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Ccryder
| | Posted on Saturday, October 31, 2009 - 07:46 am: | 
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Play the engineer card around here and you are liable to get trumped. The are many with degrees, including myself, and many without that are just as knowledgeable.
My bottom line to this discussion is to keep the rider safe. IMHO what you are proposing many not result in a safe condition.
Can you or I prove it one way or another here on the internet..... no, but we do know that changes within the normal adjustments of the suspension can make major changes in how the motorcycle will handle. These changes you are proposing are outside Buells recommendations and outside of the envelope that has proven to be safe.
Time2ride
Neil S.
Mike, sweet looking X1, hope you kept it. |
Zac4mac
| | Posted on Saturday, October 31, 2009 - 08:27 am: |
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I may be way off base, but I think changing the ride height would have the most negative impact on the belt.
The tension is set for a specific amount and is held constant(close) thru it's arc.
A different arc, well, different tension...
The suspension/drive on the 1125 is a bit unorthodox and works well as executed.
Zack |
Chessm
| | Posted on Saturday, October 31, 2009 - 11:12 am: |
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my vote is shave the seat foam then get this
that and just deal with it.
lowering the bike and screwing with handling just so you can ride the bike comfortably? just tells me the rider bought the bike to pose on. its a buell not a ducati. |
Fmaxwell
| | Posted on Saturday, October 31, 2009 - 12:44 pm: |
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@Ccryder:
Play the engineer card around here and you are liable to get trumped.
Not by someone playing the joker card.
In summary, I recommend that anyone insistent on lowering an 1125 reduce the height of both ends equally. Sport Rider magazine's article on lowering sport bikes made the same recommendation.
You said that such a recommendation was based on "VERY flawed logic." Then you concocted a very vague statement about "compound angles of the suspension and the interacting aspects of the geometry" when I produced the quote from the Sport Rider article. When pressed to identify specifics or cite any reputable article which supported your claims, you were unable to do so.
You wrote, "My bottom line to this discussion is to keep the rider safe." Yeah, we could tell by your recommendation of "Good luck and let us know what works or doesn't."
You went on to write: "These changes you are proposing are outside Buells recommendations and outside of the envelope that has proven to be safe."
I'm not "proposing" any changes. In fact, I strongly recommended against lowering the 1125R and, instead, encouraged the purchase of a bike like the XB12Scg designed for a shorter rider.
@Bikejunky: Sorry if there was any confusion, but I specifically referred to lowering each end of the bike by equal amounts, not shortening the forks and shock by equal amounts.
@Zac4Mac: Just referring to the rear suspension here, lowering it with a shorter shock would just put the swingarm in a different point in its arc. In other words, it would be like it had already used up the first part of its travel. You would not be changing the geometric relationship of the countershaft, rear axle, idler wheel, or swingarm pivot point. Thus the belt tension would remain within Buell's design envelope. |
Ccryder
| | Posted on Saturday, October 31, 2009 - 02:36 pm: |
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You sure are working hard at defending something that you are not proposing???
Nothing concocted here except in your mind. The burden of proof is not on my shoulders since I'm not proposing anything that has not already been proved by Buell.
Joker card, it's all your's, always has been. Just keep it up, you are proving it all by yourself.
I was talking to one of our CO Buelligans about the subject of reducing seat height and have finally decided that the safe three step process is:
1) Shave the seat padding.
2) Taller boots.
3) Let all the air out of the tires.
After #3, anything else doesn't matter.
Hey Fred, try some of these things out on your 1125 and let us know what works best for you.
I hate to run off and go ride my 1125rt and miss all this fun but........... I do have my priorities.
Time2Ride
Neil S. |
Whynot
| | Posted on Saturday, October 31, 2009 - 02:40 pm: |
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Take a look at this thread for a lower seat -- beyond shaving:
http://www.badweatherbikers.com/buell/messages/290 431/485352.html#POST1542591 |
Fmaxwell
| | Posted on Saturday, October 31, 2009 - 04:37 pm: |
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@Ccryder,
"You sure are working hard at defending something that you are not proposing???"
In case you missed your Ritalin this morning, Neil, what I proposed was:
"Buy her an XB12Scg or other bike designed for those of shorter inseam."
I recommended against lowering the bike, but cautioned that if the other poster was insistent on lowering it, then he should not lower one end more than the other. I stand by that caution. So does Sport Rider magazine. You said it was "VERY flawed logic" but were laughably unable to provide even a single source to support your claim. (I won't stoop to your level by claiming that you 'proposed' lowering the bike different amounts at each end.)
"Joker card, it's all your's[sic], always has been. Just keep it up, you are proving it all by yourself."
Nope, you're way out of my league there -- with your comments about "compound angles of the suspension and the interacting aspects of the geometry." You should write for Star Trek.
Hey Fred, try some of these things out on your 1125 and let us know what works best for you.
Hey Neil, your recommendations, so maybe you should try them out. With taller boots you might even be mistaken for a man. |
Ccryder
| | Posted on Saturday, October 31, 2009 - 05:30 pm: |
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Wow had a great ride around TN. Looking for a better ride tomorrow.
Fred if you want to continue these personal attacks, have fun. I have much better things to do and I'm most of the other Buelligans do to.
Back to the topic.
Brian I hope you have some answers to your question.
TTFN
Neil S. |
Andros
| | Posted on Saturday, October 31, 2009 - 06:15 pm: |
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I dont see how changing the fork an rearshock height by equal amounts would change the handling??? Isnt that the exact same difference as the ss and scg? |
Moosestang
| | Posted on Saturday, October 31, 2009 - 06:32 pm: |
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Moosestang
Whatever you may think about wimmins, DON'T think they can't ride. I know several that could probably run circles around you on the track.
I'm sure because I don't race, never have, never will. I think women don't have the upper body strength of a man and you need that upper body strength to hold on for dear life. Good thing she probably never uses 1st on a race track. |
Jumpinjewels
| | Posted on Saturday, October 31, 2009 - 06:38 pm: |
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It looks like I'll be getting another seat to work with and try to help reduce some height for the CR and me. Will be doing some reupholstering on it and hopefully drop maybe an inch or so. That would definitely help.
I must say, tho, and please don't take this negatively, She knows she will very seldom if at all get out of second gear. Nor will she use all of its power.This may not be the bike for her. I feel that I am a fairly decent rider and this bike does somewhat intimidate me. That being said, I hope I can run this bike within my limits, and that means getting into high rpms and as fast and I'm comfortable with and still staying in my 80% safety zone. I'm planning on getting this bike on the track as well.
I too, am an RN (not in ICU) but I do see a fair amount of people coming in with some good road rash. If I felt like I'd never get out of 2nd gear I'd be steering clear of a bike like this. My Scg was a big jump for me when I got it 3 years ago and it took me about 1 1/2 to 2 years to really feel comfortable on it. And I'm sure this bike is going to take a while to adjust to as well.
Please, have her be very careful with this bike as I hear it's got some get up and go. Again, best of luck and I hope it all works out. |
Fmaxwell
| | Posted on Saturday, October 31, 2009 - 06:46 pm: |
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Andros,
Changing the height of the front and back of the motorcycle (e.g., height above ground for a fixed point at each end) by equal amounts might make a minute difference in the wheelbase. The reason for this is the angle of the fork (compression moves the wheel up and back relative to the chassis) and the arc through which the swingarm travels. We are probably talking a couple of tenths of inches.
But it would not change the rake or trail.
That is the suspension difference between the XB12S (not Ss, which has a longer wheelbase and different frame) and the XB12Scg. The other difference is the shorter seat on the XB12Scg. |
Fmaxwell
| | Posted on Saturday, October 31, 2009 - 07:42 pm: |
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Since things turned a bit snippy here, I'd like to summarize my recommendations:
1. Consider some kind of deal where she ends up with a new, or like new, XB12Scg.
2. I recommend against lowering the suspension on an 1125R.
3. Shaving padding off of the seat is a good, safe option to help her legs reach the ground.
4. If she does not possess the experience, strength, coordination, or reflexes for an 1125R, be honest with yourselves, sell the bike at a profit, and buy something that's more suited.
If you elect to lower the bike anyway:
1. Refer to articles in respected magazines and books on the subject of lowering modern sport bikes.
2. Get the advice of engineers with a good understanding of motorcycle chassis design and dynamics.
3. Don't trust random people on forums -- including me -- unless they, or you, can find published corroboration for their claims/advice from recognized experts .
4. Remember that people make unsafe modifications to suspension and often get away with it. A lack of a crash is not evidence of a safe modification.
5. Don't make any change that you cannot, or cannot afford, to undue. A lowered bike with modified suspension from a defunct manufacturer doesn't usually command a very high resale price. Also, you may find that the modifications don't work as intended, so make sure you have a means to undue them.
Given the high praise that you (Buzzie) have received as a mechanic, I'm sure that the workmanship is not be an issue with any modifications that you make. I hope that she's happy and safe with whatever direction you two go with this.
Regards,
Fred |
Ccryder
| | Posted on Saturday, October 31, 2009 - 08:17 pm: |
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Fred I fully agree with your following recommendations:
1. Consider some kind of deal where she ends up with a new, or like new, XB12Scg.
2. I recommend against lowering the suspension on an 1125R.
3. Shaving padding off of the seat is a good, safe option to help her legs reach the ground.
4. If she does not possess the experience, strength, coordination, or reflexes for an 1125R, be honest with yourselves, sell the bike at a profit, and buy something that's more suited.
This was some of the first discussions about lowering an 1125. This was the discussion back in April 2008 that may give you some of your answers you were looking for. Take it or leave it, believe it or not, that is each person's own decision. I am presenting this as some more background information.
>>>lowering the bike the same amount on both the front and rear does not change the suspension geometry.
That's a patently inaccurate statement. It would be closer to true **IF** the front forks legs were perfectly vertical.
Changing the ride height can make the handling of a motorcycle very unpredictable and compromise the designed in positive dynamic stability.
I was once sent to ride a motorcycle after an American Airlines stewardess had experienced three crashes. She brought it to a dealer. When I spoke to her, she just thought that getting tossed off from time to time was part of riding. I flew to the dealers, did my normal pre-ride inspection and set out. The first time I went to turn I got the surprise of my life. The bike was nearly impossible to control. I asked if it had been modified and sure enough a "friend" (odd use of the term) had fitted it with a pair of lowered rear shocks and lowered the tubes in the triple trees what they thought was a similar amount.
There is a reason that a group of folks spent better than a year dialing in the precise geometry of your 1125R. It represents the BEST comprise between safety and spectacular handling elements of the continuum. I'd change it only with input from a qualified suspension person, not advise from the internet.
I mentioned yesterday, in another post, about one of the most exciting test bikes I'd ever ridden. It was a R&D S3 test unit that had the fork tubes relocated 1/2". It was a very stable ride. . . .that part worked. But suspension is a bit of a zero sum game. When you change one thing, you change many others things. . . . intended and unintended.
There are a couple of better ways (My SCU is quite experienced in Buell get-offs) to deal with shortosity.
Court
For the full thread: http://www.badweatherbikers.com/buell/messages/290 431/349663.html
Later
Neil S. |
Fmaxwell
| | Posted on Saturday, October 31, 2009 - 08:51 pm: |
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Neil,
Thank you for pointing me to that discussion and for quoting Court's post. Something that caught my eye was "had fitted it with a pair of lowered rear shocks and lowered[I assume Court meant raised. FM] the tubes in the triple trees what they thought was a similar amount."
That doesn't sound like they necessarily did achieve an equal drop, that the drop was less than 1.5", or that it was done per the recommendations of the article I cited. Specifically, the article, including part that I initially quoted, cautioned against dropping a bike that way:
Those of you who use our recommended suspension settings as a starting point have noticed that we often lower the front end to compensate for different tires by raising the fork tubes in the triple clamps. So why not just lower the front end even more by using the same method? The reason is that there's very little room to play with before the front fender and tire hit the lower triple clamp under hard braking. This could cause the fender to jam itself into the tire, resulting in the front tire locking up, and well...you know what happens next. Shortening the suspension basically brings the fork or shock farther down into its travel, while altering the spring rate so that it behaves normally (more on that later).
Also, I have no idea whether the shocks were appropriate for the bike (probably not), whether the spring rates were appropriate (probably not), whether the compression and rebound damping was right (almost certainly not), etc.
Court went on to write "I'd change it only with input from a qualified suspension person, not advise from the internet."
Which is certainly, 100% in keeping with what I wrote:
"2. Get the advice of engineers with a good understanding of motorcycle chassis design and dynamics.
3. Don't trust random people on forums -- including me -- unless they, or you, can find published corroboration for their claims/advice from recognized experts . "
Again, I'm completely against lowering an 1125R/CR. Period. That said, if someone is insistent on lowering it anyway, there are things that they absolutely should not do (asymmetrical lowering, lowering by raising the forks in the triple tree, lowering by moving the shock attachment point, etc.).
As you will note, I wrote "Modest suspension lowering involving shortening, revalving, and respringing the forks and shock is usually okay as long as both ends are dropped the same amount -- or the back end just slightly more." Note that I said "usually." I probably should not have added the part about lowering the back end just slightly more, if for no other reason than "slightly" is open to interpretation. But about the worst thing that one could do on the 1125 is make the steering rake steeper and the steering quicker.
Can we call this hatchet buried? I hope so. I think we are pretty close to being in agreement, anyway.
Regards,
Fred |
Ccryder
| | Posted on Saturday, October 31, 2009 - 09:22 pm: |
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Yep we are in agreement. Next time you are in the Nashville area, I'd be glad to buy you a cold beverage or two (adult or otherwise).
Ride long, Ride safe, Ride more.
Neil S. |
Littlebutquick
| | Posted on Sunday, November 01, 2009 - 02:58 pm: |
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do they sell them boots in the uk    |
Ccryder
| | Posted on Sunday, November 01, 2009 - 03:41 pm: |
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Yeah they sell them in the UK but not at M/C shops ;+} (Hint, someplace with whips and...) |
Buzzie
| | Posted on Sunday, November 01, 2009 - 05:19 pm: |
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Well.. I sure stirred the pot didn't I?
Honestly though guys...I was actually considering more of a change in the seat and subframe assembly.
If I lower the the seat portions of the subframe and shave the seat..I wont be changing any of the suspension.
Seems you guys may have missed that idea while considering lowering seat height.
Well thanks a lot for your thoughts I learned a lot from you fellas thanks |
D_adams
| | Posted on Sunday, November 01, 2009 - 06:48 pm: |
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Lowering the subframe could prove to be an interesting exercise. One option is machine out some lowering links to move the whole assembly down some, but it will leave a gap at the seat/airbox mating area. Not sure if it will affect the wiring any, ie; stretch to fit. I haven't had my seat off in a while, so don't remember the exact configuration of the mount points on the frame. |
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