Can't shift to largest gear when on the small ring - SRAM RED
 

Hello,

I have SRAM Red 2013 group installed just a week ago on a brand new frame. Bike has less than 100 miles. Cassette is 11-28T, chainring is compact, 30/54.

My problem is I can't shift into the 28T cog and small ring. I have verified:

- derailleur is not bent
- L limit screw is properly adjusted (I can shift to the 28T by holding the shifter lever, or by pulling the cable, but it won't stay there, as soon as I release it downshifts)
- All other gears work properly on both rings (no hesitation or difficulty in shifting)
- chain catcher on front is not rubbing against the chain when I manually shift to 28T.

I have tried adjusting the cable tension either way but no luck. What else can I try?

put the bike in the smallest rear sprocket, pull gently on the cable, and see if there's another gear position past that on the shifter. if so, cinch up on the cable so THATS your high gear, readjust the indexing to align with a middle gear, and try for the small ring - big cog combo again ...

wouldn't that cause an up-shift? that is going to next larger/easier gear. But you may be onto something, because when I shift to smallest cog I can tap the shifter one more time, like it thinks there is one more to go (harder gear that is).

By cinch up you mean tighten up the cable? if so, can I use the barrel adjuster, or do I need to release the cable, pull on it and retight? do I need to be on the big chainring?

the chain ring shouldn't matter but since we're talking about the small cog, I'd use the big chain ring.

I doubt there's sufficient range on the tension adjust for this. I'd unclamp the cable at the rear derailleur, and pull on it while clicking the 'up shift' button or whatever, to see if it clicks to one more higher (smaller) gear position. if so, I'd screw the tension adjuster most of the way back in (guessing its been cranked out moderately far), pull the cable snug, and tighten the cable clamp, then go through setting the index adjustment on a middle gear, and then try for low gear again.

Installed by whom?

Don't know what you mean by "no luck" - specifics are needed whether something works or does not.

Increasing cable tension must help the shift complete unless as noted above you have run out of adjustment, as that's no different than you pulling on the cable or lever, but probably causes problems in other gears. If so inconsistent shifting, especially between different chainwheels, often indicates an alignment problem. Either the hanger or the derailleur itself (specifically the pulleys) may be twisted left or right in relation to the plane of the freewheel.

If the hanger is bent it would be the responsibility of the provider of the frame. If the derailleur is the problem then it's that provider. If a shop did the installation they should have shifted through all the gears, noted and corrected the problem.

From the Op's initial discription it seems that while the der will move far enough to shift into the large cog the lever won't engage a index "click" there. So either the cable is too loose, and when on the second from largest cog the lever is actually in the large cog position (as pierce said). Or the cable is too too tight and the lever wants a little bit more travel to engage the click. This should be an easy diagnosis for some one with experience. To repeate the question cny-bikeman asked, who set this up? Andy.

just be sure your chain length is correct as well, in case you added some gears in the rear cog.

[ Partial QUOTE=pecos;15203133]Hello, I have SRAM Red 2013 group installed just a week ago on a brand new frame. Bike has less than 100 miles. Cassette is 11-28T, chainring is compact, 30/54. My problem is I can't shift into the 28T cog and small ring. [/QUOTE]

OP Pecos: You are supposed to know not to try to do that! Little/Little is not a viable gear combination. Shifting 101. You need to shift to the large ring before you get to the small cog.

OP Pecos: You are supposed to know not to try to do that! Little/Little is not a viable gear combination. Shifting 101. You need to shift to the large ring before you get to the small cog.[/QUOTE]

Pecos, I assume you meant 34/50 up front. Ksisler, he's trying to get into the big cassette cog, and regardless of the effectiveness of certain combinations, all rear cogs should be accessible from both front rings.

To adjust derailleurs well you really need a workstand. Hang the bike by a hook from the ceiling if you have to.

Study the video "SRAM RED--Derailleurs Installation and Adjustment," at this link, http://www.sram.com/service/sram/3,502. I don't know whether your system was installed properly at a shop, installed improperly by the shop, or installed properly or imporperly by you. I would hazard to guess that if you did the installation properly you wouldn't be writing to us, but you never know. The video explains the process better than I can.

I have to say that double-tap adjustment is less intuitive and slightly fussier than Shimano STI, and even trickier if your bike has hidden shift cables. If, after working from the video, you still aren't getting it, call back with more details about the symptoms and what you did. Also, indicate whether your shift cable is hidden or exposed. Knowing that will make giving you instructions a lot easier.

Heh, what cassette has a 28t for the small cog?

: p