Question about electronic shifting

[martinrjensen]

A friend of a buddy was riding a bike equiped with Di2. don't know the bike or anything but this is what happened. They went riding and he dropped a chain and when he clicked to upshift back onto the chainring the chain got wedged and torqued a link, resulting in a new chain being required.
This got me to thinking about the times when I drop a chain. I delicately shift to see if I can get the chain back on the chain ring and usually it works but my question is, or statment is that with electric shifting, you can't just delicately try to shift. It is either going to work or you are going to jam the chain, you can't just stop when you feel resistance correct?(Cause you don't feel resistance).
Now I know that techinically, you should never have a chain drop but it happens, and I have noticed that while all my 4 road bikes are running Campy 10 spd, all have different chainlines and I think that plays into it too.
So I'm wondering what others think. I don't think this is only about Shimano, I would thing the same situation would exist with EPS. This ever a question to you? I never thought about it before this came up and no I don't really know the exact circumstances of how it happened. I was not on the ride.

[fjaws]

1. You're right, if adjusted properly it shouldn't drop

2. Lots of folks with expensive plastic bikes are using the K-Edge as an extra precaution to ensure it can't happen

3. If it does happen and you're concerned about torquing the chain....stop pedaling, make the shift, and pedal slowly until you're sure the chain has engaged the little ring so you can pedal it back on.

[martinrjensen]

Thanks, reply 1 is obvious, reply 2 may be the answer for electronic shifting?. Regarding reply 3, I have a question . If you shift electronic shifting, wouldn't it try to shift all the way over regardless or where the chain actually was? i.e. you really couldn't shift then pedal to see if it moves over? This is where manual shifting comes into play I'm thinking
Regarding reply 1. I have adjusted my derailleur about the best I can and I can still drop a chain if I just slam the shift button all the way down (Campy) when in the low range on the rear (sometimes). I learned to only shift a couple of clicks to get the chain over and that works. If I need to adjust trip, I adjust trim after the fact. I am thinking that depending on chain line, this may be the best you can get at times. note that after I figured this shift technique out, I never drop the chain.
1. You're right, if adjusted properly it shouldn't drop

2. Lots of folks with expensive plastic bikes are using the K-Edge as an extra precaution to ensure it can't happen

3. If it does happen and you're concerned about torquing the chain....stop pedaling, make the shift, and pedal slowly until you're sure the chain has engaged the little ring so you can pedal it back on.

[fjaws]

If it's really that frequent an occurance, I'd go with the K-edge, Chain watcher, or some similar device that makes it impossible to drop the chain. The K-Edge is popular enough, that the new SRAM RED FD comes with a similar device built in.

IMO the front shifting on the DI2 is probably one of its nicer features....it's super smooth and dead on. I haven't heard of any issues with it dropping.

[martinrjensen]

maybe it was just not adjusted properly then....If it's really that frequent an occurance, I'd go with the K-edge, Chain watcher, or some similar device that makes it impossible to drop the chain. The K-Edge is popular enough, that the new SRAM RED FD comes with a similar device built in.

IMO the front shifting on the DI2 is probably one of its nicer features....it's super smooth and dead on. I haven't heard of any issues with it dropping.

[SoCalSteve]

maybe it was just not adjusted properly then....

Exactly!!!

[fjaws]

Exactly!!!

I agree, but he said it was dropping despite being adjusted properly.

[SoCalSteve]

I agree, but he said it was dropping despite being adjusted properly.

I don't see how that could be possible unless his bike is SO flexy that it throws it off that way...

My 2 bikes that have DI2 have never mis-shifted nor have thrown a chain.

[martinrjensen]

I will go with your answer. the big thing that got me thinking about all this was not so much that the bike was mis-adjusted or not was "if" you did drop a chain, when you went to shift the chain back onto the gear, that it could jam and just keep trying rather forcefully to get the chain on the gear come hell or high water. It's very possible that it wasn't properly adjusted also.I mean I always considered that random chain drop to be part of biking. I drop a chain everyonce in a while, maybe once every 10 rides, not really often.I don't see how that could be possible unless his bike is SO flexy that it throws it off that way...

My 2 bikes that have DI2 have never mis-shifted nor have thrown a chain.

[woolly]

I drop a chain everyonce in a while, maybe once every 10 rides, not really often.

1 in 10, that's a lot, isn't it?

[SoCalSteve]

1 in 10, that's a lot, isn't it?

With a properly adjusted fr and rear derauiller, it should be more like 0 out of every ride for the rest of your life...

Just sayin'

[Jack Brunk]

You gotta keep turning the cranks when you upshift. If you think it's going to do it for you then maybe take a cab. It's not rocket science.

[67-59]

1 in 10, that's a lot, isn't it?

I think so. If I drop a chain 1 in every 100 rides running Record 10, I wonder what's wrong...

[oldpotatoe]

I don't see how that could be possible unless his bike is SO flexy that it throws it off that way...

My 2 bikes that have DI2 have never mis-shifted nor have thrown a chain.

All drivetraines 'may' chuck a chain, even electronic ones. That's why they can be 'adjusted'. Chrianrings, chains wear, der plates wear...it sometimes happens, even on those that move ders with trons.

[martinrjensen]

I was just guessing. Actually it's less than that now that I think about it. I have one bike that if I am in certain gears and just slam the button down to shift the chain ring, I might drop. I tried adjusting the limit screw but then I got a touch of chain rub so I backed it out again. I found that if I just don't slam the button down I never drop the chain and it shifts just fine so I learned to do that. Once I do this, I never dropped the chain again. I have another bike that I don't think I dropped a chain on it for well over 2 years and one bike I never dropped a chain one. that leaves one bike that I just don't remember the history on, poor bike. but I do try to ride them all at least. 1 in 10, that's a lot, isn't it?

[martinrjensen]

Referring to the jammed chain maybe this is what the guy did, I don't know, but that certainly would explain jamming when you shift..You gotta keep turning the cranks when you upshift. If you think it's going to do it for you then maybe take a cab. It's not rocket science.

[martinrjensen]

Do you think that you could drop a chain if you tried to on purpose? I don't think the guy did this but it does bring in to the question proper pedaling technique or skill. In my case I slightly changed the way I downshift to eliminate dropped chains as adjustment didn't seem to do it.I think so. If I drop a chain 1 in every 100 rides running Record 10, I wonder what's wrong...