GB4 Stiffener Plate

I was wondering, how well does the GB4 Stiffener Plate work? is it a good option other than the very expensive carbon fiber seat base? Does it do anything for the posture of the seat, like tilt it up a little sort of like a rail adapter?
Any feedback would be great.


It doesn’t change the profile of the seat in the way a rail adapter does. Basically, it keeps the shape and angle of the seat the same, while increasing weight and decreasing bendability.

I installed the plate on my original coker seat to facilitate adding the GB touring handle. I was very impressed with the added stiffness. It definitely creates a rock solid platform, and if your handle is also stiff (like the cool Steve Howard ones are…), you notice no give at all when hopping or jumping. Pretty much all energy gets directly transfered.

Between that and CF, I think it’s basically a weight vs. dollars vs. hassle decision. CF is lighter, but also more expensive and (in my view) more of a hassle to install because you have to do all the filing to get the round holes you drill square for the carraige bolts.

Bruce has my Coker with the GB plate setup, if you want to see it applied in a coker setting. JC and I both have CF setups on our muni if you want to check that out.

Thanks Tom, So its a good altenative to the CF seat base, But it ads a little more weight, correct?
I think once i get some new pedals and get rid of my primos (really heavy expensive paper weights) i’ll look into a GB4 stiffener pate.


I’ve got the GB4 stiffener in my freestyle seat. It works well. The handle and front part of the saddle are now much stiffer and stronger.

The GB4 stiffener only protects the middle and front part of the seat. It does not extend to the back of the seat. That means that the back part of the seat is still vulnerable. Max mentioned in the wanted carbin fiber seat!! thread that he has broken his freestyle saddle in the back landing 180 uni spins to sitting. The GB4 stiffener wouldn’t protect against that breakage. I’ve also broken a Miyata saddle in the back on my muni. That was back before the GB4 stiffener and carbon fiber base were available. But yeah, you can break the back of the seat.

The GB4 stiffener will keep the seatpost bolts and front handle bolts from spinning. However, it does nothing to keep the two rear bumper bolts from spinning.

Installing the GB4 stiffener can be a bit tricky. The stiffener is a bit thick so you may need longer bolts for the front handle or the seatpost. I also had some problems getting the three holes in front for the handle to line up so I could get the bolts through and put the handle on. I had to drill and file the plastic base a bit to get the three front bolts to go through correctly. I also had to switch to using longer 1/4" carriage bolts for the front handle because the stock bolts were too short.

The GB4 stiffener does nothing to change the posture of the seat.

The GB4 stiffener is thick and you may notice it through the foam padding. Kind of like the Princess and the Pea. You may be able to feel the plate and/or the bolts under the foam.

The GB4 stiffener works well and is quite a bit cheaper than the CF seat base.

The CF seat is stronger and reinforces the entire seat base. The CF seat also solves the spinning bolts problems for all of the bolts, including the rear bumper bolts. You can also tweak the profile or posture of the seat a bit by drilling the seatpost holes a littler farther back.

its alot heavy by the way.

So would it be a good choice for my trials uni?


But we’ll need to figure out something to fix the spinning bolts for your back bumper.


I might see you at practice this tuesday john,
Thank you everybody for the feedback.

-Sabin A.