Post by oldchopperguy on Aug 24, 2013 2:33:45 GMT -5
Well, guyz n' galz...
Any members who've followed my posts for the last 5 years on the various sites know I ride a 2007 Xingyue Eagle 150. And, I've done all they typical mods. It's reliable, it runs GREAT and it's never been anxious to go much over 50 mph.
For the record, I weigh 235 and my tach and speedo are accurate. With 13-gram rollers in my Prodigy variator, I once got it to 55 on the level, but lost acceleration and hill-climbing. Back to a mix of 12 and 13-gram rollers and it was back to decent low-end, but top-speed down to 51-52 mph.
So tonight, I'm leaving Wally World turning right onto a surface street that has just been changed to a limited-access highway exit. I enter traffic and it's WAY faster than the old posted 35 limit. So... instead of rolling on the throttle as usual, I twist Lil' Bubba's ear HARD to WOT, nervously watching "my six" as traffic is boring down on me... The tach shows 8K and stays there... To my amazement, I'm starting to match traffic! I glance at my speedo, and it's 50, 52, 54, (revs down to 7,000...) 58, 60, 62... WHOA... WHAT is UP here???
So I'm now PASSING traffic! Never, NEVER had THAT happen... LOL!
I ease off the throttle, and happily maintain 58 mph at a decent 7,200-7,800 revs. Hmmm... Next stop, I roll on the throttle and ease it to top-end. Back to 52 mph tops.
Next stop, I roll on the throttle up to 10 mph and then go wide-open. Tach goes to 8K and Bubba keeps right on up to near 65 again! Back off a little and it cruises at 55 easy as pie.
Double-hmmm... I do believe after 5 years, I just learned something new about these CVT trannies!
My best guess (and it's ONLY a guess) is that with 9 hp, the ponies (and torque) just are NOT there to accelerate past 50 or so, from a 7K rpm "cruise". BUT... From near stopped, a quick WOT runs the engine up to max revs, and keeps it at or above the "sweet-spot" until it's PAST 50 mph. THAT gives the little wheezer the momentum to carry it "over the hump" and PAST the magic 55 mph barrier... Once there, it can maintain it at only 7K or so revs. But it can't get there from 6 or 7K running. Maybe? Inquiring minds want to know... LOL!
After five full seasons, I thought I knew this scooter inside out... But I'm an old clutch n' gears guy. New to CVT trannies. Apparently, there's MUCH more to getting the most from them through driving technique than I realized. To get the most performance from these tiny engines, it appears you must REALLY master the throttle at EVERY speed.
The only other experience I've had like this was LONG ago with a Honda 4-cylinder 500cc. Drive it "normally" and it was a DOG... Keep the rpm way up, and stay "on the pipe" and it was pretty quick.
Unfortunately, the only way to keep a CVT scooter "on the pipe" is to thrash it from 10 mph or less, and "let it rip" hoping the revs will be there to carry it "over the hump" at 50 mph, on up to near 60 or so.
Or, I could lose 75 pounds...
Anybody have any other explanations? They are welcome!
Leo (still learning the little weird habits of these) in Texas
PS: Since changing from my stock exhaust, to a full 1-inch I.D. header on a 2-stroke style "chamber" exhaust, my 150's "sweet-spot" has DEFINITELY changed from around 7,000 rpm to 7,800 to 8,000 revs. This may make a noticeable difference in the way it needs to be ridden for best performance.
I do NOT like to "thrash" any engine, and in normal surface-street riding up to 50+ mph, it's not much different from before. BUT... Now, instead of LOSING power near 8K rpm, it still GAINS power up to about 8,500 revs.
Any members who've followed my posts for the last 5 years on the various sites know I ride a 2007 Xingyue Eagle 150. And, I've done all they typical mods. It's reliable, it runs GREAT and it's never been anxious to go much over 50 mph.
For the record, I weigh 235 and my tach and speedo are accurate. With 13-gram rollers in my Prodigy variator, I once got it to 55 on the level, but lost acceleration and hill-climbing. Back to a mix of 12 and 13-gram rollers and it was back to decent low-end, but top-speed down to 51-52 mph.
So tonight, I'm leaving Wally World turning right onto a surface street that has just been changed to a limited-access highway exit. I enter traffic and it's WAY faster than the old posted 35 limit. So... instead of rolling on the throttle as usual, I twist Lil' Bubba's ear HARD to WOT, nervously watching "my six" as traffic is boring down on me... The tach shows 8K and stays there... To my amazement, I'm starting to match traffic! I glance at my speedo, and it's 50, 52, 54, (revs down to 7,000...) 58, 60, 62... WHOA... WHAT is UP here???
So I'm now PASSING traffic! Never, NEVER had THAT happen... LOL!
I ease off the throttle, and happily maintain 58 mph at a decent 7,200-7,800 revs. Hmmm... Next stop, I roll on the throttle and ease it to top-end. Back to 52 mph tops.
Next stop, I roll on the throttle up to 10 mph and then go wide-open. Tach goes to 8K and Bubba keeps right on up to near 65 again! Back off a little and it cruises at 55 easy as pie.
Double-hmmm... I do believe after 5 years, I just learned something new about these CVT trannies!
My best guess (and it's ONLY a guess) is that with 9 hp, the ponies (and torque) just are NOT there to accelerate past 50 or so, from a 7K rpm "cruise". BUT... From near stopped, a quick WOT runs the engine up to max revs, and keeps it at or above the "sweet-spot" until it's PAST 50 mph. THAT gives the little wheezer the momentum to carry it "over the hump" and PAST the magic 55 mph barrier... Once there, it can maintain it at only 7K or so revs. But it can't get there from 6 or 7K running. Maybe? Inquiring minds want to know... LOL!
After five full seasons, I thought I knew this scooter inside out... But I'm an old clutch n' gears guy. New to CVT trannies. Apparently, there's MUCH more to getting the most from them through driving technique than I realized. To get the most performance from these tiny engines, it appears you must REALLY master the throttle at EVERY speed.
The only other experience I've had like this was LONG ago with a Honda 4-cylinder 500cc. Drive it "normally" and it was a DOG... Keep the rpm way up, and stay "on the pipe" and it was pretty quick.
Unfortunately, the only way to keep a CVT scooter "on the pipe" is to thrash it from 10 mph or less, and "let it rip" hoping the revs will be there to carry it "over the hump" at 50 mph, on up to near 60 or so.
Or, I could lose 75 pounds...
Anybody have any other explanations? They are welcome!
Leo (still learning the little weird habits of these) in Texas
PS: Since changing from my stock exhaust, to a full 1-inch I.D. header on a 2-stroke style "chamber" exhaust, my 150's "sweet-spot" has DEFINITELY changed from around 7,000 rpm to 7,800 to 8,000 revs. This may make a noticeable difference in the way it needs to be ridden for best performance.
I do NOT like to "thrash" any engine, and in normal surface-street riding up to 50+ mph, it's not much different from before. BUT... Now, instead of LOSING power near 8K rpm, it still GAINS power up to about 8,500 revs.
