wheel building.
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vrooom

Original Poster:

3,763 posts

290 months

Tuesday 11th November 2008
quotequote all
Now I enjoy the challange of building wheels, I wont take it to the shop. I have built 3 wheels before.

I got the new hub.
It is this DMR Casettee hub.


But I noticed the one side of hub nearer to disc mount is different diameter to Casettee part of hub.

so that mean I need different spoke length? if so, how do you work out what size spoke length?

Jay

Akers

463 posts

258 months

Tuesday 11th November 2008
quotequote all
This should solve your problem....

http://www.dtswiss.com/SpokesCalc

snotrag

15,496 posts

234 months

Tuesday 11th November 2008
quotequote all
Slightly confused as to how you've built 3 wheels without understanding spoke lengths, but yes, you need different length spokes than if the flanges were the same.

If your hubs not on DTswiss site then email DMR or measure it up with some calipers.

neil_bolton

17,113 posts

287 months

Tuesday 11th November 2008
quotequote all
Me too, all you've done is assemble a wheel with some parts and tension it correctly. You really should be trying to understand why there are different spoke lengths, and what you've previously built.

Proper wheel building is the art gained over time, which includes the trial and error of slowly but surely getting to know whick spokes fit which rims etc and making a note in a little book that will become the holy grail of a bike shop over the years... biggrin

The DT Swiss calculator is an excellent resource for the amateur (and pro) wheel builder, however, its worth taking a read through Sheldon Brown's (RIP) site for some very well informed info on what and why you choose regarding spokes smile

Edited by neil_bolton on Tuesday 11th November 19:36

vrooom

Original Poster:

3,763 posts

290 months

Tuesday 11th November 2008
quotequote all
It odd i never needed to calculate spoke length. i just took it to shop ask for same size spoke.

that site is useful thanks

neil_bolton

17,113 posts

287 months

Tuesday 11th November 2008
quotequote all
vrooom said:
It odd i never needed to calculate spoke length. i just took it to shop ask for same size spoke.

that site is useful thanks
There are many different variables:

For instance, disc wheels require different length spokes on the disc side and the non disc side. It is the same for rear wheels, especially ones with 9/10 speed hubs, and fixed wheels do not.

Confused yet? You should be, because in 15 years of doing it, I'm still learning. Study the DT Swiss site carefully, and make notes as you build, and read the Park and Sheldon Brown websites and you should be fine.

I trust you've understood the finer points of tensioning wheels, dishing them and then stressing them afterwards?


vrooom

Original Poster:

3,763 posts

290 months

Friday 14th November 2008
quotequote all
Back then, I was building two of bmx style hub, a very simple hub with free wheel bolted on. I was using sheldon brown website, good site but really strange bloke!.
Three of my wheel held up really well after bedding them in and tensioning the spokes.

I hope that I do the same to this new hub, I find wheel building enjoyable thing to do.
It is good for those long winter nights!

My calculation on this setup.

DMR Casettee
left flange: 34mm
right flange: 20mm
left PCD: 57mm
right PCD: 45mm

Sun S-type rim
599x34mm
Effective Rim Diameter: 530

so spoke length is
Precise
Left: 252.90mm
right: 254.00mm

Rounded
left: 253mm
right: 254mm

So the DMR hub I am using has big difference at size of left/right flange size but the spoke length is only just an 1mm difference. That is what worries me about...

Jay


Trooper2

6,676 posts

254 months

Friday 14th November 2008
quotequote all
Best book that I know of for explaining bicycle wheel theory and building, is "The Bicycle Wheel" by Jobst Brandt, if you are into math the last chapters are almost all math, IIRC.

http://www.amazon.com/Bicycle-Wheel-3rd-Jobst-Bran...

pdV6

16,442 posts

284 months

Friday 14th November 2008
quotequote all
vrooom said:
So the DMR hub I am using has big difference at size of left/right flange size but the spoke length is only just an 1mm difference. That is what worries me about...
Yes but the right (drive) side will have a straighter "run" for the spokes from the rim to the hub, to allow space for the cassette.

I rather suspect that that is precisely why the hub has different size flanges in the first place, to allow you to build the wheel with spokes all of one length (more or less).

fixedwheelnut

744 posts

255 months

Friday 14th November 2008
quotequote all
If anyone wants to have a go I just put some pictures up at various stages of a wheelbuild on my flickr page here;
Wheelbuilding pictures and text

zagato

1,136 posts

224 months

Tuesday 18th November 2008
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I leave my wheel builds to a man with 18 years experience. Too many variables!

Saddle bum

4,211 posts

242 months

Tuesday 18th November 2008
quotequote all
zagato said:
I leave my wheel builds to a man with 18 years experience. Too many variables!
With 30 years experience, I agree.

alecw35

6 posts

211 months

Saturday 20th December 2008
quotequote all
as youve found out the spoke lengths will be nearly the same.
if its a box section rim I would use all the same length spokes.


switchltd

18 posts

207 months

Friday 26th December 2008
quotequote all
Saddle bum said:
zagato said:
I leave my wheel builds to a man with 18 years experience. Too many variables!
With 30 years experience, I agree.
Totally get what you mean about building, truing, tensioning and dishing your own gear but these two are right.
whether Downhill, Freeride, Park, xc or whatever, your wheels are only goin to save your ass when you get it wrong IF they have been built correctly by someone who knows exactly what they are doing and also has picked up a few tricks to make em stronger.
if youve built three so far and they have lasted your either
A) Lucky
B)Light
C) Not Pushing it bar the odd kerb
or
D) EXTREMELY talented and should stop what your doing right now, go get your Cytech tickets and make your hobby your life yes

BTW using a good bike shop regularly and getting to know those that run it is an awesome way of picking up little tips and techniques on how to setup up your bike for specific riding. I use the hub and perth city cycles for anything i cant do myself
The reason i got into riding was because of the happy, accommodating and generally all round helpful sods most riders are.
keep on pushing up

Edited by switchltd on Friday 26th December 12:38