one bolt Chinook mast base

RichardMueller · Joined: 26 Jan 2007 Posts: 85 Location: Phoenix, AZ

Is there a one bolt Chinook mast plate ?

I no longer want to use a screw in mast plate with a tendon on my SUP. Am now using a 2 bolt Chinook mast plate. Only using one of the bolts.

dllee · Joined: 03 Jul 2009 Posts: 5329 Location: East Bay

Twist on bases are one bolt, all I"ve used since 1986, surf, speed trials, slalom racing, and freeride. I like the added adjustment room, so I can go old school slalom or modern wave style on the same board.
Once total had a problem, the slug broke. At least 2,000 days of windsurfing.

cgoudie1 · Posted: Tue Jun 21, 2016 5:40 pm Post subject: Re: one bolt Chinook mast base

Yup they do:

http://www.windance.com/Chinook-1-Bolt-Mast-Base-US-WSBE3009MC/

-Craig

swchandler · Joined: 08 Nov 1993 Posts: 10588

Are you screwing into a mast track or a bonded insert?

If it's the latter using the 2 bolt base, I would question having an offset universal attachment point and dealing with the 360 degree leveraged load that could occur. With one point of attachment, what's going to prevent the 2 bolt base from rotating and lifting?

If you really have your heart set on using the 2 bolt base and the easy of use of a pin type connection design, I would highly recommend adding a second insert to screw into. You need that solid connection, and it will better disperse the mechanical load. If you wanted to, you could incorporate some ability to adjust your mast base position by adding two new inserts, one fore and one aft of the existing insert.

U2U2U2 · Posted: Tue Jun 21, 2016 7:19 pm Post subject:

Richard

Chinook and Streamlined both make ONE bolt mast bases
.
I think your board must just have a fitting for a screw,
RATHER THAN A MAST TRACK.

http://chinooksailing.com/index.php/windsurf/bases/us-base-cup.html

MalibuGuru · Joined: 11 Nov 1993 Posts: 9300

You can drill a hole in the middle of the 2 bolt system and use one of the bolts there, and pocket the other bolt. Make sure that the hole isn't big, and USE THE WASHER.

swchandler · Joined: 08 Nov 1993 Posts: 10588

If I've got you right, you're talking about drilling a new hole in the cavity of the pin attachment system installing the universal. A single point of attachment along centerline, like a single bolt design, is always good.

However, the question must be whether there is sufficient material in the design to take the stress at that location. To get some idea, you might want to compare the reenforcement layout in the 2 bolt base, contrasting the normal attachment points with the central point. Larger washers are a way to reenforce a weaker area, but the devil is in the engineering details.

You have to wonder why folks like Chinook or Streamlined haven't covered this area in promoting their products. Lots of folks like the idea of a single pin when it comes to your universal attachment to the board. I have to say that I really like the Euro-pin connection between my mast extension and universal.

MalibuGuru · Joined: 11 Nov 1993 Posts: 9300

You are correct Chandler. I received one with a hole in the center from Chinook. I have no idea why it's there. Brain fart on my part, I don't think it'll work like I thought. I'm going to ask Chinook.

RichardMueller · Joined: 26 Jan 2007 Posts: 85 Location: Phoenix, AZ

Thanks for response !

U2U2U2, the 1 Bolt mechanical mast base (without the us cup) is exactly what I want. I already have a us cup I can plug into the base. It seems this product must be bought with the us cup.

MalibuGura, great idea to drill hole in middle of base and add washers to strengthen. I'm not SUP/sailing in big wind so it could be the simple solution.

U2U2U2 · Posted: Wed Jun 22, 2016 1:11 pm Post subject: