Hi All,

Could not reply to the old topic from 2020 called "Neil Pryde MXT base" created by "flatchat", therefore creating a new one...

I too got interested in the problem with MXT bases, where the central screw gets too loose over time, to a point that the mast base falls apart - happened to me once on the water. Luckily it was a small lake so I made it to the shore with all the gear.

I've had 4 MXT bases so far and all of them developed this play around the red washer within several months of use.
It's not a big issue to get a new base every half a year or so but the whole situation seems like a Neil Pryde MXT tax - you have to throw away a base that looks solid, except that play in the middle, and buy a new one.

Long story short - I managed to get to the bolt and tighten the nut to remove the play - below are the steps...

1) Unscrew 2 small screws at the top an remove the cap, then press the button and pull / remove the spring that holds the button

You can see the nut that needs to be tightened, which is impossible without getting to the bolt on the other side


2) Take 3mm allen key and hold the the middle bolt (or nut) on one side, then unscrew them using another 3mm hex socket on the other
side - picture below. Then you can remove the top part of the base to find the 5mm hex socket of the bolt holding the nut from the picture above


Tighten the nut by holding the bolt on the opposite side

3) Put it back together in the reverse order

Hope that helps

Yes but

what is making the looseness? ie what is wearing thinner
It may not matter in this case but on some it's a countersunk bolt head wearing the aluminium cup so tightening it is fine but it's wearing the vee in the countersink so much it becomes a lot weaker
second tightening is getting dangerous ...

Select to expand quote

eperf said..
Hi All,

Could not reply to the old topic from 2020 called "Neil Pryde MXT base" created by "flatchat", therefore creating a new one...

I too got interested in the problem with MXT bases, where the central screw gets too loose over time, to a point that the mast base falls apart - happened to me once on the water. Luckily it was a small lake so I made it to the shore with all the gear.

I've had 4 MXT bases so far and all of them developed this play around the red washer within several months of use.
It's not a big issue to get a new base every half a year or so but the whole situation seems like a Neil Pryde MXT tax - you have to throw away a base that looks solid, except that play in the middle, and buy a new one.

Long story short - I managed to get to the bolt and tighten the nut to remove the play - below are the steps...

1) Unscrew 2 small screws at the top an remove the cap, then press the button and pull / remove the spring that holds the button

You can see the nut that needs to be tightened, which is impossible without getting to the bolt on the other side


2) Take 3mm allen key and hold the the middle bolt (or nut) on one side, then unscrew them using another 3mm hex socket on the other
side - picture below. Then you can remove the top part of the base to find the 5mm hex socket of the bolt holding the nut from the picture above


Tighten the nut by holding the bolt on the opposite side

3) Put it back together in the reverse order

Hope that helps

The nut in question generally tightens down until the thread ends on bolt, also be sure to put plenty of good quality thread lock on that nut when doing the reassembly.
I have experienced many of these bases increasing in joint play, but never has the plastic failed separating my rig from the board, I believe this will only happen if nut comes loose due to lack of thread lock.
Cheers TK

Select to expand quote

Mark _australia said..
Yes but

what is making the looseness? ie what is wearing thinner
It may not matter in this case but on some it's a countersunk bolt head wearing the aluminium cup so tightening it is fine but it's wearing the vee in the countersink so much it becomes a lot weaker
second tightening is getting dangerous ...

Nothing is getting thinner as far as I can see - just the nut get's unscrewed over time (because of insufficient thread lock?)
This is how my base disintegrated on the lake - the nut just eventually unscrewed.

Select to expand quote

tonyk said..

The nut in question generally tightens down until the thread ends on bolt, also be sure to put plenty of good quality thread lock on that nut when doing the reassembly.
I have experienced many of these bases increasing in joint play, but never has the plastic failed separating my rig from the board, I believe this will only happen if nut comes loose due to lack of thread lock.
Cheers TK

I'm thinking this too - for now I just re-tightened the nut
But I will replace it shortly with a new nut with unworn thread lock or, even better,
couple of thinner nuts that would lock each other out so they just stay in place forever guaranteed

If it's lack of thread locker that's pretty crap
obviously a cheap Nyloc so it's not holding, and no Loctite applied in the factory

OTOH I have had a few chinook bases where I couldn't do anything as the locking compound was too good .. And enough heat to undo it would wreck the nearby plastic
So careful what I wish for huh

Select to expand quote

eperf said..

tonyk said..

The nut in question generally tightens down until the thread ends on bolt, also be sure to put plenty of good quality thread lock on that nut when doing the reassembly.
I have experienced many of these bases increasing in joint play, but never has the plastic failed separating my rig from the board, I believe this will only happen if nut comes loose due to lack of thread lock.
Cheers TK

I'm thinking this too - for now I just re-tightened the nut
But I will replace it shortly with a new nut with unworn thread lock or, even better,
couple of thinner nuts that would lock each other out so they just stay in place forever guaranteed

Put some of this on the nut and thread, then you should be fine