SRAM Shifting Problem - Anybody else?
 

Just curious if anybody else experiences this and if it's exclusive to SRAM or if it's just because i'm shifting stupidly. When I'm in the big ring in the front and I'm starting to get into a cross-chain situation, I'll hit both levers at the same time so that I shift to the small ring in the front and shift to a smaller/harder gear in the back. When I do this, every once in a while, the drivetrain locks up and the rear derailleur gets sucked up and i think slams against the chain stay. I have never actually damaged anything from it happening and I just release tension on the pedals and it fixes itself. I avoid shifting in this manner as much as possible but was just curious if this is normal since the RD has so much slack to make up while it's trying to shift. So, anybody else have this?

Oh yeah, I think I've only noticed it on my Force bike and not on my Rival bike. The Rival is newer but I don't think that should matter.

Your RD is hitting your chain stay? I doubt it. I believe you that it's getting jammed up, just not because of your chain stay. It's not a specific trait to SRAM, just ease off for a half a pedal stroke.

I'm just guessing here, but I think the more 'in-tune' your FD/RD are the less likely this is to happen. I remember this happening to me in the past, but not since I started working on my own bike and getting everything really dialed in. So it might just be correlation that it doesn't happen anymore (since I probably soft pedal a bit and don't think about it) or it might be causation (because my drivetrain is better tuned now).

A suggestion that might help, increase b-tension on your RD. I might be totally wrong though, so take with a couple grains of salt.

Yeah, I'm sure it doesn't actually hit the chain stay but it seems like it...it gets pulled that direction as far as it can go. I'll give the b-tension a shot. I haven't messed with that at all since I built my Felt so who knows, maybe that'll help. Other than this little issue, the bike shifts perfectly so I'm not really that worried about it, was mostly curious if others had run into this. Thanks for the suggestion.

Don't shift both at the same time. Do one than the other. You will find it is much smoother. Also soft pedal as you shift.

With SRAM you don't have to soft pedal. But I don't recommend shifting both rings simultaneously.

I was climbing up a hill and shifted from large ring to small. SNAP! there goes the chain. SRAM Red 1090R w/ Force FD... sux, I wasnt even mashing it..

I believe what you are doing it creating too much slack in the chain at one time. Shift front to small then quickly shift rear where you want it. I've had what you are talking about happen with DI2 when I was playing with the Front Derailleur shifting back and forth as fast as I could trying to get it to mess up.

I too have had that happen. Don't shift both at the same time.

Train yourself to do front, wait a tiny amount of time, then back. The shift is just as quick as the back shifts much quicker and it'll go better for you.

But, no, I've never had that happen.

+1 This

^fo sho.

quick motion... BAM(front)-CLICKCLICK(rear)

I think you answered your own question in your post. Don't shift at the same time.

I do this often and have never had it jam up.

I don't use the Sram chain (although I have one on there now as it's a new bike), preferring to use a stockpile of 7800 chains I got a while back. I have a Sram chain on my Rival bike that's in a trainer right now, shift it up and down under load in the trainer sprinting cadence, no sweat.

Stuff breaks. Nothing's forever. But I'd be pissed if it happened to me. I'm pretty picky about chains. If they get even a little stretched, off they come.

Just happened to me the other night on the trainer. If I recall correctly I was shifting the same way when it happened. First time that it happened. Mental note not to shift at the same time.

Cool, thanks guys. I will just make sure I avoid shifting like this in the future. I was thinking and maybe the reason my Rival bike doesn't do it as much is because I cross-chain a bit more freely on that bike. It has the front trim in the big ring and maybe that makes me more comfortable cross-chaining. I don't know.

I have not had this problem with my SRAM but again I don't shift both at the same time.

i've dropped my chain once doing that with shimano. haven't attempted it since. as others have said, i think that method is the issue rather than the SRAM.