Trek Rail with Fox DHX2 coil

Raph-1970

New Member
Dec 1, 2021
15
4
Belgium
Hi guys
I want to replace the RockShox Deluxe on my Rail 5 for a Fox DHX2 , but I have no experience with shock absorbers and their measurements
and I wouldn't want to be wrong ... I saw this DHX2 2020 ( 230x60 ) on sale and I need your advice to tell me if this Fox would be compatible on my Rail 5 size L ( my weight is 210 lbs ) and what I would need to install it .

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Rob Rides EMTB

Administrator
Staff member
Subscriber
Jan 14, 2018
6,146
13,219
Surrey, UK
2022 Rail 9.9 in XL, Carbon

Ohlins TTX22M in 230 x 62.5 and enough clearance on seat stay bridge with spring off and slammed to the bottom of the bumper.

PS - Anyone wanting to convert the Through Shaft to regular metric, @Offset have the mounting kits. Just need to then get the Trek Bolts from Trek Direct of TF Tuned.


IMG_1220.jpg
 

magic82

Member
Nov 18, 2020
13
2
italy
Hi Guys,
who among you uses a DHX2 230x57.5 on the tek rail 2020, which setting use (rebound and compressions)? I have a 550 coil spring black.
 

DubbyMcDubs

Member
Nov 14, 2021
31
23
Sydney
I understand the concern. That pic was taken with the bump stop still in and no spring, bike fully loaded down. I was worried about it making contact so kept an eye on it. When I used a 450 spring and no damping, on some bigger jumps I was able to bottom out the shock completely (metal on metal feel). Inspection of the paint at that potential contact point remains untouched. So I believe that it's not hitting under worst case. I've switched to a 475 spring since and the bike feels magical. Haven't been able to bottom it out yet.

What size frame are you running?
 

DubbyMcDubs

Member
Nov 14, 2021
31
23
Sydney
After reading over the thread a couple of times, it is still unclear to me if the 21/22 DHX2 or X2 will clear on a medium frame when fully compressed.

Does anyone have experience with this?

Cheers!
 

Battman85

New Member
Feb 10, 2022
21
32
Wollongong
Thanks to everyone for the great advice and tips in this thread.

Just got myself a 2021 DHX2 230x65 which i should be fitting up to my rail 7 (size L) in the next week or so once it arrives and i get the spring. will be ordering a progressive spring as i really want to get the nice plush feel but with the extra bottom out protection of the Prog. spring.

I will post how it goes once done to assist with anyone else looking to do the same.

Watching this thread has been so great, and helpful in making the decision on what to run with. Just signed up and keen to get involved with the forum

cheers,

Wayne
 

DubbyMcDubs

Member
Nov 14, 2021
31
23
Sydney
Thanks to everyone for the great advice and tips in this thread.

Just got myself a 2021 DHX2 230x65 which i should be fitting up to my rail 7 (size L) in the next week or so once it arrives and i get the spring. will be ordering a progressive spring as i really want to get the nice plush feel but with the extra bottom out protection of the Prog. spring.

I will post how it goes once done to assist with anyone else looking to do the same.

Watching this thread has been so great, and helpful in making the decision on what to run with. Just signed up and keen to get involved with the forum

cheers,

Wayne

Look forward to your updates!

I am planning to do the same, and bought a Float X2 yesterday in 230x57.5, which should be here tomorrow. I'll post pics of the clearance at different stroke lengths, as I belive it can be adjusted internally. This is for a medium 2022 Rail 7, which has not been documented much in the various threads.

In preparation for a DHX2, I also bought a Cane Creek 65mm 450-550 progressing spring.
 

Battman85

New Member
Feb 10, 2022
21
32
Wollongong
Look forward to your updates!

I am planning to do the same, and bought a Float X2 yesterday in 230x57.5, which should be here tomorrow. I'll post pics of the clearance at different stroke lengths, as I belive it can be adjusted internally. This is for a medium 2022 Rail 7, which has not been documented much in the various threads.

In preparation for a DHX2, I also bought a Cane Creek 65mm 450-550 progressing spring.

Nice one, keen to see how you go. The photos in this thread of the float X2 seem to show its pretty close to the seat tube so hopefully works out ok with the medium.

I have just ordered the exact same spring. Wanted the DVO ProRate spring (as its Black) but they dont have stock of the one i needed for 3-6 weeks. So ive ordered the Cane creek one to get me through in the meantime. Its white and wont really suit the bike, but i want to get riding on it ASAP :LOL:
 

DubbyMcDubs

Member
Nov 14, 2021
31
23
Sydney
Nice one, keen to see how you go. The photos in this thread of the float X2 seem to show its pretty close to the seat tube so hopefully works out ok with the medium.

I have just ordered the exact same spring. Wanted the DVO ProRate spring (as its Black) but they dont have stock of the one i needed for 3-6 weeks. So ive ordered the Cane creek one to get me through in the meantime. Its white and wont really suit the bike, but i want to get riding on it ASAP :LOL:

Nice! Look forward to the pics.

My shock literally just turned up in the post. Will post some pics tonight.
 

DubbyMcDubs

Member
Nov 14, 2021
31
23
Sydney
Float X2 on a Medium Rail aluminium install photos posted below. They serve as a good reference even for coil options.


With coil shock options, the Fox DHX2 has the same 87.1mm high (from eyelet center) control/resevoir/piggy back as the Float X2, therefore theoretically it would have the same limitations as the Float X2. That same measurement on the Ohlins TTX22 is only 42mm, and Jade X 73mm. For reference, this is the dimension I am referring to:

1644832330286.png
 
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Battman85

New Member
Feb 10, 2022
21
32
Wollongong
Ok, So i just mounted my DHX2 at 65mm stroke on my 2021 Rail 7 (Large).

Some things to note:

- Used the stock trek mounting hardware, but had to chuck some standard DU bushings in the Fox shock first

- To achieve 65mm stroke (169mm travel) i had to put rear frame Mono Link in HIGH setting (i tested with no shock in, measuring the eye/eye of shock mounts, rear frame hits seat post at 65mm stroke in LOW setting, Rear frame hits seat post at 69mm Stroke in HIGH setting which will give some clearance for the 65mm stroke. If i went back to 62.5 or 60mm stroke i could put back into LOW setting)

- Piggy back/Resevoir clearance to the down tube is TIGHT haha (possibly too tight lol). At best i could measure i have 1mm clearance at bottom out haha (didnt mount the top of shock, bottomed out frame to get the right line for the eye/eye. lined the shock up with this line, then measured from the resevoir down to the frame with a metal ruler). So i may end up changing shock back to 62.5mm stroke should it be needed. Im going to run the risk at this point and i think worse case scenario on a hard bottom out it may just "tap" the frame, but i dont think its going to be a shock/frame destroying issue if it happens. so if it does happen i'll reduce the stroke to avoid it happening again.
(** unfortunately due to not having the right tools to press the hardware in/out of the shock myself, i wasnt able to "properly" test the bottom out of the shock with no spring in. As the spring doesn't fit over the hardware, i had to put the spring in before going to LBS and mounting the hardware. i did a test before the hardware was mounted and it showed plenty of clearance, but this wasn't super accurate as the shock wasnt sitting in the "correct" eye/eye position with the hardware not in the shock.)

- Plenty of clearance between the spring and the seat tube

- In regards to TFtuned spring calculator and working out what spring to get. I have ended up with 28% sag on the 450-550lb cane creek spring (im 86kg as tested). To achieve this 450lb number on the calculator i actually need to NOT add the 5-7kg that they recommended you do when calculating for E-bike. My exact rider weight at 28% setting ends up at 450lb on the calculator, which is what i got in reality... so this is something to considering when buying a spring. I believe the extra weight of the E-bike will come into play more so when actually riding the bike. So this is where the progressive spring will come into play and avoid the bottom outs.

- from an aesthetic standpoint, i didnt plan to get the white spring. But unfortunately the Black spring from DVO wasnt available in the spring rate it appeared i needed. So rather than wait another 6 weeks for it, i just went for the cane creek spring for now. Will probably change to DVO when its available as the black spring will suit the bike alot better of course.

- I had to remove the water bottle cage. The cage itself wasnt an issue, but with a bottle in it the piggy back resevoir was definitely going to foul on the bottle. So water if off unless i can find another cage that might offset more and potentially avoid fouling.

- went for a little play on the street out the front, doing little jumps off of gutters and off the kerbs on sides of peoples driveway. Feels fantastic already, can definitely feel the difference from the air. So i'm looking forward to heading out for a proper test tomorrow. Which im sure is going to need some dialing in of the settings before getting the full effect of the upgrade. Initial feeling is great though.

- ** Only 2021 or 2022 DHX2 will work as they have the smaller resevoir than previous years.
- ** DHX shock wont work as its Piggy back resevoir hangs down much further and will foul on down tube
- ** If you wanted to go the 65mm Stroke and be certain of ZERO clearance issues, then from what im seeing the DVO Jade X and Ohlins TTX22 are your first ports of call due to thier different Piggyback design

Hope all this helps. cheers

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Arron M

Member
Oct 14, 2021
67
45
Australia
This is a large 7 with 65mm RS air shock, all my weight (95kg) on the bump stop, which feels like a hard plastic stop, not rubber. I cannot get it any closer than this bouncing on the bike.
IMG_0943.jpg


I agree that 62.5 would certainly be a safe bet, but still don’t think it’d touch at 65 even on a decent bottom out.
 

andygua

Member
Jul 13, 2022
9
1
Chile
Hi everyone! New to the forum, and new to e-bikes as well with a new 2022 Rail 7. I've owned a Slash for a few years now and when compared to the Rail, my only complaint is the shock on the Rail...so, before I pull the trigger, I just wanted to make sure my plan will work: replace the shock with a new 2021/2022 DHX2 230x60. I know this will add a few mms of travel (which is fine because I'm going with a Fox 38 170mm in the front), but just wanted to make sure it'll fit in the 2022 Rail as well? Should I perhaps go with a 230x62.5 even?

Many thanks in advance!
 

JP-NZ

Well-known member
Feb 17, 2022
998
754
Christchurch - New Zealand
Hi everyone! New to the forum, and new to e-bikes as well with a new 2022 Rail 7. I've owned a Slash for a few years now and when compared to the Rail, my only complaint is the shock on the Rail...so, before I pull the trigger, I just wanted to make sure my plan will work: replace the shock with a new 2021/2022 DHX2 230x60. I know this will add a few mms of travel (which is fine because I'm going with a Fox 38 170mm in the front), but just wanted to make sure it'll fit in the 2022 Rail as well? Should I perhaps go with a 230x62.5 even?

Many thanks in advance!

They are all the same DHX2, They can be adjusted with travel spacers from 230x57.5 to 62.5. If 62.5 is too long then one more 2.5mm spacer and 60 would work fine.
 
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andygua

Member
Jul 13, 2022
9
1
Chile
They are all the same DHX2, They can be adjusted with travel spacers from 230x57.5 to 62.5. If 62.5 is too long then one less spacer and 60 would work fine.
Didn't know that, thanks! Just looked at fox's website and changing those spacers looks like a very simple job. Guess I'll go with 62.5 then, and reduce travel if needed.

So final confirmation: the DHX2 will fit on a 2022 Rail 7 (size Large)? I suppose geometry didn't change from the 2021 model, but wanted to double check.
 

JP-NZ

Well-known member
Feb 17, 2022
998
754
Christchurch - New Zealand
So final confirmation: the DHX2 will fit on a 2022 Rail 7 (size Large)? I suppose geometry didn't change from the 2021 model, but wanted to double check.

I wouldn't put my life on it but I would be pretty confident it should be fine with a 2021 or 2022 DHX2 with the small piggyback like the one pictured above.
 

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