7900 shift levers with 7800 groupset

[DarkWing]

Hi.
My right Shimano dura ace 7800 shiftlever has broken, and I was wondering if I could replace the shift/brake levers with 7900 levers or maybe even SRAM red? The rest of my groupset is 7800.

Also if some of you have some input on 7900 levers vs. SRAM red levers.

Thanks in advance.

 

[Magnus]

According to bikeradar, you can't:

Compatibility

Shimano say the revised cable pull ratios on 7900 essentially make backwards-compatibility with 7800 brake callipers and front derailleurs a no-no. Sadly, we’ll have to mostly agree.

Mixing brake components yields either a too-firm lever with reduced power (7900 levers with 7800 callipers) or a somewhat spongy lever with grabby response. In either case, the distinction is subtle but still noticeable and definitely doesn’t come close to matching the performance of a properly matched 7900 set.

The situation with the front derailleur is an entirely different beast, though. 7900’s increased cable pull is such that any combination of new and old simply doesn’t work at all.

 

[Bustedknuckle]

Hi.
My right Shimano dura ace 7800 shiftlever has broken, and I was wondering if I could replace the shift/brake levers with 7900 levers or maybe even SRAM red? The rest of my groupset is 7800.

Also if some of you have some input on 7900 levers vs. SRAM red levers.

Thanks in advance.

All you need to change with 7900 levers is the front der...all else will work. No go with sram...need rear der with sram levers.

Better reliability and far better FD action on 7900. Red/sram has a way to go in this department.

 

[James Huang]

DarkWing:

What's wrong with your 7800 lever? Oftentimes it's just that the original grease has stiffened up and won't let the little spring-loaded ratchet engage the cable spool. If you haven't tried it already, those shifters (and nearly any other Shimano STI or Rapidfire shifter) can typically be resurrected by purging the old gunk with an aggressive solvent (brake cleaner, White Lightning Clean Streak, etc) for a minute or two, letting it soak in, repeating the purge, then relubing with a heavy oil. I've lost count of how many shifters (and how many hundreds of dollars for my customers) I saved during my shop years.

 

[DarkWing]

thanks guys,
I already tried spraying it with WD 40 - didn't help.

I'm now thinking about getting the new ultegra - shifters, brakes and FD.
Anyone know what the difference is between the ultegra and Dura Ace? other than weight.

 

[James Huang]

Darkwing,

WD-40 really isn't much of a solvent in comparison to the others I've mentioned. If your shifter is displaying the usual symptoms (can't engage the cable spool to shift to easier gears) then one of the two stronger solvents I mentioned should still work. If anything, WD-40 may worsen the situation as it tends to gum up as it dries.

Ultegra vs. Dura-Ace: Virtually no differences aside from materials and weight. Functionally, they're nearly identical as in years past.

Here are links to my reviews of both:

http://www.cyclingnews.com/reviews/shimano-ultegra-6700-group
http://autobus.cyclingnews.com/tech.php?id=tech/2009/reviews/shimano_dura-ace_7900_group09

Hope that helps.