[Josef]

Does anyone have experience removing the bottom out bumpers in their fox 40's? I am interested in the effects of this not the process.

When I was changing my oil out last night I noticed them for the first time and removed them because I had never seen them in there before so I removed them (I recently sent my fork to fox to replace the stanchions and bushings in my lowers). Anyways, the fork does feel much more plush (I know its cliche) after removing them. I know a big portion of this is the seal cleaning and oil change but I am curious if these bumpers have played a roll in some harshness I have felt lately. I am also interested if the decrease in volume that they were taking up in the lowers plays a roll in this. In my internet search on the subject I have only come up with a couple of hits. One from here: http://www.ridemonkey.com/forums/f19/tuning-revalving-fox-40-a-221930/ where someone says that Mojo suggest removing them but doesnt say why. Another was in the avalanche cartridge installation instructions where it says to remove it, and the other is a fox service page saying that they are not replaceable.

I guess my questions after all of this rambling are:

Have you done this?
Whats your experience?
Do I have to worry about grenading my fork at bottom out?

Attached is a photo that I ripped from the avalanche instructions of the part.

 

[bdamschen]

I'd leave them in there. Metal smacking metal at high speed is never good for metal.

 

[Josef]

I was thinking that as well but I am not sure they actually do what their name implies. There was zero scoring on them as I would think there would be with the bottom outs I have had since getting the fork back from Fox. I am also not sure why avalanche would recommend removing them as well.

I am going to pop my spring when I get home tonight and see if the fork actually goes compress lower with them removed.

 

[tacubaya]

You don't want to remove them, trust me.

AVY removes them from the damper side because they use their ABS cone.

 

[Sugar_brad]

You realize that the improvement in performance in your fork is attributed to servicing it right? It has absolutely nothing to do with the bottom out bumpers. Please do not remove your bottom out bumpers unless you want to ruin your fork. Whenever an aftermarket company recommends removing them they have a cone or bumper built into their cartridge.

 

[Josef]

Fine Ill put them back... You guys are now fun. I do realize that the service played a role in it but there werent that many hours on it since the last service. I saw the two bumpers in there that were not in there before I sent the fork to Fox so thats why I asked the question. I am guessing the reduced volume in there is what is making up the difference.

 

[blindboxx2334]

were your stanchions chewed up? i dont see how they could have been if 'there werent that many hours since the last service'.

 

[Josef]

The stanchions were replaced because of a previous bushing issue. The new stanchions are fine. Since I got the fork back from fox this is my second oil swap. I didnt notice the bumpers down in the lowers the first time I changed the oil. Its no big deal. I will probably just throw them back in tonight. I was just curious if anyone has any experience with them removed but it doesnt sound like anyone does. I am just going to mess with oil levels until I get rid of the harshness I am experiencing.

 

[Udi]

You can placebo yourself into thinking that all you like, but the reality is that the internal volume of the 40 is huge, and the oil volume (let alone the miniscule volume of the bumpers) makes very little difference to the spring curve of the fork. The volume the bumpers take up is mathematically insignificant compared to the total volume of the fork.

Save your oil level tuning for your Marzocchi, unless you want to change the factory 50ml/leg to over four times that amount and risk blowing your seals out.

Any difference you felt post service is due to the service / oil change itself. Any harshness you are experiencing is likely due to stanchion and bushing tolerances - both of these should be changed at once if there is a problem with either (and stanchion wear has occurred). There is break in time involved after a bushing change, and if done incorrectly, stiction can persist forever.

Were the bushings changed with the stanchions? Who did the work?

 

[Josef]

Yes the bushings and stanchions were changed semi recently (2 months ago). I sent it into fox for the work. I put the bumpers back in last night. There was zero change. I guess it was all for not.

 

[canadmos]

You should have just tried it now. It always works.