| Author | Message | ||
     Markp |
Anybody care to share thier real life experience with this mod. I understand I should get an additional 10.5% torque. I'm interested in the fun factor, how does it wheelie and what does it do to how the bike revs. | ||
| Gotj |
It doesn't change the engine torque, just the torque on the rear wheel because of the lower gear ratio. I don't know about wheelies but you can simulate the XB9 gearing's effect at highway speeds by riding your XB12 in fourth gear. It is about 10% lower than fifth. GOTJ | ||
| Markp |
Seems like 1st would wind out very quick with this setup then. | ||
| Gotj |
"Seems like 1st would wind out very quick with this setup then." Revs out just like the XB9. | ||
| Reepicheep |
Almost like the XB9... the 9 has a higher redline so it will actually rev a little higher. If there was an easy way to drop the gearing on my 9 just a little it would be tempting to do, so I can see why somebody with a 12 would do it, especially something like a Uly. | ||
| Gotj |
Reep, "Almost like the XB9... the 9 has a higher redline so it will actually rev a little higher." Quite so. I stand corrected. Just forgot that part. | ||
| Markp |
I appreciate the feedback but your not really telling me how the bike will change in performance. With the mods I have done I'm getting 100+rwhp from the engine and not really interested in top end speed nor is my insurance but there is no law against how fast you get to the speed limit. So will this make the bike quicker? | ||
| Littlefield |
It's like you put in a closer ratio 6 speed transmission with the same 6th gear ratio and never shift into high gear. It'll make the bike some quicker but not 10% because you have to upshift sooner. If you want to know how much quicker you could get a quarter mile simulation program and see how the numbers change. | ||
| Panic |
Doesn't change the ratio spread; the RPM loss on each shift is the same. The effect is the same as increasing the rear pulley size by the same proportion: more torque and more RPM but less MPH. | ||
| Cavi |
this is exactly what I am looking to do on my Uly, the top speed of the bike is way higher than I will need ever, and i want more grunt in the bottom to make manuvers slow speed manuvers easier in 1st gear and 2nd gear. | ||
| Jandj_davis |
Can the opposite be done? Can the 12 primary be put in the 9 to decrease revs at speed? Has anyone done this? | ||
| Cavi |
I am 100% sure it can be done, just keep in mind that you will loose low end torque. | ||
| Jandj_davis |
What parts are needed to do the swap? Is it both sprockets, or just one? How hard is the swap to perform. It might be worth it to me to keep both sets around so I can swap them for long trips but leave the 9 stock for in-town driving. | ||
| Shaiss |
thanks guys for shedding the light on this. Considering riding performance I was told that doing the gear reduction will make daily driving a pain as you'd be constantly shifting. Anyone know if this is true? The parts are: Stock XB9 Primary Chain Stock XB9 Engine Sprocket Stock XB Primary Gasket $193 from American Sport Bike http://www.americansportbike.com/shoponline/ccp0-p rodshow/A17150.html | ||
| Spike |
I haven't done the swap myself, but this gearing calculator may help illustrate the change: http://www.cryohold.com/bike/gears.html It has a 2004 XB12R as a preset, but the rev limit is listed as 7000 instead of 6800. Load that preset, change the rev limit to 6800, then change the primary drive ratio from 1.5 to 1.676 to see the difference in speed in each gear. The result will be a noticeable increase in torque at the rear wheel in each gear, but the road speed in each gear will be reduced. The bike should definitely feel faster and more responsive, but will be turning more RPM while cruising in top gear. | ||
| Gotj |
Spike +1 Performance judgments. Very cool calculator. I would have set it up so that the column headings were mph and the output was rpm. You could then assess the change in rpm for a given speed. If I knew how, I would generate it. | ||
| Shaiss |
The gear rations on that calculator are a bit off. Here's the specs of buell.com 1st 2.648 2nd 1.892 3rd 1.407 4th 1.166 5th 1.000 | ||
| Spike |
Gotj- My brother in law came up with that calculator, you can get all the info by right-clicking on the site and selecting "view page source." Shaiss- The XB tranny changed in '06, I wouldn't be surprised if all the ratios changed slightly as well. When he made the chart he used the specs that were on the Buell site at the time. | ||
| Shaiss |
ok, then I'll take his word as I have an 05. Why dont you ask him to create more features, some people here might pay few $ to use it | ||
| Gotj |
Spike, I did the right click thing and what I saw made my head hurt. | ||
| Sweatmark |
Spike - that's a very handy web page. Please pass along my thanks. This topic hits home for me: planning to do a bore & stroke kit on my XB9, while keeping the XB9 primary. Doesn't look like "streetability" will be compromised too much with the shorter primary ratio (is "wheelyability" a word?), though now I'll get passed by everyone on the front straight at trackdays, via lower top gear speed! | ||
| Cavi |
Okay I just had the swap don just a few hours ago, and I can say that it is awsome, on the Uly it feels like it should, slow speed manuvers are now possible, and it still will do over 100mph, I was at 5250 at 90mph, and personally I don't much over that most of the time. The difference is major, the bike just feels better and more responsive. | ||
| Shaiss |
Where'd you have it done? A local shop or Harley dealer? | ||
| Cavi |
Well....I used a local shop that works only on old harleys, the local dealer couldn't take it till next week and they wanted it all day. | ||
| Markp |
How does it wheelie | ||
| Shaiss |
I'd emagine being a uly that thing would come up easily even in 4th! so Covi, pleaes share details for all us mouth drulers | ||
| Cavi |
yes the front will go skyward real easy. Just crack the throttle | ||
| Shaiss |
I'm making a mount for my bike. I'm gonna ride it normal and like hell before and after the conversion and post videos here. Check back in about 2-3 weeks. | ||
| Markp |
Cavi & Shaiss I'm surprised that more people have not done this mod before. I wish there were an easier way to accomplish like changing out the drive pully's so it's more easy to go back. When I raced motocross depending on the race I use to do this all the time depending on the course. | ||
| Markp |
Shaiss, how you making out with the video | ||
| Diablobrian |
the main reason people haven't done this mod is because gearing wise 5th gear becomes more like 4th gear with stock primary gearing. Even though most people rarely use the top speed of their bikes they are very attached to the fuel efficiency they get while buzzing along in 5th gear. It all comes down to this, is the reduction in fuel mileage worth the increase in torque for the way you use your motorcycle? Personally, I'd like to have an overdrive 6th gear in addition to my stock gearing  | ||
| Shaiss |
I was actually just about to post the link. http://www.livevideo.com/shaiss All of the videos there posted before today are with the stock xb12 primary setup. I did the conversion to the xb9 primary yesterday. So check back later in the week, I will post some videos showing the differance. I dont know if the videos will do justice. But all I can say is "WOW". There is a very noticable differance. 1st gear wheelies are cake, barley need any throttle. Havn't tried second yet. Buzzing along on the freeway at 75 your at 4000 rpm. open the throttle a bit and you shoot up to 90 and 4700 rpm (about). The bike in general feels so much quicker and this is deffinately worth while. | ||
| Jlnance |
Even though most people rarely use the top speed of their bikes they are very attached to the fuel efficiency they get while buzzing along in 5th gear. It all comes down to this, is the reduction in fuel mileage worth the increase in torque for the way you use your motorcycle? I've been trying to quantify the reduction in fuel mileage, as I'm considering this mod, and I want to know what I'll be giving up. For the last week I've been riding around w/o shifting into 5th gear. Mileage has been in the low to mid 40s each time I've checked it, which is what it normally runs when I'm using 5th. I have not yet done a 150 mile run down the interstate at 80 mph, which is where the most dramatic difference would show up; I'll try that soon. But whatever the reduction in fuel efficiency is, it isn't dramatic. | ||
| Shaiss |
hey guys. Sorry I havnt posted videos after the change. My clutch bearing broke in half after the change. What happend was my clutch was already out of adjustment and grabbed to much. but with the stock sporocket it wasnt really a big deal. Switching to smaller sproket I think caused so much tension, the dam thing broke right off. I got the bike running, need to do some more adjustments and I'll start filming again | ||
| Blake |
Are you talking about the clutch throw-out bearing? | ||
| Shaiss |
yeah, I think thats what its called. Its 3 2 peices with 8 bearings in between and sits on the adjustment screw. btw. New videos posted. |
