Should we be surprised e-bike deaths are up in the dark months, or amazed any motors survive at all? And what can you do to nurse your Eeb through to Easter? Guy Kesteven gives his advice.


Up until now, most of my e-bike riding mates see winter as a time for smugness. Showering me with roost as they spin sticky rear tyres past me on climbs so I can’t even stand up on. Boosting through the occasional snow rides and constant slop rides with double the power I’d have even if I’d kept to those New Year training resolutions. Getting enough descents in a quick ride to actually make it worth all the bike and kit cleaning afterwards.

Get the right kit and you can wave puddles goodbye (get it?!)

Submerging your e-bike will put a damp squib on your riding.

This past month though, it seems like karma has been coming down the charging cables of every e-biker I know. Bikes that have been running sweet for months suddenly not playing ball. Motors just a few hundred miles young repeatedly throwing up error codes halfway through a ride. Even box-fresh examples of the best e-bikes have not been running right from the start, despite several returns to the shop. And all the different motors seem to be affected; Fazua, Shimano, Bosch or Brose, it doesn’t seem to matter. If there’s something else turning the cranks besides your legs, it seems like February has been the month for it to crap out.

Vitus E-Sommet VRX 2023

Winter riding at its bleakest – this is purgatory for anything electrical.

The only unifying factor between all of them is that the weather has been almost unrelentingly grim, and none of their bikes can cope. If you start looking at the ‘weather protection’ of most designs it’s not remotely surprising they’re dying either.

For a start, weatherproofing ratings on motors range from a “protected from prolonged spray” IP6 or even the basically waterproof IP7 on Specialized Levo SL units, to an “occasional splashes” IP4 rating on some cheaper bikes. No surprise then that e-bike servicing specialists that I talked to said 70-90% (depending on brand and age) of all the issues they see are related to water/moisture penetration.

That only covers the motor casings too. Not the many other potential water ingress and short circuiting (the infamous error 505 on a Bosch) points across batteries, head units, charger connectors, sensors and other parts of the system. Even the magnetic connectors used for that ‘clunk home’ docking vibe in a lot of charger junctions can potentially pick up any debris with a metallic element. Users of early removable Bosch units will remember how often dirty or damp connectors could cripple the whole bike too.

Vitus E-Sommet VRX 2023

Cold and damp hampers batteries and kills connections.

Given that electrical components and water are obvious enemies, what really surprises me is how badly sealed these sensitive areas are from a basic design point of view. While suspension pivots, headsets and hubs have developed multiple levels of sealing to stop premature death, and a lot of brands now seal cable entry points and even seat post collars, they seem happy to just to slap a plastic fascia over the top of the motor. Often with a very obvious gap around the outside for water to flood in which could easily be sealed with a rubber gasket. Others have massive holes in the back or underside which often aren’t obvious to their riders but are filling with spray and filth from the first ride. Unsurprising then that when most riders open their casings during winter, they’ll often find them full of wet mud and filth sitting on sensitive connectors and bearings even if the rest of their bike is clean and dry. In fact once you start looking into the issues it’s amazing any e-bikes work at all in winter.

Washing your e-bike

Protecting displays is a good idea if they’re not easy to remove.

So with all these potentially issues in mind, what’s the best way to keep your motor running in winter? First up, while we always say using a jet wash is a bad idea (even one of the best portable pressure washers), it’s a REALLY bad idea on an eMTB. Even IP6 rated components can’t cope with a high pressure rinsing, and you can easily physically loosen connectors with a misplaced blast of water too. Don’t just avoid the motor area and blast the rest of the bike either. Sensors, screens, switches and the wires joining them together means there aren’t many places you can point over 1000 psi of hydraulic pressure without doing digital damage.

Washing your e-bike

Always use a hose and mains pressure, rather than a pressure washer, on your e-bike.

I had no idea how many people washed their e-bikes upside down until I read some forum chains researching this piece. But it turns out (up?) they do. And when they do water runs up into parts it never would normally. This includes battery housings designed to drain downwards and the backs of top tube display modules that designers presumably thought were safe from anything less than fording a meter-deep stream.

Washing your e-bike

Remember to dry areas where moisture can sit, such as the charging port.

Don’t just clean the bits you can see either. Presuming they’re designed to be removed take off motor casings and battery protectors regularly to check you’ve not bought half the trail home with you. If you’re riding on the road, be sure to watch for salt corrosion too.

Finally if there are some obvious places where you can add sealing to the system without affecting the warranty, then get your DIY on. Even a bit of gaffer tape over a gap is better than nothing and you can peel it off easily to restore original cooling airflow if we ever get a summer again. Protecting connectors with a suitable grease can reduce the chance of corrosion and/or needing to get the WD40 water displacer out later too.