Lowering the Seat Height

What tool is used to shave seat foam to make a seat lower. A sharp knife and then use an abrasive to smooth it out? :)

My son (vertically challenged, 12 years old) has a hard time one legging a full size bike but is determined he is going to ride a full size bike. We are not in the bike selection phase, we are committed to a full size bike(KX125).

We are also considering lowering the sub frame mount to lower the seat height also.

I know there are mostly large folks riding the BRB... But has anyone seen or heard how this is done? :D


I created a notch where the seat meets the tank. I used a black felt tip pen to outline the area to be removed and made an initial cut with a razor knife. Then I used a long fillet knife that extended beyond the foam and made a fillet-like cut removing the whole section.

I slide up into the notch when I come to a stop. This and a kouba lowering link allows me to get my feet on the ground.

Seat foam cutout

Seat foam cutout upside down view

Kouba lowering link

Later I hollowed out the center of the foam toward the rear and added softer foam, building up the area for comfort on longer rides.

Seat foam added

Full side view

I took my XR seat to an upholsterer, he removed half of the standard foam and put half again back but in. The bit he put back in was in the form of that "gel" type stuff. It is lower by about 2" and also more comfy on a longer ride.

Some people have had success using an electric carving knife.

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