1

I have heard there can be issues when dissimilar metals are in prolonged contact. Would that apply to titanium and chromoly? Ive got may eye on a new titanium fork for my old chromoly frame bike.

  • 1
    There is no inherent "danger" in having dissimilar materials for fork and frame. The two are separated by the bearings. Though understand that 1) the stress response characteristics may make them incompatible from a handling and "ride" standpoint, and 2) the bearings themselves must be compatible with the materials they contact (though here one could conceivably use dissimilar cups and cones if one had a real fetish about this). – Daniel R Hicks Jan 19 '18 at 22:35
  • The grease will mostly eliminate direct contact between the metals. For bolted connections, keep some separation by lubricating with some copper grease (copperslip) which has a metallic clay base. – Criggie Jan 20 '18 at 0:35
  • I've never heard of copperslip. I'll have to get some. Thanks. – dylanmac Jan 21 '18 at 21:44
2

As the comments to the question reasonably state, the problem of dissimilar metals contacting is really not applicable in the case of a fork and a headtube, because there is no direct contact.

  1. The fork contacts either bearings' balls or one of bearings' races. Balls rotate, so unless you leave your bicycle in a cellar for a year, they will not get a chance of chemically reacting to the point they stick. And if the race binds, so what, the bearing will still rotate, and if the case of bearings replacement procedure the fork still can be extracted and races removed.

  2. There should be enough of consistent grease to prevent both bearings' rusting and materials binding. That is the thing that one can control when installing a new fork, and then periodically refresh it with a new grease.

Where things may bind is where heterogeneous surfaces contact and do not move relatively to each other. The most notorious pair is seatpost and seattube. For a titanium fork, the stem/steering tube contact point should be something to watch for instead.

  • This makes sense. Thanks for your answer. – dylanmac Jan 21 '18 at 21:43

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.