UltegraSL brakes ok with DA 7900 shifters?

Triathlon Forum
1

I have read some conflicting statements that UltegraSL caliper brakes don’t work so well with DA 7900 shifter/brake levers due to a different leverage ratio? Anyone ever heard of this? Several bike companies spec Ultegra brakes with the new DA brifters so it seems odd they would not be compatible.

2

While I’ve never experienced it to know for sure, I can tell you that AFAIK all Shimano parts have the same pull ratio for the very reason to make them interchangeable. As well all the aftermarket companies would have to make 2 versions of their brakes for different pull ratios, and we know that hasn’t happened. Whomever told you otherwise is likely misinformed. That said, Campagnolo brakes wont work with them because of this issue, but that wasn’t your question.

3

I don’t have any specific information for you but I can hardly imagine that they wouldn’t work just fine.

4

You aren’t misinformed, the new DA does have a different actuation ratio.

It isn’t, however, so different that the older brake calipers won’t work; they just won’t work as well. Most people won’t even notice the difference, it just depends on how you like your brakes and how picky you are as to whether it will be OK for you.It certainly works well enough that there is no safety issue.

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5

Thanks for that definitive word. I noticed Specialized, for one, specs some pretty high end bikes with DA 7900 shifters and ders but uses Ultegra calipers. I know the down spec is to hit certain price points but I would assume they wouldn’t do it if there were significant performance issues.

6

On the 2010 bikes, they are speccing the new Ultegra, which has also changed to the different actuation ratio…

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7

Supposedly the DA7900 has a gain ratio of 1.4 and the older Shimano brakes were 1.3. I have no idea what a gain ratio is, except maybe it pertains to the amount of leverage created by cable pull.

I do know that the new Ult 6800 will be using the new leverage, so you could “downgrade” the brakes with the new 6800. I’m guess you would not want to use your old brakes with the redesigned levers.