Thursday, July 22, 2010

Changes to the Burley Tandem

This is a follow-up to my blog on our Burley tandem that my bride and I ride Our Burley Tandem. I have made two changes for the better. First I switched from a Nitto mustache bar to a more conventional drop bar, the Nitto Noodle bar; called the Noodle bar because it has some extra small tweaks and bends to make it more user friendly. The switch went remarkably and has played out as a much more comfortable cockpit than before. This also resulted in an embarrassing but very positive discovery that I have had my Shimano 9 speed bar end shifters setup wrong for years. All this time I figured it was natural for the shifters to index the first 3 gears, then friction the next three and index the final 3. Well it turns out it only does this if you screw up when you install them. You can install the shifter levers in 4 possible configurations, but only one way is the right way. Once I read up on the right way to set them up, I actually had all 9 gears index! You have no idea what a difference this is. I usually have no problem with friction shifters, but trying shift smoothly when your not sure whether the next shift is friction or index is near impossible.

The next change was too replace the triple crankset with a compact double; the reason can be summed up in one word, "chainsuck" (I don't know is that two words?). The original "Cyclone" crankset (not Suntour), was a middle of the line crank, similar to a Shimano Tiagra or Sora, with a Shimano 105 derailleur. The problem seemed to be the middle chain ring. When we would get occasional chainsuck, it would sometimes deform the middle chainring, leading to more chainsuck. I would remove the middle chainring, pound it flat and re-install it; it would work for a while, but eventually chainsuck would rear it's ugly head, which has resulted in us falling over several times and sometimes having to limp through a ride with no workable middle chain ring. My bride made it clear, "This is your thing, I don't care what you have to do; fix it!"

I had two thoughts. The first was a better crankset would fix the problem, but there are limited choices. My thought was if I could find a highly quality square taper crankset, then I wouldn't need it to be tandem specific. My other thought was to go with a compact crank and eliminate chainsuck entirely. FSA is the main player with tandem cranksets with their Gossamer aluminum ($205) and SLK carbon ($305) including FSA exterior bottom brackets. I also had the plan of buying a DuraAce triple and converting a Ultegra arm by heli-coiling reverse pedal threads. The DuraAce crank was an ebay item, that while I paid for it with "Buy-it-now" they were never delivered. I finally spotted this Sugino Alpina2-800D, compact 48/34. It was one of the nicest square taper compact cranks I have seen (second only to Sugino Mighty Tour) and my choice was made. The primary issue with the compact crank was losing the low, 30:30 gear. My solution was upping the cassette to a from a 11-30 to a 11-32, leaving me with a 34:32; almost the same gear ratio. We went for our first ride and it was magic. Before, every time I down shifted the front derailleur from the middle to granny gear, I would wince, hoping it would not chainsuck. Now, no worries! The gearing was spot on and no chance of chainsuck ever. More important, my bride was very happy.

No comments: