Front end searching

johny said:

Thanks dale, i haven't got your technical know how, so would 18mm clamps reduce or increase the trail?? :?

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It will increase the trail. As it will move the vertical line from the center line of the front axle where it meets the ground, backwards away from where the steering axis line meets the ground. That is how trail is measured.

Are your clamps the changeable ones from 22 to 18?

I have another question for you.

I just went back and re read your first post, you have a 7.2 spring in the rear with 100 mm's of sag.

That tells me me two things. The spring is too light for your weight, and that means you have a lot of pre load on the rear spring.

If you would not mind, can you measure the compressed length of the spring, and then back off the adjuster and measure the un compressed spring and let me know how much spring pre load you actually have? I bet it's well in excess of 10mm. And while you are at it, have a look at the spring coils and see if you have been coil binding the spring. You will see where the paint or powder coating has been disturbed or rubbed off where the spring coils may have been crashing into each other. Again, just a guess here, I bet you will find that the spring has indeed been coil binding due to the over compressed spring to achieve proper rider sag.

Oh and before you start, measure the static sag of the bike as well, I'm betting that it is well under 30mm's, my guess is it is about 20-25mm's.

Correct spring pre load, static sag, rider sag, and ride height are critical on all PDS systems. Once in the sweet spot they work great, and small changes in pre load or clicker adjustments yield instant results.

So, based your description of what is happening, everything is fine while you are on the power, but, when you back off the throttle, all of that pre load you have on the rear shoves the nose of the bike into the ground causing over steer.

If my guess is correct, your bike is under steering while under power, and over steering while off the power. IMHO you have adapted to these characteristics, and it only becomes a real problem when in the ruts and you chop the throttle.

What do you think?

Dale

johny said:

What do i think, I'll tell you, you know what your talking about, this is the 3rd time you've helped me, and everything you've said has been spot on, i cant do the spring just now dale, because of my shoulder, when i did try the 76 on the rear with the .46's i just couldn't dial it in perhaps i just never tried enough, I'm feeling rejuvenated now, Jesus how i wish i could ride.
when i can get someone to help me, I'll Pm you once again thank you so much
johny

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Thanks for the compliment and you are more than welcome. There is a lot of hyperbole floating around, and throwing parts such as triple trees etc is not always the answer.

One has to achieve a proper balance of componentry if you will before ANYTHING else can be done, otherwise one just ends up chasing their tail. That is why I started doing suspension work. I was seeing a lot of people spend a lot of money to places that make their living off of suspension work, selling folks things they don't need to make more money, and to top it off, the set up was messed up. I don't mean to sound arrogant, or that I am some kind of Oracle, but, I was so tired of seeing people get ripped off for a crap set up, and in some cases where there are no ethics or morality, people would get charged for work and all the places did was adjust the clickers and put on their stickers and charge people a chunk of change.

was running mine with either none or minimal preload.

rigth spring in the rear with minimal preload also seemed to work well on the rear.

I have been following this interesting thread and I have a question.
Does any one know why the 09 tripple clamps are samped 18-20 when they are actually 19mm offset? :?

Steve

tazer said:

I have been following this interesting thread and I have a question.
Does any one know why the 09 tripple clamps are samped 18-20 when they are actually 19mm offset? :?

Steve

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If memory serves....................... The bottom clamp is the 18-20 variable, without the variable part, in this case an offset stem I think, and the top clamp is a 19mm or visa versa. So if there is no offset stem, then it would make sense to me that the offset would be 19mm.

If you look in the parts book on page 4 parts 32 & 34, they both indicate 19mm, the telling part is the last two numbers of the part number which denotes measurement "X" or the off set.

johny said:

Ive read the triple trees lol,i can see now why i had 4 turns of preload on the forks to try and compensate for the over preload of the rear, and just how easy it is for me and many others to get completely lost in the setup of the bike and totally frustrated, so two heads are better than one and three are better than two, but good advice just stands right out, and rings a bell 8)

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I don't think that a sag of 100mm against someone else's 105, 106 or 107 is the problem so finding your rear pre- load isn't in itself going to be the answer. as I said back at the beginning, you have a basic tipping motion onto the front wheel and either lowering the rear, raising the front or several clickers or whatever are going to be the answer.

I have 106 sag and both lines on the forks showing. at 91kilos I'm on 50s up front and 84 rear. to me, you're undersprung on the front, probably on the rear too and the clickers are in there too.

I find the steering fantastically reactive and just love it. DaleO's advice is spot on but all I'd disagree with is that the steering becomes more reactive when compressed but that is a small detail.

anyway, good luck with it

regards

Taffy

Ditto. You may have convinced me to keep my bike and run it another year.

I know it's undersprung, my suspension guy left it that way because I'm a beginner riding woods. His idea was to leave it soft. But once the sag is set correctly and so the spring has too much preload, it's not really soft, and it's not right.

Ruts have really been messing me up, same as described in Johny's first post.

And guess what's at the bottom of every big hill, since that's where everyone pours on the power... I have no control through the rut so I can't get any momentum for the hill.

If you can't do ruts, and can't make it up hills, you're gonna be pretty slow!

Taffy said:

johny said:

Ive read the triple trees lol,i can see now why i had 4 turns of preload on the forks to try and compensate for the over preload of the rear, and just how easy it is for me and many others to get completely lost in the setup of the bike and totally frustrated, so two heads are better than one and three are better than two, but good advice just stands right out, and rings a bell 8)

Click to expand...

I don't think that a sag of 100mm against someone else's 105, 106 or 107 is the problem so finding your rear pre- load isn't in itself going to be the answer. as I said back at the beginning, you have a basic tipping motion onto the front wheel and either lowering the rear, raising the front or several clickers or whatever are going to be the answer.

I have 106 sag and both lines on the forks showing. at 91kilos I'm on 50s up front and 84 rear. to me, you're undersprung on the front, probably on the rear too and the clickers are in there too.

I find the steering fantastically reactive and just love it. DaleO's advice is spot on but all I'd disagree with is that the steering becomes more reactive when compressed but that is a small detail.

anyway, good luck with it

regards

Taffy

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Agreed Taffy,

I started to go down that road in my diatribe, but, decided against it. But it is totally true, and when undersprung, the front is riding down in the travel causing just what you said among other things.

Dale

i have issues with the frontend of my 450, basically it didn't go around corners !! and misbehaved in ruts, i have had advice given on this forum but ultimately its springs that need changing, what i have done until i can afford new springs is too soften the suspension up as much as i can and raise the forks through the yokes by 12mm until they almost touch the bars !!! i have also started to sit further forward which helps, the up shot is, its improved the handling through woods and cornering

Definitely gonna fix this and run the 650 another year.

I'm at 100 kilos dry, and the springs are 46 front, 84 rear. Way off.

Everything I've read says to get the right springs first, this is the most critical item.

50s and 92 would be about right.

most people get the sags but the pre-load is really high to get it.

I run a 95/111 and it's well wound up.

regards

Taffy

Just a thought, on my bike after only 40 hours the head set bearing were rusted and it was quite notchie, only noticed it on the bike stand. Water had got in the steering look.

Worth a look if you haven't already done so.

I just like to share my experience with going to stiffer springs.

I changed the springs in my husaberg from 0.49kg/mm front and race tech P30 rear (starts @9.5kg/mm)
To a 5.4N/mm (0.55kg/mm) front and PDS-12 (10kg-13kg/mm) in the rear.
Staic sags are 30mm front and 40mm rear. I need someone to help with the rider sags.

I open the compression from 15 clicks front and rear to 25 clicks.

The bike is so easy to control, it is frim but plush and the tyres are like they are glued to the ground.
Ruts are easy pesy now, where horrible before and it loves rocks.

Regards