Stupid question, removing spokes.
When I rebuild the front wheel on my bike I only needed the hub out of the stock front wheel, I just let all the air out of the tire, loosened all the nipples with a wrench and pulled the spokes out. The nipples are still in the rim, and I'm sure they're chewed up a bit, but I have no intention of ever reusing them.
Are you replacing one or two broken ones, or do you wish to replace an entire set? How old/corroded is you wheel?
You might get a spoke out with the tyre and tube on, it's a gamble whether you can get the new replacement spoken back in as the nipple may retract back into the rim. If you are replacing a complete set, no, as it would make centering the rim and checking for up and down runout difficult.
If it just one or two, take the gamble.
If you are putting on a larger diameter rim, and don't need the old spokes, bolt cutters or an angle grinder is the quickest and easiest way.










