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View Full Version : Performance difference between Shimano R785 vs R8070 Calipers?

thermalattorney
06-12-2018, 12:14 PM
Been riding the first-gen Di2 hydro setup since 2015 and have loved it. It worked great, despite the wonky levers. Decided to upgrade to the new R8070 Ultegra levers, along with a flat mount fork and matching R8070 front brake.

The result has been underwhelming and I'd love some input as to why. Despite being properly bedded in and having firm lever feel at the front, one-finger braking from the hoods with this new setup is harder. Even tried the old front caliper out using the ridiculous looking flat-post adaptor and the results were noticeably better.

Old setup:
Whisky No7 post mount fork
R785 levers
RS785 post-mount brakes
BH59 hose

New setup:
Hylix flat mount fork
R8070 levers
R8070 front brake
RS785 rear brake
BH90 hose

Those R785 brakes are just rebadged XTs and it looks like the pads have easily a third more contact area. Is this just down to the size of the brake pad? Does it have to do with the lever shape/design? Could this come down to the flat mount needing to be faced?
Gummee
06-12-2018, 03:27 PM
Is that the right hose for the calipers? I don't have the Shimano compatibility chart in front of me

M
thermalattorney
06-12-2018, 04:28 PM
Yeah, I bought the levers and calipers as a set (the only was I could even get ahold of the levers at the time). It's the BH90-JK-SSR kit.
ergott
06-12-2018, 04:47 PM
I heard the new gen brake hose isn't as stiff so it kills the feel a bit (but it's lighter:rolleyes:)

If it's compatible, I'd consider changing to XTR brake hose. That's a relatively inexpensive mod.
NHAero
06-12-2018, 05:53 PM
Same rotor?
thermalattorney
06-12-2018, 07:58 PM
I heard the new gen brake hose isn't as stiff so it kills the feel a bit (but it's lighter:rolleyes:)

If it's compatible, I'd consider changing to XTR brake hose. That's a relatively inexpensive mod.

That would be a bit of a bummer if true. I've already got an extra section of BH59 hose, maybe I'll order extra some olives and barbs to test this out.

Same rotor?

Yup :confused:
Gummee
06-13-2018, 09:38 AM
Could also be the difference between metallic and organic pads

Dunno

M