I'm taking my usual approach to learning how to fix things - I've acquired a bike in need of repair (for free!), and am working it out as I go along. In this case, the bike got caught in a flood and spent a week or so under a couple of metres of river water.

So far, I've disassembled and cleaned everything, and so far as I can tell:

  • The bottom bracket is dead, so I'm getting a new one.
  • The frame, somewhat surprisingly, seems fine: no signs of rust anywhere.
  • The brake disks had some minor surface rusting that came off with the mud, and now seem fine.
  • The headset bearings were full of river water, so I've disassembled and de-greased, and will be re-greasing when I reassemble it.
  • Given that all of the other bearings were knackered, I assumed the same for the wheel bearings, so have cleaned and re-greased both.
  • The whole drivetrain seems OK, after much cleaning.
  • The pedals are a bit rusty, but I'll be swapping them anyway, so I'm not bothered.
  • The shifter cables seem OK.

For things that I know I'm not sure about:

  • What do I do with the front suspension? Previous bikes have all been road bikes, so I've no idea what I'm even looking for here. It's one of these. I assume the river water will have done a nasty on it, but what's the best way to go about fixing it?
  • This bike has hydraulic brakes (Tektro M286). What do I need to check about these? Any likely problems?

Finally, is there anything that I've not listed above that might have been damaged and not be obvious at a glance?

  • Consider that River water is better than Sea water in terms of damage caused.
    – Criggie
    Commented Feb 16, 2020 at 18:54

2 Answers 2


I'd consider replacing the shifter cables and housings, as this is a relatively low cost fix. Water will have seeped deep into the housings.

The hydraulic brakes are of course nominally sealed, but a bleed may be good idea in case water has got into the system. The braking system is obviously critical so I'd do it.

Water probably got past the fork seals. You don't want that sitting in the fork and the seals are not preventing it from coming out. If it's a coil fork it should come apart fairly easily (search youtube for videos), if it's air it's trickier. I notice there are service manual downloads on the Suntour page. You can also try contacting Suntour.

  • Consider drying the frame inside with hot air. If it is aluminium there's no big problem. If it's steel treat it with some rust converter. Also apply some wax-based coating, where possible.
    – Carel
    Commented Feb 16, 2020 at 21:49
  • 1
    I would be tempted to take the stripped fame and water blast the inside to wash out any residue, then dry it with hot air and treat with a frame saver.
    – mattnz
    Commented Feb 17, 2020 at 2:50
  • There's probably dirt suspended in the river water, and I'd bet that at least some got into the shifter cables. Also, I'm not sure how thoroughly the shifter housings would dry out, given that the openings are small. So, I'd agree on just preemptively replacing the cables and housing. I agree with @NoCoRider that the shifters themselves should probably just get WD40-ed and dried.
    – Weiwen Ng
    Commented Feb 18, 2020 at 18:03
  • The shifters themselves have had the thick layer of silt washed out so far, and are sitting drying out. Looking at everything else, it seems like river water got in everything, no matter how small the holes involved. Commented Feb 18, 2020 at 19:59

If the frame is in fact steel (easy to confirm with a magnet), I would suggest spraying some WD40 into the various frame tubes and spinning the frame around to get the WD40 to cover the inside of the tubes. WD40 will flush out any remaining water and provide a coating which will slow future rust. There are better and more expensive rust inhibitors such a JP Weigle Frame Saver which will provide better protection if the bike will be used in wet conditions.

Aluminum frames aren't affected by river water but if it had been salt water then I'd definitely want to flush out any remnant of the salt which will cause corrosion.

Brakes: I would be surprised if water got past the seals but it never hurts to flush.

Shifters: WD40 is a good at flushing out water. Rubbing alcohol is also good at flushing out water and sediments. It dries quickly.

  • Looks like it's an aluminium frame, which is lucky. Going well so far, except that the bottom bracket is jammed in beyond belief. Commented Feb 18, 2020 at 18:23

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