| Author | Message | ||
     Buellshyter |
Whatever happened to this KTM concept??  | ||
| Buellshyter |
The architecture of the Harley engine must be essential to this as it can be placed low with the crank close to the front axle to get more of the total bike's weight onto the front wheel. I thought the idea was to keep weight off of the front wheel. Someone please explain  | ||
| Spatten1 |
Weight as low and forward as possible to get traction on the front tire when cornering, especially when under throttle. Look how long the swingarm is on the KTM. They must use a stacked tranny to achieve those dimensions. | ||
| Sparky |
What Sp1 said, also the ideal is to make the front wheel/tire combo (unsprung weight) as light as possible. Perhaps this is what "keep weight off of the front wheel" really means? | ||
| Jaimec |
In response to Steve MacKay above... don't compare the 990cc KTM engine to the 1203cc Buell engine... compare it to the 984cc Buell engine which is much closer in displacement. NOW look at the performance differential! You begin to understand the criticism of the Buell engine when you look at it in that light. In order for the XBRR to be competitive in Formula Extreme against the 600cc Japanese bikes, it has to displace more than TWICE the volume! Make no mistake... I LOVE my XB12Ss. Where I live, there are no places I can safely run even this engine WFO so I have no need for a more powerful engine. I love the flexibility of the existing engine, and I love the low-maintenance aspect. However, to sell sport bikes in large numbers you have to push the envelope with unrealistic performance numbers. Rationality has very little to do with sportbike purchase decisions, sadly. | ||
| Jlnance |
I thought the idea was to keep weight off of the front wheel. Someone please explain The idea is to make the weight of the front wheel itself light. This allows it to move quickly when it hits things. The weight of other things which press on the front wheel through the suspension do not affect the speed with which the wheel can move. This is the difference between "sprung weight" and "unsprung weight." | ||
| Ft_bstrd |
Jaime, What does it matter what the displacement is? They aren't charging you by the CC, are they? The weight is the same OR LESS than competitive I-4s. What does it matter? The only folks that care about pure CCs are folks that race bikes in the magazine spec tables. | ||
| Spatten1 |
Ft: The weight is not close to competitive with 600s, and neither is the power. I just put an XB engine together, and the damn lifters weigh more than the whole valve train does on a newer engine. Forget about all the weight in the rockers, primary chain, extra tranny parts, etc. The XB chassis must be very light to get to the numbers it does hit, because the motor is not. | ||
| Teddagreek |
Its not called LUMP for nothing... | ||
| Spatten1 |
LOL | ||
| Spatten1 |
There is something cool about riding a fairly light and great handling bike powered with a sportster motor. However, light and powerful it ain't. Fun, yes, relaxing, yes, special and different, YES. | ||
| M1combat |
"In response to Steve MacKay above... don't compare the 990cc KTM engine to the 1203cc Buell engine... compare it to the 984cc Buell engine which is much closer in displacement. NOW look at the performance differential! You begin to understand the criticism of the Buell engine when you look at it in that light. In order for the XBRR to be competitive in Formula Extreme against the 600cc Japanese bikes, it has to displace more than TWICE the volume! " Yeah Jaimec... If you look at it in that light you do indeed begin to see why people criticize the Buell engine, but you also begin to move farther away from understanding engines and what makes them useful or not in their intended application. You're looking at it from a certain point of view... The other one (that I prefer) says that for the 600's to be competitive with a fledgling XBRR racebike, they need four times as many valves, they need to rev twice as high, they need to use more fuel, they need water cooling, they need overhead cams, they need four throttle bodies etc... When you look at it from that point of view you begin to understand the point of racing. It's not about displacement. It's about swept volume and how much the package weighs. A race bike is a system. The engine is a reasonably important part of the system. Displacement is merely a characteristic of an engine. It doesn't define it. Just like the cam driving system or number of revs doesn't define it. They're all merely characteristics. I'm glad you love your XB12S. Find a good canyon road and put 10K miles on it. You'll understand the point of the engine when you pass 1000ccIL4s on that road and when you get to the end of it they'll say "Wow... How much HP does that thing have?"... You can then say... "About half as much as yours.". Watch they're jaws drop. Or go drag racing... it's your choice  . | ||
| M1combat |
"The weight is not close to competitive with 600s, and neither is the power. I just put an XB engine together, and the damn lifters weigh more than the whole valve train does on a newer engine. Forget about all the weight in the rockers, primary chain, extra tranny parts, etc. The XB chassis must be very light to get to the numbers it does hit, because the motor is not." You're correct about the weight and power Spatten, but tell me then... How come a well ridden XB will give a well ridden 600 fits in the canyons? Same for a 1000 BTW... WHY?! Power is useless when leaned over but if you can put a little more power down earlier then you can start gaining speed earlier (let alone the slightly higher mid-corner speeds). This means that the other bike needs to not only spend time getting TO the same speed, but it then has to HAVE enough time to get enough MORE speed to make a pass. It's not easy. The XB excels in exactly the areas that it needs to in order to dominate the "tight canyon roads". I know there are plenty of people who disagree with me but it's still the truth. For the record... Tight canyon roads are not the same as a racetrack. I've been on both. The Buell does very well on the track and astonishingly well in the canyons. On the main straight of firebird west (which is admittedly a pretty tight track) the 600's can gain about 10'. The 1000's gain about 30-40. I can gain the 10' between the next two turns because of the higher corner speed. I can then get around them wherever I choose because I don't have to shift. It takes a couple corners to catch back up to the 1000's, but after that it's the same story. I hang out behind them for three turns and then pass them coming out of the fourth turn/into the fifth and sixth after the straight. WHY?! Handling. The track is a little bumpy and they can't use any more power than I can in the turns... They have to shift, I don't. That said, the 1000's don't have to shift as much as the 600's, but they have more trouble putting the power down. Sorry man... The XB's work. One more thing... Because the XB handles so well, I can enter a corner on a line that's 8" outside whoever is in front of me. I can kink the turn mid way through and straighten it out and start getting on the gas and heading down a line that's inside the other bike. Why can't they do that? I don't know... but it sucks to be them . For the numbers... The XB engine weighs about 50lbs more than the current 1000cc IL4's. The bike is withing pounds of them (lighter as of last years bikes as I recall). What does that mean? The rolling chassis is about 50lbs lighter than the competition . BTW... The XBRR engine is 40lbs lighter than the current XB engine . Keep watching . | ||
| Jaimec |
Already have over 11,000 miles on my XB12Ss. Unfortunately, no canyons on Long Island... | ||
| M1combat |
That sucks... I feel for you man . My driveway drops me of on turn three of an eleven mile stretch of BRILLIANT canyon road. I've put on about 12-14K of the 34K miles on the bike on that road . | ||
| Teddagreek |
A Twin and Inline 4 both have their strengths and weaknesses.. Engineering is slowly closing this gap. | ||
| Ft_bstrd |
Spatten, "Love the XB. Just a beautiful innovative design that works very well. Looks like a refined pitbull. Also, gotta dig the HD mill in a real sport chassis."  (Message edited by ft_bstrd on December 27, 2006) | ||
| Rubberdown |
I was under the impression that the Buell engines and the Sportster engines came off the same production line at the same plant. Not the same engines, but both are HD mills. No? | ||
| New12r |
This thread is really entertaining!! | ||
| Rubberdown |
Am I wrong?  | ||
| Spatten1 |
Yep: you'll see the HD shield cast into the Buell engines. | ||
| Court |
>>>>Am I wrong? Kinda yes; kinda no. it's futile trying to discuss this on the internet. You are neither ALL right or ALL wrong. For extra points take a crack at what country that bar and shield gets cast into the head in . . . . | ||
| Ft_bstrd |
I hear Bangladesh is casting some bitchin' engine parts these days.  | ||
| Jaimec |
I created this topic on the "Quick Board" to direct KTM SuperDuke discussions over there. Sorry for the hijack of this thread here. http://www.badweatherbikers.com/buell/messages/406 2/248314.html?1167265547 | ||
| Blake |
Rubberdown, The internet should not dissuade us from informative discussion. I think one point to note is that without Buell's significant influence, the HDMC produced Sportster-based engines would not be like they are now, so they deserve to be called Buell engines in some respect. But HDMC does indeed produce them. | ||
| Rubberdown |
I agree Blake. I've had two XB's and one new generation Sportster 1200R and I've always seen it the way you just said it.  | ||
| Xl1200r |
I'm the last one that would disagree that the XB's coudln't use more power, but I think some people are missing some pretty good points. An air-cooled, long-stroke, pushrod V-twin is good for a lot of things, and to be honest it's probably one of the best usable street engine designs around. Break it down: Air-Cooled - You can't be the simplicity. I personally admire the fact that these engines don't have water pumps or radiators to worry about. Does this limit power? A little, but nothing to worry about, at least not in my opinion. Long-Stroke - This is probably the best part. Long-stroke means not only big torque, but it comes in down low in the rev range - perfect for a street application. Pushrod - along with the air-cooled, just the simplicity. Pushrod valvetrains allow for low (or no) required maintenence, and form geometries that are great for low-revving engines. Look at the Corvette. Surely, Chevy could make loads more power with a DOHC V8, but they stick with a OHV design and still make huge power for relatively low costs. They make up the difference in supposed "technology" with displacement, and still manage excellent fuel economy. I don't know... say what you want, but I would prefer an XB engine in my Buell as opposed to a V-ROD engine. If the rumors are true, and Buell does come out with some high-revving, OHC, water cooled powerplant for 2008, I'll be glad that my 2007 will be one of the last "real" Buells. | ||
| Teddagreek |
Dude... Bore VS. Stroke? Thats age old argument. Hmmm, Oh Yea guess what has a short stroke.. The XBRR Bore is 4.079 in. x Stroke is 3.125 in Stroke is same as the XB9 but with a bigger bore. The 9 Revs higher they must have made a mistake.. | ||
| Midknyte |
I'll be glad that my 2007 will be one of the last "real" Buells. Why's it gotta be one or the other. I have no doubt that we'll see a water cooled powerplant *someday* (you gotta build what is marketable to make money - people want it), but I don't believe it will be at the expense of the other. | ||
| Jaimec |
Actually, a long stroke is not necessary for big bottom end power. Yamaha proved this with the Vision V-Twin back in the early 80's. It had a very short stroke, but it did have a long connecting rod, which is what gave it a good mechanical advantage in turning the crank (not as much deflection). So there you had an engine with good bottom end torque AND it revved to the moon as well. That engine went on to become the basis for the V-Max engine (Double Vision) by the way. In a completely different state of tune it also powered the original Venture and today's Royal Star models. |
