sorting through spoke voodoo; building a wheel.

[blokeinamoke]

Hey all,

So ive got:
SRAM A2 Automatix hub
700c rim

How does one join the 2 in perfect harmony, never built a wheel before, no idea if i need 36 spokes of the exact same length or if the lovely couple need alternating lengths...

flange diameter 70mm, flange spacing 53mm no idea what the ERD of the rim is (not too sure how to obtain that number either) i will assume a normal spoke layout will suffice? (no idea what that means either) im 105kg so something with strength? (yep, just something else i dont know)

I have searched on here for wheel building how too's to no luck... any help would be amazing (what to buy or where.... )

Cheers,
Matt

[find_bruce]

Hi Matt,

I have replaced plenty of spokes over the years but have only just built my first complete wheel & in less than 2 months I have built 4 wheels, so it seems I am hooked.

The reason you won't find a "how to guide" here is because there is no need - just lob £9 Roger Musson's way & his pdf "book" will take you through the complete process step by step from measuring your components, his website has a spoke length calculator, & the instructions are clear & easy to follow.

All it takes is some simple tools & a bit of patience.

[familyguy]

Try Spocalc (by Damon Rinard?), or the DT Swiss website spoke calculator. Should be able to plug in figures of offsets, flanges, ERD and such to determine a length required for each side.

You might be lucky enough to have symmetrical spokes with the A2.

Jim

[jules21]

just go on YT, or buy the book bruce linked. building a new wheel is easy, as the rim is straight.

is it a front or rear wheel? if rear, the spokes will tend to be different lengths. to be honest, i find this the most difficult bit to get right. i've used the DT Swiss calculator, but have found the results to be quite sensitive to accurate measurements. my tip: select spokes on the longer side, as the ends can safely poke into the rim cavity. however - too long and you'll run out of thread and won't achieve sufficient tension.

fortunately, you can buy sets of spokes off online shops like this link is broken quite cheaply, so getting it wrong isn't a disaster (unless you're looking for special, high end spokes).

a 3-cross pattern will give you decent strength, as will the meaty DT swiss spokes that c-reaction sell. (most wheels seem to run 2-cross on the drive side of the rear wheel).

for a front wheel, i'd have thought a 2-cross pattern was sufficient, due to the lower weight on it.

[find_bruce]

just go on YT, or buy the book bruce linked. building a new wheel is easy, as the rim is straight.

is it a front or rear wheel? if rear, the spokes will tend to be different lengths. to be honest, i find this the most difficult bit to get right. i've used the DT Swiss calculator, but have found the results to be quite sensitive to accurate measurements. my tip: select spokes on the longer side, as the ends can safely poke into the rim cavity. however - too long and you'll run out of thread and won't achieve sufficient tension.

fortunately, you can buy sets of spokes off online shops like this link is broken quite cheaply, so getting it wrong isn't a disaster (unless you're looking for special, high end spokes).

a 3-cross pattern will give you decent strength, as will the meaty DT swiss spokes that c-reaction sell. (most wheels seem to run 2-cross on the drive side of the rear wheel).

for a front wheel, i'd have thought a 2-cross pattern was sufficient, due to the lower weight on it.

Um Jules, I suspect you may have missed some comments in the OP
(1) the SRAM A2 Automatix hub is a rear wheel &
(2) the interwebs suggest that the flange diameter (69 mm) and the flange distance (30 mm) are the same left and right, so will use the same length spokes on each side

I should have added that Musson provides a free extract of the book that tells you how to measure the ERD & the flange distance http://www.wheelpro.co.uk/spokecalc/calc-measure.pdf" onclick="window.open(this.href);return false;

As jules21 says though, even at 105kg, a 36 spoke wheel with a 3-cross pattern should give a nice reliable wheel. I would spend the extra couple of bucks on double butted spokes (DT Swiss, Sapim etc) but YMMV. The real question for you is what rim to buy - ideally you want to have it in your hands to measure before you buy the spokes

[wqlava1]

Try Spocalc (by Damon Rinard?), or the DT Swiss website spoke calculator. Should be able to plug in figures of offsets, flanges, ERD and such to determine a length required for each side.

You might be lucky enough to have symmetrical spokes with the A2.

Jim

They are all giving good advice above. As a variation on Spocalc, I prefer the web interface offered by the spoke calculator on

http://freebiketools.org/" onclick="window.open(this.href);return false;

which the guy who supports it says has a tidied up version of the Spocalc database.

[blokeinamoke]

Cheers for the replies everyone!

So i plugged the numbers into the spocalc spreadsheet (alot of data in that badboy!) got to my spoke length of 288.5mm

Started compiling a basket at chain reaction:

36x288mm DT spokes
40 red nipples (hehehe)
114 link Single Speed chain
shimano bb

and a couple of other things... $102 bucks worth on its way as we type... I guess i should probably start playing with the frame sometime soon get it ready for paint and read a few how to build a wheel books!

Cheers again,
Matt

[queequeg]

Cheers for the replies everyone!

So i plugged the numbers into the spocalc spreadsheet (alot of data in that badboy!) got to my spoke length of 288.5mm

Started compiling a basket at chain reaction:

36x288mm DT spokes
40 red nipples (hehehe)
114 link Single Speed chain
shimano bb

and a couple of other things... $102 bucks worth on its way as we type... I guess i should probably start playing with the frame sometime soon get it ready for paint and read a few how to build a wheel books!

Cheers again,
Matt

Hope those red nipples were brass instead of alloy

[find_bruce]

Hope those red nipples were brass instead of alloy

Hope you realise brass is an alloy

[Mulger bill]

Hope those red nipples were brass instead of alloy

Hope you realise brass is an alloy

Touche!

[queequeg]

Hope those red nipples were brass instead of alloy

Hope you realise brass is an alloy

:-p