Velo Distractions

The $25 DIY Bike Stand constructed last month has proven to be a very worthwhile project. I love this thing, since building it I am constantly finding excuses to use it. Be it periodic inspections, maintenance, cleaning, or just to stare at the bike. While functional, the PVC stand is still not perfect. Drawing from a little hands on time and the lessons learned from the original build, I worked out some improvements.

The threaded union was added to allow the clamp to rotate into multiple positions. Unfortunately, no matter how much the union was tightened, it did not have enough friction to prevent rotation of the clamp on a suspended bike. The union consists of two pieces of PVC pipe that screw together with an o-ring in between them. The O-ring is designed to form a seal , and limit the rotation between the two pipes in the joint. While it is sufficient for plumbing, it is by no means adequate for holding a bike.

 

Another area for improvement is the clamp itself. The clamp design consists of a 1 1/4 inch PVC T joint, cut in half, hinged on one side, and a latch added to the other. To clamp the bike, you cover the seat post with foam pipe insulation and place it in the clamp. This idea proved inadequate in a number of situations. Specifically, the pipe insulation will compress, causing the seat post to rotate to a diagonal position in the clamp. The bike would then slide down in the clamp until it reached the top of the post. This transfered the weight of the bike to the bottom of the seat, causing the bike to effectively be hung by the seat. This slippage did not occur immediately, but would happen slowly over a period of time. The heavier the bike, the quicker this would happen.

 

The compression of the pipe foam also caused the seat post to rest up against the screw heads in the clamp. After a few trips into and out of the clamp I noticed a scratch on the carbon fiber seat post of my OCR2. After some investigation, I determined the clamp bolt heads created a pressure points and additional stress to the side of the post. While this stress is small enough to be of no major concern to an aluminum post, I was nervous about its implications to a carbon fiber post which could cause it to weaken.

The solution to this problem, needed to meet the following criteria:

• Provide sufficient friction in the union joint ends to prevent unintentional rotation of the bike in the stand.
• Prevent the seat post from sliding and rotating in the clamp.
• Provide protection to the seat post from the bolt heads of the clamp.
• Economical, remain in the spirit of a 25 dollar-ish stand.

After scouring through a number of hardware stores, I came up with a $3 solution that could address all of these issues:

This is a simple kit for making home made gaskets for $2.99 plus tax. It includes 3 square sheets for gasket making, one made from rubber, one cork, and one paper. The cork and paper gaskets can be used for padding of the bike clamp bolt heads, and the rubber gaskets for improving the hold of both the union joint and pipe clamp.

Making the gasket for the union is extremely simple. Using the rubber gasket sheet, trace around the union end, trim it out and glue it to the union end. Gluing can be accomplished using Epoxy or Gorilla Glue. Lay it aside for at least a few hours for the glue to set.

For the post clamp, cut at least one layer of the cork and paper gasket material, and glue into position as before. This material will provide padding between the seat post and the bolt heads, eliminating their pressure points. Depending upon your availability of sheets in your kit, you may wish to use multiple layers.

Repeat the procedure using the rubber gasket material as the outer layer. Glue as many layers needed to guarantee the clamp fits snuggly on the post. Being careful with the glue, you can clamp the post on your seat post while it dries to hold everything in place.

Once the glue has dried, take an sharp knife or razor to clean up the gasket edges. The pieces will shift during the gluing process, I found it works best to trim up the gaskets as the last step.

These additions have made a considerable improvements over the original stand. Rotation of the stand at the union joint is no longer a problem, and the carbon fiber post of my OCR2 fits snuggly in the clamp with no fear of damage against the bolt heads.

Links to some other stands.

The original Instructables Design

Improved design on Bitness.com

Even simpler design