Spoke Size / Spoke Length Database - What size spokes do I need?

ok cheers was coming up with two different answers for that.

i want radial cos i'm a tart, simple as, so despite the advice i'll go ahead anyway.

Hey guys! Building up some wheels this Christmas too, IRO hubs and open sport rims, 36h, 3 cross, 290mm spokes right?

Is cyclebasket still the place for cheap spokes?

290 -292 mm sounds about right. Open sport have a ERD about 2 mm more than open pro but the difference is small enough no to matter.

Cyclebasket is still the cheapest, it's just the postage is flat rate so try to find something else you need on the site.

my usual spoke calculator came up with 306 3x for a rear high flange phil to open pro. Which I've been told is really really stupid, just used ehrenfriedchicken's spoke calc and that is now giving me 293.3 for the left and 291.6 for the right.
spoke to dogsballs at the christmas party and he was saying off the top of his head spoke length for that build was about 292.
Just lookin for confirmation that 292mm or 294mm is the way to go.

many thanks

by the way these wheels are going to go on the travelling bike.

What is your usual spoke calc? open pro to most high flange comes in around 292, 306 is way off because the flange would have to be smaller than DA small flange, which is small.

I get 288.781and 290.34 using

hub | OLD | flange diameter |center to flange distance
AVH421 Rear Track Single Fixed | 120 | 67.0 | 42.5 / 29.0

605 erd on a open pro

what numbers are you using?

which hubs though?
http://www.philwood.com/wp-content/docs/wheelbuilding_break.pdf

it's 291 for rear/double fixed.

293/291 for single.

(though unless it was easy to get them, I would settle for 292 all round)

What cacl are you using RPM, I'm getting 290/289, This one never failed me http://www.recumbents.com/wisil/spokes!.asp

my usual spoke calculator came up with 306 3x for a rear high flange phil to open pro. Which I've been told is really really stupid, just used ehrenfriedchicken's spoke calc and that is now giving me 293.3 for the left and 291.6 for the right.
spoke to dogsballs at the christmas party and he was saying off the top of his head spoke length for that build was about 292.
Just lookin for confirmation that 292mm or 294mm is the way to go.

many thanks

by the way these wheels are going to go on the travelling bike.

292 still sounds about right to me...

What cacl are you using RPM, I'm getting 290/289, This one never failed me http://www.recumbents.com/wisil/spokes!.asp

DT

I don't usually bother cross reffing with others any more, it's always been right, but then I do measure the hubs and rims myself too.

Well done for that.

I'm only curiose because I've had not problems before and use 292 with hubs with smaller flanges, 292 just seems too long.

well my spoke calc (downloaded this one from harris cycles http://www.sheldonbrown.com/rinard/spocalc.htm)
came up with 294 for the front, (293.3 l, 291.6 r) which I just got from jimbilly yesterday
it seems like all the evidence is pointing to 292mm so thats what I'll get, just hoping that the 294mm spokes I bought for the front aren't too long.

anyone know how that spoke calc could be so far out on the rear?

User error

Spocalc works fine; 293.3l and 291.6 r are taken from spocalc output for 32h single sided rear hi Phil.

Have you bought the rims already? wanna split postage on some cheap black 32h OP £30 each

so steve which are the right measurements, am I okay with 294mm for high flange front, and 292 for high flange fixed/fixed rear?

I've already got the rims, just need to collect them monday/tuesday.

292mm all around like RPM sed.

Front flanges are only 4.7mm wider (33.7mm) from centre than rear drive side (29mm) which means the spokes only need to be about 0.2% longer in length.

If you imagine looking at the wheel face-on and make a triangle with rim at the top, centreline of the hub at the bottom and the spoke hole on the bottom right, moving the spoke hole left or right a few mm makes no difference at all really to the length of the longest side of the triangle from spoke hole to rim.

The rim ERD and the flange diameter have a much bigger impact per mm of change.

bollocks, will have to go to jimbilly and swap the 294's that I got for 292's then.
and the information you just gave went way over my head...

Wierd. I usually use "ed the online spoke calculator" but it went spastic giving me different readings....

...one of which was totaly out. I used the sheldonbrown download excel thingy... hoping for the best.

Also does anyone know of a cheap alternative to cycle basket - they don't have one of the lengths I want and its jacking up the price of my wheel :(

outspoken cycles

cheers, I'll check them now.

Thanks RPM! - thats saved me a tenner or so... the temptation is to browse the site to see how to spend the £10 saved ;)

A friend is picking up a set of Dodici rims for me from TFG on Monday, I am gonna lace them to System Ex hubs (which I have found to be perfectly good quality before anyone points out that I am lacing decent rims to wack hubs :-p)

I have come up with these calculations for spoke length, can anyone confirm that they look correct before I order the spokes?

FRONT
Hub: System Ex
Right flange ø: 61.7
Left flange ø: 61.7
Centre to right flange: 33.5
Centre to left flange: 33.5
Spoke hole ø: 2.6

Rim: Dodici
Effective rim ø: 561
Offset spoke bed: 0
Spoke length for 32 spokes
Crosses Right Left Tension L/R
0 250.1 250.1 100%
1 252.7 252.7 100%
2 260 260 100%
3 270.5 270.5 100%
4 282.4 282.4 100%

BACK
Hub: System Ex
Right flange ø: 61.7
Left flange ø: 61.7
Centre to right flange: 28
Centre to left flange: 28
Spoke hole ø: 2.6

Rim: Dodici
Effective rim ø: 561
Offset spoke bed: 0
Spoke length for 32 spokes
Crosses Right Left Tension L/R
0 249.4 249.4 100%
1 252 252 100%
2 259.3 259.3 100%
3 269.9 269.9 100%
4 281.8 281.8 100%

Thanks everyone :-)

Ty
http://www.thefootdown.co.uk

looks about right.

are the hub measurements definitely correct? i don't think they are :-s

Well that I can't say, because I don't have a set of system ex hubs in front of me to measure, but they do look very much in the right ballpark for most generic LF track hubs