Vestigial Air-port?

[eXo_oUtSiDeR]

lol c'mon give me a break it had just stopped raining outside when i took that picture lol

[nippinout]

The threaded hole is used to assemble the grip material onto the VFG.

[eXo_oUtSiDeR]

hmm interesting

[p8ntbal4me]

What is this for?






It's 1/8" NPT threaded for air fittings... but it isn't an air-thru grip...

So...

I think I have the answer to the question.

Classic R/T Vertical grips have a 1/8th threaded hole in the bottom and are gas-thru to a 1/8th hole on the left side (or depending on how your R/T was setup when you got it)

From there, there is a "hard line" than runs to the back of the rail and into one of the ports which was also a 1/8th port. The 2 smaller holes in the back were machined to connect all the ports on either side with eachother for "future added use" <-- Tom said this in a thread on here when refering to a discussion about the E-Mag battery voltage and its expanded use for the future) Then the air pipes into the banjo bolt and up into the valve.

So what you have there is an R/T Pro Fore-grip. Because the R/T Pro itself uses the newer "X-Valve" that no longer uses the banjo bolt, there is no need to have a second 1/8th port on the top of the fore grip on the R/T Pro.

I say all this because when I purchased the SAME grip from MANN last year as you have shown,... I was wanting to use it for the same purpose. But once I got it here,... I saw that I needed to drill it out to make it work for a gas thru. The only reason I can see that they DIDNT go wtih a gas thru design was cost. They elimnated the cost forthe machining of a second port,... that has to same them some money if they pump out over 100 pieces in a run.

The other thing I noticed with yout grip.... the hole thats on the bottom is freshly tapped. Mine is annoed that way. So either mine came with it like that from AGD for some reason, or the grip was tapped and re-annoed and assembled by the previous owner for some project lost.

Either way you can make that grip a gas through. Send it to Luke and he can take care of it.

~ P8nt

PS: I dont agree with you on the Classic R/T grip over the Bike Grips,... the older version IS better!

[Hilltop Customs]

p8nt....mine was tapped after anno too, so maybe yours was a re-anno. You would think AGD would have bored the gas-through hole, drilled, and tapped all in the same setup as the exterior features were being machined on a lathe. It makes sense to get rid of the gas through option, since it cuts one setup out of the machining process, but its odd they would drill and tap the bottom hole without also drilling the vertical air passage at the same time.

Maybe the bottom hole was used to hold the parts while dunked in the factory anno bath? I guess the resulting anno wouldnt look like those pics though

Old finger groove RT grip > bicycle grip :)

[Watcher]

The 2 smaller holes in the back were machined to connect all the ports on either side with eachother for "future added use" <-- Tom


The only reason I can see that they DIDNT go wtih a gas thru design was cost. They elimnated the cost forthe machining of a second port,... that has to same them some money if they pump out over 100 pieces in a run.

What Tom meant by that IIRC, is that the other 5 ports adjacent the hardline's could be used for gas expansions and accessories they made later. The idea of a pneumatic feeder was toyed around with, but ultimately the warp-feed was made instead.
I'm guessing it would have been like the Cyclone...

I don't think he was refferring to the 2 holes being used for the expansions, just as linking the channels.

So I was right in my earlier post that they drilled those holes to connect the air-ports but then had to cap them with screws.


If it was cheaper to not make it gas through it would be even cheaper to not machine and tap the bottom hole.


So far the most promising answer has been from nippinout and Hilltop.

He said it was used to assemble the grip material. I don't see how though.

The Anno idea makes sense also, but I don't see how the anno solution woun't have gotten into the threads even a little bit. I think it would be a bit sloppy.
PLus why didn't they just drop the whole part in the bath?

[Dawg047]

I believe it was to assemble the grip material would be the best answer. Think of this. If there was a table or jig with a 1/8 NPT nub sticking out of it, the grip could be screwed into it allowing a very sturdy base for the grip material to be slipped over the grip. I mean, that stuff is on there tight and could you imagine trying to put it on while holding the grip. It would be quite difficult. Just a hypothesis.