Spoke Length Help

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euphi223
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Spoke Length Help

Postby euphi223 » Sun Dec 10, 2017 5:37 pm

Hi all!
I'm building my own wheels for the first time. I have the Rims, 26" 28 hole togia's. I have the hubs also. i know there are programs and apps etc to calculate spoke length by feeding it various measurements. However the hubs i purchased are not traditional round flange, they are.....well its hard to describe so ill get a pic.
Image

Any help to figure out what spoke length i need would be fab!
thanks very much!! :D

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Duck!
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Re: Spoke Length Help

Postby Duck! » Mon Dec 11, 2017 11:55 pm

The DT Swiss spoke calculator has the capacity to deal with straight-pull hubs and spokes. he only tricky bit will be measuring the flange diameter; being 28-hole they'll have 7 lobes, so no diametrically-opposed pairs. You'll need to find a part of the hub flanges where you can get a true diameter reference, then measure one spoke bed lobe height from your reference point to the centre of the spokes, then double that figure and add it to your initial reference figure.

The DT calculator takes its flange spacing measurement from the centre of the hub to the centre of each flange; to measure the flange spacing, it's simply the same method as a regular J-bend flange. Start by halving the hubs' Over Locknut Dimensions (OLD) - the length of the axle between the outer faces of the locknuts, excluding the "knob" on the end that fits in the dropouts - standard disc-brake hubs are 100mm front and 135mm rear OLDs, so your half figures are 50mm and 67.5mm respectively. The easiest way to measure it is to butt the locknut (again excluding the smaller axle stub on the end) against a bench edge or something with a nice square edge to use as a reference point, and measure to the centre of the near flange, then subtract that figure from 50 or 67.5 as applicable. The result is the flange distance from hub centre. Being disc-brake hubs, they will be asymmetrical (the disc-side flange on the front and the drive-side flange on the rear will be further inboard than their opposite), so you will need to measure both ends of both hubs.
I had a thought, but it got run over as it crossed my mind.

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queequeg
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Re: Spoke Length Help

Postby queequeg » Tue Dec 12, 2017 11:59 am

Probably worth adding, the lacing pattern for straight pull hubs is pretty much dictated for you by the hub design.

If you are building a wheel for the first time, the Wheel Building book by Roger Musson is excellent. HE also has an online spoke calculator that is compatible with straight pull spokes, and the book explains in clear detail how to measure the hubs so that you enter the correct numbers into the calculator.

https://www.wheelpro.co.uk/
'11 Lynskey Cooper CX, '00 Hillbrick Steel Racing (Total Rebuild '10), '15 Cervelo S5

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Duck!
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Re: Spoke Length Help

Postby Duck! » Tue Dec 12, 2017 10:07 pm

Good point about the lacing pattern. On that note, the overlapped/opposed spoke heads in each lobe are considered a cross in the lacing.
I had a thought, but it got run over as it crossed my mind.

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euphi223
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Location: Rosebud, Mornington Peninsula, Victoria, Australia

Re: Spoke Length Help

Postby euphi223 » Thu Dec 14, 2017 5:15 pm

Urrrgh!!! I sense a massive headache in the close future!!
Thanks for the help guys!! really appreciate it.
Yes this will be my first wheel build. I have NO money,so paying someone to do it for me is out. Generally speaking, new wheels are hellishly expensive! Over the last year i've searched for cheap components to build my bike from the frame up.
I read a great tutorial by SHELDON BROWN on wheel spoking etc.

BTW if anyone needs New 26" 28Hole rims drop me a PM

uart
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Re: Spoke Length Help

Postby uart » Thu Dec 14, 2017 9:02 pm

euphi223 wrote:Urrrgh!!! I sense a massive headache in the close future!!

What's your starting point euphi223? Do you know what cross pattern you should be using?

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queequeg
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Re: Spoke Length Help

Postby queequeg » Thu Dec 14, 2017 9:57 pm

euphi223 wrote:Urrrgh!!! I sense a massive headache in the close future!!
Thanks for the help guys!! really appreciate it.
Yes this will be my first wheel build. I have NO money,so paying someone to do it for me is out. Generally speaking, new wheels are hellishly expensive! Over the last year i've searched for cheap components to build my bike from the frame up.
I read a great tutorial by SHELDON BROWN on wheel spoking etc.

BTW if anyone needs New 26" 28Hole rims drop me a PM


I use the Wheelbuilding Book by Roger Musson. It is very clear, has full instructions, has templates for building your own truing stand etc, and has an online spoke calculator that pairs with the book. It includes diagrams on how to measure those hubs you have for the straight pull spokes.

The Book costs about $15 (electronic delivery) and you get free upgrades to later editions as he releases them

https://www.wheelpro.co.uk/wheelbuilding/book.php

If you are concerned about messing it up, go find some council cleanup wheels and pull them apart and put them back together so you can learn the process. The first wheel is the hardest one to wrap your head around. After that it gets easy.
'11 Lynskey Cooper CX, '00 Hillbrick Steel Racing (Total Rebuild '10), '15 Cervelo S5

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Duck!
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Re: Spoke Length Help

Postby Duck! » Thu Dec 14, 2017 11:21 pm

The hardest part about lacing a wheel is working out where to start. On a rear wheel, work the drive-side first, on a disc-braked front, do the disc side first.

First, locate any logos on the hubs, they will give a reference point for aligning with the valve hole. If the hubs are unmarked, start anywhere..... They can also be a clue for whether the hub is designed for 2-cross or 3-cross lacing (for 28-hole you can go either way, but for disc brake I'd err toward 3-cross if the hubs allow).

Working with 3-cross in mind.... any hub logos should sit between two flange lobes. Start at the second lobe to the left of the logo, and feed a spoke from the left side of that lobe (the hub drilling will determine if it's the inboard or outboard hole, thread in from the large-bore side), and attach to the rim at the hole immediately to the left of the valve hole. For your second spoke, Skip two lobes to the right of your start point, and through the third, thread a spoke from the right side up to the second hole to the right of the valve hole. You have your lacing reference spokes in place.

Fo 2-cross, only skip one lobe at this stage, otherwise the process is the same. If the hub is optimised for 2-cross, the logo will align closely with a lobe on each side.

From your reference spokes, thread from each lobe up to each fourth hole around the rim; after your primary spoke, go to the next hub lobe to the right, and to the fourth hole around from that spoke, or second hole past the second spoke (around the rim, spokes alternate from left side and right side, and on each side, leading and trailing spokes, hence going to every fourth hole). Work around and fill in the gaps to this pattern, interlacing at the outermost cross; those spokes that seat in the inboard hole of each lobe will stay under the next spoke (remembering that the lobe itself holds the first cross), then lace outside the final crossing spoke. Be consistent with how far you screw each nipple on, and be careful not to go too far; screw each nipple down to where the tip of the nipple aligns with the bottom of the thread. Once that side of the wheel is completed, flip over and do the other side.

You'll notice here (if you haven't already) that the lobes are not perfectly aligned with each other. From your second spoke of the first side, which you'll now find is two hole to the left of the valve hole, trace down to the hub, and find the pairing lobe that is offset just a little bit to the right. Thread a spoke up and into that hole immediately left of the valve hole. From there the rest of the lacing is exactly the same as the first side.

Once the lacing is complete, the key to building the wheel is small, equal steps to gradually build tension, not big handfuls in one hit. Start by puling the rear drive side and front disc side up to tension first, as they're the higher-tension sides of the wheelset, then pull back with the lower-tension side.
I had a thought, but it got run over as it crossed my mind.

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queequeg
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Re: Spoke Length Help

Postby queequeg » Fri Dec 15, 2017 1:32 pm

If you follow the Roger Musson lacing method (which is pretty much the same process Duck describes above), you can follow along with this video of Roger lacing the entire rear wheel in under 10 minutes. That's about how long it should take once you have had a few goes at it.



For aligning hub logos etc, that is all covered on the book and is very easy. In terms of where to start, that first spoke is the one that aligns the entire wheel to the valve hole and hub logo. I mark this spoke with a piece of electrical tape, and when I am tensioning the wheel, I always start at this spoke and complete one full revolution of the wheel before putting tools down.
'11 Lynskey Cooper CX, '00 Hillbrick Steel Racing (Total Rebuild '10), '15 Cervelo S5

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