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The Official Iron Horse Sunday / DW-Link Tech. & Tuning Section

klunky

Turbo Monkey
Oct 17, 2003
1,078
6
Scotland
Im not sure I like the idea of purchasing a colour of frame produced for world champ racers. I think its a bit like when you see road riders out on a ride dressed in the maillot juan or whatever.
 

Eren

Turbo Monkey
Mar 18, 2006
2,874
0
mill creek, WA (now in Surrey UK)
i remeber reading a while back about ppl asking if ti springs rode difffernt than steel, im NOT taking any side to this, but im looking for a 350lb rcs spring and everyone has been out forever, so while reading through the RCS site, i came across this. . .

Do Titanium springs ride differently?
Yes. A titanium spring is more responsive then a steel spring and helps the suspension keep the tires on the ground for better traction and handling. Titanium springs have less mass and thus less inertia. As springs are rapidly compressed the material mass is displaced and generates momentum or inertia based on the product of the velocity and mass involved. In demanding applications this can cause spring surge where the spring coils are moving in the opposite direction of the shock travel. This can disrupt the performance of the suspension system and lower the ability of the suspension to follow the terrain and keep the wheel on the ground. The less mass in the spring, the better performing the suspension will be.

Lower mass systems generate less inertia and accelerate faster allowing better "responsiveness". This allows the suspension to keep the wheel in contact with the ground more resulting in better traction and handling. For more on suspension systems see Ti vs. Steel
 

S.K.C.

Turbo Monkey
Feb 28, 2005
4,096
25
Pa. / North Jersey
Eren - I think you may be incorrect:

From the Page 1 archive - this was a question that I posed to dw:

3) Since I'm switching to Ti, will this effect the "observed" spring rate that you feel when you ride it? In other words if a steel and Ti spring are listed as the same spring rate, will the Ti feel more progressive due to material or spring winds? (Maybe not necessarily your area of expertise, but I'd be interested in your take on it)

dw Ans: Spring rate is identical with ti and steel. Spring rate is a measurement of force/distance. The difference in spring WEIGHT and unsprung mass equates to about the same difference as removing the 18T cog only from your rear cassette.
 

bizutch

Delicate CUSTOM flower
Dec 11, 2001
15,929
24
Over your shoulder whispering
GOING TO THE SHOP TODAY AT 4PM TODAY!
THANK YOU US GOVERNMENT!

Oh...did I mention the Stock DT Swiss hubbed/MTX wheels on my Elite and the brand new mint green 888Rc2X are both for sale!
 

dw

Wiffle Ball ninja
Sep 10, 2001
2,943
0
MV
2007 Sunday shock pin removal

The 2007 Iron Horse dw-link Sunday uses a 10mm shock pivots with a unique expanding design that allows for zero play, high strength, and ease of maintenance. The lower shock pivot is removed and installed using the following procedure:

Tools needed:
4mm hex key wrench
screwdriver or pin to push shock pivot out

REMOVAL:

1) Loosen or remove M6 flat head cap screw on NON-DRIVE SIDE (this screw loosens the expanding portion of the pin)

2) Remove the M6 flat head cap screw on the DRIVE SIDE

3) Push 10mm shock pin out of frame using a screwdriver or pin. Shock pin removes towards the NON-DRIVE SIDE. Be careful not to damage M6 threads with your screwdriver.

INSTALLATION:

1) Lightly grease threads and countersink on the split end of the 10mm shock pin.

2) Push 10mm shock pin into frame and through shock bushing using your finger or by lightly tapping with a rubber hammer. Shock pin installs towards the DRIVE SIDE.

3) Install the M6 flat head cap screw on the DRIVE SIDE. Torque to 13 N*M.

4) Install M6 flat head cap screw on NON-DRIVE SIDE (this screw tightens the expanding portion of the pin). Torque to 13 N*M.


 

bizutch

Delicate CUSTOM flower
Dec 11, 2001
15,929
24
Over your shoulder whispering
Now...if you could tell the hamfist that installed mine not to wallow out the allen upon install. :D

Don't think i'll be taking the DHX anytime soon unless Cane Creek wants me to "test"...heh!
 

dw

Wiffle Ball ninja
Sep 10, 2001
2,943
0
MV
i remeber reading a while back about ppl asking if ti springs rode difffernt than steel, im NOT taking any side to this, but im looking for a 350lb rcs spring and everyone has been out forever, so while reading through the RCS site, i came across this. . .

Do Titanium springs ride differently?
Yes. A titanium spring is more responsive then a steel spring and helps the suspension keep the tires on the ground for better traction and handling. Titanium springs have less mass and thus less inertia. As springs are rapidly compressed the material mass is displaced and generates momentum or inertia based on the product of the velocity and mass involved. In demanding applications this can cause spring surge where the spring coils are moving in the opposite direction of the shock travel. This can disrupt the performance of the suspension system and lower the ability of the suspension to follow the terrain and keep the wheel on the ground. The less mass in the spring, the better performing the suspension will be.

Lower mass systems generate less inertia and accelerate faster allowing better "responsiveness". This allows the suspension to keep the wheel in contact with the ground more resulting in better traction and handling. For more on suspension systems see Ti vs. Steel
MX bikes use much heavier springs and lower leverage ratios than mountain bikes, both of which will increase the effect of the spring on unsprung mass, but on a typical mountain bike, the difference that the spring has on unsprung mass is insignificant. ~ about equivalent to taking the 18T cog only off of your rear cassette.
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,918
1,213
What percentage of the spring weight makes up sprung and unsprung mass? Would it be 50/50 or something else?

And how is that worked out, given that the spring is the middle line between sprung and unsprung...?
 

S.K.C.

Turbo Monkey
Feb 28, 2005
4,096
25
Pa. / North Jersey
You mean this?:

Spring rate is identical with ti and steel. Spring rate is a measurement of force/distance. The difference in spring WEIGHT and unsprung mass equates to about the same difference as removing the 18T cog only from your rear cassette.
I'm not sure I understand your response.

I do see what you are saying however in your previous post at the top of this page - the difference in materials will lend to a difference in spring performance.

However like what dw was saying, I don't think that the performance differential is particularly noticeable (between Ti and steel springs) on a MTB.
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,918
1,213
SKC - he's just saying that he didn't take any side on the ti spring issue (where you said he was incorrect), he just quoted RCS and asked if it was true or not. :)
 
L

LFB

Guest
DW,
Nice video. It's great to see a mountain bike company finally using high-tech methods of showing information.

BTW, what software did you use? 3D Tiger, by chance?
 

RichS

Chimp
Apr 23, 2007
4
0
I know there has been loads of posts about spring rates, but I still need some advise from Sunday owners.
I weigh 168 pounds (12st or 76Kg) in 'normal' clothes. I have been riding my 07 Sunday team with the stock 300 spring, which I have to admit feels fairly soft, but OK. I spoke to a mate at the weekend who's been riding Sunday's a couple of years and he uses a 450 spring. He is a similar weight to me, but reckons you shouldn't run too much sag on a Sunday.
I am about to order a new Ti spring, but don't know whether to stay on a 300 or go a bit heavier, maybe just up to 350.

Anyone out there of a similar weight got any advise?
 

dante

Unabomber
Feb 13, 2004
8,807
9
looking for classic NE singletrack
I know there has been loads of posts about spring rates, but I still need some advise from Sunday owners.
I weigh 168 pounds (12st or 76Kg) in 'normal' clothes. I have been riding my 07 Sunday team with the stock 300 spring, which I have to admit feels fairly soft, but OK. I spoke to a mate at the weekend who's been riding Sunday's a couple of years and he uses a 450 spring. He is a similar weight to me, but reckons you shouldn't run too much sag on a Sunday.
I am about to order a new Ti spring, but don't know whether to stay on a 300 or go a bit heavier, maybe just up to 350.

Anyone out there of a similar weight got any advise?
I weigh almost exactly the same (165lbs) and wouldn't ride much other than a 300lb spring. in fact when I've run certain custom tunes (on unnamed shocks) I actually went down to 250. the main issue that I've had is with bottoming out the DHX with this spring rate, but other shocks don't seem to be as affected (I'm going to be running a ROCO to start the season). you should run 33-40% sag on the sunday, adjusted to taste. :)
 

pyynö

Chimp
May 6, 2006
40
0
Finland
Helo evribadi, my name is Dr Nick!

:monkeydance: I still have play in my dw-link:nopity:

Can you guys send me those thicker magic spacers, so I can fix my bike ? Really :lighten:

Perlease :D
 

RichS

Chimp
Apr 23, 2007
4
0
I weigh almost exactly the same (165lbs) and wouldn't ride much other than a 300lb spring. in fact when I've run certain custom tunes (on unnamed shocks) I actually went down to 250. the main issue that I've had is with bottoming out the DHX with this spring rate, but other shocks don't seem to be as affected (I'm going to be running a ROCO to start the season). you should run 33-40% sag on the sunday, adjusted to taste. :)
Thanks for the advise. I hoped you would reply.
I've only bottomed out a couple of times over the 6 weeks of riding (before breaking my ankle), so I guess the 300 will be good for me too.
My mate was putting doubt in my mind with the sag issue, but I would think you know more than him.
Cheers.
 

dante

Unabomber
Feb 13, 2004
8,807
9
looking for classic NE singletrack
glad to help. it really is personal preference, but the bikes were designed to ride at 33-40% sag. of course you can try harder springs if you want to alter the current ride characteristics, but that's all up to you. :)
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,918
1,213
Have any of you IH guys worked out an air-spring pressure vs rider weight table for the DHX Air in a Sunday?

I'm about 144lbs with gear. I'm sure i'll figure it out, but if there's any data lying around from when sam/sabrina/riffle ran them that'd be useful.
 

dante

Unabomber
Feb 13, 2004
8,807
9
looking for classic NE singletrack
not sure if there are any pro settings, but those of us in the office who have tried the DHX air haven't exactly been thrilled with it, so we don't really have a rider weight table. I'd say go with 1/3rd sag, 100-120psi, boost valve turned all the way in, pro-pedal all the way out, rebound set to taste... and start from there?
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,918
1,213
Yeah thanks... kinda knew all that anyway, was wondering about the main chamber but i'll guess and check until I get 33-35% sag.

Do you know if you can reach the rebound knob with the shock in the bike?
Edit - nevermind, you can. :)
 

bizutch

Delicate CUSTOM flower
Dec 11, 2001
15,929
24
Over your shoulder whispering
So...the little custom logoed up Dw-Link, Iron Horse, THE chain guard was sitting in the box. It had two strips of adhesive tape stuck to it. But there is NO adhesive on the actual chain guard??? What should I use to adhere it to the bike?
 

heikkihall

Monkey
Dec 14, 2001
882
0
Durango, CO
So...the little custom logoed up Dw-Link, Iron Horse, THE chain guard was sitting in the box. It had two strips of adhesive tape stuck to it. But there is NO adhesive on the actual chain guard??? What should I use to adhere it to the bike?
Look closer. There is a clear film that tears off that reveals a double sided tape so you can stick it to the frame. Secure it with Zip ties for a few days to allow it to properly settle, otherwise it will start to tear up.
 

bizutch

Delicate CUSTOM flower
Dec 11, 2001
15,929
24
Over your shoulder whispering
Anybody got a suggestion for something to get that chainstay protector to stay on my bike? Zip ties and the double sided tape that came with it did not work.

Oh...and better back out the ICGS bolts and loctite them. I just had one back out after 10 5 minute long shuttles. Not a complaint...just a precaution for others.