Thanks, CDR.
Originally Posted by
carpediemracing
I wouldn't shorten the chain unless you're running a max length chain (barely clears the pulleys in the small-small) or you go to a smaller small chainring or cog.
Shortening it is mainly to reduce the chance of derailment. That is the idea, at l
Originally Posted by
carpediemracing
If you're really adamant about no front derailleur then I'd just a N-Gear Jumpstop on the inside of the ring. To the outside… don't know, but a big effort in the small-small (like a 34x11 for example) will pull the chain toward the outside of the bike. If you're leaning to the right, if you hit a little bump or something, the chain will come off. I watched it happen in front of me in a Tues Night race a few weeks ago, some jokers insist on doing the race on single speeds (another one showed up on a fixed gear and was told to pull out of the race).
we're looking at 30g or so for the n-gear or similar device. I generally don't drop the chain to the inside--and that would most often happen on a front shift. The chain line for the inner ring only would be untouched. I'd be using the inner ring + a few smaller cogs than I'd normally use, so I think the bigger risk is throwing the chain to the outside....esp as you and a few others say with the inner ring ramped to shift to the outside. A chain guard adds ~60g...so then we're not far off from just keeping the FD on there.
Originally Posted by
carpediemracing
If you can stand the idea of a front derailleur I'd either use something like the downhill racers use or get an older/worn front derailleur and cut the tail off. You want just the U shape thing at the front. While you're at it you can drill holes in it and stuff. Or you can fabricate something with a light band and some piece of welded aluminum (?) to hang a U shape cage over the chain. Remove all the cables and stuff, you just want the U shaped guide so your chain doesn't want to pop off.
Yes. Good point. I remember those on DHer bikes.
Originally Posted by
carpediemracing
Aluminum chainring bolts are just more sensitive to over-tightening. If you hear creaking then it's probably done. If you buy Ti ones you would have more reliability and you could use them on your bike normally. Just use anti-seize and loosen them regularly so they don't freeze.
Thanks! I need the shorter bolts for this application, but then I'd switch back to my normal DA 7900 rings, with the Shimano bolts.
Originally Posted by
carpediemracing
Is it possible to use downtube shifters? Or are there parts where you need to be able to go while shifting?
I'm going to run one di2 shifter on the bars.