Originally Posted by Retro Grouch
1. The purpose of the eccentric is to take up the slack as the timing chain wears and elongates. My guess is that you're going to have trouble down the road with your current adaptation.
2. The captain's seatpost clamp serves double duty because in addition to holding the captain's seatpost up it also has to resist rotation when the stoker pulls on the bars. If your stoker isn't a super aggressive rider a single bolt seat clamp will probably serve the purpose. If it was my bike I'd probably swap with the stoker's seatpost clamp and see how it works.
3. I can't tell from your post what you are really asking. Does your bike have Tektro mini V brakes that are advertised as compatable with road brake levers? If so, I hate them because they make removing a wheel a PITA. I much prefer using regular length, linear pull, Avid or Shimano brakes with Travel Agent cable pull doublers.
4. I don't know very much about cyclocross brake levers. My guess is they'd work if everything else was set up right, but I've never used them personally. I'd wonder if your partner will be able to get the brakeing power that's necessary on a tandem using cyclocross levers.
5. My guess is that a too heavy rider would shorten the lifespan of the soft elastomer. A too hard elastomer isn't going to give very much "cush". Changing elastomers everytime that you switch places is going to be a PITA.
1. I am aware of the purpose of the eccentric, and the need for proper timing chain tension. In general, for a given timing chain, proper tension will be achieved in one of two positions. What longevity problems do you forsee? The only thing I can think of is that it could be bad to have indentations from the set screws on both sides of the eccentric rather than just one.
2. Swapping the seatpost collar sounds like a good idea. I'll try it out if the seatpost OD's are the same.
3. I'm not by the bike at the moment, but now I'm certain they are Tektro Mini-V's. I found a posting from Bill McCready:
http://www.sudibe.de/articles/billonrimbrakes.html
Chris Timm, along with Vince and Sue, wonder about mini-Vs. I agree with Rich Shapiro's assessment that these brakes are not the best answer. Most other Burley dealers I've talked to about this have reached the same conclusion. While it is true that you could ditch Travel Agents if a V-brake's arms were 50% shorter, the resulting brake would be too short to clear tires. A mini-V's arms wlll clear 700c tires (but not 26-inch tires) because they are only 20% shorter. Since mini-Vs will cause your brake levers to bottom out unless the pads are adjusted close enough to the rim to prevent quick wheel removal, many Burley dealers installed Travel Agents on mini-Vs in order to keep their customers happy. Put simply, mini-V's (originally designed for BMX) are a poor match for integrated road bar levers. The manufacturer, Tektro, who now combines them with a longer stroke lever and markets them for "comfort" singles, does not recommend them for tandems.
I have experienced the annoying wheel removal you guys referred to with the Tektro Mini-V's. I can still get the wheels off without tools, but I have to bottom out the micro-adjusts and apply fairly significant force to get the cable free. I haven't seen these levers attacked as unsafe yet; just inconvenient.