my 'One by.' I'm running a 13-30 7 speed cassette with a 40 tooth chainring. LX long cage derailer (it was on the bike before) and a suntour power ratchet shifter (actually the front shifter, mounted upside down. The rear is on my GF's 1X9). The handlebars are a moded wald 8095, bend to make the sweeps almost parallel to the top tube.



The chainguard is a 45 tooth chainring, previously shark-toothed to death, that had an unfortunate accident with a grinding wheel. it actually does a great job of keeping my pants from getting caught in the chain, but it turns out it does a lousy job of preventing derailment. For the first 100 miles or so my chain kept jumping off, and I couldn't figure it out. After very carefully watching the chain, I realized the chainguard was catching it, and deflecting it just enough to cause derailment. A few mm spacers and it was solved, not a single derailment issue since. Oh, there's nothing to stop derailment on the inside.



Trust me, I've tried to derail it. The shifter is just at my thumb, so the temptation to shift is great. I've gotten into the habit of shifting way down at stop lights, and starting up in such a low gear that I pop a small wheelie. I'm sure this is enhanced by the upright riding position (yeah, the handlebars are a little lower than the seat, but the reach is almost nothing, so I end up rather upright). Even shifting fast as I can from one end of the cassette to the other, I can't derail the chain. I'm sure it's just some variant on chainstay length, derailer tension and a little bit of voodoo.