Spoke length for new bigger hub in 24" Electra wheel

[Grenade]

Hi
In Australia we have to have front brakes. I emailed Electra about this as I thought they might already know, but I never got a reply. I'm hoping some one here has done this with Electra wheel. I would like to take a roller brake hub out of a 26" electra front wheel the pic with the brownish gold rims and put it in a 24" electra front wheel the pic with silver rims. Any ideas what spoke length I need to use. The hub on the 26" wheel is larger in diameter than the hub in the 24" wheel. Could I just measure one of the spokes from the 26" wheel and just subtract 1"

 

[pholTmonx]

In california when they started makeing laws in response to choppers, motorcycles required a front break.. ive seen a few late 60s choppers with v brakes to skirt the law

 

[GuitarlCarl]

Google Sapim spoke calculator and follow the directions...

Carl.

sent from a phonebooth...

 

[Frankie plekhand]

Maybe you can use the spokes from your old wheel if you use another pattern or cross it 1 extra time but like Carl said go to the Sapim site and take their spoke calculator follow the directions

Verstuurd vanaf mijn GT-S7710 met Tapatalk

 

[Grenade]

Thanks I've looked up the sapin calculator and also found heaps more other calculators but I'll go with the sapin one. I'm not sure about where to measure for the internal rim diameter it says eyelet to eyelet yet the fuzzy diagram looks like its from the end of the spoke nipple. I see that other calculators ask for the ERD. Seeing if I can do another cross over pattern is a great idea, thanks

 

[Bicycle808]

Yeah, the generic term used by the majority of wheelbuilders I've run into is the ERD, or "effective rim diameter." If your rims are name brand popular rims, you should be able to google a manufacturer's spec for ERD. If they're just oem Electra-only rims, I'd contact Electra and ask for the ERD. I generally like to measure the ERD myself, and have someone else's specs to doublecheck myself, but....

FWIW, i learned how to measure hubs and rims from the EDD spoke calculator. They, like many other online calculators, use the term "ERD". https://leonard.io/edd/howtomeasure

 

[Frankie plekhand]

You can also check this
http://www.sheldonbrown.com/spoke-length.html
There is also a spoke lenght excel sheet somewhere but I cant find it that fast.

 

[Bicycle808]

Sheldon taught me how to build wheels. FWIW, he's also the one who put me on to the EDD calc--- back at a time when there were only 3 or 4 spoke calcs on the internet.

 

[Grenade]

That Sheldon link looks good I quickly skimmed over it but I will need to spend a bit more time reading it in depth. I will try and email Electra again, as mentioned in my first post they never replied to my email a few weeks ago.