Rigoberto Uran at the 2013 Vuelta.

SRAM S-700 10speed Hydro Road Rim Brake (HRR) Fitment and Bleeding

The release of SRAM RED22 this year started the next major change in road bike setup, the Hydraulic brake. Available in both disc and rim brake version, they are showing up on all types of road and cross bikes. SRAM also released a 10speed offering called S-700. This has the same workings as RED, and while dropping the ti bolts and carbon lever blades, it adds only 35g per end over RED22HRR. To put it another way, S-700 Hydro Rim Brakes will add about 175g to the current 10spd SRAM setup. That’s not much of a trade off to get the power and modulation of Hydraulics.  We got our hands on a set of S-700 HRR brakes to set them up and give this new (to the road) technology a go.

Fitting them to our SRAM force equipped bike meant that the shifters were fitted to the bars after removing the bar tape and leveled and the gear cables slipped into place and connected straight to the existing derailleurs.

The front brake is fitted in exactly the same manner as if it was a mechanical caliper. Run the line in the same fashion as a cable, taped to the bar until the bar tape will cover it. Just remember to centre the caliper using a 13mm spanner on the mount bolt as the caliper is floating on the centre pin more so than a standard brake. The hose may well be too long but we will get to this soon.

The rear brake on our bike was a full length cable outer so fitting the hydro line through the frame was exactly the same as normal. Some frames have removable cable guides at the entry points so these can be modified or removed to run the line. They should be available from your bike supplier so removing and drilling them works well in our experience. If your bike runs the rear brake on the outside of the frame, two small cable ties or aftermarket cable guides will work best to secure the hose along the frame.

Once the calipers are fitted and secure, remove the brake pad holders and pads to keep them away from any brake fluid. Then cut the lines to length using a Hydro Line Cutter which will ensure the ends of the hose are clean and sliced perfectly. Measure the length of the hoses twice as they sit inside the caliper a few mm and may end up short if you’re not watching. New ‘barbs’ and ‘olives’ need to be fitted to the hose after the securing nut is slid back over the hose. A small amount of ‘SRAM Dot Grease’ should be used to help the barb and nut sit correctly in place. On some frames, it might be easier to now remove the caliper again to refit the hose as the 8mm nut can sit close to the frame in some circumstances making it difficult to tighten. If so, remember to hold the caliper pivot pin with a 13mm spanner when removing the mount bolt.

Bleeding the system is next. You’ll need to get your hands on a bleed kit from your IBD, plus new fluid, barbs and olives while you are there. Any off roaders out there switching their road bike to hydro, be aware the process is not exactly the same as for MTB brakes, so you will need to learn the road process. To help out SRAM have a very helpful video of the process on their You-Tube channel.

The lever bleed port is found under the top of the hood and is seated in a recess to help keep everything clean and dry.(IMG 2706 or 07) SRAM recommend either removing the rubber hood completely or pulling it back and covering it with rags to keep it free from brake fluid. The caliper port is easily seen on the front of the caliper arm. 

The barrel adjuster on the caliper also needs to be rotated clockwise until it reaches its stop. This brings the caliper arms closer to each other and will help with bleeding.

Once the syringes are connected to the bleed ports, fluid is passed from the caliper end to the lever to help remove any air that might be in the system. The brake lever is then pulled against the bar and secured with a toe strap to seal off the lever from the rest of the system. The caliper syringe can then be pulled lightly to suck any remaining air back out of the system. You will see bubbles coming from the caliper into the fluid in the syringe when you do this. You can see tiny bubbles expanding seemingly from nowhere in the fluid as the pressure inside the syringe drops during suction. 

Once these bubbles are out of the way, fluid can then be pushed back into the brake as you remove the toe strap and return the lever to its original position. The caliper end of the bleed is now complete. The syringe can be removed and the bleed screw refitted. Unwind the barrel adjusters to their original position and remember to clean any fluid spills with isopropyl alcohol!

The lever then gets the same treatment of pulling lightly on the syringe to remove any random air bubbles. The lever blade also needs to be pulled in and let go to stir up any trapped air in the reservoir.  Light pressure is then applied to the syringe to ensure the system is full before removing the syringe. Some fluid will overflow into the recess around the bleed port, this is fine as it ensures that the system is topped up. Refit the bleed screw and clean the entire area around the bleed port with isopropyl alcohol and also under the rubber hood if any fluid has escaped past your rag. Then give the lever a few good squeezes to ensure there are no leaks. It is a good idea to leave the shifter with the hood still rolled back at this stage to let the area dry completely. Refitting the brake pads and wheels will keep you busy for long enough.

Once the shifter is dry, refit the hoods, grab some new bar tape and adjust your gears as normal. The brake pad position is adjusted with the barrel adjusters at the calipers and they have plenty of room for the new style wide aero rims that are showing up on bikes these days. The lever position is also adjustable from under the shifter arm. Access this one after pulling the shift lever to the bar. The shift lever can then be adjusted to suit the brake lever. At this stage you should have a solid feeling brake lever, fresh looking bar tape and a new reason to get out there and ride, just like we are going to do. 



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