[slimshady]

Hey Monkeys, could anyone with a RS Air Adapter Tool take some measurements and post them over here? We are about to go on a bike trip to start 2018 the right way and a friend's Monarch needs a rebuild. We have already sourced the necessary o-rings and seals but we can't find the adapter anywhere down here, and if we order it from CRC or Jenson it wouldn't make it on time.

We have access to a lathe, so we thought of making one ourselves.


This is the one I'm talking about:

I'd need the thread pitch/length for both ends and also the length/diameter of unthreaded "shoulder" after the o-ring at the smaller end.

 

[KenW449]

Have you tried Amazon? They have it in the states for 2 day shipping.

 

[slimshady]

Have you tried Amazon? They have it in the states for 2 day shipping.

Yup, but I'm in Argentina and just clearing customs would take over two weeks.

 

[KenW449]

Gotcha. Didnt know if there was an Argentina amazon or not.

 

[StiHacka]

I'll try to get you those dimensions later today. The bottom part with the threads has a Schrader valve dimensions, that's where you attach the pump. IMHO the only piece you need to be concerned about is the small thread + oring at the top, and a long enough shaft.

 

[slimshady]

I'll try to get you those dimensions later today. The bottom part with the threads has a Schrader valve dimensions, that's where you attach the pump. IMHO the only piece you need to be concerned about is the small thread + oring at the top, and a long enough shaft.

Thanks so much!

 

[StiHacka]

Thanks so much!

So, take this with a gain of salt, I am not a mechanical engineer.
The small thread: pitch 0.75mm (my best guess), diameter 5.25mm, length 3.0mm.
The o-ring groove is 1.5mm long, 4.25mm diameter
The neck under o-ring is 1.5mm long, 5.3mm diameter
The shaft is 9.0mm long, 6.0mm diameter
The Schrader valve thread is 5/16"x32

 

[slimshady]

So, take this with a gain of salt, I am not a mechanical engineer.
The small thread: pitch 0.75mm (my best guess), diameter 6.25mm, length 3.0mm.
The o-ring groove is 1.5mm long, 4.25mm diameter
The neck under o-ring is 1.5mm long, 5.3mm diameter
The shaft is 9.0mm long, 6.0mm diameter
The Schrader valve thread is 5/16"x32

Excellent, thanks again!!! I'll get my hands dirty on the lathe later.

You've saved us A LOT of trouble.

EDIT: Could somebody please rep @StiHacka for me?

 

[StiHacka]

Excellent, thanks again!!! I'll get my hands dirty on the lathe later.

You've saved us A LOT of trouble.

EDIT: Could somebody please rep @StiHacka for me?

I've just found a typo and fixed it - the diameter of the small thread is 5.25mm, not 6.25!

 

[slimshady]

I've just found a typo and fixed it - the diameter of the small thread is 5.25mm, not 6.25!

Got it!

 

[StiHacka]

Got it!

And the o-ring OD seems to be ~6.2mm,and seems to be ~1mm thick.

 

[StiHacka]

One more note - there is a bore at the tip - 2.5mm diameter, 1.5mm deep, with a chamfer. IIRC it seats against a valve.

 

[slimshady]

One more note - there is a bore at the tip - 2.5mm diameter, 1.5mm deep, with a chamfer. IIRC it seats against a valve.

Thanks, I got that one from a thread at MTBR. OK, time to get that lathe running.

Again, thank you. We wouldn't have been able to put the trip together without that darn tool. In fact, I think I'm going to make a couple just to make sure we have at least one always available.

 

[johnbryanpeters]

Excellent, thanks again!!! I'll get my hands dirty on the lathe later.

You've saved us A LOT of trouble.

EDIT: Could somebody please rep @StiHacka for me?

Covered...

 

[6thElement]

Looks similar to an old Marzocchi adapter, not sure if I still have one to check against the posted measurements in case your group has one laying around.

 

[slimshady]

Looks similar to an old Marzocchi adapter, not sure if I still have one to check against the posted measurements in case your group has one laying around.

The threads on the small end are different, there's a post on emptybeer detailing the differences between the Marz, SID and Monarch ones. The SID one has the same threads as in the Monarch, but the SID one doesn't have the "shoulder" after the O-ring.

 

[jonKranked]

that looks like a standard adapter for shocks & forks from like, the late 90's. can't believe RS is still using those things, they were super prone to stripping threads due to the small diameter.

 

[Adventurous]

that looks like a standard adapter for shocks & forks from like, the late 90's. can't believe RS is still using those things, they were super prone to stripping threads due to the small diameter.

Probably just their rigid belief and adherence to standards that prevents them from changing.

 

[slimshady]

Good news fellas! The adapter came out pretty decently. At least it fits the Monarch Plus the way it's supposed to, so we will be doing a full rebuild tomorrow night. Just in time for our first 2018 trip to the mountains.

@StiHacka I owe you a big one!

Probably just their rigid belief and adherence to standards that prevents them from changing.

"If it ain't broke, you better create a new standard capable of being broken more easily".

-- The SRAM creed