You might have heard about the new CEN regulations that are coming into force for mountainbikes in the near future. They are to protect customers from dangerous bikes, but due to an odd fatigue test – with high forces, there was a rumour going around that steel frames weren’t going to pass, or would be horribly heavy.
We put a lot of time and thought into the construction of the Blue Pig frame to ensure that it passed this new test. And in doing so, having to sit down and think about how we design and weld steel frames, we’ve made something that’s better than any steel frame I’ve done before.
Now, it’s pretty clear than the more you do something (like designing frames), the better you get at it (as you remember what broke before and where, what didn’t break, what flexed, what didn’t). But designing something to pass the new CEN regs was tough, as lots of people in the industry were getting awfully upset about it.
Even as late as the Taiwan show, I was taken to one side by one manufacturer and asked to join a group to push for the standard to be lowered, to make it easier for steel frames to pass.
As I’m incredibly grumpy, quite bad with people, and just like to sit in my shed in Calderdale, I carried on anyhow, as I enjoyed the engineering challenge of trying to get something through a tough test without simply throwing lots and lots at metal at it.
What we did with the Blue Pig (and I say we, as it’s me and my factory, the engineers and welders there too), was to look at the three tubes at the front of the bike (headtube, downtube, top tube) and really analyse what was going on during riding, and during the tests that they were using to simulate riding. We examined videos of frames in testing, and quickly realised that there was a whole heap of flex going on in the headtube area, that was concentrating stress on the downtube/headtube joint.
By picking some new tubes, adding some reinforcement to stiffen the headtube area, increasing the downtube diameter, decreasing top tube diameter (to introduce some flex to dissipate the load) using our standard 0.9mm/0.6mm/0.9mm tubeset, we were able to get a frame to exceed the CEN test, even when fitted with solid steel “test forks”.
All this might be quite dull, and I might have lost you on the second line. But the deal is this. The Ragley Blue Pig passes stringent standards that aren’t even law yet, to ensure you get a tough reliable frame that will last. Sure a 5.5lb weight is more than some, but we think most of that extra weight comes from our chainstay bridge (which we love for tyre clearance and chainsuck issues), and our dropouts (which let us run lighter rear stays for better rear triangle compliance and cleaner disc brake mounting).
Anyhow – here’s the test details in full.