Bike Medicine Purple Extreme Synthetic Chain Lubricant
The Bike Medicine Purple Extreme Synthetic Chain Lubricant has been around a few years but was apparently devised for lubricating chains in mining equipment and oil rigs. Notoriously harsh environments, which bodes well for winter road and indeed, mountain bike duties. Given this pedigree, I was expecting something epic.
Pros: economical, good lubrication and corrosion resistance, durable.
Cons: long curing times, attracts more dirt than some.
Bike Medicine were predictably tight lipped about the chemical composition but would say it’s a unique Thixotropic Lubricant, blended with a solvent carrier. Thixotropic? This means it will assume a more fluid state under load, thus optimising the quality of lubrication, but without “fling”. Theoretically metal on metal wear and corrosion are greatly reduced.
Bike Medicine also claim it will extend the life of older components and make new stuff perform even better. The solvent carrier traffics it deep into the links, evaporating and leaving the tough filmy synthetic lubricant behind. With these contexts in mind, I wasn’t surprised to discover Bike Medicine also suggest it for other bike related applications. Pedal threads, brake and derailleur pivots, seat post clamps, cable housings, spoke nipples being a few candidates.
We’re always banging on about getting drivetrains surgically clean before introducing a new lube and its imperative here. Test chains, cassettes and rings were blitzed using Squirt Bike Cleaner Concentrate bike and toothbrushes. I even gave the chains a wipe down with white spirit afterward. Whatever your chosen stripper, get everything dry and then fetch some clean rag, paper towel and if you haven’t already, don those
examination/mechanics gloves. These harvested, give the Purple Extreme a good shake to thoroughly mix solvent and lube.
Pop the spout and drizzle the purple fluid into each link, rag beneath to catch the overspill. Once you’re done, wipe the side plates, jockey wheels, rings etc and leave to cure. In a pinch, say when a mate has turned up unexpectedly and invited you out for a blast, you can lube and scoot off. However, you’ll need to re-lube a lot sooner.
Wherever possible give it a few hours to cure. There’s no prescribed waiting time but ideally leave at least four hours, better still overnight. It cures to a virtually clear state, which is a helpful visual cue.
Ursula, my miler munching four seasons’ go anywhere tourer and my fixed gear winter/trainer were the obvious candidates. The fixed had recently been treated to a new chain, Ursula a KMC with 750 winter miles service. Registering .5 on the chain checker, I was keen to test Bike Medicine’s boast of it extending drivetrain life. From a common or garden 10speed chain, I usually return 1150miles through winter. Smaller threaded components-bottle and mudguard screws, seat bolt binder bolts, derailleur jockey wheels and recessed fasteners also received a drop.
Provided you’ve been careful when prepping, from the first few pedal strokes, drivetrains feel slick and silent but without feeling syrupy and remote like some stiff, wet lubes can. That said, though crisp, shifts lacked the zing I’ve associated with Rock 'n’ Roll Gold LV and indeed, its Extreme sibling. Fling has also been conspicuous by its absence and performance remained consistent in temperatures between minus 3 and plus 15 degrees-stability claims have cut muster.
Though it’s a bit stodgy for lock and derailleur mechanisms, trailer hitches and control cables (better served with a blast of GT85, Juice Lubes JL69 and similar maintenance sprays) in a pinch, it’s a decent grease substitute for cleat hardware, mudguard and similar fasteners. All spun free with a deft nudge of a 4mm Allen key and chains aside, there’s been no hint of freckling in recessed Allen bolts either. Ursula’s KMC chain has passed the 1300mile mark, without hitting the .75 point on the chain checker, which is also favourable.
Even when it reaches a superficial, filmy state, that clings on quite tenaciously, keeping shifts smooth and the drivetrain silent. Indeed, when I have needed to deep clean the cassette, it required at least two helpings of A few drops applied via clean rag, to electroplated frame/fork ends, or indeed paint chips will mothball them nicely too.
This has been broadly on par with Bike Medicine’s 400 road mile claims and reassuringly good, given the conditions. December and January have meant plenty of waterlogged lanes, salt peppered roads, freezing temperatures and several sudsy bucket washes in between. The first application hit 350 miles before the faint metal on metal tinkling set in.
The next helping achieved 375, which again fell slightly short of the 400 cited but still very respectable, given the contexts I.e., flooded lanes, salt strewn main roads, freezing temperatures and the odd boggy bridlepath detour for good measure. 125miles short of Zefal Extra Wet Nano Ceramic and 25 fewer than Weldtite TF2 Performance All Weather Lubricant However, the Purple Extreme also runs a fair bit cleaner, than the Zefal in comparable conditions.
Forgoing the curing phase, I only returned 100miles from a single application, so wherever possible, leave it a few hours before heading out.
Middling, in a word, provided you’ve been meticulous with your drivetrain prep. On balance, during a predominantly wet test period, this seems comparable with Weldtite TF2 Performance All Weather Lubricant. Every week or so, I’ve needed to wipe a thin layer of residual gunk from the side plates, derailleur cage(s) and jockey wheels, but we’re talking a cat-lick, rather than deep clean.
It doesn’t transfer to skin, as readily as some but I’d still be inclined to carry some disposable examination gloves, or something like these Muc Off Mechanics Gloves should you flat or succumb to a similar roadside mechanical.
To some extent, this depends how we’re measuring things. There’s a lot of decent lubes for a good bit less, but you can easily pay a good deal more. Steve returned 750 winter miles from a single helping of Chain L High Mileage Chain Oil which is a good bit cheaper. However, it also attracts more dirt, so requires more rider involvement to prevent it becoming a grinding paste. Then of course, there’s Rock n’ roll Extreme LV Lube which runs very cleanly and with similar durability. It
is very runny and therefore, potentially messy to apply and this also means it’s not suited to lubing fasteners and other generic, “while I’m here” jobs. Peaty’s Link Lube Premium All Weather is a whisker below £15 but has impressed us with its blend of cleanliness and durability. Tru Tension Banana Slip Tungsten Wet Lube returned 600 miles along some very intensely wet roads. However, it’s also £10 for 50ml and again, is very much a chain only prep, no cheeky drops on the cleat hardware, recessed bolts, etc.
Oldie, but goodie, in a nutshell. Purple Extreme faces stiff competition and there are some cleaner and/or more durable options out there. Nonetheless, as reliable middleweight formulas go, Bike Medicine Purple Extreme still covers most bases well. A good default, for general riding, especially if you wanted a reliable lube that would go year-round and were prepared to accept some minor compromises.