Yokozuna Reaction Brake Cable System

The Japanese firm Yokozuna (from Wikipedia: Yokozuna (横綱) is the highest rank in sumo. The name literally means "horizontal rope") has been supplying high-end cable systems to pro road teams and manufacturers for decades. Available to consumers since 2005, the Reaction Brake Cable System will give your cable-actuated rim or disc brakes a reputation that they frankly don't deserve. Almost like they are attached to a rope being pulled by a sumo wrestler, if you will.

Yokozuna cables come as a brake set (£35.99), a shifter set (£25.99 ), or a combination of the two (£59.99). Their proprietary 'jet lubed' process fills the outer with just the right amount of special grease, to keep things ultra-slick.

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I'm the first to admit that it's nigh-on impossible to get a truly accurate like-for-like comparison between cable systems, so all I can offer you is what can be observed from one person's experience over a few months of installation then use.

Under pressure

For the uninitiated, there are two types of cable outer on your bike – gear and brake. Gear cable needs high accuracy through low compression loss, but is subject to tiny forces. Brake cable is more tolerant of compression loss, but must withstand comparatively enormous forces. Therefore the cables are built differently.

Gear cable has lots of thin wires running the length of the outer (longitudinally), so in theory when you shift gears the outer does not compress, keeping things accurate as all the tension put on the cable end at the shifter is transmitted to the derailleur. Brake outer is spiral-bound, making it impossible for the inner wire to burst through the outer under hard braking, but the trade-off is that there is room for the spirals to compress together – there's a tiny amount of space between them, otherwise they wouldn't be able to flex around the bends of your bike.

Yokozuna's magic sauce is the double layer of longitudinal wires wrapped in a circular binding to keep them in place. Other brands such as Jagwire use a Kevlar wrap to keep the longitudinal wires in place on their 'compressionless' housing, but in my opinion they don't do as good a job.

Critical path

Because of the double layer, the Yokozuna outer is stiff. Very stiff. Yokozuna advises: 'Brake housing is stiffer than normal housing. Set-ups that need tighter bends may not be possible with our Rapidwire brake housing.' In reality I had no issues fitting a full run of the housing inside the frame of my Merida Ride 5000 – but Merida has done a pretty good job of minimising bends and putting the cable entry/exit points where they should be. I could imagine on more esoteric designs or full-suspension bikes, things could get pretty tight.

As with all internally routed setups you need to have a good plan for getting from A to B, the easiest of which is not to pull out the old outer before you've threaded the new outer onto the end of the run using a protruding bit of the old inner cable to hold it aligned. A combination of pushing the new while pulling the old should do all right – smear a light layer of grease on the new outer to make things a lot easier.

Tooled-up

Yokozuna advises: 'Housing is very stiff and strong; for best results cut with a sharp cable cutter or a Dremel tool. We do not warranty housing ruined with dull cutters.' I concur – the outer is much harder to cut than standard Shimano SLR outer. I cannot imagine doing this with a set of pliers. I'd suggest spending £10-15 on a decent set of cable outer shears as a once-in-a-lifetime purchase and be done with it.

Being a certified fettler, I use a bench grinder to tidy up my cable outer ends – and on the Yokozuna outers it earnt every penny of its £18 price. The combination of the two layers made for quite devilish work getting them completely tidy and square-on. I found the outer spiral binding to be very springy, and under even a small amount of heat from the grinding process the plastic sheath gave way, allowing the very sharp end to spring free. I'd recommend practising on an offcut to get your eye in before a final, critical-length installation.

Getting the ends clean and tidy is critical for subsequent installation into the shifters, where the cable is inserted without any sort of endcap. You should check the depth of the hole, then lightly mark the outer to be one hundred per cent certain that it's seated all the way home. I found the fit to be so tight (Ultegra 6800 levers) that I had to partly remove the lever from the bar to allow the outer to slot in the hole – even the slightest bend in the outer trying to do this with the lever bolted to the bar made the job impossible. Again, a dab of smeared grease on the outside made the exercise easier.

As mentioned, you really need a bench grinder or at the least a Dremel tool to tidy the ends of the cable, so once I'd threaded everything through and confirmed the correct length, I then unthreaded them, putting the old housing back in place (with inner as a guidewire) to allow a proper tidy-up of the second end. This sounds like a faff, but in reality takes only a minute or so – assuming you remember to reinstall the old outer/inner as a guide. If you don't, god have mercy on your soul and wallet as you head off to purchase Park's rather nifty Internal Cable Routing Kit...

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Once your outer is all settled in place, the inner is installed just like any other. It's stainless steel to remove corrosion as a risk and die-drawn to further reduce friction. The inner ends are both road and flat-bar lever-compatible, so make sure you cut off the right one.

Rinse and repeat for the front brake, being acutely aware of how the cables interplay at the front end when turning the bar. When you re-secure your bar tape you might find you need a bit more electrical tape to hold the much stiffer outer in place – it's unlikely that the tacky branded stuff included in bar tape packages will be up to the job.

Reaction time

The benchmark for this test was the Jagwire KEB-SL Kevlar-wound outer, which came factory-installed on my Merida. At one end the aforementioned Ultegra 6800 lever, at the other the excellent TRP Hy/Rd hydraulic cable-actuated calliper. While fully hydraulic systems have come down markedly in price there is still a premium attached, and people looking to retain the Ultegra levers might not be keen to fork out the £630 RRP (often half that) for the same shifting but better braking. You can pick up a set of new TRP Hy/Rds for around £100 (used for less), spend the £36 on Yokozuna cable, and hey presto!

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I think this is where the Yokozuna cable system fits best – as a means to get hydraulic-grade braking for full-length rear cable runs at a fraction of the cost. And I can honestly say that is my view after two months riding the new setup – that my brakes are now on-par (as memory best serves) with the hydraulic RS-685 levers/callipers I used earlier in the year. In fact, the performance change using the Yokozuna cables over the Jagwires was so marked that the first few rides I had to make a conscious effort to think about braking – fewer fingers required, more control on tap, and on one occasion where an emergency stop was required, a stern word with a recalcitrant muscle memory used to pressing down much harder on the stop button. I don't recall being that impressed with the Jagwire system when it was new – to the point of wondering if it was the compressionless version. So again, anecdote – but informed anecdote.

A major issue with full-length cable runs is the inherently higher friction preventing the calliper return spring from retracting the inner cable when you release the brake – leading to a rattling lever that can be maddening. With the Yokozuna cables the lever snaps back into place every time, no visit to the niggling noise therapist required.

The long run

Only having done two months' riding since installation, my anecdotal greatly improved performance can only be that. I'll pop back and update this review next spring, after a winter's worth of water, crud and freezing temperatures have done their best. But based on the experience to date, I suspect I'll only have good things to report.

Verdict

Improves braking performance to unheard-of levels