Fenwicks FS-1 Bike Cleaner Concentrate

Fenwick's FS1 bike cleaner concentrate is a highly efficient, versatile degreaser stock that forms the basis of their FS10 bike wash. Free from anything caustic, the 1 litre version makes 10 litres or so of FS10 but there's also a 5litre workshop size. Safe on all surfaces-including matt and carbon fibre, it's one of my all-time favourite cleaning products.

Precise ingredients are Coca-Cola secret but comprise non-ionic surfactants, cationic surfactants (which burrow beneath grease and grime, breaking it down on a molecular level) and Citronellal, which is basically a harmless, lemon/rose type fragrance often found in cosmetics and mosquito repellants - though Fenwicks make no claims about keeping the bugs off.

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The recipe for FS10 bike wash couldn't be simpler. Pour 100ml into a 1litre bottle, fill to the brim with tap water, screw on the pump spray and the sudsy elixir is ready for blasting over filthy bikes.

Modus Operandi is identical to most bike washes I've used. Pop bike(s) outside, spray liberally from a distance of 30cm or so and then leave to marinate. Fenwick's suggest two minutes which is a tad longer than most of the bike washes I've used, but hardly a long time.

Unless you are using to wait to give drivetrains a good strip, now's the optimal time for gathering bucket(s) of warm water, sponges, brushes and other scrubbing kit.

In practice, the full 2minutes is only really necessary for caked on winter cocktails of mud, spent diesel, salt and similar contaminants.

Mud and other organic stuff slithers away in thirty seconds, more complex light to moderate gloop-including stuff clinging to rings and bottom bracket shells will budge after 45 seconds when worked into a sudsy lather using a soft/medium bristled brush.

Rinse through with tepid water and you're left with a streak free, squeaky clean steed. Effects are uniformly good across the board on painted, polished, lacquered or anodized finishes. While following manufacturer guidelines religiously is best-if only to avoid warrantee hassles; I have a tendency to tweak recipes to suit...

Making a neater blend based around a 20/80% concentrate/water mix produces a richer, faster acting mix that is just about stocky enough for shifting lighter oil based drivetrain dirt-without being unfriendly to delicate finishes. However, stripping rings, cassettes and derailleur cages bare of congealed wet lubes, or stubborn ceramic lubes calls for neat.

As a lube stripper, chain baths are the most obvious and arguably neatest method. However, I prefer the old school mechanic's technique of pouring a small amount into an old sawn-off water bottle, parking this on the seat tube cage and brushing the concentrate into the desired spots

Agitate as before, leave for two minutes or so, then rinse off. This method is also more time and product efficient on encrusted grime around the bottom bracket shell, rear triangle than bike wash. Extending waiting times by several minutes hasn't result in residual streaking or blemishes either.

Some really tenacious chain lubes required a second helping but most relented first time when rinsed in warm water. Greases vary. Simple lithium and PTFE types are easily dismissed, so long as you've got the Fenwick's foaming, left it the full two minutes and rinse surfaces with warm water. Cutting edge polymer type lubes are more tenacious and needed three treatments.

While Fenwick's is solvent free, it does evaporate, so unless decanting into a sealed container afterwards, pour small amounts and add more if necessary to avoid wastage. Adding 20ml of water to the residual amount slows this process, although I've tended to add 100ml and recycle any leftovers in my parts washer, or as a hand wash. Fenwick's have always made a point of saying its gentle enough for these duties, although you'll still need to work it into a lather and rinse with hot water to get ingrained grime from the pores.

Ultimately, there are faster acting concentrated cleaners both organic and otherwise. However, they can be quite harsh (I've cleaned patios and even drains with one neat formula). Compared with some other household names, Fenwick's performs well and in the longer term, seems kinder to surfaces and user alike.

Verdict

Extremely versatile, effective and yet gentle degreaser cum bike wash. Recommended.