Jagwire “Racer” DIY cable/housing kit (~$45) offers consumers an improvement for shift/brake performance as well as aesthetic tweaks to their machines. The Racer kit is targeted to roadies, contains cables and housing that fit both SRAM and Shimano systems. The Racer kits have a lot of technical features including teflon-coated cables, “L3” lined housing, sealed ferrules. The brake housing is probably the most special, since it consists of coaxial reinforcing wires rather than spiral-wound flat ribbon like typical brake housing. Coaxial reinforcement is standard nowadays for indexed shift housing, as the coaxial housing compresses less than spiral-wound, but it is generally unsuited for brake cables because the higher loads of brakes threaten to burst the coaxial wires outward with the housing collapsing like an accordion, resulting in dangerous lack of braking. Jagwire defeats this problem binding together the coaxial reinforcement wires with a sheath of woven Kevlar.
Techincally, there is no such thing as “compressionless” housing (as Jagwire calls it), but this stuff is quite stout. Under full pressure, the Racer brake housing feels as stiff as Nokon segmented housing. However, Nokon housing has the advantage of being very flexible in the sense that the housing can easily follow tight radius housing runs. The Jagwire compressionless housing is unyielding to the point of affecting brake caliper return, especially on a small bike like mine with short housing runs and tight bends. A minor issue is that the housing is difficult to cut unless you have really good housing cutters. A home mechanic using straight-edge dikes (not dykes…that’s something different) will probably just mangle the job.
I’ve always been on the fence with Teflon-coated cables….it seems like the coating tends to wear off easily after a while, but it doesn’t cause much harm either. I think these stainless steel cables are lower friction mainly because Jagwire draws them through a die to smooth the exterior of the wound cables; though most quality cables are treated like this, I think Jagwire does it better than anyone (Shimano included). If these cables weren’t coated, I wouldn’t care. A sealed ferrule is another item that usually is better in theory than practice. In this case, the longer length of the ferrules complicated the tight housing runs on my bike, so I ditched them. In contrast, Gore’s Ride-On system is in a different class; the fully sealed system and Gore-Tex sheathed cables really do require you to use the included ferrules and housing. Ride-On is distinctly better in terms of decreased cable friction. I’ve solved some difficult shifting problems on customer bikes with the Gore/SRAM product, particularly on TT bikes with mile-long internal housing runs. The trade-off is a more tedious installation and greater cost.
The Jagwire Racer DIY kit is a quality cable/housing setup that may offer a degree of performance enhancement to your bike, but it does not solve the tight brake housing bend issue like Nokon segmented housing. Nor does the Racer kit offer a different magnitude of friction reduction for shifting like Gore Ride-On. However the Racer kits do give single serving portions of colour coordinated housing in a variety of flavours. In my case, I wanted Bianchi celeste and that’s what I got…with no compromises in quality. A good product.