mbr investigates

We’ve all heard the tales about pressure washing: that it flushes bearing grease, strips paint, punches holes in tyres and causes tsunamis. But is it really true?

What we did

We blasted a typical hub (nothing too posh, the kind of wheelset you’d find on a £2k trail bike) with the jet washer on full power, and at point-blank range, giving the stream enough time to fire off all the mud.

What we found

Unsurprisingly, when we pulled the hub apart there had been some water ingress, meaning that, over time, this abuse would wreck your bearings.

So does it all come out in the wash?

It goes without saying that our completely unscientific experiment is a no-no, and please never, ever, treat your bike this way; it’s cruel. What it does show is that overenthusiastic jet-washing can wreck your bearings and remove the grease.

However, years of pressure washing has also shown us you can wash your bike without damaging it in any way — if you’re careful.

How to do damage-free dousing

Find the right power balance — too low powered and you won’t blast off the dirt and you might as well use a normal hose. Too high and you’ll be buying new hubs, BBs and headsets next month.

Pressure washers like the Karcher K4 Full Control are pricey but you can get the sweet spot for pressure by reducing its power
down to 20bar with a turn of your wrist.

There’s a cheaper way to do this too — buy one off eBay for £30 — chances are it’ll have a lower advertised pressure and a substantially lower real-world pressure.

There are also some tricks to master for perfect pressure washing. No spraying directly onto hubs, BBs, headsets or suspension seals is a given. It’s also best to stand back a couple of feet from the bike to lessen the power and stop yourself getting soaked with splash-back.

Full power for…

Tyres, frame, saddle, and shoes.

Low power for…

Hubs, bottom bracket, headset, suspension seals, links and pivots.