Bike computer with race wheels?

I hope this isn’t a dumb question, but how do most of you use your computer when you switch out your training wheels for your race wheels?

I have a new pair of H3cs and I just realized that my speed magnet isn’t exactly designed to work with it the tri spoke wheel.

Do you just glue on a magnet? Do you race without the computer? Do you just use a srm/powermeter/garmin? (not an option for the poor)

Thanks

Get these magnets from radio shack and glue them on

http://www.radioshack.com/product/index.jsp?productId=2102642

jaretj
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