| Author | Message | ||
     Ferrisbuellersdayoff |
is it just me or is the XB9 geared significantlly lower than most other HD powered bikes? I was next to a `97 Road King perfectly even at the same speed, yet I could hear his engine wasn't turning as much as my 9 was. It got me thinking my Buell is smaller and lighter yet he gets better MPG probably because his RPMs are lower. WTF? | ||
| Johnnylunchbox |
It probably is geared lower. The Buell engines, are worked for good (relatively speaking of course) top end power. They are not like the loafing big twins, where power down low is more desirable. | ||
| Etennuly |
The City-X has the lower gears in the primary. | ||
| Pwnzor |
I'm thinking the difference in the exhaust note might have something to do with the apparent discrepancy in rpm. Another possibility, he might have a sixth gear? A lot of guys I know with Harley cruisers have upgraded transmissions. Just grabbing at straws. | ||
| Ferrisbuellersdayoff |
he's got a stock 5 clicker and his exhaust is a 2 to 1 with some baffles. We were discussing it and he's got a tach somewhere, he's going to put it on and we're gonna ride, weather permitting, tomorrow. Hopefully my pegs will be done polishing by then. | ||
| Mikef5000 |
I just assumed the Buells were geared lower for better acceleration, and Harley's were geared higher for cruising. I thought all the XB's got 40-50 mpg. I'm suprised the harley gets better gas milage than you. As a "Fix" you could swap primary's with an XB12. | ||
| Clutchless |
I think mikef5000 is on to something there. If I can remember right ....(strains brain....and starts to bleed)... The xb9 r/s has a lower gearset in the primary chaincase than the xb12 r/s. To make up for the power differences. From what I understand people swap out for various reasons. If you go down to that xb12 rpm you might lose your real smooth power band on your ride, it might not be there at all. BUT you will get down maybe 500 rpm? (dont quote me on that, just trying to help) and my xb gets 40-50 mpg. check your tires? using good gas? pulling a parachute? | ||
| Johnnylunchbox |
A big twin has more torque which can take advantage of taller gearing. | ||
| Stretchman |
X nay on the MPG either. he's lucky to get 38 to 40 mpg. You probably get 55-60? | ||
| Ferrisbuellersdayoff |
49.84 if my math is correct but then that means every drop of fuel and maybe even some vapors. And I didn't even break 80mph! I short shifted most of the time. | ||
| Ferocity02 |
You are right about the high RPM's on the highway. I was surprised too. However, gas mileage doesn't really depend on engine RPM. It depends much more on load/throttle position. In some cases you can hurt gas mileage by reducing the drive ratio because you lose some of the power that you need to accelerate to pass people on the highway and thus need more throttle/fuel to compensate. However, I doubt this will happen on a big 984-1200cc motor in a small vehicle. With mostly highway use I get 55-60mpg. Mostly city use I get 35-40mpg. It depends heavily on your riding habits. As mentioned, you can go with the XB12 primaries(I think thats what they are) and it's supposed to reduce the ratio by 10% I believe. That will give you an extra 200-400RPM on the highway, but you will lose some low end torque that makes these bikes so fun. |
