| Author | Message | ||
     Chaser |
Anybody know what the new top speed for an XB9R would be? Free Spirits XB9 Extra Speed Pulley Kit Superbly crafted aluminium billet drive and rear pulley kit designed to improve top speed or as an overdrive(Gives 10% RPM reduction). Surface hardened for long life and hard anodised in dark grey. The front pulley has a removeable steel inner section. Retains standard belt and tensioner. http://www.britnett.net/trojanhorse/listings/312.html | ||
| M1combat |
Well, if it's a 10% RPM reduction... Assuming that it has the HP to get there it should be exactly 10% faster. | ||
| Aaron |
No, 11.1% | ||
| Daves |
I have a set in stock I'll make you a deal on! Ride to the edge! Dave Iowa HD/Buell (Buell Cycle Center) | ||
| Chaser |
So if top end increases 11.1%. What would be the new average top speed of an XB9R? What would be lost? Just asking because I dont know. | ||
| Daves |
Aaron? Blake? other math guys? I figure with a stock top end of about 135 you'd gain about 15 MPH? Ride to the edge! Dave | ||
| Freyke |
535 Quid.... blub,bub,blub,,,whhhhhhhifffffffffff.......... ahhhhhhhhhh....... kk//kef | ||
| Blake |
100/(100-10)=1.111 or as Aaron already stated, 11.1% higher theoretical top speed. Whether or not the engine has the juice to push it that fast is entirely another matter. If so, what Dave said.  135*1.111=150 mph But if your rear wheel is spinning...  | ||
| Daves |
Blake, you can just smell a math question can't you! Hell I can't believe I got it right! On another note, our favorite guy on SACBORG is still running his mouth, can you go east with me this next season so we can settle this? Ride to the edge! Dave Iowa HD/Buell (Buell Cycle Center) | ||
| M1combat |
OH yeah, 'cause there's two ratio changes... damn. | ||
| Court |
>>>Aaron? Blake? other math guys? I figure with a stock top end of about 135 you'd gain about 15 MPH? Dave: You are an experienced dude, imbued and overflowing with wisdom. You KNEW better than to ask those guys that question! PATCH FINE! Get the letter? | ||
| Daves |
Yes I did, thank you very much for your help Court. I'll keep you posted. Ride to the edge! Dave Iowa HD/Buell (Buell Cycle Center) | ||
| Geofg |
Slightly off topic: What would the sprocket change do to the speedo readout? Would it alter it similarly to changing away from stock wheel/tire size on a car, or does the XB calculate speed/mileage some other way? -Geof | ||
| Glitch |
Can you hold on to an XBS at over 125? The wind is awful at 80 plus... For me anyway... | ||
| Daves |
Yes. Ride to the edge! Dave | ||
| Mikep |
Likely my XB9R would not make it to 150 mph. It takes a reasonable amount of time to climb from 120 mph to 125 mph with my mere 150 lbs tucked as much behind the windscreen as possible. I would be fun to try though . . . mikeyp | ||
| Mikep |
As Blake once calculated: "HP goes up with peak speed cubed, so if you want to increase peak speed by 20% you would need 73% more power (1.2 cubed)." In this case it is 1.15 cubed (15% increase in speed), which amounts to the need for 52% MORE HP, or 106 ish HP at the rear wheel of my XB9R, and the new gearing kit. mikeyp | ||
| Austinrider |
Dave (iowa harley dave) Got my replacement bag in, thank you very much. Out of curiosity, what kind of deal you got on the pulley? | ||
| 99buellx1 |
Mikeyp, Wouldn't that only apply if you are at the maximum speed available from the motor and looking to increase speed? I don't think 135 is the maximum speed that the motor can achieve, therefore it may have enough power to pull the higher top speed (given there are more factors to top speed than just the motor and gearing) Just throwing more what-ifs out there. Craig  | ||
| Americanrice |
Is it safe to assume that this kit hurts low end power? | ||
| Daves |
The pulley set goes for 856.00 My XB9R will hit the rev limiter in 5th real easy so it would gain you some top end. Ride to the edge! Dave Iowa HD/Buell (Buell Cycle Center) | ||
| Mikep |
99buellx1, I believe that since my stock xb9r takes a bit of time to accelerate from 120 mph to 125 mph, that this indicates that I am nearing the limit of the power available. I have not found a road deserted enough and long enough to reach 135 mph indicated. Maybe someone else can comment on how long it takes to get to 135 mph or so on a STOCK XB. mikeyp | ||
| Mikep |
99buellx1, Oops, I forgot to answer part of your question. The engineers at Buell (and pretty much anywhere else that deals with motorized vehicles), I am sure would have optimized the stock gearing to provide the greatest max speed for the power available in the production package. That said, these guys do know what they are doing, and my xb will likely not go much faster than 135 mph no matter how I choose to gear it. Comments, anyone? mikeyp | ||
| Mikep |
99buellx1, Now that you got me thinking, I will just have to go out and try to reach 135 mph (do not tell my wife). mikeyp | ||
| M2cyclone00 |
With a stock XB9, the pulley kit may actually lower top speed. Stock XB9's peak hp is at or very near redline, is it not? Therefore, with the pulley kit, it would be at about 6750 rpm at 135 mph and the engine would be making about 3 hp less. Maybe enough reduction in hp for it not to be able to pull 135. If you shifted down to 4th, it would do 127 mph at redline. | ||
| 99buellx1 |
I think the real answer is that there are too many factors to top speed than just the engine and gearing. Rider weight, wind, road, balls(at which to reach that speed on a public road) which may also play havoc with overall rider weight! Ok, so i was kidding about some of that. But it all makes a difference, and there are alot more factors also. But you know that 127 in 4th gear sounds pretty sweet! Craig | ||
| Stot |
Increasing HP like that for extra speed is with same gearing? XB top end is limited by the rev limit more than gearing so I think the gear change would let you see 145-150 I actually find that my XB pulls quickly from 110-130 and have had it to 135 indicated with a wee bit more to go. Gotta say though I think it would be less fun on normal roads, go the other way and buy the reduction set, scrub 10% off the top end and wheelie in every gear  Cya Stot |
