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Snowscum
Posted on Tuesday, October 24, 2006 - 07:41 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Ok so I screwed around with my rear suspension the other day and cant seem to get it back to where it was. What is the trick to the 06
front shocks, to get rid of that wimpy sag under breaking? I had the rear set so it wasnt to bad but now that I screwed with it...
I weigh about 190. The front is set to the factory setting(set by the dealer if its done right). So the upper setting(preload or?)
is on I think the 5th line. Any help would be appreciated.
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Windrider
Posted on Tuesday, October 24, 2006 - 07:57 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Snowscum, In your owner's manual there is a nice table that lists all of the recommended settings per rider weight. Try that first.

As far as the fork dive under braking you can replace your fork springs with the progressive springs that are stock on 07s or you can try putting a little more oil in the forks.

Happy Trails,

WindRider
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Snowscum
Posted on Tuesday, October 24, 2006 - 10:28 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Thanks Windrider!
So no matter what I do it is going to be mushy? Is it preload or rebound that Im feeling?
I had it set since the first couple of weeks i owned it and thought it was settled down the best. Then out of the blue I wanted to try something different. Now I dont remember where it was. haha I'll try the preload in the front next time I ride it and see if it stiffens the front some.
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Windrider
Posted on Tuesday, October 24, 2006 - 11:28 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Snowscum,

I think that the dive is just 6.5" of travel succumbing to centrifugal force of the weight of the bike under hard braking. I haven't ridden an 07 but I know from my experience with KLRs that progressive rate springs help a lot with fork dive under braking on those long travel forks.

I don't think that there is a lot that can be done with the stock 06 setup to lessen it. The only thing that you could do would be to increase the spring preload and compression damping but that would make the bike really stiff. I prefer to error on the soft side with suspension settings because I feel like if you are a bit soft you will stay on the road but a bit firm and the rubber can leave the road causing, uh, pain.

There was another thread that went on at length about the differences and what could be done and someone suggested putting a little more oil in the 06 forks to accomplish the same thing.... not sure if it will work or not but it is very cheap to try. As I recall the 07 progressively wound springs were also pretty inexpensive.

I plan on trying a set when I hit the 10K mark and service my forks.

Good Luck.
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Blake
Posted on Wednesday, October 25, 2006 - 12:46 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Not fork preload or rebound. Dive under breaking would be affected by spring rate, oil level, oil viscosity, fork compression damping setting and even a little rear shock rebound damping.
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Birdmanrh
Posted on Wednesday, October 25, 2006 - 12:56 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Bump your front fork compression way up and then back it off to where you like it.
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Jim_sb
Posted on Wednesday, October 25, 2006 - 01:25 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I just reset all my suspension settings tonight. Probably took all of 6 minutes to do preload, compression and rebound damping front and rear. EASY.

I did notice my FSM lists slightly different settings for my weight than the Owner's Manual. I went with the FSM for now.

Blake, please explain why fork dive would not be reduced by additional fork preload, that seems counter-intuitive to me as compressing the spring further should reduce it's ability to travel to an extent.

???

PS. Brake dive doesn't bother me at all, I have had my Uly set pretty soft for off pavement work, but tonight, for grins, I set everything per the book for my weight + gear. We'll see.

Best,

Jim in Santa Barbara
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Blake
Posted on Wednesday, October 25, 2006 - 02:29 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Preload doesn't compress the spring further. It raises the front end. Think...

1. Same spring

2. *Same load on the same spring

3. Thus same spring compression

*There is a slight cosine effect on the applied loading due to the change in chassis geometry (elevating the front of the bike, rocking back of the rider), but it is minimal within the normal range of adjustment for front end preload.
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Jim_sb
Posted on Wednesday, October 25, 2006 - 02:29 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Hi Blake,

I guess you're certain because you sound certain!

Raises the front end? I can see that happening.

But are you saying that I can (while riding) compress the fork as much now as I could before?

That's the part I'm struggling with conceptually. It would seem that if the fork is compressed further initially there is more tension and less room for it to compress further...

I am half tempted to go home and crank up the front and rear pre-load and go ride the darn thing. Somehow in my mind I feel that should reduce brake dive.

Weird....

Jim in SB
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Red_chili
Posted on Wednesday, October 25, 2006 - 03:39 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

The *spring* compresses as much. Preload just makes that happen 'higher'. The forks themselves do not compress as easily, because it is as if they are already partially compressed if that makes sense. But it does nothing to solve the dive problem; preload is a different parameter than spring rate.

Snow, start with the owners' manual settings, by the book. Then try to incrementally (meaning, no more than a few clicks) changing things. Preload *to a point* will help only because the spring is pre-compressed; compression damping can help with the *speed* of the dive, but not the dive itself.

Be warned, if you crank up the rebound to an extreme you really will have no idea what is wrong, because it can feel like too much preload or too much compression damping. (ask me how I know that) It's called 'packing'. The suspension never returns to static sag before the next deflection, and it keeps packing down.

The poor man's effective way of creating progressive springs is to raise the oil level a bit. The resulting smaller air chamber compresses more quickly for a given deflection, essentially creating a progressive spring.

Note that oil level is changed by measuring LEVEL, not by volume. Nevertheless you could probably get away with adding 10-20cc at a time - for a couple of times. You won't know if it is even left and right, but you can try it out just to see if you like it better. With a slightly higher oil level, sometimes you can back off on the compression damping a bit and restore a nice supple ride.

Preload should be set for a given static sag. Your preferences may vary. The manual is quite accurate though, for starters.

Most important rule: start at the factory recommended baseline and change ONE thing at a time.

Being an old dirt rider, I find the dive not at all objectionable, and pretty normal for long travel forks (you should try my XR650R sometime). I do have settings for a rider maybe 30 lbs. heavier FWIW.



(Message edited by red_chili on October 25, 2006)
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Blake
Posted on Wednesday, October 25, 2006 - 04:29 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Jim,

When/if you increase front preload (decrease rider sag), the front forks will have increased compression travel and a diminished rebound travel as measured from the static rider sag position. Meaning, that in addition to changing ride height, adjusting preload/sag changes the proportion of total suspension travel that is available for compression versus rebound.

Sometimes it helps to imagine extreme scenarios. Imagine if you could somehow back off the fork preload/sag adjusters so that you have a whopping 5.5" of total sag. Then you'd only have around 1" of compression travel left, right? The result being that the front would bottom out very easily.

Conversely, with the front forks set for just 0.5" of total sag, you'd have 6" of compression travel, so the bike may dive a lot under hard braking, but it may not ever bottom out.

Considering only the effect of the springs (neglecting dynamic/damping and air volume effects), in each above case, it would take the same abount of load to compress the forks that first 1".

Meaning that no matter where you set preload/sag, the magnitude of static loading required to compress the forks from rest through any given amount of compression travel remains the same.

I think I'm confusing myself. Hope you can make sense of that blathering. : )
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Snowscum
Posted on Wednesday, October 25, 2006 - 07:35 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Thanks for the help guys. Ill put it back to stock and try to slow down the speed of the front. It just feel unsafe right now if I had to do a high speed brake. Have to wait till the next snowstorm is out of here. Maybe this weekend.
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Josh_cox
Posted on Wednesday, October 25, 2006 - 09:47 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Snowscum,

Add 5mm of fork oil to the forks. I think you will like the result.

It's much cheaper than going with the 07 springs.
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Jim_sb
Posted on Thursday, October 26, 2006 - 04:16 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Okay Blake. I've never heard it put like that before. Thanks.

Hmmm...

Jim in SB
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Snowscum
Posted on Thursday, October 26, 2006 - 09:21 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Thanks Josh. Is that per shock? Thanks Blake and Red for the discussion
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Red_chili
Posted on Friday, October 27, 2006 - 09:33 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

He means measure your compressed, no-spring oil level in each fork, and add oil until it is 5mm higher than that.
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Snowscum
Posted on Friday, October 27, 2006 - 11:12 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I do not understand that statement......
Please explain further. Should I come down and have you do it Red?
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Chrisb
Posted on Friday, October 27, 2006 - 11:22 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Wouldnt you have to drop the fork out of the tree to do the oil addition? Unless your going to just add a measured amount as Red Chili suggested.
I wouldnt try adjusting the problem away with the settings. Either do the oil addition or wait until your 10k service and install the 07 springs.

For me it was the 07 airbox addition that has really caused the dive to become annoying to me. How in the world could an airbox do that you ask? Easy...
Acceleration is quite improved with the 07 airbox. My typical commute route involves numerous "jogs" where I make a right go 300 yds and make a left or vice versa. So the bike gets moving quicker so I have to work the binders harder, front end dives more.

(Message edited by Chrisb on October 27, 2006)
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Red_chili
Posted on Friday, October 27, 2006 - 11:55 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I've not done it on the Uly (lots of times on various dirtbikes, none inverted to date), but heck, in a couple months I'll fire up the salamander in the new garage, we can break out a Guinness, and we'll do the deed.

Have shop manual for procedure and welder for fabbing necessary goofy tools, will give it a go.

Yeah, you have to pull the forks from the triple tree and clamp them (gently, with cushy rags) in a vise, and pull the springs and collapse them. It never hurts to change fork oil annually, or at least biannually, anyway.

Or you could cheat and just add a measured amount of fork oil in each leg. You won't know the actual level (for next time), and you can add too much (5mm is not that much oil), but it's an easy is imprecise way to try it.
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Blake
Posted on Friday, October 27, 2006 - 12:33 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Chris,

I suggested adding "a measured amount" of oil to the forks?
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Chrisb
Posted on Friday, October 27, 2006 - 12:54 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I stand corrected.

Add a measured amount of oil as Red Chili said.

Blake, I'm sorry. I hope someday you can forgive me.

(Message edited by Chrisb on October 27, 2006)
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Red_chili
Posted on Friday, October 27, 2006 - 01:24 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

He just don't want the blame for my suggesting a shadetree method!!!
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Danab973
Posted on Monday, October 30, 2006 - 01:26 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I want to buy the buell xb9sx(city) I'm going to use the seat from the xb12scg because its lower. I still need to lower the bike about 2inches. Does anybody know any companies that make lowering kits or shocks? this has been very frustrating for me, I currently own a blast and have out grown the bike. I know its not easy for a girl thats 4"11 to find the right bike. I hope somebody can lead me in the right direction so my next move would be actually buying the bike.
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Red_chili
Posted on Monday, October 30, 2006 - 01:34 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Dana, I don't know the technical situation where you hail from in NJ, but a good suspension shop or tech can do the deed for you. Good performance bike shops, or dirt bike shops, can provide a referral to a good suspension tech.

It may mean you are building a bike fit only for you, which may be hard to sell come that day... but heck, that's part of the fun. BTDT. It works out.

The nice thing about Buell using Showa suspension is that it is fairly common and a known entity. Be sure to mention the Showa suspension when you query the tech, in case he gets scared off by 'Buell' being in the sentence.
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