Need advice about spoke lenght...for new Venn rims

[emartin]

Hi,
I'm about to received new rims from Venn cycling, the Venn Rev 35TCC. It will be my first wheel built ...I'll have access to the knowledge of my friend who own a bike store but I'll order the spoke online because locally, only boxes of 72 spokes are available.

So, I will use DTSwiss 350 straight pull hubs(rim brake) and probably Sapim race spokes with alloy SILS 14 mm nipples.

I used the DT spokes calculator, enter the ERD of 569mm provided by Venn, choose my hub, DT Comp race spoke( equivalent of Sapim race imo) and 14mm nipples.

For the front, 20 spokes, the lenght is 273.9mm and they recommend 272mm spokes
For the rear, 24 spokes, non drive lenght is 283.9mm, they recommend 282mm spokes, drive side is 282.2mm and they recommend 280mm spokes.

Does everything seem right, I have no idea if lenght change between brands, but for shure, I don't want to order the wrong sizes.

Any input will be much appreciated, thanks

[fabriciom]

Ohh boy this has so much wrong I can't even begin.

First off. if this is your first wheel don't go using straight pull hubs and spokes. They are harder to get right and stay on right.

Second of all I would not venture into building a wheel unless you have ALL the tools required for the job.

Last, you should go read Professional Guide to Wheel Building 6th Ed by Roger Musson before even looking at a spoke or a hub.

Good luck!

[emartin]

Thanks for the reply, yes this is my first build but In real life, I will assist my friend who build wheels (mostly mtb wheels) on a regular basis. I already have the hubs and the rims should arrive next week. My main concern was to order the right size spoke based on the DT calculator and be shure that spokes sizes between brands DT/Sapim were the same. Thanks

[joejack951]

Wheel building isn't all that difficult but you need to focus and be methodical. It is very easy to lose track of what you are doing (every spoke and nipple looks pretty much the same!) if you are easily distracted. There are also some simple mistakes that new wheel builders make which will make the process far more painful than it needs to be. Luckily, it sounds like you have a decent mentor so you should be alright.

As far as the recommended spoke lengths, rounding down is generally a good idea so that you don't risk running out of threads on the spoke before the spoke reaches the desire tension. If you don't want to round down a full 2mm, order from Danscomp.com and they'll cut your spokes to the exact millimeter you specify, and they have some of the best Sapim spoke prices out there.

There is no difference from manufacturer to manufacturer when calculating spoke lengths. About the only time you'll encounter a spoke that doesn't act like its true length is when using 1.5mm diameter spokes which can stretch considerably at high tension.

[sugarkane]

straight pull is actually easier to build for a beginner as the lacing patten is hard to screw up.

worst thing with straight pulls is calculating the spoke lengths as they don't calculate the same as a j bend hub.
the good thing about the dt calculator is it knows how to calc the dt SP hubs.. i recommend waiting till you get the rims and actually measuring the ERD using the nipples you are going to use in the build. Never trust the mfg's ERD numbers until you've verified that they are right and constant

[sugarkane]

also if you want some light reading on 'modern' wheel building techniques then Ric's blog is a gold mine of modern ideas and methods

http://www.wheelfanatyk.com/blog/catego ... ding-tips/
i recommend starting at the beginning of this and working through the posts

[Marin]

If you are patient and double check everything it's not hard at all to build a wheel. Have fun!

[emartin]

Thanks for the replies, tips and link. I'll do some reading and probably wait , as advice, to measure the actual ERD.

[bm0p700f]

why not measure the erd of the rim yourself. as a wheel builder the one thing I don't do is trust anyone else ERD measurements. I often find manufacturer ERD measurements to be wrong. H plus Archetype for example published erd 595mm real erd 593mm.

wheel building is easy it is a process that is easily defined. building with SP hubs and spokes is not different to building with J bend spokes. you turn the nipples in the same way!

[emartin]

why not measure the erd of the rim yourself. as a wheel builder the one thing I don't do is trust anyone else ERD measurements. I often find manufacturer ERD measurements to be wrong. H plus Archetype for example published erd 595mm real erd 593mm.

wheel building is easy it is a process that is easily defined. building with SP hubs and spokes is not different to building with J bend spokes. you turn the nipples in the same way!

I will definetly wait for the rim to arrive and measure the ERD, thanks!