Could you use gear cable as brake cable if you did not have brake cable ?
I know gear cable is not as strong as brake cable
The gear cable is thinner gauge. It stretches when you don't want it to.
And when exactly, might you want a cable to stretch? Does the same cable stretch when used for changing gears - no (otherwise the indexing would be wonky). Does a brake cable stretch a bit when applied? Yes, but so little as to have no functional effect (think about how the brake levers operate the cable and the cable operates the calipers). And so, being thinner gauge, the gear cable would stretch too, and maybe a tad more, but, again, so little as to have no functional effect. So I agree:The gear cable is thinner gauge. It stretches when you don't want it to.
A gear cable used as a brake cable would be (much?) less effective because the rider is running a thinner (but still very unstretchy) cable in brake cable outer and this will result in reduced effectiveness and swift deterioration of the outers as the thinner cable damages them. This is likely what @Racing roadkill discovered (and put it down to 'stretch').stretching it in a brake application is probably not what happened
I don't know where to start with that little lotAnd when exactly, might you want a cable to stretch? Does the same cable stretch when used for changing gears - no (otherwise the indexing would be wonky). Does a brake cable stretch a bit when applied? Yes, but so little as to have no functional effect (think about how the brake levers operate the cable and the cable operates the calipers). And so, being thinner gauge, the gear cable would stretch too, and maybe a tad more, but, again, so little as to have no functional effect. So I agree:
A gear cable used as a brake cable would be (much?) less effective because the rider is running a thinner (but still very unstretchy) cable in brake cable outer and this will result in reduced effectiveness and swift deterioration of the outers as the thinner cable damages them. This is likely what @Racing roadkill discovered (and put it down to 'stretch').
Imo; emergency measure (ie on the road till the next bike shop or, if closer, home) only.
Not a "good" bodge ever. But it's better than nothing.Good bodge for touring but you need to change it at the next chance you get.
I don't know where to start with that little lot