Fox 5-piece polymer DU shock bushings on Monarch?

[Nambra]

Hoping for some assistance from the brains trust...

I've read quite a few posts on the interwebs about people replacing the stock Rockshox DU bushing hardware on the Monarch with the Fox 5-piece low friction polymer bushing kit and have experienced better small bump sensitivity from their shock. I got curious and tacked a Fox kit on to a recent online order to see if it would work for me too, as the existing stock Monarch setup seemed overly stiff.

I'm trying to install it on a bog standard Monarch RT3. I removed the stock bushing using the proper tool. I watched the Fox bushing installation video and it looked like a piece of piss - tool free apparently. But my experience differs somewhat. I managed to get the two yellowish coloured polymer DU bushings into the shock eye, but they were noticeably more difficult to push in than the video suggested. The axle itself I simply could not push in by hand, I would have needed the bushing tool to force it in, but that didn't seem right as the video guy did it without tools.

Have I missed something here? Is the Fox kit not compatible with RS - both have 15mm shock eyelet bore diameters don't they? Or is there some Fox v RS incompatibility trickery going on... It's as if the Fox polymer bushings get compressed slightly as they go in and the internal diameter is reduced such that the axle just doesn't go in or rotate easily. Removed from the shock the axle and bushings fit together perfectly and there is very little friction between them.

Any thoughts, before I give up on the idea?

 

[Boom King]

Pics of the shock eyes with no bushings please.

 

[Nambra]

Here you go BK - not certain what help they'll be? They are exactly 15mm diameter measured with the Vernier.

 

[Boom King]

What's the OD measure on the polymer bushes?

 

[teK--]

They definitely don't press in by hand gotta use a vice and sockets (the axle too)

 

[Nambra]

What's the OD measure on the polymer bushes?

Same Vernier, 15.1 OD, 12.8 OD, axle 12.7.

Tek, are you referring to Fox bushings in a Rockshox shock?

 

[teK--]

Same Vernier, 15.1 OD, 12.8 OD, axle 12.7.

Tek, are you referring to Fox bushings in a Rockshox shock?

Yes. Have used them in fox, rockshox, and cane creek shocks. Had to press them every time.

 

[Nambra]

Yes. Have used them in fox, rockshox, and cane creek shocks. Had to press them every time.

Thanks mate - so would you rate them over the stock Rockshox bushings? They must loosen up after a bit of use?

 

[teK--]

Thanks mate - so would you rate them over the stock Rockshox bushings? They must loosen up after a bit of use?

Not sure if they loosen up, nor are they meant to? Even when I remove the hardware to transfer the shock to a different bike I've had to use a vice to press it back out. I didn't buy the Fox ones because I thought it would actually provide better function; they just seem a lot more durable than traditional DU bushings. The fact that I never wore out any of the 3 sets of Fox bushings I've had seems to support that theory.

 

[Nambra]

Not sure if they loosen up, nor are they meant to? Even when I remove the hardware to transfer the shock to a different bike I've had to use a vice to press it back out. I didn't buy the Fox ones because I thought it would actually provide better function; they just seem a lot more durable than traditional DU bushings. The fact that I never wore out any of the 3 sets of Fox bushings I've had seems to support that theory.

That's good to know that they are tight fitting but durable - makes me think it will be worth trying them. Worst case is I end up in the FW thread...

 

[Capt.Gumby]

Have you looked at installing needle roller bearings instead? Really easy to install and my shock spun around like a set of brand new wheels!!!! I had installed a set on my lower eye on my Monarch for my Trek Slash, sourced them from DIYMTB.

https://www.diymtb.com.au/displayItems.asp?cid=46

I sent them an email noting my frame, shock etc and they supplied the appropriate bearing and spacers etc. At $25 a pop, I bought a few for spares thinking they wouldn't last too long but after 6 months of riding (often rain and mud...Cairns) they were still running smooth. Replaced the bearings after 12 months, not that I had to but I had a new set sitting there.... pushed them in by hand.... I will see if I still have a spare set lying around and will post a pic.

 

[Nambra]

Have you looked at installing needle roller bearings instead? Really easy to install and my shock spun around like a set of brand new wheels!!!! I had installed a set on my lower eye on my Monarch for my Trek Slash, sourced them from DIYMTB.

https://www.diymtb.com.au/displayItems.asp?cid=46

I sent them an email noting my frame, shock etc and they supplied the appropriate bearing and spacers etc. At $25 a pop, I bought a few for spares thinking they wouldn't last too long but after 6 months of riding (often rain and mud...Cairns) they were still running smooth. Replaced the bearings after 12 months, not that I had to but I had a new set sitting there.... pushed them in by hand.... I will see if I still have a spare set lying around and will post a pic.

I did look into the roller bearings, the RWC ones seemed like the goods in that they come with three slightly different diameter axles, so you get a perfect fit. But then I read somewhere (mtbr perhaps?) that someone thought they were a bit of a maintenance pain, didn't really see much improvement running them and swapped back to the Fox hardware.

I'm sort of wondering if I'm chasing an imaginary gain here. If the Rockshox / Fox OEM bushings are so bad, then why do they keep supplying them? Does it really make a difference having shock mounts that can rotate relatively freely?

 

[Flow-Rider]

I did look into the roller bearings, the RWC ones seemed like the goods in that they come with three slightly different diameter axles, so you get a perfect fit. But then I read somewhere (mtbr perhaps?) that someone thought they were a bit of a maintenance pain, didn't really see much improvement running them and swapped back to the Fox hardware.

I'm sort of wondering if I'm chasing an imaginary gain here. If the Rockshox / Fox OEM bushings are so bad, then why do they keep supplying them? Does it really make a difference having shock mounts that can rotate relatively freely?

I run them on my trail bike and they lower the break away point of the shock and make the bike feel more lively but it's probably going to be dependant on the bike you use them on whether they make a big difference or not.

 

[moorey]

Have only used one set...that came installed in a shock. Ran them for a while then swapped for standard type, but proshock offsets. Personally didn’t notice and bump sensitivity improvement. That said, nor did I on a set of needle bearings*


*gumby rider disclaimer.

 

[Nambra]

I run them on my trail bike and they lower the break away point of the shock and make the bike feel more lively but it's probably going to be dependant on the bike you use them on whether they make a big difference or not.

Thanks for that feedback. After teK saying the Fox bushings are tight, I did fit the Fox kit to the lower eye of the shock and mount it on the bike, but it was tighter than the original bushing, so I've gone back to the OE bushings. I'm somewhat surprised that the Fox stuff doesn't move more freely.

 

[Flow-Rider]

Have only used one set...that came installed in a shock. Ran them for a while then swapped for standard type, but proshock offsets. Personally didn’t notice and bump sensitivity improvement. That said, nor did I on a set of needle bearings*
*gumby rider disclaimer.

They do transmit some harshness or feed back as you have metal on metal in the bearing but I noticed when I preloaded to jump that I had a bit more springiness out of the suspension and the back wheel tracks a bit better in the loose ruts. I had the shock retuned by NSD for climbing and it made the mid stoke a bit harder but it seems to work quite well with the bearings, I was able to run a lot less psi in the aircan.

 

[Capt.Gumby]

The gains from installing the needle bearings were not enough for me to pursue it again with my new bike. To be honest, I not a good enough rider to do it any justice anyway..... I am one of those types that love to tinker with my set ups, that if I thought it could make a difference, I would give it a go. Hence, why I installed the bearings. Though, for only $25, the ease of installation and the fact that I got over 12 months riding and they were still going strong, you really have nothing to lose.

 

[link1896]

Also depends on linkage design.

If you have a linkage that puts SFA rotation thought the shock mountain points, then there are no gains. If you have a linkage that requires lots of rotation at one end of the shock (say 30 degrees or more of rotation), then you notice a huge difference over the Teflon impregnated DU bushings, not so much over fox's 5 piece plastic bushing kit.

I have a GT I drive and needle bearings in the end of the shock with lots of rotation make a massive difference.

A FSR style geometry with SFA shock rotation, don't waist your time or money.