The table below gives model specifications and general recommendations based on boat size.

If still in doubt contact us and we’re happy to discuss it.

1. At Maximum Pin to Pin length.
2. Maximum stroke at initial Pin to Pin
3. Maximum stroke at min. Pin to Pin. Stroke is travel when flexed. 1″ of stroke
equates to approximately 7″ at the aft end of the boom.
* Uses webbing sling at boom instead of track fitting. 

Boomkickers  use two coated solid fiberglass spring rods to provide the force necessary to support the boom and mainsail. The rods are clamped into teflon coated, anodized aluminum end pieces and attached to universal mast and boom fittings.  Fittings are included along with machine screw fasteners, the proper drill and tap and hex wrench. The mast fitting includes a round slide which, used in the luff groove, avoids drilling into the mast. Flat slides in varying widths are available from the factory.  The slides can often be inserted at the sail opening above the gooseneck and slid down reassembling the fitting in position. If slides are not usable, the fitting can be attached directly to the mast using the same drill and tap provided for the boom.  The custom extruded boom track is contoured to fit both round and flat bottom booms. The track has an adjustable clevis pin to set the maximum height the Boomkicker will lift the boom. The track length forward of the pin allows the boom to move higher if needed.

The pictures below show the basic set up of Boomkicker models 500, 750, 800, 1000, 1250 and 1500 with a multipurchase vang.  Models 500 and 750 are identical except for rod diameter, the same goes for models 800 and 1000, and then models 1250 and 1500.

        

The purpose and benefit of the track is to allow the Boomkicker to slide forward if the boom is allowed to raise beyond the Boomkickers’ straight position or maximum travel. Sliding prevents the unit or fasteners from being overloaded in tension and used as a vang. Vang tension loads can be as much as 10 times the compression load the Boomkicker needs to support the boom.

The Boomkicker  model K0312 works basically the same as the larger models by flexing as show below, but instead of attaching directly to the boom, a  webbing sling, suspended between the two spring rods, supports the boom. Designed for smaller daysailers, these Boomkickers are easy to install with no drilling or tapping required. All parts fit in the luff groove of the mast. For trailering, the design makes rigging and de-rigging a snap, simply remove the boom and fold the Boomkicker up against the mast for storage. 

The sling, because it does not attach directly to the boom, allows these models to work with the simplest of goosenecks. Even if the boom just slides onto a pin at the gooseneck, or can roll, the Boomkicker can not push the boom back or restrict it from rolling around its central axis to follow the sail.

                            

Where both the K0312 and K0400 models have webbing slings, the mast end for the 312 is made of UHMW polyethylene, a stainless steel mast bracket and luff groove slides of teflon coated anodized aluminum. Sold since 1995, the design has proven simple and extremely durable. 

The Boomkicker  model K0400 works basically the same as the larger models by flexing as show below, but instead of attaching directly to the boom, a  webbing sling, suspended between the two spring rods, supports the boom. Designed for smaller daysailers, these Boomkickers are easy to install with no drilling or tapping required. All parts fit in the luff groove of the mast. For trailering, the design makes rigging and de-rigging a snap, simply remove the boom and fold the Boomkicker up against the mast for storage.

The sling, because it does not attach directly to the boom, allows these models to work with the simplest of goosenecks. Even if the boom just slides onto a pin at the gooseneck, or can roll, the Boomkicker can not push the boom back or restrict it from rolling around its central axis to follow the sail.

                            

Both the gooseneck eyestrap for the line and the mast fitting have standard 3/8″ diameter slides to fit in the luff groove and avoid drilling. 1/2″ diameter is also available. The length of the line positions the sling along the boom and determines the initial boom height. The gooseneck eyestrap also serves as a stop if the gooseneck slides in the luff groove.

Where both the K0312 and K0400 models have webbing slings, the model 400 mast end is all aluminum, basically the same one used on the model 500. Both models K0500 and K0400 share the same rod diameter and force, so the only difference or choice is whether you prefer the sling attachment or aluminum track fitting.

The K0400 can also be installed to flex down. It’s highly recommended when the angle to the boom is lower then 40 degrees. As the rods flex down, the sling arms become more vertical, better capturing the boom.

Some answers to common Boomkicker questions:

Q: Is buying a larger Boomkicker model always better?
A: Not necessarily. Using a larger model than needed can result in too much force making it difficult to pull on the vang and mainsheet. If however the length of a larger model will fit the area above the vang better, we can substitute or exchange the standard spring rods for optional lighter ones.

Q: Do I need a vang with the new track fitting.
A: Although a vang is recommended for sail shape, there is usually enough travel in the track compared to the original boom fitting, that a vang is not required.

Q: How do you get the  mast slide in the luff groove when the mast is stepped and the gooseneck is in the way?
A: The slide is removable from the fitting and can often be inserted where the sail goes in above the gooseneck, then slid down into position. Using string to lower the slide is one option. Dropping it is another, making sure the slide can not go all the way to the keel.

Q: A round slide came standard, the luff groove requires a flat slide, are these available?
A: We stock flat slides from 1/2″ to 1″ wide depending on the model. Slides are 1/8″ thick stainless steel. Measure the inside of the existing groove or the sail slides to determine the required width. Flat slides can be bought direct or from a distributor. 

Q: The luff groove is not usable or does not exist below the gooseneck. How is the fitting attached?
A: The mast fitting bracket can be attached directly to the mast using the same drill and tap provided for installing the boom fitting. Extra long screws are included if needed. The slide goes unused. For unusual cases, for example where wiring runs in the luff groove, we can supply custom brackets to span the luff groove.

Q: There is a groove on the underside of the boom, are there slides available for the boom fitting?
A: Yes. Contact us with the required inside width. Slides are 1/8″ thick stainless, drilled and tapped for the fitting. Shorter screws are also available. Before ordering, check for access.

Q: The existing gooseneck is adjustable up and down the mast. Is this a problem?
A: The Boomkicker works best with the boom gooseneck fixed at one location on the mast. After installation, the Boomkicker boom attachment becomes a lever point. Raise the gooseneck and the aft end of the boom drops.  It is preferred to select the best gooseneck position, when using the halyard or a cunningham to tighten the luff. Use the downhaul/sailstops to fix the gooseneck in that position. We also sell slides separately as stops.

Q: The boom rolls on a gooseneck pin. Is this a problem?
A: Not with the smaller Boomkicker models, but as boats approach 30′, to avoid undue stress on the boom fitting, it is best if  booms are fixed in the upright position.  If necessary we have a fitting which mounts on the mast, under the gooseneck to hold the boom in the upright position.

Q: Does the Boomkicker need to be installed parallel to the vang?
A: Usually it looks best, but it is not essential. So long as there is room to flex and it provides enough support, the installation is fine. For more see next question.

Q: For installation, is the best angle to the boom 45 degrees?
A: Actually, the farther out the boom the better the leverage for support. The best angles to the boom for all models except the two smallest are between 35° and 40° but customers often install them successfully at angles close to 30°.  If shortening the Boomkicker is necessary to fit above the vang, shorten only the minimum amount required. The exceptions are models K0312 and K0400. Both work best if installed between 40° and 45°, see their installation instructions for more.

Q: How high should I set the boom for installation?
A: With the new boom track fittings’ extended travel, setting the boom height is not as critical as the original fitting. Generally it should be slightly above the normal sailing height with consideration given to reefing, head clearance when in port, lifting the boom in light air to improve sail shape and different mainsails.

Q: Can I install the Boomkicker upside down so it flexes downward?
A: Yes, the Boomkicker works the same whether it flexes up or down. Customers have installed it “outside” the vang, flexing it down away from the vang but vang leads and interference with crew should be considered.  We have also heard of customers running the vang between the rods, one fitting outside, the other inside the vang. The two smaller models which use a webbing sling at the boom actually benefit by flexing down. As the rods flex, the sling becomes more vertical, better capturing the boom.

Q: When leaving the boat for an extended time, does the Boomkicker need to be left in the straight position?
A: No. Leaving some flex in the spring rods is fine. If left heavily flexed in hot weather for an extended period, some set could occur.

Q: How much travel or flex is available?
A: If uncut, the spring rods provide around 6 feet of travel at the aft end of the boom depending on the setup. Most boats require only a foot or two of travel.  Shortening the spring rods reduces travel. At their minimum lengths, travel is still around 3.5′  at the aft end of the boom, again, depending on the setup.

Q: Can the spring rods wear out?
A: The indication since 1990 is no.

Q: Once installed, the force is more than I like. Are smaller diameter rods available?
A: Yes. If uncut, the spring rods can be exchanged for an optional set, see the parts sheet included with the Boomkicker for specifics. Rods can also be purchased on line at the price list or by email and phone.

Q: After using the Boomkicker for a time, I would prefer the boom higher. Do I need to order longer spring rods or drill more holes.
A: No, not with the new track boom track fitting, just adjust the clevis pin stop. Additional stop holes can be drilled for the 3/16″ diameter pin using the inscribed line along the track as a guide.

Q: Do I need to increase the purchase of an existing block and tackle vang?
A: If there was enough purchase before installation, adding the Boomkicker should not require more, but it depends on the spring rods choosen and vang demands.