Anyone seen this before?? Blown up Fox DPS

[RustyMTB]

I'm servicing a Float E Vol DPS for a friend of mine. He jumped it to flat & blew the shock. We assumed it would be a straight forward seal service but on taking off the air can, it's clear the damper shaft has sheared in two. Now wondering if this is saveable, I've certainly not seen anything like it before.

 

[Mteam]

it probably is repairable by getting hold of a new shaft and rebuilding it, but it looks like a good opportunity to upgrade to a better shock to me

 

[RustyMTB]

New damper shaft ordered for £12 & off we go again. Interesting part of the removal process is the shock cap has to be heated with a blow torch prior to removing the damper shaft in order to release the Loctite on the threads.

 

[steve_sordy]

................Interesting part of the removal process is the shock cap has to be heated with a blow torch prior to removing the damper shaft in order to release the Loctite on the threads.

Ooh err! That's a bit beyond where I would want to go. Be careful not to melt the shock cap!!!

 

[RustyMTB]

Since the Nitrogen has had to be released from the rebound circuit to get it to this point, it will be going off to a suspension builder for reassembly anyway. A look round the forums suggests these shocks from around 2016-2018 can be susceptible to the damper shaft failing in this way but it's a new one on me.

 

[Squamish Sucks]

Since the Nitrogen has had to be released from the rebound circuit to get it to this point, it will be going off to a suspension builder for reassembly anyway. A look round the forums suggests these shocks from around 2016-2018 can be susceptible to the damper shaft failing in this way but it's a new one on me.

I snapped the shaft in DPS on my 19 Levo twice. Upgraded to DPX2 and then no more problems.

 

[peteandsoo]

TF repaired mine with a new shaft under warranty ( 2 years)

 

[ebsocalmtb]

I have seen this happen on a few different bikes over the years that side load the shock as they compress it (mostly yoke driven bikes)... most notably, specialized stumpjumpers. It's likely obvious, but it happens because the shock goes under a great deal of bending force towards bottom out, and the overall extension of the eye to eye that the yoke creates amplifies this. This is why bikes like the stumpjumpers and levo's, eat shocks up, and they require full shock service annually (potentially even more often depending on shock, such as a dhx2). You'll find that the thicker shaft, 10mm shock shaft, shocks hold up better, such as the dpx2, float X, super deluxe, however those are still going to need a much shorter rebuild cycle.

I digress, that inner shaft can be purchased as a part, it can be fixed/rebuilt. If your buddy is riding as hard as it sounds like he is, this will likely happen again. I'd buy a replacement shock asap, get this one warranty repaired and sell it, or keep it on the shelf in order to cover the downtime from rebuild cycles.

 

[RustyMTB]

It is indeed a 2018 model year shock from a 2019 Stump jumper.

 

[thebarber]

I have seen this happen on a few different bikes over the years that side load the shock as they compress it (mostly yoke driven bikes)... most notably, specialized stumpjumpers. It's likely obvious, but it happens because the shock goes under a great deal of bending force towards bottom out, and the overall extension of the eye to eye that the yoke creates amplifies this. This is why bikes like the stumpjumpers and levo's, eat shocks up, and they require full shock service annually (potentially even more often depending on shock, such as a dhx2). You'll find that the thicker shaft, 10mm shock shaft, shocks hold up better, such as the dpx2, float X, super deluxe, however those are still going to need a much shorter rebuild cycle.

I digress, that inner shaft can be purchased as a part, it can be fixed/rebuilt. If your buddy is riding as hard as it sounds like he is, this will likely happen again. I'd buy a replacement shock asap, get this one warranty repaired and sell it, or keep it on the shelf in order to cover the downtime from rebuild cycles.

I just watched this explaining side loads....

 

[RustyMTB]

Me too, the essence of it, according to that guy is eyelet & yoke mounted shocks in particular can undergo heavy bending/side loading forces, related to play in the bushing, frame deformation & in the case of yoke mounted shocks where the effective unit length can be doubled by the existence of the yoke itself, seriously weakening the rigidity.

The phenomenon is worsened by the rise of Ebikes & the consequent loss of space caused by the incursion of motors & that guy's view is frame designers, forced into compromises by the constraints on them push the issue back to oem suppliers, as their position as customers allows & so the problem persists as oem's are forced to produce what amounts to compromised designs demanded by the bike brands.

 

[Levo Laland]

I’ve snapped 2 shafts now on my DPS, fitted to 2019 Levo, repaired both times under warranty by Silverfish in the UK. Apparently, these have a two-year warranty, which was handy. I will have to upgrade to DPX2 or new Float X if it happens again and just not economically to repair these things.

 

[thebarber]

Did you watch the video?
I think the levo and the likes with opposing eyelets and extended yolk are more susceptible going off that.

 

[Levo Laland]

Yes, he’s spot on. I had a lengthy conversation with the warranty manager at Silverfish after I suggested to them that the DPS was not fit for the purpose. I’ve since fitted a cascade linkage that is beefier than the stock one and changes the leverage curve, maybe that will help things as it is the part linking the back end to the shock. Both my shocks blew in cornering situations and not on drops.

 

[RustyMTB]

Yes, he’s spot on. I had a lengthy conversation with the warranty manager at Silverfish after I suggested to them that the DPS was not fit for the purpose.

Guessing they couldn't agree, what with being the UK Fox distributor and all?

 

[Planemo]

Since the Nitrogen has had to be released from the rebound circuit to get it to this point, it will be going off to a suspension builder for reassembly anyway.

I have rebuilt Fox at home using air and they have been fine. As a point, RS use air as stock afaik.
But yes, obtaining and fitting the required schrader valve for Fox and getting the required pressure can be a bit of a faff. But once its done its done, and no more messing around/costs with specialist servicing.

 

[RustyMTB]

I get that you can do them with air, otoh It's not my shock, so we've talked it over & agreed to get it recharged by the book. His bike, his choice. What was interesting was when I released the grub screw, barely any gas came out, so I hope it hasn't knackered the valving assembly but I wouldn't bet my house on it.

 

[Peter#DK#]

Mine did that aswell, last summer shuold wait 6 weeks if fox should repair it on the warrenty, so i paid myself so i could ride the summer time