There has been an on going saga/drama I have had to deal with regarding the seat frame on my Vison R40. I have had the bike since 2001. In that time frame 5 of 8 welds in the seat frame have broken and been repaired. Advanced Transportation, the company who used to build Vision recumbents went out of business and before they did they redesigned the Vision frame and seat frame. As a result I can not find an exact replacement anywhere that will work with my bike. I did find at Hostel Shoppe a seat frame that with the use of an adapter and some other adjustments to my bike would work to fit with my Vision frame. The problem is the geometery is differant than my original and it hurt my hips and lower back to ride it so I had to return that seat frame and adapters as a result. I have been wanting to have a custom seat frame built out of 4130 cro-moly for some time. I found a shop that builds funny cars, drag racers and does custom work on classic muscle cars that can build one, but for almost $700. A new bike would cost me $1800. I gave up for a while until recently. I found another shop that builds custom motorcycles who will do it for about $300. I have no problem paying that much. The shop owner is using my existing seat frame to get the geometry correct. It will be ready by the first week of March. The problem with the aluminum seat frame is multi-fold. First it is not heat treated. Second it is fastened in to places to the cro-moly bike frame. There is constant vibration transmitted up through the seat frame causing the fatigue thus resulting in the failed welds. I have said this once and I will keep saying it: Which would you rather sit your ass on? A material that has been wround for 2,000+ years and is tried, trued and tested? Or a material that has barely been in use for about 200 years and by comparison is still in it's infancy? Can cro-moly or steel fail? Yes. But I wager it will last a whole lot longer than aluminum. If the guy who is building this seat frame does as good of a job that his reputation has shown I will give him a huge kudos and spread the word if anyone in my area needs custom fabrication done for a motorcycle or bicycle to contact him.
I sure hope that works for you. I believe it will. You're right, in that application, aluminum was a poor choice. BTW, I think the original design was replaced mostly for safety. The early seats were called "ejector seats" because the quick release holding the seat angle would sometimes slip out of the slotted bracket. Not having had one, I'm not sure of the vectors involved, but it didn't sound pleasant. If you have the style with the open slot, you might consider having your builder close off the ends. Or better, instead of a slot, use a series of holes.
Freemason - Have you ever looked at any of ADC's homebuilt stuff? He makes a mesh (or web) seat that many claim is the most comfortable available. See here: How the seat frame is made Good luck finding one that works for you in any case.
The QR connection at the seat stays and the main boom frame tube has never been an issue as far as coming undone. Nor has the aluminum brackets that the QR tightens against has ever shown any fatigue where the slotted bracket sits or rests on the QR piece that is tightened down. Only the welds have ever shown the fatigue and failure. I think the verion of seat you're talking about is before my model was built. That problem was solved but the problem with using non-heat treated aluminum was not.
Good to hear that you haven't had the 'ejector seat' problem. ADC at Recycled Recumbents is a big guy, so I'm sure his seats are strong; but I don't think he uses 4130. He uses what he has, which might be something as plain-jane as mild steel or even conduit. I know about non-heat-treated stuff and cracks in the heat affected zone. I'm on my third Baron frame. Optima finally outsourced their frames to Asia, and now, finally, my latest frame is heat treated.
Who made the Baron frames before they were outsourced to Asia? Or rather what country were they made in? Advanced Transportation Products, ATP, the company who used to build Vision Recumbents went out of business in about 2003 - 2004 I think. Everything from the company was auctioned off. Prior to that, around 2002 they changed the seat frame design and started using a heat treated aluminum one. The new seat frame and seat stays are virtually this: Hostel Shoppe Recumbents - the world's largest source for recumbent information, bicycles, trikes and accessories. Hostel Shoppe Recumbents - the world's largest source for recumbent information, bicycles, trikes and accessories. The new seat frame style uses a "top hat" style nut to keep it secure with the QR: Hostel Shoppe Recumbents - the world's largest source for recumbent information, bicycles, trikes and accessories. The adjustment at the back of the seat were with the seat stays, not a long open slotted bracket like mine has. The hardware listed above is what is used on the Volae recumbents. Volae frames are built by Waterford Cycle. Waterford is owned by a descendant of Ignaz Schwinn. I think it his great, great, great grandson. Some of the Volae's are very, very similar in design to the Vision's. Very similar geometry, feel style, etc.
Optima formerly made their own frames in the Netherlands. The story I heard was that they overbuilt them to compensate for not heat-treating them, which is why they were a bit on the porky side. They apparently didn't overbuild them enough. My first broken frame would have been under warranty except I wasn't the original owner. Interestingly, the first owner had already replace the frame under warranty. I got a discount on the new one that time. My second broken frame was still under warranty, so that one was free too. Technically, the bike has had 4 frames now, with two of the three replacements covered by warranty. Not a good way to run a business.
Tomorrow I meet with the custom shop owner with the bike to make sure the new seat frame will work before he finishes it. He has it started but needs some confirmation on the geometry. If all goes well I could be riding in the next 2 weeks or so if the weather is at least 35 degrees F and it is not too sloppy out with the melting snow.
I took the bike to the custom shop. The new frame is a perfect match. the tubing is fully welded together. but the guy doing the work had to make sure the brackets that attach to the QR's which hold the frame on the bike were correct in the geometry before he finished the welds on those. Let me put it this way. If the frame were complete, not tack welded and was painted I would swear I have 2 identical seat frames. The new frame is literally nuts on compared to the old frame. He will finish welding it and put a primer coat on it and have it ready for me to pick up on Monday. The cost is going to come in right at $300 or just under.
It is a great price considering another place I could have taken it wanted to charge me over twice that amount. The other place is a muscle car shop. They build custom funny car, stock car and dragster frames. I still need to come up with a color to paint it. I am going to rattle can it with Rustoleum. It will be primered and the seat cover will cover most of it. But what is not covered will be seen. I would like a high vis color, especially one that easily seen at night. the bike frame is red but I am not really worried about the color of the seat fram matching the frame color. The original seat frame is black. What color does anyone suggest?
