| Author | Message | ||
     Stevo |
People talk about doing it, but know body ever says how they like it. So how bad does the gas mileage get and what is it like at highway speeds? I'm thinking about converting my 12 over to 9 set up for the low end grunt, but don't want to sacrifice to much of my 5 gear at highway speeds. | ||
| New12r |
You will lose about 10 or 20% of your top end. I thought about it but opted not to. It would be fun in the mountains. | ||
| Tigerbythetail |
hi................9 in Germany means 34/57........12 in Germany means 38/57...... I would do it. In particular if you use the XB9 Race ECM reprogrammed with the 12 Race ECM curves, as this gives you additional revs (rev limiter 7500 _ I ride with a shift indicator and shift at 7200) and you do not loose the top speed. The XB12 engine takes this quite well..........just in case somebody starts to winge about it! Regards tiger | ||
| Hogs |
Stevo, If ya don`t do much on open up Highway Driving its worth it... ( 10 ) percent is more like the difference BTW. Fun factor goes way up down low end, so its up to you Gas mileage is not a whole lot different depending on how ya drive down low... Top speed hurts way up top if thats where ya drive or like to blast up there even on the highway just at say 75-80 mph its reving and ya can notice it IF ya like to cruise at them speeds 500 rpms more but feels like more top speed is lowered of course and it seems to be screaming way up top.. I have it on now for the last 10,000 miles or so IF ya got any other questions on it let me know.. | ||
| Hogs |
REving higher is sure not something I wd. want to do on the stock 12 bottom end bearings ,thats pushing it I wd. say my .02 cents on that.. | ||
| Gentleman_jon |
On the other hand............. Another way to skin this cat is to go to a chain conversion. This has two advantages over changing the primary gearing. 1. you have a greater selection of available ratios, which can easily be changed to suit different conditions. 2. You get rid of the belt, with its potential for breaking, Inexpensive chain conversions, like Saintly's, among others, cost around the same as the primary conversion, or the new upgraded "unbreakable" 2006 belt. Or, you could change BOTH the primary ratios AND convert to chain, as I have. Don't ask..................  PS. I have geared my bike down about 10%, ( What you get by changing the primaries from the 12 to 9 ratios on a twelve). I don't do much highway cruising, so I enjoy the increased acceleration. As I have a Lightning model, and since I am a bit larger than average, I do not believe my actual attainable, as opposed to theoretical, top speed has been lowered much, but I have not tested it. (Message edited by gentleman_jon on November 16, 2006) | ||
| Wolfridgerider |
This sounds like a FUN thing to do! Will the speedo need to be calibrated? Do you need to buy a new primary chain? Wheelie bar? | ||
| Tigerbythetail |
hi.......no recalibration needed when you change the primary. When you change the secondary yes. Wheeliebar also not needed..........we have build for a german Stuntrider a 26/57 solution for a 9 and I have test ridden this.....its not manic and certainly not when doing the 34/57 job.......but you can feel it and I personally think its nice.........by the way one of my mates has ridden a XB12 for the last 3 Years and clocked up more than 40000 km with a programmable ECM ref limiter set at 7200 without problems so I would worry to much about that. tiger | ||
| 99buellx1 |
What's a km?  | ||
| Wolfridgerider |
Thanks Tigerbythetail, that gives me something to think about for the winter..... | ||
| Asdf |
I like the lower XB-9 (Sportster 883) primary gearing on my Ulysses very much. Slow speed operation, particularly while in stop and go traffic, is excellent. Of course, 10% more "Grunt" from idle to red-line in every gear is a perpetual smile generator, too! Do not forget that you will also get about 10% more engine - compression braking with the lower gearing. With the lower gearing, 60 MPH = 3250 RPM, 70 MPH = 3800 RPM. Theoretical maximum speed, which on Buells is ultimately limited by the Rev Limiter, will be reduced from about 138 MPH to about 122 MPH. These figures for RPM and Speed are taken from the Tach and Speedo on my Ulysses while riding. Therefore, they are subject to some error. The parts for the Primary Gearing change were about $195 USD. I could be off a bit, but that is pretty close. Motor Sprocket Assembly Part Number 32493-02 was $114, Primary Gasket Part Number 25352-00YA was $15.85 and the Primary Chain was about $65. I suggest getting the Motor Sprocket ASSEMBLY that has the Stator Cover already riveted or bolted to it. I feel that removing and then reinstalling your current Stator Cover is not worth the time, money or hassle. Have fun! | ||
| No_rice |
a blast primary in my 9 huh? lol. oh nevermind | ||
| Tigerbythetail |
hi.............65 bucks for the chain is actually quite irritating this sells in Germany for 195 Euros............so you US guys get a cheap deal! tiger | ||
| Stevo |
Thanks for the feedback. I live pretty close to the mountains now that I'm back in Utah, so I wont be on the freeway for to long, and for the periods that I am I think I can live with the 5 or 600 RPM increase. I do plan on doing a chain conversion also, but that will have to wait till next winter. Steve | ||
| Daves |
for those interested Primary sprocket 94.50 Chain 56.70 gasket 14.26 | ||
| Jandj_davis |
So, all the 12 owners want to use the 9 primary, but are there any 9 owners that want to use the 12 primary? I know that I would not have any problem with more top speed, better gas mileage, and lower revs at a given speed. In my opinion, the 9 has enough oomph to move the 12 primary in a pretty quick fashion. Has anyone tried this? | ||
| Anonymous |
With 34/57, you can use an XBRR primary chain, which is stronger and made of improved materials. | ||
| No_rice |
if i remember right a couple have tried the 12 in the 9 and not been to fond of the results. |
