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

**4130biker** · 01-08-2013, 11:01 AM

Kicking around the idea of getting an '06 sunday for a good deal. Supposedly this is the world cup. Is there any way to tell? Any durability issues to look for? I read here that the lower link is updated, so that's good...
I saw that the american 07 factory is lighter than the taiwan frames- is this 06 world cup the heaviest version? After reviewing the first post, I'm still unsure. Am I wasting my time, or should I look into it. A little leary of a six year old frame, but I've been seeing enough people still using them that I'm considering it. Do the headtubes ever shear off of these things? Ok I think thats it.

**Sandwich** · 01-08-2013, 11:04 AM

They seemed pretty durable to me. Two seasons under a trumpore and about 2.5 with me, no signs of cracking or anything.

I think they were heavily revised in 07...ie, the 0506 frames were a bit different than 0708, but if you're not scared of a half pound of weight...

If you get a good deal on it, I'd still consider it. Mine was a pretty fun bike, but figured out the shock ferrchrissakes...being able to pick any shock I want on my current bike is really pretty nice.

**4130biker** · 01-08-2013, 11:15 AM

Can't give you rep for helping out, but thank you. I'll see how low this dude will go and decide from there. I like the idea of a cool foundation that can be used for some mods and make a fun bike- kinda like what you're doing!

**Sandwich** · 01-08-2013, 11:20 AM

Haha, sure. The best thing about the sunday frames, besides their geometry and robustness, is the wealth of information you can get on them. Plus, they're cheap. They really don't do anything wrong besides the regressive shock rate, but you can supposedly correct that with an RC4. You can get anglesets, drill out your seat mast, run them single crown, double crown, etc. They're neat bikes that pedal really well and rip through the corners, but their taiwaniness can lead to issues, and mine had a nasty spike 2/3 into the travel that I think was related to my DHX. I never got it retuned or pushed or anything, mostly because I was an idiot, but I wanted to try something else.

**Udi** · 01-08-2013, 03:51 PM

All 07+ frames are 0.9lbs lighter than previous frames, and all have the updated F7 linkage. It's worth getting an 07+ if you can, but there are no glaring durability issues with the 06 frames apart from maybe having a few little linkage dramas (which you can upgrade anyway, if you can find the parts). I retired my 07 after riding it for about 6 years (two swiss alps seasons and one whistler season) and it's still sitting in my room with zero cracks or failures.

Like Sandwich suggested, the coolest thing is that they were quite far ahead of their time when they came out and left a lot of room for modernizing, so it's easy to still be competitive on one today. Acceleration is second to none, and cornering is still class-leading. They do work best with an RC4.

The shock rate really does not digress that much (we measured it quite accurately on a custom jig and fed the data through linkage) and is easily corrected with any progressive shock to resist bottoming. What makes it less than perfect is actually that there isn't enough progression at the beginning of the stroke (even though it is still progressive) so it won't take the edge off bumps quite as well as a more modern design. The other thing is they aren't the poppiest bike, partially due to the lack of strong progression initially, and partially due to generating end-stroke progression via damping (which absorbs energy) rather than mechanically / via spring rate (which stores and returns energy to the rider).

With careful shock choice and shock tuning though they are still brilliant bikes though.

**Udi** · 01-08-2013, 04:01 PM

Originally Posted by An0maly

What size shock reducers does the frame require ?

30x10mm for 07+
I am unsure for 05-06 frames without an F7 linkage.

Originally Posted by edmo

I take it there's no actual difference with the pivot locations in the two linkage types? The 07 linkages just have different diameter holes and less material on them, right?
I'm guessing running an 06 upper link and 07 lower link wouldn't be any issue?

No difference in pivot locations, geometry and suspension kinematics of Sunday frames were identical throughout production for consumer frames (05-09). Some small geometry changes for Sam Hill I believe. No issue with running different year links like you said.

Originally Posted by the_maxis_233

what kind of loctite recommend?

As richgardiner said, to fix play between the rear pivot of the lower linkage and the link itself, loctite 609 retaining compound works well. It is a green liquid. As bengxe said, it is good to be generous with it and clean up the excess later, and it's very important to leave it for full cure time (at least 24 hours) immediately after assembling the pivot.

**allen** · 01-08-2013, 05:17 PM

Originally Posted by Udi

30x10mm for 07+
I am unsure for 05-06 frames without an F7 linkage.

23x8mm on the older pre F7.

Some may disagree on the play or need for a bearing on the lower shock eye but I'm a fan of the RWC bearing on the older pre F7 lower link. I find its hard to get everything to squeeze together adequately when you tighten the lower pin and keep shock reducer bushing from spinning instead of the du busing rotating around the shock reducer.

On my friends with the older link running updated max-e bearings and the addition of shims from mcmaster we got that thing dialed. It took and allot of patience but it can be done.

The F7 fixes all this so that's why its such a recommended up grade.

I thought I read somewhere that Fox has some new busing instead of a DU that is less friction. That would be sweet instead of the RWC bearing. Any one have a link to that info?

Al

**Udi** · 01-08-2013, 05:42 PM

Al - I think needle bearings are a bad idea on a low rotation pivot as wear is greatly accelerated, and even on the top pivot I found life before play developed quite short. I found an easy solution to the excessive friction in standard DU bushings is to lathe down the OD of the bushing slightly so it is not clamped as much when pressed into the eyelet, thus decreasing friction greatly. Done correctly, reducer hardware will press in by hand.

This is the new Fox "five piece" hardware you speak of, which seems to work quite well too:
http://www.foxracingshox.com/technol...=mh&ref=topnav
It uses IGUS glide bushings.

**allen** · 01-08-2013, 07:01 PM

UDI, thanks for the fox info. Im in agreement on the rwc stuff. It was kinda like choosing between two evils but your tip of tweaking the du is cool. I'll have to give it a try when I go over things for next season on my bike and my friends if for some reason I can't get the fox stuff.

Al

**An0maly** · 01-09-2013, 04:23 AM

Originally Posted by allen

23x8mm on the older pre F7.

Some may disagree on the play or need for a bearing on the lower shock eye but I'm a fan of the RWC bearing on the older pre F7 lower link. I find its hard to get everything to squeeze together adequately when you tighten the lower pin and keep shock reducer bushing from spinning instead of the du busing rotating around the shock reducer.

On my friends with the older link running updated max-e bearings and the addition of shims from mcmaster we got that thing dialed. It took and allot of patience but it can be done.

The F7 fixes all this so that's why its such a recommended up grade.

I thought I read somewhere that Fox has some new busing instead of a DU that is less friction. That would be sweet instead of the RWC bearing. Any one have a link to that info?

Al

I have the new fox ones in the top. Only just put them in so can't comment on durability or anything yet but they do look nice.

**4130biker** · 01-09-2013, 08:39 AM

Thanks for the input- I think I'll keep looking for an 07+ then. Sounds worth the wait to me. I got excited when I saw a large for sale- it seems like they aren't as common.

**ritche** · 01-10-2013, 02:21 PM

I picked up a 9.5x 3.00 kashima fox rc4 shox, with a sticker that says F TUNE any idea what it is?
Is it ok to use it on IH sunday?

**richgardiner** · 01-10-2013, 04:58 PM

Building up my 09wc, does it matter which side the black and silver jumbo hex bolts go on? I know the shock pin can only pass through them in a certain direction but does it matter which way around we have the hex bolts?

**bengxe** · 01-10-2013, 07:05 PM

I guess you could swap them, but you probably want the axle to go out the non-drive side.

**Udi** · 01-10-2013, 10:39 PM

As above, axle slides out of the non-drive side in factory form (bigger ID hole on non-drive side). I'd keep it that way, as it means you can remove shocks without touching the chainguide. If you swapped them, it might make that harder.

ritche -
I've never heard of that before, doesn't sound like a fox tune, try it and see.