| Author | Message | ||
     Badlionsfan |
it seems to me that my speedo is a liar. i think it says i', going faster than i am, esp at higher speeds. in 5th gear at 4000 rpm, my xb9sx thinks it's doing 75. how close to the truth is that, cuz it sure doesn't feel like 75 in the seat of my pants. | ||
| Damnut |
5th gear @4K my bike is doing 80 mph. 04 XB12R | ||
| Badlionsfan |
so it's pretty close then. well wait aren't the two geared differently? | ||
| Badlionsfan |
can anyone provide any more info, esp on the xb9sx? i'd hate to find out via radar gun. | ||
| Dongalonga |
My 03 XB9S is the same. 4K rpm = about 70mph. And no 70mph doesnt seem fast....but 100mph you feel the wind!! | ||
| Barker |
Get a bud to ride with you and compare speeds. | ||
| Badlionsfan |
i don't have any friends. seriously tho, i was gonna do that too, just thought someone may know what rpm = what speed. | ||
| Gentleman_jon |
Bad, According to my calculations, you are doing 71.1 mph at 4.000 rpm. (4000/1.67)/2.5 * 0.00123715 x 60 =71.1 mph This assumes that you are using a new tire the same size as a Dunlop Qualifier, and that your tach is working. The difference between the theoretical speed and the observed speed is about normal for a speedometer. Actually %5 is pretty close as far as these things go. After I changed my primary and secondary gearing, I decided I wanted a more precise reading of speed, so I taped the GPS from my car, (Garmin Nuvi 660) to my airbox, and ran down a straight road, comparing my speedo and the GPS. Incredibly enough, after all that, the speedo was spot on, at fifty, sixty, seventy and eighty. First time that ever happened!  I was delighted, because that meant I could go out and buy one of Typeone's new dash faces, knowing it would read properly.  | ||
| 07bamafan |
At 4000 in 5th it says I'm going about 77-78. 07 CityX. I haven't checked it with anything accurate. | ||
| Jkkj |
http://www.terra-glide.net/harley_tech.html There is a wheel speed calculator on this site. Just plug the numers in. You can find everything but tire diameter on the Buell website. | ||
| Punkid8888 |
I will double check on my ride home tonight (provided traffic allows me to hit 70mph) But I am pretty sure 4000 is just a little over 70mph, maybe like 72mph. 06 XB9SX But what the hell is the deal with the speedo and the tick marks on these bikes. I find them extremly anoying because the 5 and 10 tick incriments are the same size. At speed I find you have to actually stare at the speedo for a second to verify your speed. | ||
| New12r |
Yall actually look at the speedo??? | ||
| Xbullet |
Yall actually look at the speedo??? New12r -- don't you still have tape over yours? | ||
| Glitch |
Speedos can be dangerous, I've heard that they make an atomic wedgie feel good in comparison. | ||
| Badlionsfan |
i got the stock scorpion syncs. thanks for the info guys. | ||
| Punkid8888 |
double checked last night, 75mph is dead nuts 4000rpm with 7000 miles on the syncs(almost to the wear bar). | ||
| Badlionsfan |
thanks. guess it's right. also guess i should slow down, or maybe not. | ||
| Itchybro |
A GPS will give you accurate ground speed. (at least my SP III will.) | ||
| Prof_stack |
For many years the speedometers have been purposely made to read a little high. So going, say, 65mph on the speedo means you're actually going slower, perhaps 62mph. In the "old" days (meaning when I started riding in the early 70's) the Honda's were WAY optimistic. I guess that we have a built-in safety factor! | ||
| Rhun |
The few times I have used my GPS on my bike a 2005 SX the speedo and GPS were within a mph. If you have changed from the sync tires to another brand the circumference could be different and thus the speedo will be off. I've switched from stock to Mich lien power CT , but haven't mounted my GPS since. Easiest way is to time yourself on a measured mile. Those little posts with the number on the highway work well. divide the seconds it took you to go that mile into 3600 and that is you MPH. For instance hold speed constant at 60 you should come up with 60 seconds. divide that into 3600 and you get 60, that's the MPH. say it took you 59 seconds then you actually went 61 MPH and your speedo is off by one MPH. | ||
| Badlionsfan |
if the former police chief in my township that i've known since i was in grade school hadn't retired i could've had him help me with his radar gun and none of this would be needed. oh well, lots of good ideas, some of which i thought of and others i didn't gettin thrown out there. | ||
| Corporatemonkey |
Just purchase a cheap gps from ebay. I have an old garmin etrex with handle bar mount that I used. I think it was $75 new. I suspect they are really cheap now (sub $20) Now I have a slightly more advanced system... |
