I use my bike (gt avalanche 1.0) to commute to work. Now it's autumn and so rain can happen just every day.

So the questions are: is leaving my bike outside harmful? Should take the seatpost with me or better leave it in place?

  • Just put a plastic bag or a shower cap over the seat. And make sure the chain is properly lubricated. And you may want to take off your bike computer, if you don't normally. Oct 1, 2013 at 11:23
  • @DanielRHicks, I take off a bike computer and both lights 'cause they can be stolen easily
    – k102
    Oct 1, 2013 at 11:52
  • 1
    Just as an anecdote: My bicycle (mid-range trekking bike) has spent about half its time outside for the last five years, in rainy western European climate, and it's just fine. So don't worry - just keep your chain well oiled.
    – sleske
    Jul 22, 2016 at 11:50
  • @sleske That sounds good, thanks! Now switched to wet lube (since this summer switched to rain) - all good for now
    – k102
    Jul 22, 2016 at 12:41
  • Ever seen photos of bikes in Amsterdam? Many of those are never under a roof, and believe me, it rains plenty in Amsterdam. And round the year, not just in Autumn. (But I have to admit that most of those are build to withstand a bit of rain. And all of them have their seats, so no risk of rain going in the seat post.)
    – Willeke
    Jul 23, 2016 at 18:10

3 Answers 3


It's no problem, but there are a few things to consider:

  • Keep all the moving parts well oiled. Note that even if you only ride on roads there will be more dirt getting on it, so you'll need to give the chain a good clean, let it dry, and oil it. This should stop the mechanicals getting too rusty, some screw heads will rust but not too badly.
  • Wet rims don't brake as well, especially if the wet isn't pure, so after riding off the first stop may take longer (and be noisy). If the rain has stop it may be worth applying the brakes (carefully) once or twice right after starting your ride, to get the rims dry.
  • Get a waterproof saddle cover, then take it off when you want to ride - so much more comfortable than a wet saddle, especially if the saddle has stitching which lets the water in. This is better than a plastic bag, because you can leave it on, and only remove it if it's wet. Alternatively, get a saddle with a plastic surface, then you can just wipe off the rain.
  • If you're expecting really heavy rain, your lights might not take it (as I found out recently) so you might want to take them with you (of course you might want to anyway so they don't get stolen). This is for removable lights; if you have lights that are meant to be installed permanently (for dynamo use), they will gererally be watertight.

If you ride in the rain, then keep the bike in a shed on a damp day, it won't dry out properly for hours anyway, so the actual outside storage isn't much extra punishment on top of the ride (assuming of course that it's wet all day)

  • Thanks! Never thought about saddle cover, always used s plastic bag :)
    – k102
    Oct 1, 2013 at 11:06
  • Great answer! I took the liberty of proposing some additional information.
    – sleske
    Jul 22, 2016 at 11:48
  • The best saddle cover made is a lady's shower cap. (Although the floral designs are a bit much.) Jul 22, 2016 at 12:08
  • @DanielRHicks having tried a shower cap I find they slide around too much to ride on, the covers I have can be left on and only removed if they're wet.
    – Chris H
    Jul 22, 2016 at 12:38
  • @sleske - thanks, I made a little addition to your addition. Hopefully you'll see why.
    – Chris H
    Jul 22, 2016 at 12:39

Avoid taking the seatpost with you if you expect rain. Rain will get into the inside of the frame, and pool down in the bottom bracket. This will soon lead to a very squeaky bottom bracket.

I would refine the comment above: the drivetrain should be both well lubed and dry (no water and no oil). An oily or greasy chain is a magnet for dirt and wears much faster.

It's also probably worth trying to see if you can find a way to store your bike indoors at the office. One day in the rain won't hurt your bike too bad, but continuous storage outdoors will add up.

Be sure to clean that drivetrain often as you ride in the wet.


  • 2
    Disagree on the lube. If its wet, use wet lube (oil). When the chain gets wet (with water), the dirt and grim sticks to the chain and dry lube is not able to migrate around to where its needed. It is normally recommended dry lube for dry and wet lube for wet riding. Proviso on this is the drive chain is maintained regularly - riding in wet conditions requires more maintenance. The gt avalanche has a sealed BB - water entering the frame will not get near the BB bearings (however, good point about best not to let the water in)
    – mattnz
    Oct 1, 2013 at 20:15
  • @mattnz -- If the "sealed" BB is at all similar to the Shimano crank I replaced on my bike, it's fairly important to keep it reasonably dry. When I pulled mine out after about 5 years it was covered with rust. (Replaced it with a stainless Phil Wood unit.) If this were a steel bike it would also be well advised to remove the cartridge and coat the inside of the housing with grease, to discourage rust in there, since water likes to collect in the BB shell. Oct 2, 2013 at 18:13

I'd say that water falling on a bike for a short period of time, will not cause any harm, if by short we consider less than an hour. The water staying in the bike though may cause corrosion. That is, it takes time for corrosion to occur.

That's why you can perfectly wash your bike, provided that you shake the excess water off and let it dry before you store it in an enclosed place.

If you "park" the bike outdoors I would consider some factors like time of the rain event. I would say that it is worse for your bike if it rains on it in the morning and it stays stationary and wet for the rest of the day, giving enough time for corrosion to occur. If the bike gets soaked but is ridden shortly after, vibration from riding and circulating air will shake water off and in some cases almost dry it, so a rain in the afternoon, just before you get out of the office will do almost no harm.

Another factor is whether splash will drag dirt and other foreign matter onto the bike. That's why it helps if you lock the bike in a clean, dirt free location. These concerns, however, are no different than riding on wet streets/trails. A properly lubricated bike should survive with no problems.

As with water, a little or even a lot of mud will cause no harm if cleaned off soon enough.

I ride mostly XC in a tropical country, here it rains all year round (some seasons more than others) so it is highly usual to get home with a muddy bike.I just wash it as soon as possible, shake it a little and let it rest indoors. I have absolutely no problems caused by water or mud.

An aluminium frame will mostly have no problem at all with water. An steel frame should be kept with a good paint job, covering any metal-exposing scratches with any suitable paint or even nail polish. I also reccomend sealing vent holes (Near the ends of stays, they are there to let out welding fumes during fabrication). This can be done with hotglue, gasket silicone or electrical tape. I would seal or cover the seatpost collar and headset bearing if I suspect water can easily get in.

Sealed bearing hubs and bottom brackets are almost immune to gentle rain. Others have proper "dust caps" tha makes them well suited for rainy environments as long as mudy riding is not involved. For non sealed bearings with no adequate gaskets, repacking them frequently with fresh grease is recommended. I would suggest once every two months, depending on the particular conditions.

For the drivetrain, specially non covered chain with derailleurs, frequent cleaning with proper lubrication is the only way to go. I rely on visual inspection to determine whether it is necessary to clean "now!". When there is obvious grit accumulation on cogsets or the chain is covered with a paste-like oil-dirt mixture, it is time. And old toothbrush and 20 minutes of patience is enough. Lube after drying.

All of these tips are my regular preventive maintenance for mountain bikes ridden on dirt trails. For commuting on good city steets same measures apply, only not so frequent.

  • 1
    A properly maintained "normal" bike will not be harmed by spending an occasional day out in the rain. Having no sheltered place to park a bike is not a valid reason to forgo commuting to work, etc. Likewise, no "normal" bike will suffer significant harm from riding in the rain. And, aside from the chain, you're more likely to harm a bike by cleaning it rather than by leaving it dirty. Oct 2, 2013 at 15:27
  • @DanielRHicks, "you're more likely to harm a bike by cleaning it rather than by leaving it dirty" really? Are there any researches on this? Always thought that cleaning can do no harm
    – k102
    Oct 3, 2013 at 8:51
  • 3
    @k102 - It's quite easy, when cleaning a bike, to get water (or, worse, soap) into the bearings. Using a hose (at anything other than a gentle trickle) greatly amplifies this risk. Whereas (aside from the chain and sprockets) leaving a bike dirty causes no damage at all. Oct 3, 2013 at 11:55

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