| Author |
Message |
    
Rfischer
| | Posted on Thursday, July 24, 2008 - 02:54 pm: | 
|
Fact is, there shouldn't be any wheelbase difference as a shorter belt will completely deal with the larger pulley issue.
Dunno where the "longer swingarm" specification referred to above came from.... |
Xl1200r
| | Posted on Thursday, July 24, 2008 - 02:59 pm: |
|
Larger pulley needs a longer belt, not shorter. |
No_rice
| | Posted on Thursday, July 24, 2008 - 03:20 pm: |
|
i am thinking more along the lines of the specs are a typo or something similar.
why spend the money to redesign a swing arm for that. that would be nuts.
i will be amazed if the swap onto an R takes more than a BIGGER rear pulley and a LONGER belt! |
Rfischer
| | Posted on Thursday, July 24, 2008 - 03:38 pm: |
|
"longer belt"
My bad; you are correct.
(Message edited by rfischer on July 24, 2008) |
Xl1200r
| | Posted on Thursday, July 24, 2008 - 03:42 pm: |
|
From the Buell website:
1125CR
"A new longer cast-aluminum swing arm design optimizes the suspension geometry with the lower final drive gearing."
1125R
"The cast-aluminum swing arm has been specifically designed for improved rear suspension geometry while its stiffness has been tuned for the 1125R."
I would guess that both models are using an updated swingarm based on the words "new" and "improved" in the descriptions.
I gotta agree with No_rice - I think these are typos. Take for example the overall length figures - According to Buell, the CR is 2.7" LONGER than the R. Seeing as how both bikes overall length is limited by the outer ends of the tires, this figure should be the same for both models (seeing as how the front-end geometry is the same). |
Anonymous
| | Posted on Thursday, July 24, 2008 - 04:13 pm: |
|
The CR uses a different belt and a slightly longer swingarm than the R, to maintain the proper belt geometry with the new gear ratio. |
Rfischer
| | Posted on Thursday, July 24, 2008 - 04:17 pm: |
|
Well now.....that's going to make for an expensive gearing change! |
Jdugger
| | Posted on Thursday, July 24, 2008 - 04:23 pm: |
|
> I don't get it, I ride 65-75mpg in 6th all day long. What's the problem?
My *opinion* is that cruising on the 1125r is significantly smoother with the motor in the 6k range.
The power is more readily available, and the engine will rev quicker coming on hard from 6k than it will from 4.5k.
Couple that -- meaning I rarely use 6th on the bike -- with a tall first gear, and it peaks one's desire to have slightly shorter gearing.
That's all.
The bike is a bit "surgey" at 4-5k. It's hard to maintain a stable speed. It's real smooth at 6k.
Again, my opinion. |
Fresnobuell
| | Posted on Thursday, July 24, 2008 - 04:45 pm: |
|
The bike is a bit "surgey" at 4-5k. It's hard to maintain a stable speed. It's real smooth at 6k.
Hmmm....there HAS to be significant variation between 1125r's then because at the 4-5K range is extremely smooth on my R. I can actually go down to below 3K RPM in the low gears with just a hint of surging. No re-flash yet.
Surging to a point where it is hard to keep a stable speed? Now that is problematic. |
Jdugger
| | Posted on Thursday, July 24, 2008 - 05:07 pm: |
|
> I can actually go down to below 3K RPM in the low gears with just a hint of surging
No way for me. It takes just the slightest crack of throttle to run the motor that slowly, and I can't find a happy place. Lower gears just make the problem worse.
When I cruise, I aim to be 5500 to 6000. Then it's very, very smooth, and big power is quickly on tap.
I have had the update. I can't tell a difference with the update other than I'm getting 2-3 better MPG. |
Fresnobuell
| | Posted on Thursday, July 24, 2008 - 05:59 pm: |
|
2-3 better MPG
That would be really nice for sure, but I don't want to mess up what I have with the re-flash. I am supposed to take my bike in tomorrow for the 5th gear recall and they KNOW not to re-flash.... |
Palerider
| | Posted on Thursday, July 24, 2008 - 06:47 pm: |
|
"Well now.....that's going to make for an expensive gearing change!"
After years of chain drive I really liked the belt, but I have to admit I think it's much easier to re-gear with chain and sprockets. Guess I'll have to do a price check on swingarm and pulleys. Probably have to hide another parts purchase from the missus. I feel the bike would be better geared lower, at least for my riding style. |
Fresnobuell
| | Posted on Thursday, July 24, 2008 - 07:05 pm: |
|
I want to say the swingarm (R) is in the neighborhood of $450. Not sure where I saw that.... |
Jedipunk
| | Posted on Thursday, July 24, 2008 - 07:51 pm: |
|
Thanks for backing my post up anon. |
Jedipunk
| | Posted on Thursday, July 24, 2008 - 07:59 pm: |
|
It really sucks trying to share some info with fellow buellers and having people slam it. That'll teach me to try and address postings on the board. |
Josh_
| | Posted on Thursday, July 24, 2008 - 08:00 pm: |
|
So you want the bike geared low enough so that 6k RPM is 55MPH? Or you want it remapped so that it's smooth down to 3k?
I've had two cars with 6-speed trannys and neither was useable under 65MPH.
My bike is fine at 6th/4k RPM/65MPH all day (or at least all the way home) |
Xl1200r
| | Posted on Thursday, July 24, 2008 - 08:21 pm: |
|
The CR uses a different belt and a slightly longer swingarm than the R, to maintain the proper belt geometry with the new gear ratio.
Anon - Can you elaborate a little more on this?
Why would anything besides a longer belt be needed to maintain the proper belt geometry? It seems this could have been done with simply a different belt rather a whole new swingarm with a very minor difference.
My *opinion* is that cruising on the 1125r is significantly smoother with the motor in the 6k range.
The power is more readily available, and the engine will rev quicker coming on hard from 6k than it will from 4.5k.
If you're just cruising, why do you need power to be readily availible? It takes all of .3 seconds to downshift.
I haven't ridden an 1125 yet so I can't speak intellegently on this, but I know a lot of people who like to "cruise" on XBs in the 5000rpm range for the same reasons, and it just seems like undo wear on the engine. |
Bigblock
| | Posted on Thursday, July 24, 2008 - 09:04 pm: |
|
I would imagine the larger diamater pulley changes the the path that the belt rides in, so you have to change belt and swingarm length or tensioner position to allow constant belt tension.
(Message edited by bigblock on July 24, 2008) |
Xl1200r
| | Posted on Thursday, July 24, 2008 - 09:16 pm: |
|
Or just a shorter belt, which he said they have.
It almost sounds like instead of one moderate change to one part, they've made a bunch of little changes to a couple parts. It doesn't seem logical to me, but then again, I'm not an engineer. |
Spike
| | Posted on Thursday, July 24, 2008 - 10:03 pm: |
|
Since there's no slack in the belt, the belt length has to be perfect. The belt length can only be changed in full tooth increments, so it's possible that revising everything was necessary. |
Xl1200r
| | Posted on Friday, July 25, 2008 - 08:50 am: |
|
Spike - I think that makes the most sense - Both the belt and the pulley needs to have all complete teeth. Maybe the little changes to everything are a result of getting everything as close to how it was as possible with the new ratio. |
Anonymous
| | Posted on Friday, July 25, 2008 - 11:23 am: |
|
Geometry on the Buell belt drive system is very carefully calculated to give constant belt tension over the full travel. There are 5 variables to contend with: sprocket sizes, idler position, idler diameter, belt length, and swingarm length. To get the proper result, you can never change just 2 of the variables, and rarely just 3. |
Xl1200r
| | Posted on Friday, July 25, 2008 - 01:33 pm: |
|
Makes sense now - I didn't consider that the swingarm moved and constant tension needed to be upheld. |
Ceejay
| | Posted on Friday, July 25, 2008 - 02:58 pm: |
|
Would anyone know if the belt tooth spacing and pitch are the same on the rotax powered bikes vs. the XB's? |
Spike
| | Posted on Friday, July 25, 2008 - 03:27 pm: |
|
Just a thought while we're discussing belt length/geometry: If Buell is willing to change the length of the swingarm (surely not as easy as it sounds) to keep the belt length/geometry/tension correct, why would anyone conclude that the belt tension on the XBs was merely 'good enough' and capable of being improved with an aftermarket spring-loaded idler pulley? |
Xl1200r
| | Posted on Friday, July 25, 2008 - 03:44 pm: |
|
Because then someone makes money. |
Jdugger
| | Posted on Friday, July 25, 2008 - 09:44 pm: |
|
> If you're just cruising, why do you need power to be readily availible? It takes all of .3 seconds to downshift
Because a car just cut me off and my lane is shrinking and pulling around/forward is safter than looking to see if there's an open spot to either side.
I guess I picked a scab with this gearing thing. Hey, I'd like the gearing overall to be a little shorter. It's preference thing. I'm not totally alone in this. |
Zac4mac
| | Posted on Saturday, July 26, 2008 - 12:18 am: |
|
If I can hitch a ride to Bonneville, I'll see how fast I can go.
Otherwise, lower gearing would be fun.
Sux being so high up...
Z |
