Dura Ace Di2 Hydraulic brakes (R9170)

Discuss light weight issues concerning road bikes & parts.
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JayUK
Posts: 44
Joined: Sat Jun 03, 2017 2:56 pm

by JayUK

Hi all,

Can anyone with this setup let me know where the free stroke screw is located on the levers? For the life of me I cant find it :(

Also, I have a lot of travel on the brake lever (it virtually pulls back to the handlebar). I have bled the system, it does this on both front and back. Is there a way to adjust this? (I don't think there is). This is not a reach adjustment issue.

Thanks,

J.

by Weenie


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ms6073
Posts: 2427
Joined: Fri Jul 23, 2004 8:24 pm
Location: Houston, Texas

by ms6073

Checkout page 166 of the Shimano DM-R9150 Dealer Manual and you will find the image below:

Image
Michael - The Anaerobic Threshold is neither...

boots2000
Posts: 1440
Joined: Mon Oct 15, 2007 9:28 pm

by boots2000

Interesting- I just shortened the reach on mine, free stroke felt pretty spot on.
If you have too much level travel, you might need more fluid in the system?

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wheelbuilder
Posts: 444
Joined: Wed Feb 08, 2017 2:10 am

by wheelbuilder

boots2000 wrote:Interesting- I just shortened the reach on mine, free stroke felt pretty spot on.
If you have too much level travel, you might need more fluid in the system?



This. With the pads installed and the red pad spacer between them, attach your syringe to the caliper bleed port only. Open the valve and force some fluid into the caliper. While you are still applying pressure to syringe, close the valve. This will reduce pad travel.

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ms6073
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Joined: Fri Jul 23, 2004 8:24 pm
Location: Houston, Texas

by ms6073

JayUK wrote:(it virtually pulls back to the handlebar). I have bled the system

Based on my experience with two sets of the ST-R9170 levers, 9150 calipers, and BH-90 hydraulic hose, if lever travel is excessive, then the system is not adequately bled. When I bled ours with the yellow brake block installed, I bled them until lever travel was very minimal.

Which rotors? Brake calipers? Are you using Shimano BH-90 hydraulic hose? If you are using 3rd party rotors, I think many of the super light rotor options come in at only 1.8mm thick versus 2 mm for the RT-99 IceTech or the Dura Ace SM-RT900 rotors which might account for the added lever travel. As for hydraulic hose, the SM-BH59 is the old wider bore hose that was spec'd for the non-series ST-R785 levers and SM-BH90 is the newer narrow bore hose that should be used for the 9150/9170 levers.
Michael - The Anaerobic Threshold is neither...

JayUK
Posts: 44
Joined: Sat Jun 03, 2017 2:56 pm

by JayUK

Hi all,

After a ride I re-bled the system and it seems better now.

Thanks for replying :)

J.

ps - BH90 hose, R9170 callipers and rotors

by Weenie


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