Bicycle Mechanics - Can I replace a 14 g spoke with a 15g?

Broke my spoke and want to fix it quick.I have a 15g spoke that fits.What's the down side to replacing it with the thinner spoke if tensioned and trued properly?Thanks in advance for your input.

It's less than ideal but will work in a pinch. The only real problem is that the 15g spoke has only about 80% of the cross section of the 14g spoke, so at the same tension it'll be strained 25% more. Not much of a problem on the left flange, but could be on the right.

I'd go ahead and do it as a quick fix, do a quick true, then get a correct replacement and do the job right at my earliest convenience.

Broke my spoke and want to fix it quick.I have a 15g spoke that fits.What's the down side to replacing it with the thinner spoke if tensioned and trued properly?Thanks in advance for your input.

The large hub-flange holes which make life easy for lacing machines may not properly support the 15g elbow thus resulting in breakage until you replace it with one having a 14g elbow.

It'll also take a 15g nipple.

FWIW, with enough spokes (as a retro-grouch owning only 32 and 36 spoke wheels I couldn't tell you how many less than 32 you could get away with) you can get the wheel true enough to run with normal brake shoe clearances with one spoke missing.

Any port, in a storm, is a good place..

have a set of all 15 gage spoked wheels , 72 of them.
has worked for decades.. though the bike is ridden less as I get Older.

are both spokes straight guage? I could be wrong but you have to change the nipple too right?

Though it's not ideal to mix spoke gauges, the main issue will be spoke tension. Measure this with a tensiometer.

Mechanically it'll be fine. I'd say the biggest issue is likely to be trying to keep the wheel tensioned properly in the future. You can remember the first one while you're building and truing, but a year from now, you may need to re-true the wheel and you'll forget.

Which spoke needs to be touched? Pluck them. Plonk, plonk, plonk, PLINK! That one is too tight! Loosen it, and now the true is way off. Loosen the ones around it. Now there's a hop in the wheel. 45 minutes into the job, you'll remember there's this one that's a different gauge. Fix that hop, and you're back to finding the other loose one. What could have been a 5 minute job now takes an hour.

Mechanically it'll be fine. I'd say the biggest issue is likely to be trying to keep the wheel tensioned properly in the future. You can remember the first one while you're building and truing, but a year from now, you may need to re-true the wheel and you'll forget.

Which spoke needs to be touched? Pluck them. Plonk, plonk, plonk, PLINK! That one is too tight! Loosen it, and now the true is way off. Loosen the ones around it. Now there's a hop in the wheel. 45 minutes into the job, you'll remember there's this one that's a different gauge. Fix that hop, and you're back to finding the other loose one. What could have been a 5 minute job now takes an hour.Nothing takes 5 minutes with me!!!Anyhow I have a tension gauge so that makes things alot easier.Speaking of which i just changed the spoke ( with the 15g) and trued and dished and I was amazed to see the tension all around was about perfect all around!!From 24.5 to 25.5 but closer to 25 all around on the tension scale!!Never have I been so accurate!!The 15g was about 21 which works out to a little less tension but that's fine.Wish me luck with no further breaks!!

are both spokes straight guage? I could be wrong but you have to change the nipple too right?

Yes both spokes are straight gauge.And of course the nipple match the size.