I've just bought a Goya Bolt 125 (2017 I think). The board has a normal tuttle box, it is not in my possession yet. However it comes with a fin and no bolts. As I can not measure, is there anybody that has (had) this board and can tell me the length of the bolts? I would really like to take it out next weekend and that means that I will have to order the bolts bofore the board gets here.

Any info is well appreciated!

Order them long (70+mm) then cut them to size with a hacksaw when you get the board. Fin manufacturers like to put the barrel nuts in at different heights on the tuttle head too, so no real telling what the correct size is going to be.

i say buy them that long as almost all the boards i've seen that size actually have a deep(er) tuttle box than the standard one. If it does have a standard size tuttle box, you'll be cutting quite a lot off the bolt. But better safe than sorry.

I know that Starboard has a section on their website telling you what length bolt for which model board. Maybe Goya has something similar?

Tuttle fin nuts can be all over the place , if they are not board standard. It's better to get long bolts , measure and chop.

Too bad Sandman1221 isn't around - he has that board or possibly the 2019 version. He and I find ourselves on the same water from time to time. His has a Deep Tuttle and takes a medium length bolt - I lent him a couple when he was trying another friend's foil and I think they were 50mm. I agree about buying overlength and trimming, though. I always keep a few long bolts and a battery-powered Dremel in my tool kit.

Thanks for the replies! I will get some 70mm bolts and cut them to size as soon as the board arrives.

Now some wind please!

My Tuttle bolts are 40, Deep Tuttle 70.

Chuchufleta,

I see you are in the Netherlands, so I hope you will understand the technical terms I will use in the following.

Your fin PROBABLY uses a metric bolt 6mm diameter x 1.0mm thread pitch so a 70mm long bolt can be easily cut to length. The bolts need to be made of stainless steel material. Most bolts have a Phillips 4-groove head in them.

When you buy the bolts, also get two stainless steel nuts (from your bolt supplier?) having the same thread dimensions. After measuring the bolt length needed for your board (see next paragraph), fit one nut to the bolt, cut the bolt to length, then put a chamfer on the bolt end, using a file or grinding disc. Remove the nut but rotate it several times over the chamfer. This cuts a small thread into the chamfer and allows a nut to properly align with the threads. Try the bolt in your fin to ensure the bolt will start in the fin nut. If everything is OK, repeat for the second bolt.

You will also need a soft washer and a hard stainless steel washer to go under the bolt head, so you need to take these extra thicknesses into account when you measure the bolt length required. The soft washer should be about 3mm thick and have a 6mm hole in its centre. If you can't get the exact soft washer, I've used multiple fibre washers (available from a hardware store) to make up the thickness required. The stainless steel washer has a standard thickness of 1.5mm and has a 6mm hole in the centre and might also be available from a hardware store or your bolt supplier.

On the board, the bolt is inserted through the hard washer, then the soft washer. The soft washer prevents air passing down to the fin, which could cause cavitation. The hard washer distributes the bolt load when tightened.

In the fin, remove the barrel nut and make sure there is a 6mm hole under the centre of the barrel nut. This prevents the fin bolt "bottoming out" in the fin, preventing full tightening of the fin bolt.

Hope this helps.

^^^ really really good explanation

Only thing i add is after cutting the bolt and filing a chamfer, remove the nut by pulling as hard as you can while turning. The harder the better. In a vice is good. This will often lift the very end of the thread and then you can file that bit jussstttt a littttle which makes a nice thread start/entry end bit

Thanks guys!

^^^ really really good explanation.

Gee, thanks Mark

Select to expand quote

Mark _australia said..
^^^ really really good explanation

Only thing i add is after cutting the bolt and filing a chamfer, remove the nut by pulling as hard as you can while turning. The harder the better. In a vice is good. This will often lift the very end of the thread and then you can file that bit jussstttt a littttle which makes a nice thread start/entry end bit

That's and interesting approach. I have only ever chamfered the end after cutting and it almost always doesn't engage nicely. Will try.

When filing or grinding a chamfer on the end of a screw , go towards the end , not sideways or to the head. You won't even need the nut.

I'm getting worried i'm going to have a screwtastrophe one of these days and end up at the beach without the right screws, or a dilemma finding them when I'm frothing.
Getting more fins with all different length bolts, for different boards, tuttle, deep tuttle, and to have spares - is alot.

For emergency on odd fins ,its a good idea to have a couple longer screws and a bunch of washers to get the right length.

A while back I got a set of screws and washers for every fin I had, long ones for the falcon and shorter ones for the ultrasonic, those fin screws say with the fin 2screwed in the fin and the other 2 tucked in the fin cover. If that goes wrong which it hasn't yet I have a pile of washers and some spare long screws. now the real problem is every fin fits the different boards differently so I also have a pile of plastic shims (cut up plastic bottle)

when I got back into windsurfing a few years back I said I was going to keep it simple, fox 120, 2 fins and overdrive 8.6, which I reckon would cover all the conditions I would be sailing in, now a few years later I have a shed full,of stuff. Not sure I get out anymore as I always turn up at the beach with the wrong combo

Yes I was going to keep it simple too.
But quickly many many fins have turned up.