Tuning without a Tuning Guide
BASE Measurements |
Target Speeds by Mode |
BASE: Outer - 17 I Inner - 9 I 1.75" Pre-bend I Forestay 56-1/2"
(Tuned 4/30/2026) |
|
WIND (Kts) / SEA STATE |
Loos (O / I) |
Outside (Full Turns) |
Inside (Full Turns) |
Step |
<6 , flat |
13 / Loose |
-2 (= -1) |
> - 2 (= -1) |
-2 |
6 - 8, flat |
15 / Loose |
-1 (= -1) |
-1 (= -1) |
-1 |
8 - 10, flat [BASE] |
17 / 9 |
Value |
Value |
BASE [1.75" Prebend] |
10 - 12, flat |
21 / 13 |
2 = (+2) |
1/2 (= .5) |
+1 |
12 - 13 |
23 / 16 |
3 (= +1) |
1.5 (= +1) |
+2 |
13 - 14 |
24 / 21 |
5 (= +2) |
2.5 (= +1) |
+3 |
14 - 15 |
26 / 23 |
6.5 (= +1.5) |
3 (= +.5) |
+4 |
15 - 16 |
Value |
+5 |
||
16 - 18 |
+6 |
|||
18 - 20 |
+7 |
|||
+20 |
+8 |
All-Purpose Jib Trim
Heavy-Air Jib Trim
J/70 Polar Diagram
Corrective Measure for Improving Point
In Overpowered Mode, and not pointing
1. Primary Item: Forestay Too Loose
2. Follow-up
3. Order of depowering
4. Jib
1. Primary Item: Forestay Too Loose
- Tighten Shrouds
- Specifically, inner/lower shrouds to tighten the forestay
2. Follow-up
- More effective Backstay with tighter forestay, with better main shape
- Lessen heel at all costs - flat is fast and will gain point through speed
- Heavy Wind (15 deg max, 12-15 goal)
- Moderate Wind (9-12 max, flatter the better)
- Light Wind (6-9 deg max)
- Ultra-light, <6 kts, encourage heel (12 deg)
- Keep air from getting under the stern
- Travel drop in heavy to 1 car above center and sheet Main hard
- Active main to keep boat at consistent heel - not through driving
3. Order of depowering
- Modulate Main Sheet trim in wind conditions - Trim hard to FLAT
- Outhaul, tighten until extremely high. Jib ad Main foot match shpe
- Vang - ease
- Cunningham
- Traveler
4. Jib
- Inhaul less on J2+
- Set leeward as much as inside 2 stripe.
- Preset leeward for Close Haul setting and banjo off deck for added trim