This was a request from a client in England. Long travel. 650b. 12mm TA rear. Long front center. Short stem. Short Stays. 30.9mm Dropper Post. Those last 2 things required a 1.375″ O.D. radius seat tube. That’s a significant hurdle to overcome. The nice part, was this frame was commissioned for a delivery date 1 year out to be picked up on a trip across the pond. No problem? Maybe… So I set about between builds slowly going about figuring out how to formalize the process by which I radius seat tubes, make it repeatable and accurate AND make them so they do not have kinks or ripples or take on a “D” Shape. That’s a HUGE ante to up. But I’m up for a challenge and a long time ago, I figured it out with 1.25″ O.D. tubes (and was one of the only ones with the ability to do it smoothly I may add). That method has been kept secret. TOP SECRET in some circles it would be labeled. This is Apollo Missile plans kind of stuff in the custom mountain bike world perhaps. So I employed Drew from gh2omachining.com. Drew machined the pair of dies I designed for part of my bender I dubbed “Project Heavy”. One 1.25″ die and one 1.375″ die. After a few weeks of machine time on my end I was ready to attempt my first bend. No go. The original plan was creating a bulge/ripple as the dies moved across one another. So it was time to make some modifications. On I plodded. Try after try. Still a No-Go. This was months of work just not going anywhere between builds. Slow and steady though. Keep on keeping on. Make a mistake, learn something, make modifications, try again. Well… the window to make my clients bike was starting to get close. We spoke and he was a bit disappointed, but knew I put forth a maximum effort. Honestly, I was running out of time and I had to shelve the project to let things stew for a while.
So a few weeks ago, I was doing some thinking one evening and a light came on. Project Heavy was back on kids. So after this last build (a 29″ Rohloff headed down to Circle A for some paint actually… I’ll get to that one in a few days!), I fired up the mill and went at it tooth and nail. We were making chips. Lots of them. An initial test late last week gave me some light at the end of the tunnel (it wasn’t all the way done, but done enough to make the parts move a few inches). Literally I was in outer space on a mission to the moon and now it was time to turn around, and head home for re-entry. This evening, after a day in the shop: SHIT. GOT. DONE. I was ready. A little bit of prep and this was the result:
If you look closely, about 1″ from the far end you can see a slight indent where the tube was held. The good news is that is a cut off and is the bottom bracket shell end of the seat tube. I have a modification I will make to the tube holder part of my bender I made that will solve this I think – that will get done when I return from Thanksgiving travel. But the good news: The entire beginning, and end and everything in between is wrinkle free, no bulges, no dents, no distortions, no “D” Shapes. Just a nice smooth continuous radius. I’ll note also that these are repeatable. Check that out:
Another angle. You can see where they were held in the shot below:
What’s nice about a 1.375″ O.D. Tube? Well, 30.9mm seat posts AND 30.9mm Dropper Posts in a radius seat tube so no compromises in handling have to be made if a client specifically requests dropper posts or the application requires a larger post for more aggressive riders (I have one now actually…). That’s huge. Not only can I achieve all these goals, I can do it in house right here at 44HQ. I don’t know of many others with the ability to do this. Here’s a shot with a 1.375″ O.D. seat tube using Paragon Machine Works 30.9mm I.D. seat post collar (Part No. MS2019):
It would be fully pressed in place and welded along that seam which is exposed. I will end up making my own which are 4″ in length (I will also speak with Mark at Paragon to see if he has any plans on making a 4″ long part). The other thing is I wondered about Titanium. I’ve been long at it practicing now and again. But one of my goals if/when I do offer titanium is to make my bikes like I make them now. Again: No compromises. That means making radius seat tubes in Titanium. That’s another hurdle. When I finished the above I was beyond stoked. Hootin’ and Hollerin’. Did you hear me? Maybe you didn’t because I had the Ramones way up past 11. But I digress: I have a few samples of titanium on hand, but I didn’t recall that anything I had was 1.375″ O.D. Went up for dinner… then it hit me: YES, I do have a 1.375″ O.D. piece kicking around. Back down to the shop stating to my wife Lynn “I’ll only be a few minutes.” to which she replied “Yeah right, you’re never down there for just a few minutes”, laughed and wished me well on my way. Back down in the shop I went. Set everything back up again and BLAM: That ain’t steel on the far right kids…
But before you get all in a twist about 44 Bikes XXX Titanium, let’s take a deep breath here. Titanium’s still a ways out. But, and there is a huge BUT: This little radius tube of titanium gets us that much closer to making something possible.
I’ll leave you with that one up above. I’m pretty damned stoked right now. Actually well beyond stoked. I don’t think I’ll be sleeping much tonight actually. It’s taken close to a year to get here and make this possible. Stay tuned. I have a few more tricks up my sleeve…
44 Bikes XXX Project Heavy : Radius Seat Posts of the 30.9mm Kind
So it all started with this bike:
This was a request from a client in England. Long travel. 650b. 12mm TA rear. Long front center. Short stem. Short Stays. 30.9mm Dropper Post. Those last 2 things required a 1.375″ O.D. radius seat tube. That’s a significant hurdle to overcome. The nice part, was this frame was commissioned for a delivery date 1 year out to be picked up on a trip across the pond. No problem? Maybe… So I set about between builds slowly going about figuring out how to formalize the process by which I radius seat tubes, make it repeatable and accurate AND make them so they do not have kinks or ripples or take on a “D” Shape. That’s a HUGE ante to up. But I’m up for a challenge and a long time ago, I figured it out with 1.25″ O.D. tubes (and was one of the only ones with the ability to do it smoothly I may add). That method has been kept secret. TOP SECRET in some circles it would be labeled. This is Apollo Missile plans kind of stuff in the custom mountain bike world perhaps. So I employed Drew from gh2omachining.com. Drew machined the pair of dies I designed for part of my bender I dubbed “Project Heavy”. One 1.25″ die and one 1.375″ die. After a few weeks of machine time on my end I was ready to attempt my first bend. No go. The original plan was creating a bulge/ripple as the dies moved across one another. So it was time to make some modifications. On I plodded. Try after try. Still a No-Go. This was months of work just not going anywhere between builds. Slow and steady though. Keep on keeping on. Make a mistake, learn something, make modifications, try again. Well… the window to make my clients bike was starting to get close. We spoke and he was a bit disappointed, but knew I put forth a maximum effort. Honestly, I was running out of time and I had to shelve the project to let things stew for a while.
So a few weeks ago, I was doing some thinking one evening and a light came on. Project Heavy was back on kids. So after this last build (a 29″ Rohloff headed down to Circle A for some paint actually… I’ll get to that one in a few days!), I fired up the mill and went at it tooth and nail. We were making chips. Lots of them. An initial test late last week gave me some light at the end of the tunnel (it wasn’t all the way done, but done enough to make the parts move a few inches). Literally I was in outer space on a mission to the moon and now it was time to turn around, and head home for re-entry. This evening, after a day in the shop: SHIT. GOT. DONE. I was ready. A little bit of prep and this was the result:
If you look closely, about 1″ from the far end you can see a slight indent where the tube was held. The good news is that is a cut off and is the bottom bracket shell end of the seat tube. I have a modification I will make to the tube holder part of my bender I made that will solve this I think – that will get done when I return from Thanksgiving travel. But the good news: The entire beginning, and end and everything in between is wrinkle free, no bulges, no dents, no distortions, no “D” Shapes. Just a nice smooth continuous radius. I’ll note also that these are repeatable. Check that out:
Another angle. You can see where they were held in the shot below:
What’s nice about a 1.375″ O.D. Tube? Well, 30.9mm seat posts AND 30.9mm Dropper Posts in a radius seat tube so no compromises in handling have to be made if a client specifically requests dropper posts or the application requires a larger post for more aggressive riders (I have one now actually…). That’s huge. Not only can I achieve all these goals, I can do it in house right here at 44HQ. I don’t know of many others with the ability to do this. Here’s a shot with a 1.375″ O.D. seat tube using Paragon Machine Works 30.9mm I.D. seat post collar (Part No. MS2019):
It would be fully pressed in place and welded along that seam which is exposed. I will end up making my own which are 4″ in length (I will also speak with Mark at Paragon to see if he has any plans on making a 4″ long part). The other thing is I wondered about Titanium. I’ve been long at it practicing now and again. But one of my goals if/when I do offer titanium is to make my bikes like I make them now. Again: No compromises. That means making radius seat tubes in Titanium. That’s another hurdle. When I finished the above I was beyond stoked. Hootin’ and Hollerin’. Did you hear me? Maybe you didn’t because I had the Ramones way up past 11. But I digress: I have a few samples of titanium on hand, but I didn’t recall that anything I had was 1.375″ O.D. Went up for dinner… then it hit me: YES, I do have a 1.375″ O.D. piece kicking around. Back down to the shop stating to my wife Lynn “I’ll only be a few minutes.” to which she replied “Yeah right, you’re never down there for just a few minutes”, laughed and wished me well on my way. Back down in the shop I went. Set everything back up again and BLAM: That ain’t steel on the far right kids…
But before you get all in a twist about 44 Bikes XXX Titanium, let’s take a deep breath here. Titanium’s still a ways out. But, and there is a huge BUT: This little radius tube of titanium gets us that much closer to making something possible.
I’ll leave you with that one up above. I’m pretty damned stoked right now. Actually well beyond stoked. I don’t think I’ll be sleeping much tonight actually. It’s taken close to a year to get here and make this possible. Stay tuned. I have a few more tricks up my sleeve…