[rideit]

So, I have a130 and 140 air shafts, are there any spacer tricks available to turn my fork into a 135mm travel unit?
Yes, it’s incredibly nit picky...but I have...reasons.
don’t yuck my yum.

Anyone have any trick tips?

 

[englertracing]

140 + lathe = 135.
Was going to 165 my fox 36, but too lazy.

What year is it?
Transfer rod or transfer notch?

 

[rideit]

Hmmn, I don’t know the answers to these questions. I also don’t have access to a lathe. ‘19 model year fork.

 

[Rhubarb]

Don’t know Fox forks but my service center told me I could cut up to 10mm off my 2012 Lyrik spring shaft to reduce the travel. Would be cutting the threaded end where the foot nut screws into.

 

[englertracing]

Just looked at the drawings
The 34 skipped the transfer rod went straight to self balancing from negative coil springs
The neg coil spring stuff just used a spacer to adjust travel. The 2016 and newer uses the notch self balance system, the only good way to shorten it is cutting the shaft down.

 

[Westy]

Not sure what you are attempting but I can't help but to think that you could achieve the same results with a little tuning. Extra spacer or a bit of extra grease in the positive chamber to limit travel on the 140 setup or more sag with a little bit more grease in the negative chamber.

 

[canadmos]

Will you actually notice 5mm?

 

[StiHacka]

Will you actually notice 5mm?

Something's telling me this has more to do with A-C than with the 5mm of travel.

 

[rideit]

Something's telling me this has more to do with A-C than with the 5mm of travel.

Precisely.
but I have this fork already, and want to make it work.

 

[Westy]

Precisely.
but I have this fork already, and want to make it work.

Needs moar sagz

 

[englertracing]

I would.....
Check the purple portion to see how much you can cut off and still have adequate threads

If you can get 5mm by buzzing the oring counterbore and a few threads then....

Note (the rod should have an oring counter bore at both ends)

Red, Buy a non vented foot nut from a fox 36. Install with an oring (i bet its only like 5$)

Yellow, drill the base stud with a 3/32 or 7/64, (check the diameter of the hole through the center of your vented foot nut for drill size to maintain appropriate wall thickness.)

This will incorporate your spring rod as part of your negative volume like on a 36, and be like a free fox 34 luftkappe.

This will also make the top oring unnecessary.

For a less exciting route you could just shorten the end with the foot nut...
Since it's already vented the oring groove is unused
A skilled crapsmen or monkey could scribe 5mm on that end with a pair of calipers and twirl the rod on a belt or disc sander and get it flat enough to work.... but a lathe is most preferable.....

Orrrrrrrr
No shorten the rod
Get the non vented foot nut.
Carefully drill the base stud.
And expect that the extra negative volume will pull you down a little bit

 

[rideit]

I was hoping for ‘get a 5mm automotive spacer, and shove it somewhere on the air shaft, then drink a vanilla milk’ sort of instructions.
I would certainly fuck up one of the above options.

 

[englertracing]

option 2 is the easiest...
Option 3 Only requires you to drill a hole and change a part....
Option 4, you could get somebody to do option 1,2 or 3 for you

 

[6thElement]

 

[SkaredShtles]

It's too bad you didn't have a Ribbon coil - it's adjustable to any "inbetween" travel easily.

 

[rideit]

It’s too bad I never hooked up with Emily Batty, either.

 

[djjohnr]

You could just use a +5mm crown race on a 130mm fork.

 

[rideit]

If I am going to raise the front end, damn straight I am going to add travel...I’ll figure something out. I don’t need this anytime soon.
to give more background, if Rocky doesn’t come out with a fairly lightweight 120/140 type bike this fall, I am flirting with the notion of converting my sb100 to the new sb115, which ups the front end travel as well. those parts likely won’t be available until the season winds down, so I am a few months out on deciding if this is the way to go.
Englert, would you do the lathe thing or whatever works for a nominal fee?
maybe a wok?

 

[Jm_]

If I am going to raise the front end, damn straight I am going to add travel...

Go back to Oury grips with their gummy rubber. There's your 5mm.

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[jonKranked]

You could just use a +5mm crown race on a 130mm fork.

I was thinking the same thing

 

[rideit]

Someone on MTBR suggested that a luftkappe would reduce travel by a few millimeters, is this true?

 

[Westy]

Someone on MTBR suggested that a luftkappe would reduce travel by a few millimeters, is this true?

Does not reduce travel but it does reduce your dynamic ride height by increasing sag by 5mm or so.

I may actually have 34 LK that was shipped to me incorrectly when I ordered a 36 LK.

 

[englertracing]

Someone on MTBR suggested that a luftkappe would reduce travel by a few millimeters, is this true?

lower dynamic ride height.

 

[HAB]

I can shorten the air shaft for you if you want. I've done a few 36s and 40s.

 

[StiHacka]

Does not reduce travel but it does reduce your dynamic ride height by increasing sag by 5mm or so.

I may actually have 34 LK that was shipped to me incorrectly when I ordered a 36 LK.

It reduces the static height by a few mms as well as the fork sags under the weight of the bike. (confirmed)

 

[HAB]

What's the reason for that on the Luftkappe? Does it move the seal location at topout to tweak the positive and negative chamber equalization point or something?

 

[StiHacka]

What's the reason for that on the Luftkappe? Does it move the seal location at topout to tweak the positive and negative chamber equalization point or something?

It increases the size of the negative air spring considerably.

 

[HAB]

It increases the size of the negative air spring considerably.

I realize, but that in and of itself shouldn't make the bike sag under its own weight if it didn't before.

 

[rideit]

Wouldn’t that also depend on how much positive air pressure (sag) you are running?

 

[Westy]

Wouldn’t that also depend on how much positive air pressure (sag) you are running?

No. As the positive and negative chambers equalize pressure the spring rate at that first little bit of travel is dominated by the volume ratio between the two chambers. As you move deeper into the travel pressure and positive chamber size affect the rate more and more.

 

[Westy]

I realize, but that in and of itself shouldn't make the bike sag under its own weight if it didn't before.

But when you install the LK, a nice fresh rebuild on a broken-in fork and bolting the lowers on while deep in the travel will.