Pitch Meter

BioRow PitchMeter was designed for accurate adjustment of the pin angles relative to the vertical axis in frontal (fore-aft pitch) and transverse (lateral pitch) planes. These settings define the blade pitch during the drive.

BioRow PitchMeter consists of a base vertical beam 1 with two floating horizontal sliders 2 and 3, which can be firmly fixed on the beam with thumbscrews. Two bubble levels 4 and 5 are mounted on the top slider and can be used for levelling a boat and for rough setting of the pitch in two dimensions (half bubble is about 1^o pitch). For accurate pitch adjustment, an electronic meter 6 is provided with magnetic mounting 6 at its bottom. The sliders 2 and 3 have conical grub screws for mounting the pitch meter on the pin.

Working with BioRow PitchMeter

1. Level the boat accurately in fore-aft and lateral axes, and fix it from movements, which is very important for proper pitching of the pin and blade.
2. Fix firmly the meter 6 on the base 1 and re-zero it: set the pitch meter horizontally (the bubble level could be used for this), turn the meter ON (long push on “On/Off-Ref” button), then re-zero with short push on the same button.
3. Mount the PitchMeter on the pin: fix the bottom slider and insert its conical screw into centring hole of the bottom nut, move the top slider down to insert the top screw into the hole, then fix it with the thumb-nut. Make sure that the pitch meter can rotate of the pin freely without a backlash.
4. Measure the pin pitch in fore-aft and lateral axes. Recommended angles in sculling: 0^о fore-aft, 1.5-2^о lateral pitch; in sweep boats, usually it is zero in both directions (straight vertical pin). If the angles are different from the target, a pitch adjustment is needed.
5. Slightly release the fixing bolt 8 and turn C-bracket to set 0^o lateral pitch. Rotate the PitchMeter in the frontal plane and measure fore-aft pitch. If it is different from your target, release fully the bolt 7 and slide C-bracket up or down till required fore-aft pitch, trying to keep the same lateral pitch. Half-tighten the bolt 7, check the pin pitches in two directions again and if they are differ from targets, repeat the adjustment cycle again.

1. You can also use BioRow PitchMeter for measurements of the pitch at the blade. Move and fix levers 2 and 3 to mount the meter firmly on the blade edges using hooks 8 at its ends. Measure and adjust the blade pitch at desired points, usually at the catch, middle and the end of the drive.

A bit of theory

Effective bladework depends on the blade pitch – the angle between the vertical and the blade (measured at a certain cross-section) during the drive, which depends on three components:

1. The blade pitch relative to the load plate of the sleeve is usually set by manufacturers (standard 0^o) and can hardly be changed by the user.
2. The gate pitch is the angle between its load plate and the pin, which can be adjusted using plastic inserts supplied with the oarlock and remains constant during the drive. Usually set at 4^o.
3. The pitch of the pin is the most complicated component, it can be measured in frontal (fore-aft pitch) and transverse (lateral pitch) planes. The pin pitch affects the gate and blade pitches during the drive, varying them. The following rules apply:

A lateral pin pitch creates unidirectional changes to the blade pitch during the drive, So, the lateral pitch can help to maintain optimal blade depth at variations in the handle force vector direction, caused by changes in the rower’s body geometry during the drive (RBN 2010/09).

E.g., at a standard gate pitch of 4^o and lateral pin pitch of 2^o out, the blade pitch from catch to finish will be 5.7^o-4.0^o-3.0^o. After the catch, more blade pitch would help to prevent extensive blade submersion, when the force vector has an upwards component from the handle, higher towards the shoulders. Before the finish, less blade pitch would prevent the blade “washing out”, when the force vector is nearly horizontal, towards the elbow located at the same or even lower in height relative to the handle.

The fore-aft pitch of the pin results in either a convex or concave curve of the blade pitch during the drive. Say, at an aft pin pitch of 2^o and gate pitch of 4^o, the blade pitch would be 4.5^o-6.0^o–5.0^o from the catch – to the finish, so the blade would jump up and down during the drive. Therefore, it is recommended to set fore-aft pin pitch to 0^o.

Specifications

Dimensions                         250 x 100 x 50 mm

Weight                                260 g

Display resolution                0.05 deg

Accuracy                             ±0.2 deg

Battery                                Two 1.5V AAA (LR03)

©2025 Dr. Valery Kleshnev www.biorow.com