Dura Ace 7900 question

[desert rider 119]

Today when I was out riding my rear shifter suddendly went out. It would shift into lower gears with the brake lever, but it felt like a broken cable when I tried to go into a higher gear. The inner lever felt loose and would move almost 90 degrees. The suddendly it started shifting properely again. The bike is only about a month old.

When I got home I put it on the stand and it shifted flawlessly several times. Any ideas as to what is going on?

Thanks in Advance
Desert Rider

 

[Christophe]

Stuck pawl in the ratchet of the shift lever? I wouldn't expect this on a new shifter...

 

[brianf7]

Today when I was out riding my rear shifter suddendly went out. It would shift into lower gears with the brake lever, but it felt like a broken cable when I tried to go into a higher gear. The inner lever felt loose and would move almost 90 degrees. The suddendly it started shifting properely again. The bike is only about a month old.

When I got home I put it on the stand and it shifted flawlessly several times. Any ideas as to what is going on?

Thanks in Advance
Desert Rider

Without looking its hard but check the ends of the outer casing be sure the casing has not got a wire loose and into the shifter . some bike shops assemble the cables without cable ends they can get away with just crimping the casing. It dosnt last you need the proper outer casing ends

 

[Bustedknuckle]

Today when I was out riding my rear shifter suddendly went out. It would shift into lower gears with the brake lever, but it felt like a broken cable when I tried to go into a higher gear. The inner lever felt loose and would move almost 90 degrees. The suddendly it started shifting properely again. The bike is only about a month old.

When I got home I put it on the stand and it shifted flawlessly several times. Any ideas as to what is going on?

Thanks in Advance
Desert Rider

Pull the shift cable out and make sure it's not breaking at the head. Not a bad idea to flush the lever with a spray lube altho unusual for a new and 7900 lever.

 

[desert rider 119]

Thanks to all

I checked everything mentioned in the replys and looks great. When I called and talked to the store where we bought the bike I was told that the Specialized rep told them they were having trouble with some of the 2011 dura ace bikes and the shifter. They were told that the problem happens every one and a while and goes away. The dealer is being great and told me if I had any more problems he would send me a new 7900 in the mail. (he is 250 miles from here). If it goes out again I'll repost and let you know what the result is.

 

[_yngve_]

Watch this closely. 6500 series Ultegra shifters had an internal plastic cog with a nasty habit of shearing teeth over time, causing this precise problem. The failure mode is progressive, with occasional failed shifts at the onset eventually becoming a total inability to shift into a lower gear (this happened to my bro-in-law immediately before the first big climb during the Zion century few years ago. He ended up doing 50 miles with only two gears (big and small ring) before throwing in the towel at the turnaround point (conveniently close to the pizza place in Springdale UT).