Upright fin drive

does a more up right fin have less drive compared to a more raked fin?

I know a more up right fin is more pivoty by was wondering about drive.

An example of upright fins with no rake, the fins made by Cheyne Horan:

www.cheynehoran.com.au/fins/



(I used the starfin as a single fin, but alas never tried my EZ3 thruster set, as I had discovered the Quobba and had no motivation anymore to test non-Quobba fins. Plus my EZ3 set was in an awful soft plastic)

Compared to a raked fin:
- they will be more efficient: the raked tip has a long surface, which is hard to foil properly, hence lots of friction and more fin is in a turbulent wake.
- they will engage in the turn more suddenly and frankly
- at the end of the turn, they can feel twitchy, as they lack the "damping" of the raked part that kind of prevent a sudden stall, transitions are more progressive. This was a drawback of the famous "spitfire" fighter places in WWII by the way. This is why they can feel lacking drive: this "twitchyness" can make you oversteer or stall at the end of the turn, killing your speed.
- when you push on them during the turn, their center of resistance is closer to the board (less torque on the ankle) and stays forward. A lot of people like to feel they can leverage on the raked part

My opinion is that they are quite unique - and tricky - to ride as single or twin fins, but the "twichyness" is countered when used as thrusters or quads. The rear fins act as "stabilisers", replacing the role of the rake. This is why you see some quad sets having no rake on the rear fins, what is called a "controller" setup. The rake on the front fin gives you the traditional positive feel underfoot to push on, while the rear fins let the tail loose to make the board more lively.
So, basically, single of twin upright fins not so much lack drive than can feel unpredictable in hairy situations.

I even cut out the raked part of my rear Quobba fins to end up with the best quad setup I ever had: my tail is then so much looser that I can easily put the board on the rail with no latency:

It's my opinion that fins with drive work in conjunction with the rail of the board to allow you to drive the board through a turn without and drift or slip..

Many more upright fins tend to steer the board through a turn and sometimes work against what the board shape or rails wants to do regardless of how much base area there is on the fin..

It's tricky stuff..

where can you get Quobba fins, I'm curious.

After 3 tiny waves sessions, with the last one being hip high max but hollow and punchy (12s period), I definitely like this setup.
Noticeably less drag at low speeds, and a more immediate response. Faster and more playful.
A keeper for my small wave board.

No feeling of lost hold. I still have more hold than with normal M (orange) Quobbas.
The only drawback I saw is when the wind grew stronger, creating some chop, the board became a bit twitchy and less controllable in turns. It was to be expected since I basically went the opposite route of S-Wing fins(*) that act as shock absorbers in chop.


(*)

drive comes from area. upright ( rake) has nothing to do with drive (except how it is applied but that is another question) and is about hook and pivot .

I am using an upright fin setup now on my 2019 Gong Alley (the 2019 have faster rocker compared to the 2020+, I use this board when I need speed): This setup give me more speed, more nimbleness, less latency in turns.
The drawback is that it may spinout more easily if you push hard on them at slow speed with the board somewhat flat compared with a traditional template. This means I must be careful to use the rail to turn tightly to (try to) get vertical on bottom turns, but it helps releasing the fins in top turns.

Well the Quobba template is based on the AM (Al Merrick) one, which is considered more "drivey" than "pivoty".
In FCS nomenclature, the "carve" familly, in Future the "rake" one.

So it is logical that working on the template allows us to get more pivot, while keeping intact all the magic of the Quobba that lies in their base.


For vertical surfing, I tend to only reduce the central fin depth, to keep a positive grip on the sides to push hard on, while reducing rail-to-rail latency in the tail:

Obviously with trying my Quobbas for the first time I found that I had to change my slower style to a quicker style because of the speed. I found myself getting pushed out further from the pocket to the less power of the wave. It caused me to do my cutback too late & the glide slowed considerably where I lost or nearly lost the wave!
Also going to far forward of the wave where I would slow down only for the whitewash to hit me from behind harder than it would with my original fins.
But I need the speed to outrun the closeouts in front of me on those certain days when it's critical!
I remember a mate of mine saying he wished he could find a faster board to make it through. I think the Quobbas would have been the answer. His board was a good design but just needed that bit of extra speed.
I will tell him the next time we meet.
Unfortunately he has told me his surfing days are done due to age related wear & tear.
I love my Quobbas so far. But still need to test them further between foiling & Winging.

thanks!

I think I'm going to order them. Going to order with the smaller center fin.

What is the diff in feel on the carbon glass (black) ones and the glass (yellow)?

Thanks

I'm addicted to pumping and going fast, but starting to limit my surfing I think. I'm looking for sections to develop down the line, cause beach breaks I surf often have closeout sections, not nice continuous peel. On the waves that do offer a nice pocket, I'm sometimes racing out the gates in search of speed and greener pastures down the line. Then when I go for the top I try to do it out of my pumping rather than turning to the beach and dropping farther down wave for a full bottom turn. Hard to break this habit, I'm greedy with my speed.

Have new Quobbas FCS center fin w/ longboard adapter on the way so I can try on my Blurr V2 again (after cheap futures adapter didn't work out). Excited to tap into even more speed, but also wanna do more top turns and fewer cuttbacks (as much as I love them). Any of you guys run into this issue and have advice for breaking habits?