Spoke Length Help

[euphi223]

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.


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

[Duck!]

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.

[queequeg]

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/

[Duck!]

Good point about the lacing pattern. On that note, the overlapped/opposed spoke heads in each lobe are considered a cross in the lacing.

[euphi223]

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]

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?

[queequeg]

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.

[Duck!]

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.

[queequeg]

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.

[euphi223]

Really appreciate everybody help! If i could buy you all a beer, or something friendly like that, i would to repay your great kindness.
I took the hubs to my local bike shop to get their opinion. Lets just say i didn't get good news. That's why i haven't been back here to update. Apparently with no additional hub info, they're worthless.
So ive got a pair of SP hubs i cant use. That is because i dont have assorted SP spokes laying around. Apparently only a wheel builder or someone similar could put them to good use.
And ive still got a full pack of Tioga 26" rims! x10 of them!
So if anyone is feeling generous and has a bunch of assorted sized SP spokes i can experiment with, Im afraid this 'task' is over before it started.

Thanks again guys!

[euphi223]

So bottom line people, these hubs of mine are worthless without assorted a bunch of SP spokes. So if anybody wants them, send me a PM.

This is the 2nd time ive done this. Rushed in and purchased a set of hubs without knowing the relevant info for sizing the spokes.
I've learned my lesson! Ask the bike people who know a hellavalot more than me.
Ive got x10 26" Tioga 28 hole rims. 2 of which are ear marked for the MTB im building. I've got my eye on a new set of NOVATEC hubs on ebay
https://www.ebay.com.au/itm/Mountain-Bi ... 0008.m2219

My only requirements are the hubs need to be 28 hole (to match the rims). 6 bolt rotor capabilities. I have just discovered those center screw disc adapters! How great, right!

Im open to any thoughts.
thanks

[queequeg]

So bottom line people, these hubs of mine are worthless without assorted a bunch of SP spokes. So if anybody wants them, send me a PM.

This is the 2nd time ive done this. Rushed in and purchased a set of hubs without knowing the relevant info for sizing the spokes.
I've learned my lesson! Ask the bike people who know a hellavalot more than me.
Ive got x10 26" Tioga 28 hole rims. 2 of which are ear marked for the MTB im building. I've got my eye on a new set of NOVATEC hubs on ebay
https://www.ebay.com.au/itm/Mountain-Bi ... 0008.m2219

My only requirements are the hubs need to be 28 hole (to match the rims). 6 bolt rotor capabilities. I have just discovered those center screw disc adapters! How great, right!

Im open to any thoughts.
thanks

Did you look at the Roger Musson book above? It shows you how to measure the hubs and rims to calculate the required spoke length, including measuring straight pull hubs.

[euphi223]

Did you look at the Roger Musson book above? It shows you how to measure the hubs and rims to calculate the required spoke length, including measuring straight pull hubs.

Thats a big 10-4! Not only did i look at it, i purchased it! He really goes into alot of detail...not enough on the actual method of measuring each area involved with calculating the end spoke length. Im not complaining. Its more help than i had before. The DT Swiss calculator has an excellent help/tutorial on each specific aspect involved in the end outcome.
There are alot of things to do, such as:
* ERD - Effective rim dia
* FDL/FDR - Flange Distance Left & Right
* Spoke Hole dia
* Spoke hole offset
* Pitch circle
There maybe more but im still in the 'grass-hopper' stage.
I cant recall saying in my earlier posts. My hubs came with ZERO technical information! I got them of ebay from a chinese company called "bigJoy" i think (really cant remember). I asked them multiple times for manufacturing info. The result, a dead end. I looked at the large white letters printed on both hubs "Vuelta", i googled it and found one possible place that sold bike parts, and at the time, had something to do with the name "vuelta".
Although they had no friggen' idea where i got these mysterious hubs, or why they were called that name, they were very helpful & understanding.
I contacted DT Swiss (the calc. part) on suggestions about obtaining the relevant data, in particular the pitch circle dia. They replied with bad news. If it wasnt from the manufacturer, you would have no accurate way of knowing.
This is a similar problem in facing with Musson's book. He does tell you what it is the aspect is for, but is not very clear on step by step measurement techniques. I even purchased a caliper! Its better than a ruler, but there is no way to be accurate. It's like guessing that the caliper points (jaws) are approximately sort of near the center of the hole.
Dont get me wrong, its a highly detailed book! it even shows you how to make the darn tools! Just a bit vague in the SP section.


Im up to the part of spoke offset. This section goes into a bit more detail. Tells you what to do and how to do it. That being said, in order for me to achieve this measurement successfully, Mr Musson says ill need x1 SP spoke. Anyone feeling generous? Ill even PayPal you a few dollars for an old spoke. Apparently it will be cut in half. Im assuming the cheapest place for spokes is China or Hong Kong. Id rather not wait that long for 1 spoke, especially if someone here in Australia has an old one they can part with.
Apparently bladed SP spokes are the way to go when actually in the lacing phase. But for this task, i guess a normal SP spoke will do.

Anyone, please? PM me.
Thanks again.

[queequeg]

My advice would be to ask around for anyone with a wheel with SP Spokes that has had it and would otherwise be binned.
Most bike shops probably have odd spokes lying around, especially since length doesn’t matter for this purpose.
I think you are overcomplicating things a little though, which is understandable if you haven’t built a wheel before, so getting an old wheel to tinker with would be valuable.

[Paddles]

A couple of dodgy wheelbuilding tips from a back yarder that's built a number of wheels for both bicycles and motorcycles:

- use google to find good pictures of suitable lacing patterns for your proposed wheel build or if you are rebuilding an existing wheel take a few photos on your phone
- don't be scared, it's not overly difficult if you're an amateur cyclist/builder (if your building for a pro it's a definite science) Don't be scared even if you lace it up wrong, it's easy to unlace it all and start again
- if you know what size spokes you need (ie you've measured the ones that came off a wheel that you are simply re-spoking or have maybe adjusted the length to suit a new rim depth) then you'll be fine to buy spokes off ebay or wherever
- if you are in doubt, just work with a reputable wheel builder to supply your spokes ( I use Craftworx because he's near me, he's good, and I get my spokes within a couple of days). You supply all the measurments and they supply the spokes/nipples you need. If you are in more doubt then visit the wheelbuilder with your hubs/rims and get them to measure/supply the right spokes
- you don't necessarily need a purpose built jig, when you can use your bike as your jig. Flip your bike upside down and install your loosely laced wheel. Now stick a piece of masking tape across the chain stays (for a rear wheel) or the fork legs (for a front wheel) somewhere very close to your rim (the closer the better for both trueing and checking for round. Mark your preferred centreline on the masking tape and then mark a half rim width on either side of the centreline to get your targets for trueing the rim. This piece of tape is also your reference for making sure your wheel isn't tensioned out of round because you will be keeping an eye on the gap between the tape and the rim as you tension all the spokes and true the wheel

Get into it, building and riding your own basic wheels is bloody rewarding because those who still think it's rocket science will marvel at your abilities to understand rocket science and you will smugly know that it's not rocket science. However, I've only ever built basic alloy rim wheels and have never played with carbon and anything too flash, that stuff does scare me

[euphi223]

I think you are overcomplicating things a little though, which is understandable if you haven’t built a wheel before, so getting an old wheel to tinker with would be valuable.

I think that is a very good observation! Overthinking comes from insecurity, at least for me. I have little to no money, so im very particular with calculating wrong measurements. If my hubs came with all relevant specs, happy days! When i bought the hubs i didnt know i needed exact specs. Ive learned a lot since then. Honestly, i should never have purchased them. But thats life.
Ill ask my local bike shop for any spare SP spokes.

if you know what size spokes you need (ie you've measured the ones that came off a wheel that you are simply re-spoking or have maybe adjusted the length to suit a new rim depth) then you'll be fine to buy spokes off ebay or wherever.

Appreciate that advice, Paddles! Im not re-building a wheel, im starting from scratch. I have the rims & these two crappy crappy SP hubs.
I hope your correct about wheel building being a rewarding experience. This experience for me has been a friggen nightmare, and i havent even started yet!

Cheers guys

[euphi223]

In the coming weeks my wheels will be built for me. I read Roger Musson's book, recommended by queequeg, THANKYOU! Was an enormous help to me. I found a wheel building company in Brunswick that can do it for me for around $120 each. I gave up on building them myself because i just wasn't confident in my hub measurements. Next time ill be sure to buy hubs with correct specs.
Its gonna be a pain to get my rims & hubs to the shop!!

When the wheels are finished ill be sure to post a photo!
Thanks again guys!

[baabaa]

Good news and as someone who feels just the same and opts for having pro built wheels, ask for a set of spare spokes and nipples. If done at the same time as the build you never have to worry about replacement lengths or finding the same type.
I go three each, left and right from both front and rear. ( so 12 extra spokes). This more or less means even if they build a very lousy wheelset and you use third grade bits, just by having the spare spokes you will never ever break a spoke......

[P!N20]

just by having the spare spokes you will never ever break a spoke......

That must be the same rule as with carrying a pump and repair kit, you will never have a flat.

[uart]

That must be the same rule as with carrying a pump and repair kit, you will never have a flat.

Yep, basically just Murphy's Law in action.

BTW. I've built a lot of wheels, but never with straight pull spokes, so I'm kind of interested here also.

What's the main issue with estimating spoke length with SP spokes? The ones pictured by the OP seem to have good access to the flanges so they shouldn't be hard to measure. You might need to measure the depth to the countersink of the flange holes to be sure where they'll sit, but that doesn't seem hard. Other than what Duck mentioned about no diametrically opposed holes, I can't see any great difficulty.

Also, remember that unless you're using aluminium nipples (don't) then there is usually a few mm flexibility in the exact length anyway. Most nipples will allow the spoke to protrude a mm or two proud without any issue, and any good (not aluminium) nipple will still be strong enough even if the spoke is a couple of mm shy.

Also note that the radial measurements are by far the most important (to get reasonably accurate), as the lateral ones only marginally effect the spoke length anyway. Generally for every one mm error in the lateral measurements the (theoretical optimum) spoke length will only vary by about 0.1 to 0.15 mm in a typical wheel.

One question I have (and maybe this was the sticking point for the OP) is how do you tell from the hubs what the cross number must be? Can you just shove a couple of spokes though and see the correct crossing just by looking? Perhaps that is what the op really needed to know? From the pictures I can tell the op's hubs are obviously not for 1x or 4x, but I can't quite make out if they are for 2x or 3x (though I think it would be obvious enough to me if I had them in my hands).