G oog le BadWeB | Login/out | Topics | Search | Custodians | Register | Edit Profile


Buell Motorcycle Forum » XBoard » Buell XBoard Archives » Archive through September 23, 2004 » XB9 primary drive swap « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

Bradyclt
Posted on Sunday, September 19, 2004 - 12:56 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Well, 90% of my riding is Interstate so in an effort to save my motor some long term wear I'm having the primary drive swapped out on my XB9SL. It's at Tilley's right now having the engine sprocket and chainset used on the 2003 XB12S installed. Will raise overall gearing approx 12%... and worsen acceleration, increase top speed (assuming the motor has the grunt, which I seriously doubt), lower engine RPMs and increase fuel economy by a similar percentage. Parts and labor will come in just under $300, which is significantly less $$$ than the real solution: putting in a 6-speed tranny. My only concern was that maybe the "9" engine wouldn't have the torque at lower revs to happily cruise @ freeway speeds with the new setup, but as it stands now I'm using very little throttle zipping along @ 80. I suspect I'll be holding it in 4th a little longer before going into 5th (even after taking the new gearing into account) so that the motor is further into it's powerband post-shift, but that's the only difference I anticipate.

Or, I might be overly optimistic and this could be an experiment that fails miserably... a gearing setup not well suited for the motor. But at least I'll be able to go back to its original configuration should the results be less than desireable.

For those considering a similar change let me know and I'll keep you posted on how it works out.
Top of pagePrevious messageNext messageBottom of page Link to this message

Charlieboy6649
Posted on Sunday, September 19, 2004 - 10:36 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Better you than me... Just kidding I hope it works out, keep us posted.
Top of pagePrevious messageNext messageBottom of page Link to this message

Fullpower
Posted on Monday, September 20, 2004 - 06:57 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

the maniacs at soldotna HD/Buell did the opposite, installed the 34 tooth primary drive sprocket, and chain from a 9 into an XB12s, for an even 11% more torque at all speeds in every gear. i have not ridden the beast myself, but it is said to make 3rd gear wheelies at 2000 rpm, with no clutching required. sounds like a bunch of fun.
Top of pagePrevious messageNext messageBottom of page Link to this message

Wyckedflesh
Posted on Monday, September 20, 2004 - 07:02 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Been thinking about it for dragstrip runs FP, the quicker acceleration vs the loss of top speed won't be noticed on the dragstrip I think.
Top of pagePrevious messageNext messageBottom of page Link to this message

Glitch
Posted on Monday, September 20, 2004 - 07:36 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

How would you launch such a creation?
Wheelie bar?
Top of pagePrevious messageNext messageBottom of page Link to this message

Bradyclt
Posted on Monday, September 20, 2004 - 07:55 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Yeah, I thought about the opposite (9 gearing on a 12) and had read where a few folks were considering it... I'd love to see one of those in action. Not that I'd ever attempt 3rd gear wheelies myself (I have a mortality hang up), but it'd be entertaining to watch. Which reminds me of what I saw on the freeway here about two weeks ago: someone incredibly skilled, stupid, or both walking his metric bike with the front end at least 60+ degrees in the air, doing 100+, for at approx 1/4 mile. I think I saw him standing on some pegs installed in the rear axle, which in my mind is 'cheating' compared to normal riding position, but I was so mesmerized I had to watch (he was tavelling oncoming in the opposite lanes). Oh, and of course just street clothes w/sneakers... helmet only riding apparel.
Top of pagePrevious messageNext messageBottom of page Link to this message

Wyckedflesh
Posted on Monday, September 20, 2004 - 08:45 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Slip the hell out of the clutch on take off. I have gotten real good at slipping the clutch as I roll the throttle for hard launches but not actually holding any RPMS then dumping the clutch. Maybe give up half a second of 60' time to gain a second at the top end with the higher acceleration?
Top of pagePrevious messageNext messageBottom of page Link to this message

Bradyclt
Posted on Wednesday, April 26, 2006 - 11:25 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Someone sent a message inquiring about the results of the primary swap, so I'm posting my experience here. Disclaimer though: sold my bike a year ago... a close relative was involved in a major accident as a passenger on a metric bike (totally the other vehicle's fault) and seeing this person in the ICU for days made me reevaluate my priorities.

I put over 1000 miles on the bike with the new setup, and had I kept the bike it would have remained that way:

Pros:

Great setup for Interstate riding; engine not nearly as spun up; better sounding engine note (more V-twinish); less engine wear; ability to just leave it in 4th gear and forget about it on winding rural highways.

Neutral:

Fuel economy (got a very slight increase in fuel economy, but not enough to warrant it being a decision factor); Top speed (just hits it at lower engine RPM)

Cons:

Must change clutching technique when starting out in 1st as engine is more apt to bog down... the additional amount of feathering necessary would accelerate clutch wear in stop and go rush hour and/or urban riding; not a good setup for two-up riding as more frequent downshifting is needed to keep output up; takes longer to hit top speed; acceleration isn't as strong, but only took a minor hit.

Like I said, as my commute is all Interstate so I was pleased with the results of the swap, but it's clear this setup takes the 9's engine a tad out of it's comfort zone/power band. If you do a lot of solo Interstate/highway riding and keep clicking for the sixth gear that isn't there, then this is a good low-cost alternative to a new transmission setup. If you do primarily urban riding with lots of stop and go, or any two-up riding at all I would not recommend doing this mod.

The true solution is Buell developing or adopting a 6 speed transmission with 5 lower gears that are spaced so top speed is reached in 5th (like the current stock gearing), with an overdrive 6th about 12-15% taller than 5th for highway cruising... you'd retain the bike's original launch characteristics, and bikes with two on board could elect to just not use 6th in hilly terrain and be no worse off than they are now.
« Previous Next »

Add Your Message Here
Post:
Bold text Italics Underline Create a hyperlink Insert a clipart image

Username: Posting Information:
This is a private posting area. Only registered users and custodians may post messages here.
Password:
Options: Post as "Anonymous" (Valid reason required. Abusers will be exposed. If unsure, ask.)
Enable HTML code in message
Automatically activate URLs in message
Action:

Topics | Last Day | Tree View | Search | User List | Help/Instructions | Rules | Program Credits Administration