Join Date: Mar 2003
Location: Grand Prairie, TX
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Keeping in mind that I have no personal experience with Softride beam tandems, I have heard the following vigorously expressed complaints:
1. Bouncing except at particular rpm and power output. So how do you sprint at 118 rpm plus? I wouldn't own a tandem that won't sprint. It sounds awfully limiting to have your efficient pedalling rpm window narrowed like that. And what if your best rpm is not in the window? You can put effort into damping the bounce, but that won't help you go faster. Most of us do not have a perfectly balanced pedal stroke, particularly when we are trying for high power output, and that is what it takes to keep a beam from bouncing.
2. Ferocious crack-the-whip stoker lag when laying the tandem over into a turn. The beam deflects laterally too (though it is designed to minimize this), and the mass of the stoker wiggles left-right over the top of the tandem, and the tandem oscillates a lot when starting a turn.
My observations have been consistent with these two complaints.
3. One guy complained that he could feel the tandem speeding up and slowing down as the stoker went up and down. I didn't believe that one.
My recollection is that the beam comes in two sizes, for heavy and light riders, and of course you can't tune it to the exact size of your stoker, but you can at least adjust the preload and maybe the damping on a shock-absorbing seatpost. I think Kay is 4'10" or so, and well outside the normal weight range for stokers. Given that the beam has a weight/size specific design (saddle setback on the beam varies with size), it would be difficult to be confident that subjective experiences could be scaled up into the normal size range. I have heard of people using a tie-down strap from the beam down to part of the frame to adjust the preload.
Beams are not all bad. After Alex Stieda stopped racing in Europe, he did some racing on the North American continent, with (heh, heh) sponsorship from Softride. The beam gave him an edge in bumpy turns, because with the suspended rider the bike could follow the irregularities of the road better and he had more traction. Anybody trying to follow him through on his line on a "stiffy" was likely to go down or slide off to the outside and go down. He did the Co-Motion tandem stage race once and picked up a few primes that way too, with a Burley (?) with TWO beams on it.
Is there hope that one day we will suspend the wheels (both), maybe smaller wheels like an Alex Moulton single, with a jackshaft to get the wheel speed up high enough, and get smooth-riding, hard-cornering tandems? Yup. Is the Softride beam the best solution for anything, or even viably marketable long-term in a tandem application? Likely not. It seems to interfere with power production and handling too much. The only application in which I would recommend it would be one in which the consequence of not using a Softride beam would be not riding.
Have you seen those parallelogram suspended seatposts with the elastomer springing/damping?
If you can't affirmatively declare that you would feel confident laying the tandem over for a turn with singles and tandems close on either side, without fear of stoker beam induced oscillation and consequent tracking errors, you can't really do club rides with it. It does no good to have a tandem that you can ride close to the pack, when what you want is to be in the pack.