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Old 09-10-2013, 06:43 PM   #76
avc8130
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Berg,

I'm really surprised that you aren't using more front fork travel.

I am almost exactly your same weight and run .95s in the forks with Stoltec's valving.

I am able to bottom my forks when riding off road. I can easily get my fork travel indicator to about where yours is from just braking on the street.

I'm actually considering adjusting my oil level to resist the bottoming a bit more. In fact, what oil height did Frank use when reassembling your forks?

ac
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Old 09-10-2013, 07:42 PM   #77
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We set the fork oil at 150 mm. This was to give some scope to easily add some. Should be able to go to 120 mm with no issue.

This was without reference to the manual, which I've just checked, and 150 mm is the spec. Maybe I'll suck a bit out for more testing?

On my testing last weekend, I did some small jumps, solo, and aimed for some rocks and chuck holes under brakes etc to see if I could get any more travel. Not yet. It does feel a bit like its hydraulicing, so less oil might be a good first step in the process.
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Old 09-10-2013, 08:52 PM   #78
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Bergdonk,

My front springs are 90's
And although we have identical rear setups, that doesn't mean we should have identical fronts.
But it is a reference point.
AC just stated he has more spring than I on the front. (Not sure what he has on his rear Penske)

My forks have a lot more range of preload adjustment than the oem forks did. I get proper (~57mm) sag at about 8 turns in of 21 turns available.
On oem forks you might need a bit stiffer. I don't know.
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Old 09-10-2013, 10:11 PM   #79
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Thanks snake. Its all good info, and helps me with my r&d, and perhaps cost control

Its interesting, and where Frank was coming from with his thinking that lighter springs are needed, in that bikes with similar weight and much less travel still use <> 1 kg springs.

As an indicative rule of thumb, double the travel and halve the spring rate for the same net result re sags and load carrying ability.

I hope to do some more testing etc soon, so stay tuned
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Old 09-11-2013, 12:35 AM   #80
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GPS Mount

I previously fitted a SW Motech bracket here:
http://advrider.com/forums/showpost....2&postcount=38

As a temporary measure, I fitted my Montana's Rugged Mount to it with the universal SWM adjustable bracket. It worked, but was a bit untidy, and because it cantilevered out a fair bit, wobbled around more than I'd prefer.






I got a block of black Delrin and measured and cut a wedge bit off the end. Its in the pic above, below the SWM bit it replaces.





Roughed into place and its much smaller than the SWM, and lighter, and positions the GPS better, lower and at a better angle to reduce reflections.





Polished up and all in place. I also fitted a waterproof switch below the power outlet that I'll use to power the GPS, direct from the battery with an inline fuse. I prefer it this way, then it doesn't get upset when the ignition is off when refuelling etc.

I also have the switch for the driving lights, so will try and finish the wiring tomorrow.

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Old 09-11-2013, 06:59 AM   #81
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Quote:
Originally Posted by BergDonk View Post
Thanks snake. Its all good info, and helps me with my r&d, and perhaps cost control

Its interesting, and where Frank was coming from with his thinking that lighter springs are needed, in that bikes with similar weight and much less travel still use <> 1 kg springs.

As an indicative rule of thumb, double the travel and halve the spring rate for the same net result re sags and load carrying ability.

I hope to do some more testing etc soon, so stay tuned
That really depends.

You are talking this bike places that you would never dare take a bike with 4" of travel.

How many turns of preload do you have dialed in? I have NONE dialed in from the cap.

Did Frank use any preload spacers other than the factory?

What do you mean by "hydraulicing"?

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Old 09-11-2013, 07:02 AM   #82
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Originally Posted by snakebitten View Post
Bergdonk,

My front springs are 90's
And although we have identical rear setups, that doesn't mean we should have identical fronts.
But it is a reference point.
AC just stated he has more spring than I on the front. (Not sure what he has on his rear Penske)

My forks have a lot more range of preload adjustment than the oem forks did. I get proper (~57mm) sag at about 8 turns in of 21 turns available.
On oem forks you might need a bit stiffer. I don't know.
"Range" and "Resolution". You might have the ability to put more preload on the spring, or the thread pitch might just be finer to allow more resolute adjustments.

Preload and rate are 2 different animals. Preload is used simply to get proper geometry. Rate is used to control how much the suspension travels for a given input.

For someone 250lbs, .85 springs with stock oil height should travel MUCH more than Berg is experiencing.

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Old 09-11-2013, 03:41 PM   #83
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Originally Posted by avc8130 View Post
That really depends.

You are talking this bike places that you would never dare take a bike with 4" of travel.
Its not just about travel, but about the spring's ability to support the weight of the bike and travel. Ignoring preload, hypothetically, say we have a 0.5 kg spring * that travels 300 mm. To travel 300 mm it'll need 0.5 x 300 kgs load to do so, 150 kgs. Now if we have a 1.0 kg spring that only travels 150 mm, its the same 150 kgs to get full travel.

* note that spring rates here are linear, and are actually per mm, so a 1.0 kg spring needs 1.0 kg to compress 1 mm. Then it needs another 1.0 kgs to compress the next mm etc

And yes, 4" travel on the S10 wouldn't work in the S10s intened application.

So when Frank looked at rates of bikes like a Ducati Multistrada that is admittedly somewhat lighter, but has softer springs and less travel than the S10, we started wondering about the merits of up to 1.00 kg springs in the S10. Bikes like R1s weighing around 200 kgs with 4" travel use <>1.00 kg springs, so extrapolating that back to 200 mm travel means a 0.50 kg spring would do the job for the R1, if it had 200 mm travel forks.

All just indicative stuff, and with forks, weight distribution and rake make a difference when fine tuning too.


Quote:
Originally Posted by avc8130 View Post
How many turns of preload do you have dialed in? I have NONE dialed in from the cap.

Did Frank use any preload spacers other than the factory?
Right now, the preload adjusters are backed right off, but I have been trying other settings too. Internally, the preload spacers are stock.


Quote:
Originally Posted by avc8130 View Post
What do you mean by "hydraulicing"?
The forks go really firm at the end of the stroke that is available. It doesn't feel like bottoming, as its not harsh at all. It could be too much oil, I'll work through it. Its a pity Frank is 400 kms away, but he is only a phone call away. A minor complexity is that I don't have the capability to easily remove the fork springs from the S10 right now. The way the S10 forks are, a fork spring compressor is really needed to get the springs in and out, especially when I'm on my own, so I will likely have to make one, or get some more hands.
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Old 09-11-2013, 04:06 PM   #84
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I think you should check again. I'm not 100% familiar with the R1, but most modern GSXRs are sprung in the .90-1.05 range from the factory.

You are also comparing apples to oranges. The bikes with only 4" of travel are not designed to accomplish what the Tenere is designed to accomplish.

Nick has spring data from 4+ dozen Teneres he has set the forks up on. I am 100% confident that you, at 250lbs, with .85 springs are much an outlier to the norm.

I am 250lbs and I run .95s. I can bottom my travel indicator out and I have multiple times. Yes, on the street, I generally find my travel indicator about where yours is. However, once the pavement turns to dirt and I hit a few pot holes I am using full travel and can bottom out.

The Tenere forks have hydraulic lockouts at the end of the travel. As the forks near their last 1" of travel, a 2nd "piston" on the cartridge rod begins to close off the compression circuit to prevent the forks from bottoming "hard". I wonder if that is what you are experiencing?

How did you set oil height? Springs out, forks collapsed, correct?

You can use a tie down and a 3-way clamp:
http://www.harborfreight.com/3-way-e...lamp-4067.html

ac
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Old 09-11-2013, 04:37 PM   #85
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Quote:
Originally Posted by avc8130 View Post
I think you should check again. I'm not 100% familiar with the R1, but most modern GSXRs are sprung in the .90-1.05 range from the factory.

You are also comparing apples to oranges. The bikes with only 4" of travel are not designed to accomplish what the Tenere is designed to accomplish.
Quote:
Originally Posted by BergDonk View Post
............

All just indicative stuff, and with forks, weight distribution and rake make a difference when fine tuning too.
............
My example was just to try to explain the basic physics involved in how a spring supports weight. Its independent of bike type etc, and obviously specific applications vary.

Frank had no experience with the S10, or its forks before mine, and I suspect not too may here in Oz have modified S10 forks either, so we just went back to some first principles. Sometimes the pack is right, but sometimes the pack just follows what isn't alway the best way.

Apart from springs, we've no idea what internal mods Nick at Stoltec has made, or others in the US who have played with these.

Quote:
Originally Posted by avc8130 View Post
I am 250lbs and I run .95s. I can bottom my travel indicator out and I have multiple times. Yes, on the street, I generally find my travel indicator about where yours is. However, once the pavement turns to dirt and I hit a few pot holes I am using full travel and can bottom out.
Good info, thanks.

Quote:
Originally Posted by avc8130 View Post
The Tenere forks have hydraulic lockouts at the end of the travel. As the forks near their last 1" of travel, a 2nd "piston" on the cartridge rod begins to close off the compression circuit to prevent the forks from bottoming "hard". I wonder if that is what you are experiencing?
Maybe...

Quote:
Originally Posted by avc8130 View Post
How did you set oil height? Springs out, forks collapsed, correct?

You can use a tie down and a 3-way clamp:
http://www.harborfreight.com/3-way-e...lamp-4067.html

ac
Yep
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Old 09-11-2013, 04:48 PM   #86
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Quote:
Originally Posted by BergDonk View Post
My example was just to try to explain the basic physics involved in how a spring supports weight. Its independent of bike type etc, and obviously specific applications vary.

Frank had no experience with the S10, or its forks before mine, and I suspect not too may here in Oz have modified S10 forks either, so we just went back to some first principles. Sometimes the pack is right, but sometimes the pack just follows what isn't alway the best way.

Apart from springs, we've no idea what internal mods Nick at Stoltec has made, or others in the US who have played with these.



Good info, thanks.



Maybe...



Yep
Thanks for providing a mechanical engineer by trade a lesson in simple spring mechanics.

I know EXACTLY what modifications Nick makes to the internals of the fork. I can assure you spring selection is independent of damping modifications.

I'm aware of at least 3 guys in Australia with modified internals.

What weight oil did you use in the forks?

ac
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Old 09-11-2013, 05:20 PM   #87
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Quote:
Originally Posted by avc8130 View Post
Thanks for providing a mechanical engineer by trade a lesson in simple spring mechanics.
But I know that this is the interweb and this is not a private discussion, so I'm hoping to inform others too


Quote:
Originally Posted by avc8130 View Post
I'm aware of at least 3 guys in Australia with modified internals.
plus me now = 4 I guess.

Most people send their suspension to a suspension shop, spend some $ and get a result. Its usually, but not always an improvement for a variety of reasons. And with some personalised attention after refitting it can usually be better again. This mostly doesn't happen though.

Because I've had access to Frank over the years, and facilitated many, many dirt bike suspension clinics with him here on my property, I have a pretty good idea of what good and great suspension is. My DR, Bergs, and now gone 1400GTR were and are benchmarks in their application for me.

I have 10 kms of twisty sealed road outside my gate. Inside I have 10 kms of gnarly single track and a short MX track. Just beyond, depending which way and how far, I have 1000s of kms of bush tracks and roads. I have the best testing environments right here outside my shed. And FWIW I have done some road, MX and enduro racing, and have some trophies too. Like most, I'm faster than some, and slower than others.

Quote:
Originally Posted by avc8130 View Post

What weight oil did you use in the forks?

ac
Maxima, I think, but for sure 5w, or nominally 5w, as of course they are not all the same and fork oil specs are not consistent from manufacturers. There used to be some really good discussion and test results on fork oil viscosities here:
http://www.peterverdone.com/archive/damping.htm
But it seems to have gone.
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Old 09-11-2013, 05:24 PM   #88
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I know EXACTLY what modifications Nick makes to the internals of the fork. I can assure you spring selection is independent of damping modifications.
And FWIW, spring selection when fine tuning is NOT totally independent of damping. Damping CAN also be fine tuned to the spring and visa versa. And the application, and the needs of an individual who may be the same weight, but rides the bike differently. Otherwise why is Lorenzo's bike different in its settings to Rossi's, etc
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Old 09-11-2013, 05:47 PM   #89
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And FWIW, spring selection when fine tuning is NOT totally independent of damping. Damping CAN also be fine tuned to the spring and visa versa. And the application, and the needs of an individual who may be the same weight, but rides the bike differently. Otherwise why is Lorenzo's bike different in its settings to Rossi's, etc
Yes, very true. Take oil height for instance. For the general public, starting with a spring based on weight/riding style and adjusting damping to match/work is the general practice.

I agree with you, not enough people actually go BACK for touch-ups. Stoltec will be doing some touch-up to my forks in the very near future when he services them this winter.

5W nominal is good. I believe Nick swears by Motul or Silkolene.

Did Frank make any changes to the compression and/or rebound shim stacks? You mentioned he modified the valves?

ac
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Old 09-11-2013, 05:56 PM   #90
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Along with opening up the bleeds, he rearranged the compression stack for more oil flow and less high speed damping. The rebound stacks he reckoned looked OK for the time being.

And even with the mods he did to the compression, I still have the adjusters backed right off.

All good stuff, and part of the learning experience.
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