GT85 degreaser is a fast-acting aerosol designed for time strapped mechanics needing to get transmission components stripped of lubes and contaminant. It's intended primarily for derailleurs, cassettes and chains; there are better choices for degreasing hubs, headsets and other bearing surfaces.
Like most spray on formulas, it's basically a mix of potent solvents. These make it sprayable and dissolve gunk on contact before evaporating without trace. They're also hazardous to aquatic life and extremely flammable, so wear gloves if you've sensitive skin, and minimise contact otherwise. Use and store in cool, dry, well-ventilated places minimise contact with rubberised components, such as seals.
Otherwise, it's extremely convenient. Round up some old clean rag and brushes of choice, shake the aerosol for thirty seconds and apply in short bursts from 15-30cm away. A-plug in straw ensures accurate delivery to chains and small components like derailleur springs, cages, jockey wheels, cleat mechanisms and so on. Getting the very best from this and similar formulas is also dependant upon technique.
Whip out the rear wheel and angle it so the cassette is facing downwards. A few swift blasts using the standard nozzle and that toxic mascara of spent wet lube, diesel, grit and similar embedded grot will get carried away by the solvent.
A second helping followed by a once-over with a clean rag had my workhorse's grimy Tiagra sprockets gleaming in sixty seconds. Lightweight, super lean petrochemical derived summer lubes are dismissed literally first hit, a quick cat-lick of derailleur jockey wheels was about as taxing as things got.
However, ceramic lubes and some stubborn wax formulas called for a thicker layer, agitating with a stiff brush before another shot of degreaser. Don't leave it marinating like a baste-on prep, or you'll be left with softened, congealed residue. The same goes for chains. Clipping on a chain bath and spray the degreaser into it while turning the cranks minimises waste and avoids decorating the rear triangle in oily spatter.
Overall performance is pretty good by spray-on standards and when used correctly a little goes surprisingly far. Nonetheless, while it's streets ahead of Juice lubes dirt-juice-hero at a penny shy of eight quid it's almost double the price of Decathlon's super-efficient, in-house anti lube and doesn't out perform it.
Worthy, fast acting degreaser for time strapped mechanics, but expensive
road.cc test report
Make and model: GT85 Bike Degreaser
Size tested: 400ml
Tell us what the product is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
Perfect for removing grease, oil, dirt and grime from your bikes drive train and other moving parts prone to a build up of dirt. It's fast acting formula means it can cut through contaminants quickly.
Removes contaminated chain lube, dirt and grime
Reduces the wear caused by dirt, grime and polluted lubricants in the drive train
High performance formula – reduces required cleaning time
Leaves no residue / Works on immediate contact with components and leaves no residue
Prepares chain for lubrication
Fast acting and pretty efficient.
Tell us some more about the technical aspects of the product?
Appearance: Clear aerosol mist with a characteristic organic odour
pH: Not applicable, non-aqueous
Specific Gravity: 0.768 – 0.778 (base component)
Flammability: Extremely flammable, flash point below -20oC
Composition Data, as supplied: A solution of aliphatic hydrocarbon solvent, aliphatic alcohol, non-ionic
surfactant and hydrocarbon propellant.
Very effective in the main and by aerosol standards.
Quite a heady mixture so needs applying in well-ventilated areas. Gloves are also a sensible precaution if you have sensitive skin or are prone to dermatitis.
Relatively potent and quite economical when used carefully. However, doesn't match Decathlon's B'Twin degreaser in terms of bang for buck.
Tell us how the product performed overall when used for its designed purpose
Overall, this is a very convenient and relatively potent degreaser for cassettes and derailleur components. That said; while the grotty mascara of wet lube and contaminant slithers away in a couple of blasts, its best deployed to chains via the clip-on solvent bath. Derailleur cages, jockey wheels, cleat mechanisms etc still need tickling with a stiff-brush while the first round of solvent's doing its thing too.
Tell us what you particularly liked about the product
Fast-acting and reasonably economical when used methodically.
Tell us what you particularly disliked about the product
Certainly better than some aerosol formulas and brilliant when time's of the essence; its still quite pricey compared with brush-on solvents/degreasers.
Did you enjoy using the product? Yes
Would you consider buying the product? Possibly but not at full rrp
Would you recommend the product to a friend? Decent enough staple but there are store branded options offering similar bang for much less buck.
Use this box to explain your score
Extremely convenient workshop staple but you can buy two of decathlon's ruthlessly efficient aerosol degreaser for the same money and the GT85 isn't obviously better.
About the tester
I usually ride: Rough Stuff Tourer Based around 4130 Univega mtb Frameset My best bike is: 1955 Holdsworth Road Path and several others including cross & traditional road
I've been riding for: Over 20 years I ride: Most days I would class myself as: Experienced
I regularly do the following types of riding: cyclo cross, commuting, touring, fixed/singlespeed, mtb,
Shaun Audane is a freelance writer/product tester with over twenty-eight years riding experience, the last twelve (120,000 miles) spent putting bikes and kit through their paces for a variety of publications. Previous generations of his family worked at manufacturing's sharp end, thus Shaun can weld, has a sound understanding of frame building practice and a preference for steel or titanium framesets.
Citing Richard Ballantine and an Au pair as his earliest cycling influences, he is presently writing a cycling book with particular focus upon women, families and disabled audiences (Having been a registered care manager and coached children at Herne Hill Velodrome in earlier careers)