. This teaches riders to be more aware, to better at what they do and HAVE MORE FUN! Why would anyone in their right mind want to take that away and replace it with boredom and ease of use? Only a fairy thinks thats a good thing.
As for all of us riding 360 huskys, would that really be such a bad thing?
Post by: chump6784 on December 09, 2012, 06:23:12 PM
The 250f was fun because i was cutting near perfect laps, the 250T was fun because it is just damn fun. If riding was just about results and i had no shortage of money i would ride a modded 250f, but results aren't everything and money isn't endless so a 250T is the bike i choose to ride. That being said, my KTM is much easier to ride than my RM. KTM has made a bike with more power yet made it smoother and it hooks up pretty well, it still has a big hump in the torque curve but the power curve is very linear and it is much easier to ride than a jap 250T
Post by: Uniflow on December 09, 2012, 07:33:43 PM
The first 250f i ever rode was a 2011 kxf on hard pack. After only a couple laps i pulled into the pits and said to my brother "i know how you go so fast on this thing." It may have less power but i could get on the throttle earlier out of corners and it seemed to stay lower over jumps and straight away my lap times would have been neck and neck with my 250T. For those few laps i contemplated selling my rm 250 for one. Then i got back on my rm and knew exactly why i own a 250 2 stroke.
The 250f was fun because i was cutting near perfect laps, the 250T was fun because it is just damn fun. If riding was just about results and i had no shortage of money i would ride a modded 250f, but results aren't everything and money isn't endless so a 250T is the bike i choose to ride. That being said, my KTM is much easier to ride than my RM. KTM has made a bike with more power yet made it smoother and it hooks up pretty well, it still has a big hump in the torque curve but the power curve is very linear and it is much easier to ride than a jap 250T
« Last Edit: Today at 02:45:53 AM by chump6784 »
My thoughts exactly!
Post by: Stusmoke on December 09, 2012, 10:42:16 PM
Post by: motoxr377 on December 09, 2012, 10:57:46 PM
Fast forward to 2005. I almost bought a RM-Z450, but at the last second bought an RM250. Best choice, ever! I instantly destroyed that friend with the 250F!
...then sold the RM in 2006 to pay for school. I miss 250s.
Post by: Charles Owens on December 10, 2012, 04:22:45 PM
Quote
kick starting them is like trying to bring someone back to life, they force tracks to close because of the noise, they're boring and unrewarding as balls to ride and you've got to be constantly changing their oil. In comparison to a two stroke that is the opposite of just about every point there, how are they considered to be even remotely okay? They are useless and have only gotten as far as they have now because of rule changes.
Haha, agreed and thanks for the laugh!
Post by: eprovenzano on December 10, 2012, 04:41:12 PM
I'll stick with my smoker.
Post by: factoryX on December 10, 2012, 05:19:19 PM
Post by: yota on December 10, 2012, 09:49:30 PM
The 500 class was not about doing faster laps than 250's, it was about having the skill, fitness and stamina to control the beast for 40 minutes.
Post by: Uniflow on December 11, 2012, 08:05:19 AM
Post by: motoman356 on December 11, 2012, 08:43:04 AM
if you could go buy a super car what would it be? *price is non factor in this* you could have the Mclaren F1 from the 90's which was a pure drivers car. no assists. no abs, no power steering, no radio or power locks. but you had a the fastest car of its day and still competitvly fast. or would you rather have the nissan skyline. which has awd, seating for 4-ish, and has every electronic assit you could want to go fast.
last i checked my left foot wasnt a copy of colin mcrae, or any andretti and therefore is not godly enough to handle a pure unadulterated Mclaren.
your all getting worked up about making this sport "easier" if this or any sport would be retricted to the DIE HARDS who can only live on the edge of death and exciting the fields would be a little empty. seriously if i had a penny for every military person who wasnt a super soldier who belonged in the SEALS id be rich.
point is there should be options. there should be an option for the fringe guy who only rides once in awhile, or the strictly trail guy, or the i have to have the bike with the biggest HP numbers guy.
ive been back an forth on 125s and 250fs for years. and i still couldnt tell you what id rather have. i can rebuild my RM blind and put the bike wherever i wanted but i couldnt get out of the way of my own shadow. on the rmz i used to have, i could ride smooth and comfortable and i didnt worry if i wasnt Wide freaking open all the time
Post by: TMKIWI on December 12, 2012, 04:12:25 AM
Some guy called Cairoli did ok in it.
Sounds like these 4 strokes are real easy to ride. Must have ago myself.
Might be able to ride against that Cairoli fella.
Post by: citabjockey on December 12, 2012, 05:33:04 AM
That said the current rule book clearly provides a 4 stroke displacement advantage for the pros. Get rid of that and watch the two stroke ranks grow. And eventually some manufacturer will reproduce the 250F power spread in a 250. THEN it would probably be game over for the four strokes.
Not holding my breath however.
Post by: Uniflow on December 12, 2012, 06:51:58 AM
The irony was we had gone off to this trail ride to get some video of the EFI Bighorn in action. Did the first round on the YZF as a citing round. I've owned this YZF for eight months and never ridden it so this was the first time and as I say was a little shocked. As it happened the guy with the camera and I never met up, so video will have to wait for another day.
Post by: VintageBlueSmoke on December 12, 2012, 11:26:40 AM
After an Al Baker 220 kit, CR125 suspension, and a truck load of aftermarket parts, my 4-stroke WEAPON was lighter than a CR125 and had more power than either a CR125 or an XR250. To top it off, it was easy to ride and a lot more forgiving than any 2-stroke.
The week before it was to be photographed for a magazine article, then shipped to the Moana Kea 200 Enduro, the engine hand grendaded leaving not much left undamaged from the crank up.
It was replaced with a KX250.
20 years later, after retiring for GNCC's and racing (and the military), I got a new 2006 CRF250F. It was good for the first few months. I absolutely loved the start button, but I was at an extreme disadvantage on the motocross track. I had not adapted to making the 4-stroke go fast and was working it like a 2T. Being out af shape, and generally weaker than my competition, it was all I could do to break into the top 3 - when I should have been running away with it.
At the same time, I began collecting Vintage motocrossers and enduros. I found that I was just as fast on an EVO 1 bike as I was my CRF (except for starting it after a crash). Now, with more the 20 motorcycles, the only 4-stroke I own is my Quad - that I paid $200 bucks - WITH TRAILER!
Post by: SachsGS on December 12, 2012, 03:27:30 PM
Post by: citabjockey on December 12, 2012, 09:31:01 PM
Let's beat them as the present rules stand. One 2013 direct injected 2T 125 please.
Post by: Uniflow on December 12, 2012, 10:29:34 PM
Post by: 2T Institute on December 13, 2012, 12:39:01 AM
IMHO a 125 could not compete with a 250F at the pro level. Ever. The peak power required out of the 125 would mean the spread would be very narrow. DI is not going to help this. DI and other electronic tricks has the possiblity ot taming the powerband of the 250 two stroke by snitching some of the top end HP and piling it lower in the range with shorter port timing and tricks done with timing, and electronic power valve but a 125 has nothing to spare.
Don't believe that. The RSA 125 had over 50 HP for more than 2000 rpm, if you can't keep a 125 in that wide a band . Then you need to improve as a rider. You have to realise no proper engine development has been applied to a 125 mx engine since probably the late 90's. With a variable disc valve and Aprilia GP style cylinder and maybe a variable length pipe/stinger size, a 45HP/20ft/lbs torque 125 would be realised having about 4000 rpm wide band of liquid power, which would be easily enough to blitz 250f's
Post by: Jeram on December 13, 2012, 02:26:49 AM
Only big issue with a disc valves MX bike is that you'd need to put crash protectors on the bike for the carb side of the motor. This was enough of an issue on the aprilias road racers to redevelop the motor to have a rear disc valve so imagine the need for protecting the carb on an MX bike, but Im not sure us 'amateurs' would have the budget to develop a rear disc valve so stunt bike style protectors will have to suffice!
Post by: Uniflow on December 13, 2012, 03:07:59 AM
Post by: Jeram on December 13, 2012, 03:25:59 AM
What I have in mind for the 350 disc valve engine will have the engine no wider than my YZ 250 engine. Using EFI ( no carb ) and a extra trick vairable valve housing ( also throttle ). Electric driven. It's only ideas at the moment.
sounds very interesting, however what happens when you crash on the right hand side?
Post by: citabjockey on December 13, 2012, 04:35:14 AM
IMHO a 125 could not compete with a 250F at the pro level. Ever. The peak power required out of the 125 would mean the spread would be very narrow. DI is not going to help this. DI and other electronic tricks has the possiblity ot taming the powerband of the 250 two stroke by snitching some of the top end HP and piling it lower in the range with shorter port timing and tricks done with timing, and electronic power valve but a 125 has nothing to spare.
Don't believe that. The RSA 125 had over 50 HP for more than 2000 rpm, if you can't keep a 125 in that wide a band . Then you need to improve as a rider. You have to realise no proper engine development has been applied to a 125 mx engine since probably the late 90's. With a variable disc valve and Aprilia GP style cylinder and maybe a variable length pipe/stinger size, a 45HP/20ft/lbs torque 125 would be realised having about 4000 rpm wide band of liquid power, which would be easily enough to blitz 250f's
Post by: Uniflow on December 13, 2012, 05:11:57 AM
Opps in saying that I've got a valve ( rotary type ) hanging on my wall that looks like an orange peel after a piece of piston went through it. When I puled the carb off there it was like a big spring sticking out. Yes one of the problems with rotary valves is they don't suffer parts through them very well.
Post by: citabjockey on December 13, 2012, 02:54:42 PM
Post by: riffraff on December 13, 2012, 03:09:57 PM
IMHO a 125 could not compete with a 250F at the pro level. Ever.
you meant ever again right? back in the early days the 125's regularly beat the 250f's
Post by: citabjockey on December 13, 2012, 04:47:22 PM
IMHO a 125 could not compete with a 250F at the pro level. Ever.
you meant ever again right? back in the early days the 125's regularly beat the 250f's
Post by: dean100yz on December 13, 2012, 08:46:07 PM
Yes, comparing a current state 250F bikes against the early 250F's its a whole new 14,000 rpm ballgame.IMHO a 125 could not compete with a 250F at the pro level. Ever.
you meant ever again right? back in the early days the 125's regularly beat the 250f's
Yeh 4 bangers wernt arnt like they were. My modern CRF450 handles amazing and pulls like a train. Its all I use for racing in almost all conditions
I took out my RM250 tuesday on a very icy sandish track, 3 corners in and a kick of the smoker power had me highside off and dislocate my shoulder.
I know on the 450 it would have tracked better. I find the 250 smoker slower and more violent with its power but its great fun to ride, sounds a hoot and good fitness.
Post by: 2T Institute on December 13, 2012, 08:47:04 PM
All I can say is, I will believe it when I see it. Dyno charts, podium finishes and all. And if a variable stinger/header pipe and variable intake valve timing and DI are required for this then -- is it any less of a headache than a four stroke?
If you want to win it's no headache, injection is not required, what is required is more torque and a wider spread of torque. All of the electronic can be controlled by ignitions anyone can buy right now.
Post by: Uniflow on December 13, 2012, 09:21:55 PM
Post by: citabjockey on December 13, 2012, 10:08:28 PM
There are two possibilities:
1) There really is a conspiracy to have everyone on 4 strokes to keep the parts/service dept profit up in the stratosphere
2) its not as easy as some posters seem to say it is here and/or the engineering dept does not have the resource to do it (I.E. its difficult) and continue with 450F development at the same time.
To say that a road race engine is a model for a MX engine probably is not valid. A 50 HP 125? It may make over 30 over a wide range but the curve is going to be steep never the less. It would not do well against a flat power curve 250F putting out only 35 HP.
The solution is easy. CC for CC racing (at least for the 125 and 250 classes -- yes, now I am convinced. We need all three classes).
Post by: Uniflow on December 14, 2012, 12:27:12 AM
Worst case, I've got an orphan bike only I like, good, no one else will want to ride it.
Post by: citabjockey on December 14, 2012, 02:28:15 AM
You may be right, we are "farting against thunder" but I want to have a try anyway. I like the attitude of one of my workers, " How hard could it be" ? How many times that has got us in trouble!!!
Worst case, I've got an orphan bike only I like, good, no one else will want to ride it.
Post by: SachsGS on December 14, 2012, 03:14:31 AM
Post by: Uniflow on December 21, 2012, 07:06:48 AM
I've just measured the 250F against the 250T ( cases ) and the T has it's crank 20mm further forward than the F
. Swing arm is the same length. F does have a balance shaft ahead of the crank but that doesn't weigh much. T has a slightly heavier crankshaft. I would have said the T had more weight on the front wheel than the F or certainly not much difference. I believe the difference in feel is the way the two engines deliver their power only.
Post by: factoryX on December 22, 2012, 05:06:33 AM
Post by: SachsGS on December 22, 2012, 03:55:29 PM
Post by: Helmut Clasen on December 22, 2012, 04:59:33 PM
Guess what I sell most in my shop
( and its good for me....lol)4 stroke and related parts.
Happy Holidays,....you all.....
Post by: _X_ on December 22, 2012, 09:07:05 PM
Post by: Stusmoke on December 23, 2012, 03:36:37 AM
Guess what I sell most in my shop
4 stroke and related parts.
Happy Holidays,....you all.....
Timmys got smarts.
A merry christmas to you all tomorrow.
Braaaaaaap