RidingDonkeys
Husqvarna
Pro Class
It is similar to what the SW Motech uses to attach the two bars. If you look at the SW-Motech bars, they not only attach to the frame downtube, but they have a crossbrace between the two sides that connects using a similar coupler to what is mentioned above. I suspect they are talking about building the same type of cross brace on the Alt-rider bars.
I just don't see the value in it. The SW-Motech cross brace is at roughly the same height as the AltRider frame attachement point. If you go any further up for a cross brace, you run the risk of interfering with the forks as they turn. I'm not saying there isn't space, but it would require some measuring to make sure it would clear.
I think your flex issues really stem from the mounting brackets. The Altrider attachment point is engineered to be much more sturdy than the SW-Motech.
This is the SW-Motech. It uses a plate with the bars welded on a few inches forward of the mount. This plate is more flexible that the tube steel, and will flex to some degree. In my opinion, this is why the SW-Motech bars have to have a cross brace.
This is the Altrider attachment point. It is, by design, much stronger than the SW-Motech. This design would throw any flexing forces onto the tube steel, which shouldn't really flex given the thickness of it.
Also, notice that the Altrider forward frame attachment point is at the same height as the SW-Motech crossbar. The SW-Motech forward frame attachment point is actually lower than the Altrider's. This is why I think the crossbrace is necessary. They have to have that crossbrace to transfer energy over to the other side, that way the cheap bracked won't just bend or snap the weld. I'm not saying the SW-Motech is a bad design, but it meats a pricepoint. That plate bracket is a cheap method of attaching it, and it comes at the expense of strength.
I just don't see the value in it. The SW-Motech cross brace is at roughly the same height as the AltRider frame attachement point. If you go any further up for a cross brace, you run the risk of interfering with the forks as they turn. I'm not saying there isn't space, but it would require some measuring to make sure it would clear.
I think your flex issues really stem from the mounting brackets. The Altrider attachment point is engineered to be much more sturdy than the SW-Motech.
This is the SW-Motech. It uses a plate with the bars welded on a few inches forward of the mount. This plate is more flexible that the tube steel, and will flex to some degree. In my opinion, this is why the SW-Motech bars have to have a cross brace.

This is the Altrider attachment point. It is, by design, much stronger than the SW-Motech. This design would throw any flexing forces onto the tube steel, which shouldn't really flex given the thickness of it.

Also, notice that the Altrider forward frame attachment point is at the same height as the SW-Motech crossbar. The SW-Motech forward frame attachment point is actually lower than the Altrider's. This is why I think the crossbrace is necessary. They have to have that crossbrace to transfer energy over to the other side, that way the cheap bracked won't just bend or snap the weld. I'm not saying the SW-Motech is a bad design, but it meats a pricepoint. That plate bracket is a cheap method of attaching it, and it comes at the expense of strength.