This post isn’t necessarily about the SBDU, but I thought I’d write it as I get asked regularly to confirm seat pin sizes, or to try and decipher what an SBDU frame might be made from based on the seat pin and tube size. After collecting several SB frames over the years, I’ve seen lots of different seat pin sizes used in Reynolds frames. I have seat pins ranging from 26.6 to 27.4 – and 753 frames with 4 different size pins. That demonstrates just how varied their tube gauges were. So here is a little post that lists some of the most common seat pin sizes and the associated Reynolds tube gauge (wall thickness).
There are many stories about the SBDU and even more about Reynolds 753 tubing. Most of these stories travel the internet, changing and evolving each time they are told. Something as simple as which seat pin size should fit a 753 frame is one of those stories. It causes the most confusion and creates some of the longest discussions whenever it is raised. Everyone seems to have an opinion about what is right; few ever seem to agree. My latest addition, SB3800, means that I may now have a couple of frames that could finally settle the seat pin debate.
The search terms used by people who reach my blog are often connected to searching for information about the weight of a frame, specifically Reynolds 753 and Reynolds 531. So I thought I would write a little post to show the weight information I’ve collected on my own frames. I have frame weight data on several SBDU frames across a range of Reynolds tube sets. What I’ve found is that it isn’t simply a case of saying that every 57cm Reynolds 531 frame will weigh the same. Lots of factors influence frame weight.
This is the post I’ve been most looking forward to writing and also fearing with equal measure… Reynolds 753 was a tube set that took the bicycle world by storm. It had unrivaled strength while being ultra light and thin for a steel tube. It is probably the most mis-understood tube set and the one that has the most stories connected to it.
I’ve wanted to write this post for a while, and I’ve tried to start and structure it a few times, but it has been difficult getting to grips with the scale of the subject. There was often either too much conflicting information or sometimes a complete lack of information about Reynolds tubes. Hopefully I’ve got a good grasp now, although it has still taken longer than expected to get all of this out of my head and crammed into a short, informative and hopefully coherent blog post.
It’s been a few weeks since this little frame arrived, so after the small change of subject and posts about Dave Yates and his brilliant frame building course, it is back to the SBDU and Ilkeston built bikes.