Measuring spokes… in existing wheels

[Lazmo]

My wife and I are going on a 4 week trip to central Oz shortly, with a fair bit of mountain biking thrown in on the way. To cover mechanical issues, I have got a box of spares together. It is not complete by any stretch, but one thing I don’t have is spare spokes.

It might sound like a silly question, but is there a specific way to measure spokes, while in the wheel, so I can get a few spares for both bikes, in case of spoke brokenness?

 

[The Duckmeister]

Take one out of each side of each wheel and measure them.....

For a more bodgy and less accurate but somewhat passable method, measure from the face of the rim next to a spoke hole, down the spoke to the inside of the elbow, and add 4mm fudge factor for rim wall thickness + nipple head.

 

[Oddjob]

Could you calculate from erd of rim, dimensions of hub and online spoke length calculator?

Sent from my SM-G900I using Tapatalk

 

[The Duckmeister]

You can if you have a ready record of the ERD; if you don't you need to debuild the wheel to measure it.

 

[Oddjob]

You can if you have a ready record of the ERD; if you don't you need to debuild the wheel to measure it.

Speaking of which, relying on online erds is dodgy. I've got a set of Mavic tn719s that are meat to be 604 erd but are actually 614, WTF?

Sent from my SM-G900I using Tapatalk

 

[Beaker74]

Speaking of which, relying on online erds is dodgy. I've got a set of Mavic tn719s that are meat to be 604 erd but are actually 614, WTF?

Sent from my SM-G900I using Tapatalk

That's only out by 1.

 

[SummitFever]

...measure from the face of the rim next to a spoke hole, down the spoke to the inside of the elbow, and add 4mm fudge factor for rim wall thickness + nipple head.

This will get you pretty close. Err on the side of being a little short and then pack some 12mm, 14mm and 16mm nipples and then you can cover a fair degree of range either way.

Having the spoke threads properly engage with the nipple head (if alu nips) is essential on a good build, but in an emergency, miles from nowhere, a brass 16mm nipple with the spoke threaded in 4+ turns will get the wheel back into true and you out of trouble.

 

[teK--]

Have you considered one of those kelvar rope temporary spoke repair kits? Should be easier to carry and install if you're in the middle of nowhere. Maybe have one kit per bike if worried of multiple spoke breaks.

 

[Flow-Rider]

I've used this spoke calculator twice and the spokes have fitted well, it has pre set values for certain brand rims and hubs. I've broken a spoke on an old wheel and just wrapped the broken spoke onto the one beside it and kept on pedalling an 80km trip. Pretty sure you would have been able to adjust the buckle to a minimum by adjusting the spokes beside it.