Genius integrates Shimano Di2 and SRAM hydraulic components

What do you do when the bicycle industry cannot manufacture parts that meet your specific needs? If you are a design engineer and pneumatic expert Paul Townsend, you will manufacture your own products and steal parts from competing brands.
Paul commented on the function of road technology dead-end (with hydraulic rim brakes) with his unique SRAM-Shimano hacker photo, we must learn more.
As early as the beginning of 2016, the road group market looked very different from now. Shimano has not yet launched its Dura-Ace R9170 disc and Di2 combo kit (non-series R875 joysticks and matching brakes are the only hydraulic/Di2 options), and SRAM’s Red eTap HRD is still months away.
Paul wanted to use hydraulic rim brakes on his road bike, but he was not satisfied with Magura brake calipers.
SRAM’s lever with hydraulic rim brake has many discounts. He is a fan of Shimano Di2 gearbox, so he decided to combine the two into a unique DIY mashup.
This involves migrating the brake lever and shift button assembly and related electronic equipment from a set of Di2 joysticks to the SRAM hydraulic road joystick body.
The SRAM hydraulic system remains unchanged, but is operated by Shimano lever blades, and gear shifting is entirely based on Di2.
I asked Paul some questions to learn more about his extraordinary setup: how he works, his engineering background, and what’s next. Paul’s answer has been edited for length and clarity.
Before proceeding, we should point out that modifying your braking system in any way may cause serious injury, and we do not recommend that you do this. Modifications to components will usually also invalidate the manufacturer’s warranty.
Since the 1980s, I have been riding a bicycle when I was studying mechanical engineering at Coventry Poly University. At the time I had a Topanga Sidewinder and a Mick Ives mountain bike.
I have worked in bicycle manufacturing and custom settings, and have been a design engineer and pneumatic expert for a long time. I have also modified cars and bicycles for many years.
I had a Canyon Ultimate in 2013 and have always liked technology, so first I equipped it with Shimano Ultegra 6770 Di2 external cable group.
Then, I upgraded the brakes and tried Magura RT6 hydraulic rim brakes. Frankly speaking, it was troublesome, and it was troublesome to install and install.
I have made a clutch derailleur for my off-road motorcycle and put the Formula RR clone disc brake on it with Di2 shifting. It worked fine, but around this time, the price of SRAM HydroR hydraulic rim brakes and levers on Planet-X was ridiculously low.
After studying how the SRAM components fit together and knowing the space required for the Di2 module, I bought a HydroR rim brake for £100. Later, I bought four more sets for me, a partner and a person in the United States.
In the past, I also made wheels and Gravity Research Pipe Dream-style V brakes for my off-road motorcycles, and then made mashups for other bicycles.
Therefore, our idea is: hydraulic disc brakes have a rich touch and slight leverage. Maguras is painful and embarrassing, so if I want to equip a road bike with hydraulic rim brakes, I can choose SRAM, but I like Di2.
How difficult is it to combine the two? After removing the speed change mechanism, there is a large hole in the SRAM rod body, so the answer is: it is very simple.
I bought some second-hand 6770 Di2 gear levers. Because the 11-speed Ultegra 6870 Di2 is a new product, many people mistakenly sold the 6770 gear lever to upgrade [error because the 6770 can actually be used with the 6870 derailleur]. I think I bought a pair of leverage for about £50.
My setup uses the existing pivot hole in the Di2 brake lever, and pushes the metal and plastic rapid prototyping (3D printed) parts of the original Di2 brake lever onto the brake master cylinder, so the structural strength will not be so high. one question.
I cut off the excess part from the top of the 6770 Di2 handle, processed it mechanically, and then glued it to the sintered rapid prototyping nylon part.
I reamed the hole to make the hole smooth and the right size. With a little paint, or Shimano gray-green nail polish in this case, I’m ready to assemble everything.
This arrangement does not use a spare rod return spring or E-clip to fix the shaft, so the shaft is drilled and tapped to obtain a countersunk screw whose head is larger than the pivot pin. Once the lever body also sinks slightly, the head is flush.
A conical return spring is added to the brake master cylinder shaft to provide a return force for the lever.
After that, the only modification I made was to add a small cross-sectional O-ring to the old E-clamp groove of the pivot pin to prevent the brake lever blades from rattling slightly.
The Di2 cable extends in the groove on the bottom side of the 3D printed plastic head of the brake lever, so it is fixed and will not get stuck or worn.
After removing all shifter mechanisms, the only way to modify the SRAM parts is to file the grooves to lay the Di2 cable. The Di2 module is fixed with a piece of foam in the space behind.
I also ran a cracked sprint shifter system, connecting the old Dura-Ace 7970 Di2 switch from the SW-R600 climbing shift switch to the electronic module, and all the switches were connected to the left stick. The cord was extended to provide a neat plug-in solution, and when I ran the Canyon clone integrated lever handle setup, the Junction’A'Di2 box in the shaft was in it.
The brakes have titanium fittings and light brake pad brackets. They are mounted on a 52 cm frame. The total weight of the front wheels is 375g, the total weight of the rear wheels is 390g, and the total weight of the rear wheels is 390g.
Yes, I want to say that it was a success. I sold a set to a person in Hong Kong, who also shipped me SRAM Red and Dura-Ace to make this mashup.
I sold another set of equipment to a person in Australia to use on his TT bike, and sold one third to a person in the United States, so that I could pay all my expenses.
If I pay the full price for all of this, it will be a greater risk. Moreover, I can always return SRAM parts to stock mechanical shifts without any problems.
Maybe I will give the lever a stronger return spring. I do need a thread lock to stop the change in the range of travel during driving, because I completely unscrewed the brake adjuster and stripped the original thread lock.
Yes, I am developing some new rock climbing and sprint gear levers, and I am looking for a different arrangement in which the front gear lever will be an auxiliary lever, such as the thumb paddles on the Campagnolo gear lever.
The original idea was right-hand upshift and left-hand downshift, and I am still trying to use which lever blade.
I can stick to the flat SRAM brake lever blades or use Campagnolo, and then keep the SRAM lever blades for the rear derailleur gearbox and new levers for the front derailleur gearbox.
This should mean that there will be no misalignment even when wearing gloves, which may be a problem in winter under Shimano’s standard settings.
Thank you very much Paul for answering my question and providing images. For more tips about him, please follow him on Flickr and Instagram, or read his posts under the username motorapido on the Weight Weenies forum.
Matthew Allen (formerly Allen) is an experienced mechanic and an expert in bicycle technology. He appreciates the practical and ingenious design. Originally a Louis, he liked bicycles and every stripe equipment. Over the years, he has tested various products for BikeRadar, Cycling Plus, etc. For a long time, Matthew’s heart belonged to Scott Addict, but he is currently enjoying Specialized’s sublime Roubaix Expert and has a close relationship with Giant Trance e-MTB. He is 174 cm tall and weighs 53 kg. It seems that he should be better than riding a bicycle, and he is satisfied.
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Post time: Apr-26-2021