I heard someone said, mechanical base is more efficient for pumping compared to the tendon base. I am wondering if anyone had experience with this and make the change. I have been using tendon so far but thinking that for foiling may be mechanical could be better particularly for pumping.

Tendon for easy on, easy off, even in deep water.
Actual sailing performance? It's all in your head.
I use the chinook mechanical base (chinooksailing.com/collections/mast-bases-pin-style/products/1-bolt-mechanical-mast-base-euro-pin-ex) IMO, there is zero difference in pumping efficiency between that and a tendon base.
The only advantage to me is the ability to easily join a 100cm foil board with a large sail in foil deep water or change the mast base position on the water.
I heard someone said, mechanical base is more efficient for pumping compared to the tendon base. I am wondering if anyone had experience with this and make the change. I have been using tendon so far but thinking that for foiling may be mechanical could be better particularly for pumping.

I bought a couple of the new style mechanicals shown below for foiling, and used them mostly with slalom after my foiling career dissipated.
Then the rumor started that the mechanical was not to be used on a slalom board. I contacted Chinook and they "sort of" confirmed it. It was not very clear. But they where nice enough to send me a standard Euro-pin EX as a "replacement" (the nice one, single piece stainless, not the one depicted above).
Besides this little mystery I see no reason why any one type should be more efficient of faster than the other.

PS There is now an ominous warning on the Chinook Web Page *** Specifically designed for Foiling (Not recommended for Bump and Jump, Slalom or Formula Racing. If used as such warranty is null and void***
I use the chinook mechanical base (chinooksailing.com/collections/mast-bases-pin-style/products/1-bolt-mechanical-mast-base-euro-pin-ex) IMO, there is zero difference in pumping efficiency between that and a tendon base.
The only advantage to me is the ability to easily join a 100cm foil board with a large sail in foil deep water or change the mast base position on the water.
I learned how to bend a tendon joint to get it in a board flat on the water, but it is easier to float board on edge to remove rig. But the part about being able to adjust mast base position on the water with a mechanical joint is good to know, thanks.
It looks like this issue was also discussed many years ago in windsurfing and it was suggested with following features
WHAT WINDSURFING MAST BASE DO I NEED?
ProsEfficiency: The most positive, direct transfer of rig power. Ideal for maximizing sail power in light winds. Convenience: The easiest base to attach and separate rigs. Pop a sail on or off a board from any angle. No need to turn a board on its side. Durable: Chinook rarely sees issues with mechanical bases, though most mechanical base users sail in gentle winds and flat water. ConsStiff: So stiff, jumping isn't recommended. Mechanical bases offer no shock absorption for boards or their riders. Best For Light winds, wide boards, flat water, windsurf schools, and, more recently, windsurf foilers. If easy rig attachment and separation is the priority, this is the base.
bigwinds.com/windsurfing-mast-base-guide-sidebyside-comparisons/
Also in separate forum
"I cant speak for the hydro shock, but the mechanical u-joint transfers energy to the board more efficiently than a tendon or hour-glass joint. They just dont work well in the waves due to their lack of manouverability."
www.iwindsurf.com/forums/viewtopic.php?t=6593&view=next&sid=f887b9bbdf06eebdd0c15f9e654a4dcb
I don't get the chinook mechanical + tendon base. Im
trying to lower the height of my sail mast and that pokes it way up.
In 35 years of Windsurfing, I have broken 2 tendons and the safety leashes and had long swim's home.
I am 100% mechanical UJ. Safety is all that matters.
I've broken a few tendons and always made it home with the leashes. Since mechanical UJ's don't have leashes, I feel like the tendon is somewhat safer as long as you inspect the tendons regularly.
I've broken a few tendons and always made it home with the leashes. Since mechanical UJ's don't have leashes, I feel like the tendon is somewhat safer as long as you inspect the tendons regularly.
I've had a tendon break on the Chinook hybrid base after using it for about a year. The tendon showed no sign of failure before.
In 35 years of Windsurfing, I have broken 2 tendons and the safety leashes and had long swim's home.
So you have to check the safety leashes, too. They can get brittle and break just when you need them.
It looks like this issue was also discussed many years ago in windsurfing and it was suggested with following features
WHAT WINDSURFING MAST BASE DO I NEED?
ProsEfficiency: The most positive, direct transfer of rig power. Ideal for maximizing sail power in light winds. Convenience: The easiest base to attach and separate rigs. Pop a sail on or off a board from any angle. No need to turn a board on its side. Durable: Chinook rarely sees issues with mechanical bases, though most mechanical base users sail in gentle winds and flat water. ConsStiff: So stiff, jumping isn't recommended. Mechanical bases offer no shock absorption for boards or their riders. Best For Light winds, wide boards, flat water, windsurf schools, and, more recently, windsurf foilers. If easy rig attachment and separation is the priority, this is the base.
bigwinds.com/windsurfing-mast-base-guide-sidebyside-comparisons/
Also in separate forum
"I cant speak for the hydro shock, but the mechanical u-joint transfers energy to the board more efficiently than a tendon or hour-glass joint. They just dont work well in the waves due to their lack of manouverability."
www.iwindsurf.com/forums/viewtopic.php?t=6593&view=next&sid=f887b9bbdf06eebdd0c15f9e654a4dcb
Yes, but it is outdated. Chinook now offers the hybrid tendon/mechanical (that also includes a safety line). On paper might be the best option for foiling.
I have all 4 types. Generally use the hybrid for foiling, easy getting the rig disconnected for the shore break.
A straight mechanical is my next preference.
The Streamlined tendon is really durable, and the tether is dyneema so do not see it ever breaking if the tendon does.
The Streamlined tendon is really durable, and the tether is dyneema so do not see it ever breaking if the tendon does.
...the Chinook tethers are Dyneema too ...fyi...
I have been using the chinook hybrid for foiling going on two seasons so far so good it just makes attaching a bit easier, also use regular chinook euro pin tendon for wave sailing.Have had good with chinook over the years as always take time to inspect regularly.
I see that there is some issue about ease of use and safety for the selection of base but I was primarily wondering if pumping would be better with mechanical especially for foiling. It looks like Bigwind site also claims that the mechanical base for foiling would be better. I noted some foilers are using mechanical but I was not sure if that was for the ease of use or pumping efficiency. It looks like it might be both.
I pump as much for windsurfing as I do for foiling, but use rubber jount for ws and mechanical for foil.
Lots of shock windsurfing, smooth foiling.