I have taken my D/A off my old P3 and put it onto my new LOOK KG 486. Then I went for a ride. When shifting from the big ring to the small ring at the front it threw the chain off the small ring a couple of times. I was at a large ring on the rear cassette. This never used to happen on the P3.
Anyone have any advice or tips…??
Adjust the low stop on your deraileur
http://www.parktool.com/repair_help/howfix_frontderailleur.shtml
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Adjust the low stop on your deraileur
http://www.parktool.com/repair_help/howfix_frontderailleur.shtml
What he said. Adjust the lower (and probably also the upper) limit screws on your front derailleur.
While you are at it, it might be wise to check the adjustments for the rear der too. Throwing a chain off the large cog into your spokes can damage your wheel and possibly cause a crash.
I threw my chain off the big cog (into the spokes) several years ago. My rear wheel locked up. Thankfully, I was going uphill. But it took me a while to get the chain unpinched from between the cog and my spokes. The stress of the pinching apparently did some damage to my spokes, as I broke a spoke at least once a week for the next several weeks. I ended up just replacing them all.
Third Eye Chain Watcher. Cheap, light, and good insurance.
when shifting from big ring to small, it makes sense to be in the middle of the cassette.
Adjusting the stops will probably solve it - and I don’t know that you are unaware of this, so apologies if I’m insulting your experience - But, on the occasion that the chain jumps off your rings you can always flip the derailluer back the other way and it will jump back on.
This will ALWAYS work, as long as the chain is not bent and you haven’t lost much speed or cadence. It’s a useful skill to practice for any kind of race or group ride when getting dropped is a bummer.
Peace
TK
i threw 2 on my first ride of the season tuesday…
the irony is that is was JUST tuned up @ the bike shop…cost me over 150cdn…
grrr…
…tuned up @ the bike shop…cost me over 150cdn…
grrr…
There’s your first mistake. Do it yourself 
Adjusting the stops will probably solve it - and I don’t know that you are unaware of this, so apologies if I’m insulting your experience - But, on the occasion that the chain jumps off your rings you can always flip the derailluer back the other way and it will jump back on.
This will ALWAYS work, as long as the chain is not bent and you haven’t lost much speed or cadence. It’s a useful skill to practice for any kind of race or group ride when getting dropped is a bummer.
Peace
TK ____________________________________________________ no damnit, it will not always work. and anyone who believes it will is an idiot. never say never, and never say always.
Third Eye Chain Watcher. Cheap, light, and good insurance.
If only they made a big oval one to fit on non-round seat tubes.
I’m going to expand on something P2K said earlier. The reason you want to shift back and forth in the middle of the cog is to keep a decent chainline. Riding big ring/large rear cogs creates a heinous angle between the front-to-back and is likely even more pronounced on a bike with short chainstays. This angle increase friction and wears out your cogs, chain and chainrings.
For this reason there is a lot of overlap in the normal 53/42 chainring combo used with a 11 or 12-21 or 23 cassette. It is really best to keep the chain in the middle four or five cogs to keep the chainline nice and straight. Use the 12-17 with the big ring and the 14-21 or 23 with the small ring and you will normally be fine. The worst possible combo is riding much in the big ring and the last three large cogs. The large ring accentuates the bad chainline. In no case should should ever ride in the big cog and the big ring. This will create a lot of tension in your chain and the angle will be really bad.
I like to shift from the big to small ring when I hit the 17 cog because a quick double shift will get me from 54x17 to 44x14 or so. This allows you to progress up the cassette from 12-17 in one tooth jumps and then start again with the 14 back up to the 17 with more one tooth jumps. When you are trying to keep a nice consistent rpm those one-tooth jumps are the key to good rhythm.
Chad
i wish it always worked. On BOTH of the times when I dropped low this week, i was unable to get the chain back up to either of the rings w/o stopping and using my hands. Shifted to big ring, nothing, shifted all the way to the 11 cog, nothing, tried both @ the same time, nothing…it was essentially useless.