Shimano Dynamo hub

richard thoday
richard thoday Posts: 544
edited June 2007 in Workshop
I just bought a Shimano Nexus dynamo hub to build into a wheel for my winter bike but am supprised by the amount of resistance in the hub.
Spining the axle with my fingers the hub has the rumbling feel of very over tightened bearings but it's not the bearings that are tight.

Should it feel like that?

I thought that hub dynamos were low resistance these days.

Comments

  • andrew_s
    andrew_s Posts: 2,511
    Yes, it should feel like that, and all other dynohubs are the same.

    It feels stiff because the magnets are trying to hold the axle in one of 25 (ish) positions. As once you twist the axle far enough against the resistance of the magnets, it suddenly jumps forwards to the next position. When in use on a bike, you get back in the jump forward what you lost in the initial resistance, less a bit that goes into powering the light.
    You can often feel a slight vibration through the handlebars, if you are on dead smooth tarmac. This tells you that you forgot to turn the light off after getting home last night.

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