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Winter is coming! Last season I put my road bike in the garage and just rode my mountain bike all winter. Something strange happened: my suspension fork froze. When spring came everything unfroze and was a-ok. Questions:

  • Should my fork freeze when it is cold outside?
  • Do you like having suspension when it is below freezing? I mostly just do road/logging roads. There are not really any trails where I am. I don't see too much value to suspension in the winter. Comments?
  • If you want to use suspension in the winter do you need a special fork or can you service your fork somehow?
  • 2
    Your fork doesn't "freeze" -- nothing turns to ice. Rather, the oil gets so viscous that the shock gets exceedingly stiff. In addition, the seals may stick until "exercised" a bit. – Daniel R Hicks Nov 28 '12 at 4:02
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Disclaimer: I used to design and sell after market suspension parts for proflex bikes

There are three main strategies for the "spring" in fork suspension

  1. coil spring
  2. elastomer stack
  3. inert gas, e.g. air or sometimes something fancier.

Nowadays all springs are dampened somehow either by

  1. using oil,
  2. negative air (opposing force on the spring)
  3. friction (frequently used on cheaper elastomer stack forks)

Cold temperatures effect oil and elastomers but have no real affect on the other types of springs and dampers.

In sub 0'C temperatures oil can become much more viscous and can't dampen the shock properly (oil is forced through little holes to slow down the spring-back of the fork) and thus make the fork feel like it is not responding. If you keep riding, the friction might heat up the oil a bit.

Elastomers are harder to heat up. I know Proflex riders in the nineties used to pour boiling water on the elastomers before going out for a ride.

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Very timely question.

A cold winter (we have lowest -28°C here) is a big test for any fork. The third winter I rode a bike, since my fork is not cheap, I decided to temporarily change it to a cheap rigid fork (it can even be used). Last winter my fork was freezing every ride so I can imagine how much the fork is experiencing every freeze-unfreeze-freeze-unfreeze-...

  • What’s the advantage of using a rigid versus a frozen fork? Is it merely the weight savings? – RoboKaren Jan 3 '18 at 21:32
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  • Well it needs to be pretty cold, but it can happen.
  • It's really up to you. Personally I don't use suspension out of the trails. You might want to use a suspension if the road you use is particularly bad.
  • Fork oil properties will change with the cold. So if you live in a place where it gets seriously cold, you might want to look into an oil that's more adapted for winter.
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You can apply some multi-purpose lubricant on the uppers and top seals. This will keep it from freezing up, help prevent it from getting damaged and will help keep moisture out.

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IMHO the mtb fork "freezing effect" has little to do with oil viscosity variations. The cause is in the plastic slider (liner) sitting between the outer and inner stanchions (legs) of the fork. As thermal expansion coefficient of polyethylene is 10 times greater than that of steel the slider shrinks around the inner leg and even pulls out of the outer one. You may try to cut the slider vertically and glue it to the inside of the outer leg, or just block the suspension till warmer days.

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