View Full Version : kombat 97 fin sizes
20th April 2007, 04:50 AM
Anybody any experience with fin sizes for k97 ? On sail sizes over 5.8 board feels underfinned (poor upwind performance) with standard 280. Fin feels fine with 5.4 and below.
Was thinking of 30 or even 32 to match with 6.2. (Saber)???
PS love board cross wind/waves and playing but generally poor upwind?but not really experimented with fins/ Any suggestions ???
20th April 2007, 06:35 AM
When powered up on your 5.8 with the 280 fin, is the board tending to spin out - if not I would not go bigger. Have you tried the fin in different positions in the box.
Are you in waves or freeriding straps inboard or out?
With the 6.2 Saber I would suggest outboard straps move the fin back.
It may just be technique in lighter winds, have a look at this it may help
I prefer to sail overpowered so I've not run into a simalar problem with my K95.
You have plenty of variables with setup on your board/rig before needing to try another fin.
21st April 2007, 12:42 AM
Regarding using a bigger fin on the Kombat 97, I noted that Starboard shows a fin range from 22-33cm. So, in contrast to DavMen's recommendation above against going with a bigger fin, I really think you have something to gain by experimenting with a fin in the 30-32cm range.
At minimum, it's of value to think about is fin planform, as one can often leverage benefits in a stout low aspect fin that offers a bit more lift. For example, one can see quite a bit of difference when comparing onshore wave fins with down the line wave fins. I have a 24cm weed shedding wave fin that I sometimes match up with my older slalom board when sailing in waves with heavy kelp and eel grass, and it's surprising how well it works. It loosens up the board making it bit more surfy without affecting windward performance. In comparison with my classic slalom fin (a 34cm Tectonics Goldwing), the 24 wave fin is a tad bit slower, but it offers very similar power and direction upwind. In reality, the two fins are about the same overall area. Fin size, as expressed in length only, is only part of the story.
Another thing to keep in mind is one's weight. The demands that a heavier sailor puts on a fin is greater than a lightweight sailor. Folks realize this difference more readily with sail sizing, but I often think they don't see a similar relationship with respect to fins. Given the fact that the Kombat uses the US finbox, there are fin size limits to keep in mind, but I seriously doubt that you would have a problem with the slightly bigger fin sizing that you're considering. In reality, I would expect that you will be very pleased with slightly larger fin on your upper sail range for the board.
22nd April 2007, 10:12 AM
Perhaps I should have worded my reply better.
What I meant was, to play more with his set up before just rushing out and buying a new fin$$. The K's are very versitile boards and have plenty of tunable aspects. Seeing the user was wanting a try a freeride sail heading towards the upper limits of the board design and has not mentioned spin out, I was just suggesting he first try with straps and fin/mast track placement and drive the board harder.
Once these are exhausted then sure try a bigger fin. But if he has a good cash flow then just go ahead and by a fin - just hope he is sure that he knows for what he is buying it for - waves or freeride.
The advice you have given Floyd is sound and will be obviously helpful. My advice was based on K95 use (i'm 85kg).
22nd April 2007, 04:55 PM
Thanks Steve but knew that anyway !
Tried board with a 32 (Drake; I think from a K 107)
Transformed board for use with 6.2.
IMO you can mess around all day but will never overcome inherent probs. On any board a 6.2 will require around a 32cm fin (or one corresponding to this ones area)
A specific sail area needs a specific fin to go with it.
Was worried how large I could go on US type box and if anyone with a K97 had found similar probs with standard fin !:p
22nd April 2007, 11:12 PM
I'm 85 kg & sail 6.5 retro with K96 on a 30cm Gsport freeride fin. At least average upwind abiility. This is typically 15-20 knots free-ride considitions. I've sailed this rig in 20-25 knots & upwind of course gets even better.
Floyd, you're 10kg heavier so I'd expect this would can things abit. I agree the 32 cm size would be the natural fit for 6.2. Like you, I was concerned with fin box stress so got the 30cm instead of 32cm.
Consider also the shape of the fin, not just size. Perhaps if upwaind is important, you may want to look at a more pointer style fin.
- this is where I got my fin from
- good articles on upwind technique
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