Boat Trailer Keel Rollers by Stoltz

Keel roller sizes

The size in the name is the nominal length. Most sizes run slightly shorter than nominal, so check the actual length against your bracket measurement.

Stoltz keel rollers come in two shapes. The 5″, 8″ and 10″ rollers are V-shaped: taller at the ends and lower in the middle. The 10″ × 3″, 12″ and 18″ rollers are flat, with one height end to end. End height is measured at the outside of the roller. Center height is measured at the middle.

How to measure for a keel roller

Measure the inside width of the bracket your keel roller mounts into, not the outside width. Then order a keel roller that can spin freely inside that bracket. Make sure you do not order a roller that is larger than your measurement. Use the actual length in the table above to check the fit.

Check the bolt too. Stoltz keel rollers take a 5/8″ bolt. Stoltz bow rollers take a 1/2″ bolt, so a bow roller is not a substitute for a keel roller.

Keel roller or keel pad?

A keel roller spins when the bow or bottom of the boat makes contact, helping the boat roll forward onto the trailer. A keel pad doesn't move. It protects the frame, so the boat contacts polyurethane instead of the steel frame.

Keel rollers and keel pads use completely different mounts. A keel roller mounts in a bracket on a 5/8″ bolt. A keel pad mounts directly to the trailer frame. If your trailer has a keel roller bracket, you need a keel roller. If the part bolts straight to the frame, you need a keel pad.

Shop keel pads

Keel roller FAQ

What size bolt do Stoltz keel rollers use?

All six Stoltz keel rollers fit a 5/8″ bolt.

What is the difference between a keel roller and a keel pad?

A keel roller mounts in a bracket and spins to help the boat roll forward onto the trailer. A keel pad mounts directly to the trailer frame and doesn't spin. It keeps the boat from contacting the steel frame.

Can I use a bow roller as a keel roller?

No. Stoltz bow rollers fit a 1/2″ bolt and are sized for bow brackets. Keel rollers fit a 5/8″ bolt.

Which Stoltz keel rollers are V-shaped and which are flat?

The 5″ (RP-5), 8″ (RP-8) and 10″ (RP-10) keel rollers are V-shaped. The 10″ × 3″ (RP-310), 12″ (RP-212) and 18″ (RP-18) keel rollers are flat.

What is the difference between the 10″ and the 10″ × 3″ keel roller?

The 10″ keel roller (RP-10) is V-shaped, 3 1/8″ tall at the ends and 2 1/8″ in the center. The 10″ × 3″ keel roller (RP-310) is flat, 3″ tall end to end. If you have a 10″ bracket, match the shape of your current roller: order the RP-10 if your current roller is V-shaped, or the RP-310 if it's flat.

Will a Stoltz keel roller mark my hull?

Stoltz keel rollers are made from non-marking polyurethane.

Why is the actual length shorter than the size?

A keel roller has to spin freely once it's installed, so most sizes are made slightly shorter than nominal to leave room between the bracket sides. The exception is the 5″ keel roller (RP-5), which is a full 5″ and spins in a 5″ bracket. Always compare the actual length to your bracket measurement.

What is the most common mistake when ordering a keel roller?

Measuring the outside width of the bracket instead of the inside width. The roller sits between the two sides of the bracket, so the inside width is the measurement that matters.

Do you ship outside the U.S.?

No. Boat Trailer Rollers ships within the United States only.