Bar-in shapes for all-road

I finally got a chance to dive deeper into the all-road bar-in concept.

In December, I got the bar-ins installed on the all-road bike and the value (again) was instantly obvious. It’s grown to be one of my preferred positions on the bike. This is strange because you’d think that the wide grip position would be the go-to but it isn’t. The narrower stance and wrist angle work far better when using the brakes and steering the bike aren’t the most important task at hand.

What the bar-in was missing was a decent shape that would make it both easy to hang onto but also something that increased comfort when leaning on them for extended periods of time. This was the initial intention for this project but I got distracted by the other work that you’ve seen on this site. Priorities shift around and we need to come back to good things that we were forced to move passed.

The modeling for such a part is complex. The bar-in has it’s own geometry but is holding on the bar but that bar is angled 20 degrees from the horizon with a 16 degree sweep. How my arms and hands connect to it add more difficulty to figuring out the shape.

What is good about laying this out and testing is that the parameters that I’ve defined can be transferred to other schemes with good and usable shape orientations.

I had these printed on the old s-series UltiMaker printer that they have at the university library here at SFSU. They only had this ivory colored PLA material for printing but the cost was practically nothing. I’m not happy with the color or quality. It really highlights that I need to get a proper printer for my home so I can control this.

I used some 3M VHB (4941?) tape that was laying around to help hold the shapes in place. This wasn’t great and is a detail that I need to think more about.

The bars were wrapped with some salvaged red Fizik Microtex Tempo handlebar tape. I don’t need to do anything fancy or too good looking for this level of prototype work. It’s not an easy leave to make look great. I’m sure that when I go to making the proper parts, it will have a really nice look.

Initial test riding of the bike around town was awesome. What a difference!! The bar-in without the additional shaping was an upgrade but they felt cheap. They weren’t easy or comfortable. They just worked. With the shaping, they feel really really good. They are so much nicer in every way. The grip and support are really usable and good now.

Still, the shape isn’t perfect. There are a few more generations of shape to go to get it just right. I’ll be picking at that until I get to where I think it becomes worth working in metal as a proper finished part.