calculate my spoke lengths please!

[e-rider]

I just want to double check before buying the spokes. I've used 2 calculators and got 2 different results (well front was the same but rear was different)

Rims are Mavic CXP33 36h
Need to use 14mm nipples with these rims
3x spoking pattern
Hubs are Hope Mono Road dimensions:
front pcd = L,38mm; R,38mm
rear pcd = L45mm; R,54mm
offset Front = L,34.5; R,34.5
offset rear = L,35.5; R,17.5

I got 290mm fronts
Rear L,288mm; R, 285mm

Cheers

 

[Davidc]

DT Swiss have a good online calculator.

 

[e-rider]

DT Swiss have a good online calculator.

yes that was the first one I used - can I trust it? the spokes are going to cost £50 so it's a bit of a gamble!

 

[Spoked Wheels]

I got for the rear wheel:

Left spoke length: 290.3

Right spoke length: 286

 

[Davidc]

yes that was the first one I used - can I trust it? the spokes are going to cost £50 so it's a bit of a gamble!

I've used them, including for hub dynamo spokes, and never had a problem. Doesn't mean you won't have one though!

 

[Spoked Wheels]

BUT interestingly:
Using values:

rear pcd = L47mm; R,54mm

offset rear = L,30; R,47 -You had them the wrong way around - the right side is larger than the left.

and I got:

Left spoke length: 288.1

Right spoke length: 285

With a RIM ERD = 594

Same length you got.

 

[e-rider]

I got for the rear wheel:

Left spoke length: 290.3

Right spoke length: 286

hi, thanks for this, I actually got 289.9 and 286.3 which DT Swiss says means spoke lengths of 288 and 285 - not sure why they round down a little?

 

[e-rider]

I'm going for it - laced but unused spokes should sell on ebay so I can potentially get back probably about 50% of the cost if they are slightly wrong - at least then I'll know the correct lengths!

 

[Spoked Wheels]

I'm going for it - laced but unused spokes should sell on ebay so I can potentially get back probably about 50% of the cost if they are slightly wrong - at least then I'll know the correct lengths!

Did you read my second post?

 

[e-rider]

Did you read my second post?

yes, I think there is a good chance that they will be correct then - I used ERD of 599?

 

[Spoked Wheels]

ERD makes the biggest difference when calculating spokes.

 

[Davidc]

hi, thanks for this, I actually got 289.9 and 286.3 which DT Swiss says means spoke lengths of 288 and 285 - not sure why they round down a little?

The nipples will pick up the threads and tighten that way round. If the spokes are long then the nipples may tighten so they run out of threaded spoke.

If you end up with spokes too short for the nipples to pick up you can (within reason) buy longer nipples (much cheaper than new spokes).

 

[I like Skol]

offset rear = L,30; R,47 -You had them the wrong way around - the right side is larger than the left.
.

Are you sure about this RRSODL?

I've just been doing this exercise for some new MTB wheel I am building and even when discs are involved The rear hub R/H flange is closer to the axle midpoint than the L/H flange. For a non-disc hub the L/H flange would be even more offset. The cassette/freehub takes up far more space than discs.
http://www.google.co.uk/imgres?imgu...a=X&ei=x05JUuqaKJOh7AaDnICACw&ved=0CDoQ9QEwAw

 

[Spoked Wheels]

Yep, you are right. Who knows what I was thinking about

It's quite simple. It's the distance from the mid point, from end to end, to the centre of the flange. The drive side is shorter than the non drive side.

What happened is that I was using a spoke calculator that uses the distance from the end to the flange and in that case the drive side is larger than the non drive side. I like that calculator cause I find it difficult with some hubs to be accurate in measuring mid point to centre of flange. having said that, with experience I've noticed that a mm or two here or there makes hardly any difference. An error in the ERD has a much bigger impact on the spoke length.