| Author | Message | ||
     Nobuell |
The OEM throttle tube rotates approximately 110 degrees from closed to full open. See the red lines on the OEM tube. This can make accelerating out of a corner very awkward for track applications. Many times your hand is not in the right location for full acceleration when exiting a corner.  So, one of my many off-season upgrade projects was to install a quick turn throttle. I found that a quick turn throttle kit is not available for the 1125R when searching on the Internet. Adapting a generic quick turn throttle assembly offered by other companies would require having custom cables made and utilizing separate after market housings for the kill and starter switches. I wanted to try making the change utilizing the standard housings and cables.   I contacted Gary at G2 Ergonomics since they sell many replacement throttle tubes for many applications. He sent me a multi-cam machined aluminum quick turn throttle tube with Y025 and Y050 cams. It is a beautifully machined piece of work with Delrin bearings. The Y050 cam is approximately 10% larger than the stock diameter and the Y025 would be approximately 20% larger in diameter. I fitted the Y050 cam into the throttle housing only to determine if it would fit and operate without housing modification. I actually plan to use the larger diameter cam to decrease the throttle rotation further but I wanted to verify that it would work. The Y050 fits and operates without modification. For those who want to decrease throttle rotation to approximately 90 degrees and want to use the stock housing, switches and cable, get the throttle tube with the Y050 cam. Use of the large diameter Y025 cam will require the cable guide housing to be modified. The housing must be disassembled and the cable guide removed. There are 4 screws that hold the switch assemblies and the cable guide in place. Remove them being carful not to loose the little return spring that is part of the starter switch. The kill switch is enclosed, so there are no loose parts.  Remove the cable guide and install the new throttle tube into the housing. Reinstall the cable guide and other housing. Rotate the throttle tube while holding the assembly in your hand allowing the cam to slightly score the cable guide. The cam will leave silver marks on the guide where material reduction is required. Using a Dremel Tool with a small cut-off wheel, grind the radius and cable slot to accommodate the larger diameter cam. I found that I could install the tube in the housings while holding in my hand and rotate as described above, then remove and grind continuing the process until the throttle rotates freely.  Next assemble the cable guide, housings and throttle tube and slide the assembly onto the handle bar (Do not install the switches yet). Install the housing screws (the two screws that hold the housing halves together) and verify that the throttle tube rotates freely when the housing screws are tight. If the tube does not rotate freely, disassemble and remove more material as described above. There will be a little trial and error required to get the clearance for free rotation. It is not a difficult job, just take your time and remove small amounts of material from the cable guide each time. When the material removal is complete, sand and smooth the rough-cut areas using some 320 grit sand paper. In addition, I used a small flat hand file to remove the injection molding flash from the housings in the cam rotation areas to make the throttle rotation as smooth as possible. I smoothed down any imperfection in the housing that could interfere with rotation of the cam. Once you a satisfied that that the proper amount of material has been removed and the assembly rotates freely when clamped to the handle bar clean the housings using soap and water and dry. Reinstall the switches being carful to install the starter spring correctly. The large spring end is installed on the toggle side of the switch to allow clearance for the contact.  The large cam provides approximately 71 degrees of rotation from closed to open. I believe it will be perfect for my track application. The only down side is the weather. It will be a few months before I can get the bike to the track! | ||
| Froggy |
Very nice writeup, it doesn't look hard to do. What was the total cost of the parts? Also, you mention you couldn't find a kit for the 1125R, I know Twin Motorcycles sells one, although it is likely significantly more expensive than your setup. http://www.twinmotorcycles.com/webshop/artikel.asp ?guid=YXHFSC&aid=3565&cid=9683&s=&a=&aname=Buell_X B9R_and_XB12R_and_1125R_Quick_Throttle_kit | ||
| Kruizen |
Here's another one that comes with 3 cams: http://www.cyclepirates.com/main/select_by_bike?bi ke_id=79&make=Buell+&model=1125R | ||
| Nobuell |
I believe I paid approximately $60.00. When I looked into the Cycle Pirates kit it had been discontinued. I think the kit offered by Twin Motor is a Cycle Pirate. One of the problems using a throttle kit is the need to replace the existing switch housing with an after market version. If you get a $200.00 kit plus the switch, you will be $230.00 into the change plus the time to re-wire. The G2 tube assembly is US made and very high quality. | ||
| Stevel |
Nobuell, Great write up! I used a quick throttle on my hot rod Kawasaki in '73 and have been a fan ever since. It is a great mod and it is a very large improvement and highly recommended. You're going to love it! I'm ordering mine today. | ||
| Nobuell |
Glad to help. It is not a difficult mod. Once the housing is apart, it is obvious where the material removal is needed. Good luck. | ||
| Bob_thompson |
Just a question here so no negativity intended but, when I ride these canyons here in semi race mode, with caution foremost and no traffic, I'm usually using the throttle from 1/2 to full so once I start a run I reposition my hand to accommodate that as well as keeping two fingers on the brake lever for a small amount of trail braking or emergency when needed. I usually do not need a full rotation of the throttle as I'm usually running from 6000rpm to redline. SO, is it that much difference on the track and if you think so, how? In some limited drag racing and flat track years ago, I did have a quick throttle, at least for the initial starts. An honest question from me. Bob | ||
| Stevel |
Bob, When I built the Kawasaki motor, I elected to use a set of sand cast smoothbore Keihins to replace the stock carbs. These were race only carbs with no low speed circuits. Minimum engine speed with these was 2200 RPM. These came equipped with a small bell crank, so with the stock throttle grip, were very quick indeed. It took me about an hour riding before I got used to the fast throttle. In the end, after I got used to it, it was wonderful. Full throttle without a re-grip is a real plus. Try it yourself, then you'll know. You can always go back to what you have now. These throttle parts are very reasonably priced. I don't see a down side. | ||
| Nobuell |
Riding on the street vs track is completely different. On the track every turn is attacked at the highest possible speed. Extreme lean angles and body position occurs everywhere. I am not insinuating high speeds are not possible on the street. Just that track lean angles and the ability to grasp the throttle correctly require reduced throttle rotation. The stock 1125 throttle rotation was probably selected to keep some street riders out of trouble. The issue occurs primarily when one is extremely on the side when hanging off of the bike. Rotating your wrist an additional 80 or 90 degrees can be difficult and distracting not to mention the other guy is trying to out accelerate you exiting the corner. When transitioning from lower throttle to wide open, it sometimes feels like I need to re-grip the throttle. The revised decreased rotation will promote and allow better body position and easier acceleration. | ||
| Buellfirebolt31 |
I did this mod with a 2006 R6 throttle cam. There's a little engineering that's involved, but it's only $18. And works great. Cables needed a little attention, and trimming the housing, but there's a write up on here that tells you how to do it. | ||
| Bob_thompson |
Excellent explanation Tim(Nobuell) and you showed the very reason for it. I HAVE noticed when hanging off it IS harder to rotate your wrist more. That throttle does seem to be a long way out there especially on left turns and twisting becomes much harder. Even right turns my wrist seems to be cocked hard up to twist easily toward me for full throttle. Not nearly so pronounced in the more vertical flat tracking and drag racing where I used a quick throttle. Thanks, I totally agree and accept your fine input. Bob | ||
| Dannybuell |
Stevel got my attention at 're-grip'. | ||
| Nobuell |
Buellfirebolt31 I did see the R6 mod a while back. A great mod especially at that price point. I wanted removable cams in case I wanted to tune the throttle rotation. |
