S18 Shock Replacement

[Dh316]

For those that have replaced the stock   DNM shocks, can you provide any guidance on what else is needed after purchasing a shock that’s 200x57mm?

Fox Shocks and Rock Shox have a standard 12.7mm eyelet. The DNM stock shock is 12mm. How was this made to fit if I wanted one of those brands?

Also, I’ve read that people had to make custom bushings. Can these just be purchased?

[bbulkow]

This is exactly my question! I have the great suspicion that the DNM shock is... not as good as a premium mt bike shock.

Dh316, any update? Did you get a shock to fit? Any suggestions? (PS. also in the bay area here)

[Lukasz]

I am using FOX DPX2 for more than 2 months now. this is GREAT shock. I have mounted it using spacers from the standard shock, on the other side - to compensate 12 to 12.7 difference i have quickmounted it using 3 turns of the PEPSI can alu sheet. Works reasonably well.

[Lukasz]

[bbulkow]

Thanks very much for the info! Just feels smoother and better rebound?

I was thinking Fox didn't make a correct size, but now I see "imperial" 7.875 x 2.25 is the same as 200 x 57, that's what you used?

You chose it over the RockShox Monarch because....? Fox is better?

It looks like one should use "3 position lever" version because we don't have mt bike remote system :-) ?

The pepsi can spacer sounds great! I can do that :-) although here I tend to use Tecate beer cans (Tecate I use when cooking BBQ, to steam the meat, not the chef)

You've convinced me so I just ordered one. Those shocks are not cheap! so I hope I've ordered it correctly :-)

I am sure that a simple disassemble this weekend will increase my confidence.... and let me lubricate some of the joints....

Dzien dobry!
 

Edited July 9, 2021 by bbulkow

[bbulkow]

Really really really wish someone would comment on a non-pepsi-can means for shimming the 12mm to 12.7mm gap on these shocks.

[bbulkow]

I have a new Fox shock in hand and did all my measurements. Yes, I need a new part.

The method of suspension is a "three piece pin and sleeve", mostly. https://www.ridefox.com/fox17/help.php?m=bike&id=251 , according to Fox's taxonomy.

There are two bushings, and one pin (and the pin has an axel inside).

The pin is 50mm wide, which is not very standard. 51mm width is pretty common, and a fitting kit for Fox shocks and a 51mm fork would probably work.

I have found on TFTuned what appears to be the exact fit kit. Made for Fox, 8mm axel, 50mm width. 40GBP shipped to the US. TF Tuned Mount Kit 12.7mm M8 8x50 (TF850)

But because it's more fun, I am also asking a friend to manufacture the shaft I need ---  50mm wide same as original, 8mm ID same as original, 12.7mm OD which is the larger standard. (or as one poster said, wrap a tin can around the pin a couple times so it fits nicely in the eyelet, I'm going to try to do it right :-) ).

I also need to manufacture two new bushings. The Fox end is 16.5 wide, the stock unit is 14.25. This means the two bushings need to be (50 - 16.5 ) / 2 = 16.75 wide, and 12.7 ID instead of 12.0 ID. Since these aren't stressed members it's very easy to just print 4 new spacers (PETG for flexability and moderate UV resistance), so I'm doing the world's simplest model now.

I'll report back if things work. Share and enjoy.

[Dreygun]

Get a few extras made, I'm sure you could sell a few little kits for users wanting to change out

[bbulkow]

Thanks, but not interested in opening a parts supply business :-) . I can't even manage to sell things on ebay, because, shipping is confusing.

If the TfTuned kit works, it's a very reasonable price, they've shipped it to me, will update when it arrives. And, that was 40GBP for two sets (both ends of the shock) and international shipping. Compared to the price of the shock (>500USD) that's a very reasonable price.

My manufacturing guy says I want 8.05mm ID for "normal fit", and looks like I want stainless for the part. My 3d prints are a little wonky so (as usual :-/ ) I'm tweaking speeds and temps to get a nicer print. Using transparent filament looks cool though.

Edited July 12, 2021 by bbulkow

[bbulkow]

Update: this TfTuned kit DOES allow replacement of the stock 12mm eyelet part with any 12.7mm eyelet part. It's exactly what everyone who wants a shock upgrade would want, and installed flawlessly for me. The parts are higher quality than what comes with the S18.

You need to click on 8x50 and get quantity 2 (one for each end). This cost me GBP40 with delivery to the US. Delivery over Royal Mail happened with tracking number and took about a week.

https://www.tftuned.com/tf-tuned-mount-kit-127mm-m8/p2937

This is because:
1) the width of the bracket is 50mm. A 51mm might fit too, but the original part was 50mm on the nose.
2) the diameter of the axel is 8mm. This is a standard size (although somewhat rare for a part so long).
3) Then you just need a kit for the shock you're mounting. This 8x50 part comes to fit a number of shocks, I bought the fox kit.

Using this kit does not require a full disassembly. You simply need to compress the suspention to get access to the end bolts, undo the bolts, force them through the holes (requires force!), compress the new shock, line it up, bolts back in, and away you go. Getting the old bolts out requires a little finesse, as does getting the bolts back in, but patience and a few well placed hammer blows will get you through.

I am not doing a general post yet, as I think the Fox shock I mounted might not be the best for the S18 - I would consider its ride "tight" in that I get a lot of road feel on sharp transitions - which apparently is well known for this shock - but it has a lot of tuning options, maybe I haven't found the tune yet. The RockShox Monarch RT is also recommended in a different post, and it's considered "plusher" and might be a better choice for my kind of riding. It's also cheaper I think - the Fox I fit was expensive!!! The part I linked might also be the right one for the Monarch, or you might need a slightly different 8x50 mount kit.

If I get it tuned, I'll have a stock shock to sell :-) for all you who blew out yours.

PS. My manufacturing friend didn't have quite the right bit in stock for his milling machine, so we decided to wait for this part before he ordered more. A 50mm hole with 8.05 tolerance requires some particular bit he didn't have, and stainless, too.

Edited July 20, 2021 by bbulkow

[bbulkow]

The DPX2 benefits from fully Open shock setting, including the 3mm hex key (came from factory not that). Also, using the Fox Digital pump, which gives much more information as the chambers are equalizing. Instead of redistributing every 50psi, one must redistribute while watching the gauge, and and redistribute until pressure stops changing. Then, yes, start your pressure at your lbs + about 30 for the wheel's weight (it seems they think mt bikes are about 20 lbs so 30 seems about right). I know most of you don't have DPX2 and this doesn't make sense but for anyone else who does install one these are the two tips that now give me an exceptional ride.

Pity I don't have an extra $1000 to try the RockShock and Cane Creek suspension units just for fun.

[toe]

14 hours ago, bbulkow said:

The DPX2 benefits from fully Open shock setting, including the 3mm hex key (came from factory not that). Also, using the Fox Digital pump, which gives much more information as the chambers are equalizing. Instead of redistributing every 50psi, one must redistribute while watching the gauge, and and redistribute until pressure stops changing. Then, yes, start your pressure at your lbs + about 30 for the wheel's weight (it seems they think mt bikes are about 20 lbs so 30 seems about right). I know most of you don't have DPX2 and this doesn't make sense but for anyone else who does install one these are the two tips that now give me an exceptional ride.

Pity I don't have an extra $1000 to try the RockShock and Cane Creek suspension units just for fun.

So, to reiterate, if I wanted to replace my shock, I would only need the TfTuned kit? You mentioned needed something manufactured and I'm wondering if I'll need this as well.

[bbulkow]

The new shock, and that kit, and some hex keys, are all that's required.

I considered manufacturing the same essential thing just for the fun of manufacturing it, but then the kit arrived and worked perfectly so I didn't bother.

Edited July 28, 2021 by bbulkow

[EUC Forest]

I a replacing the DNM 38 which had replaced the stock leaking DNM 36 because the lower chamber gasket/ring is getting loose after just a couple of months (offroad but no jumps); this is poor, and not serviceable...and no warranty thanks very much Aliexpress.

Going for the Monarch RT3 "Debonair" (bigger chambers), also ordered the 12.7 kit mentioned by bbulkow, thanks for this! (there are cheaper options but none were in stock.)

[Ksmack]

A Rockshox Monarch Plus RCT3 just came up on Craigslist in my area. It is 200mmx51mm. I know the eye to eye length will fit, but is there a problem going with the 51mm vs 57mm stroke length?

Anyone else have experience with this shock (or any of the Monarch shocks) vs the stock DNM one?

[oromis]

On 7/28/2021 at 8:46 AM, bbulkow said:

The new shock, and that kit, and some hex keys, are all that's required.

I considered manufacturing the same essential thing just for the fun of manufacturing it, but then the kit arrived and worked perfectly so I didn't bother.

This 8x50 Kit will work with Rockshox monarch rt3? 

 

https://www.worldwidecyclery.com/products/rockshox-monarch-rt3-rear-shock-7-875x2-25-200x57-debonair-tunemidreb-midcomp-soft-pedal-320-lockout-force-d1

[jrhz06]

Amazon sells bushing kits for Fox/Rockshox. Both same size. To fit either of those shocks you need a 1/2” x8mm in the appropriate length which I believe is 50 mm. If you don’t have a shock yet check Pinkbike.com. Can usually find a nice clean used shock for lots less than new. I bought a new Rockshox vivid air for half price, guy wanted coil.
RockShox Rear Shock Mounting Hardware-3-Piece Set

 

Edited June 24, 2022 by jrhz06

[Ksmack]

I want to replace the stock axle pins that connect the top and bottom of the shock. I can’t find a replacement anywhere!the pins measure about 70 mm in length and take an M8 bolt. Has anyone found a suitable replacement?

[jrhz06]

Try dvo suspension. Their kits are for 12.7 not 12 mm, so once again they would work with Fox or Rockshox but not the stock shock.

[EUC Forest]

On 6/24/2022 at 7:42 PM, Ksmack said:

I want to replace the stock axle pins that connect the top and bottom of the shock. I can’t find a replacement anywhere!the pins measure about 70 mm in length and take an M8 bolt. Has anyone found a suitable replacement?

I got those, decent quality:

https://www.aliexpress.com/item/1005003441900941.html?spm=a2g0o.order_detail.0.0.71d9f19c0j4IHn

 

those also:

https://www.aliexpress.com/item/4000588614435.html?spm=a2g0o.order_list.0.0.76aa1802kw8Btd

[Mac]

I’ve been screwing around with the air shock on my S-18 for three years now. Sometimes it even works. 
The shock on my S-22 is set and forget. I’ve enjoyed the fact that it’s so easy to go from street mode to trail with just a couple of clicks. 
Yesterday I mounted the JFOYH adjustable oil + coil spring shock I got off Amazon. 
Wow what a difference!! It’s so quiet and smooth. You can adjust the preload softness and rebound. 
They have different weights of springs to match your weight. They will send the 550# as standard or you can replace it with a heavier spring if you need it. I opted for this shock because cause of the assortment of springs they offer. The default bushing was an exact fit. I just used the bushings from the original shock. What a difference!!

Edited June 23, 2023 by Mac