ZEFAL CRANK ARMOR
20g £7.95 set Long Term (6month) Test
Zefal Crank Armor is essentially a pair of rubber crowns that slip over your cranks, preventing them getting a spanking. They’re available in several colours and do just what they say. They are better suited to round profiles and don’t cover all eventualities, but for a tenner they make pretty good investments.
Pros: Discrete, effective and inexpensive.
Cons: Won’t protect against toestrap rub, may require cadence sensor movement.
The Crank Armor are made from a rubbery composite and weigh a barely-there, 20g. Ours were black, which compliments the crankset and the bike’s two-tone theme. However, bright green, red and grey are the alternatives, should you prefer something else to compliment/contrast.
Constrained within their packaging, they look and feel a little slab-sided. However, a quick massage with your fingers wakes their supple, malleable properties, making them easy to slip on.
Ever so straightforward, so long as your pedal threads haven’t weathered. Whip your pedals off (as appropriate) and slip the Crank Armor in situ. I found a quick shot of silicone spray, such as Muc-Off Silicon Shine makes this easier still. Give the crank threads a quick cat-lick, inspect older sets for any signs of damage, dab some grease on the pedal threads and then dial them home - done.
Talking of grease, I also went for White Lightning Crystal, since its rubber/plastic friendly and very long lived. I’ve had no compatibility hassles with round cranks - specifically old pattern Shimano, System EX , and some FSA. I should point out, I’ve only tested them on aluminium alloy, not carbon arms.
Well, almost - you may need to move cadence sensor/magnets up a little, then check they’re still speaking.
Other than being ported about to test compatibility, my tubby tourer has been the main host, and for good reason. Not only does it rack up the biggest mileage, but these are split between road and trail-contexts where they’re subjected to finish chipping stones and similar projectiles. Black finishes (even powder coated) age less gracefully than their silver/polished counterparts but particularly in these settings.
For the most part, I’ve only noticed them in the most positive sense. Though conditions have been much drier these past couple of months, stones embedded in wet, clay soil proved surprisingly plentiful along unmade backroads and bridle path.
The Crank Armor have done exactly what they promised, deflecting bigger stones, although silty gritty stuff tended to accumulate around the tops, creeping inside. Nothing serious, but worth keeping an eye on to prevent this chewing the crank’s finish undetected. Similarly, they’ve been surprisingly good at defending the arms from shoe/bootie rub.
Clear “helicopter” tapes, such as Zefal’s Skin Armor are the way forward, if you’re wanting to protect arms from toe-strap induced wear. Moderate amounts of gloop had snuck past the tops, so periodic stripping and cleaning (especially on a cross/gravel or mountain bike) would be sensible. A quick shot of silicon spray, to keep them supple wouldn’t go amiss, either.
A few weeks in, I switched them to my fixed gear winter-trainer, which has 165mm cranks and a lofty bottom bracket height. A less obvious choice perhaps, however, it served to confirm my suspicion that there may be some compatibility niggles with computer sensor/magnets. I’ve not needed to prune ours, but fitment demanded some tweaking/readjustment and longer zip-ties. TLDR - check compatibility beforehand to avoid hassles.
£7.95 isn’t particularly expensive, given the price of crank arms - even those from humble groupsets. Ignoring unbranded, auction site fare, they’re also very competitively priced Race Face Crank Boots are probably their closet comparator (£7.95). Sram Crank Arm Boots are carbon specific, made from a hard composite and cost £9.
Bottom line, Zefal Crank Armor is a neat, cost effective way of protecting crank arms from everyday wear ’n’ tear and accidental carelessness. Gravel, cross and mountain bike riders will benefit most. It’s best to check they’re compatible with your intended cranks, first.