brake pull ratios

[e-rider]

Hi, do all Shimano road brake levers/calipers use the same pull ratio?
I want to run 105 5600 sti levers with Dura Ace 9000 calipers.

 

[RecordAceFromNew]

Hi, do all Shimano road brake levers/calipers use the same pull ratio?
I want to run 105 5600 sti levers with Dura Ace 9000 calipers.

The simple answer is no.

The 9000 is backward compatible with 7900, and with that the relevant compatibility chart is here.

The newer Shimano sti's pull more cable, around 20% more. The key implication mechanically is that new levers on old calipers will give you weaker brakes, while old levers on new calipers will give you stronger brake force but the levers will bottom out more readily than expected if you don't have true rims and tight pad/rim clearance.

The complicated answer, is that since the difference is only 20% which can easily manifest in different makes/models/reach in brakes and levers, the incompatibility is generally considered to be manageable - you just have to take a bit more care in setup/test and pad adjustment/choice etc. to be safe.

Hope it helps.

 

[e-rider]

The simple answer is no.

The 9000 is backward compatible with 7900, and with that the relevant compatibility chart is here.

The newer Shimano sti's pull more cable, around 20% more. The key implication mechanically is that new levers on old calipers will give you weaker brakes, while old levers on new calipers will give you stronger brake force but the levers will bottom out more readily than expected if you don't have true rims and tight pad/rim clearance.

The complicated answer, is that since the difference is only 20% which can easily manifest in different makes/models/reach in brakes and levers, the incompatibility is generally considered to be manageable - you just have to take a bit more care in setup/test and pad adjustment/choice etc. to be safe.

Hope it helps.

Thanks, might delay that upgrade until I go full Dura Ace (probably could afford a full Dura Ace gruppo in 2020!)

 

[HLaB]

The simple answer is no.

The 9000 is backward compatible with 7900, and with that the relevant compatibility chart is here.

The newer Shimano sti's pull more cable, around 20% more. The key implication mechanically is that new levers on old calipers will give you weaker brakes, while old levers on new calipers will give you stronger brake force but the levers will bottom out more readily than expected if you don't have true rims and tight pad/rim clearance.

The complicated answer, is that since the difference is only 20% which can easily manifest in different makes/models/reach in brakes and levers, the incompatibility is generally considered to be manageable - you just have to take a bit more care in setup/test and pad adjustment/choice etc. to be safe.

Hope it helps.

Thats what I love about this forum, you learn something new every day

 

[Foghat]

the incompatibility is generally considered to be manageable - you just have to take a bit more care in setup/test and pad adjustment/choice etc. to be safe.

In my experience, Dura Ace 9000 levers work extremely well with the ('old') long-reach Shimano BR-600 and BR-650 calipers - there is little discernible difference when compared with the new standard 9000 calipers. Even with the older brakes, the braking action is very powerful and smooth (all with standard Shimano-issue blocks), and of course the blocks are suitably far away from the rim with such a set-up.

Whatever Shimano says, I've found the new levers are very compatible with old calipers (long-reach ones, at least, and I expect the standard short old calipers would work just as well).