Wheelbuilding / Wheel Building / Wheel build help

Can't see any problem with that, wheelbuilding is a relatively low risk activity.
Don't put 'em on a bike though.

Can't see any problem with that, wheelbuilding is a relatively low risk activity

You say that, but bringing spokes which are much too short to full tension might easily lead to a catastrophic nipple failure, and the free part can fly off at surprising speed. Not a problem once you have tape on the rim bed, but on the truing stand with your face in the firing line that could have your eye out.

1 Attachment

The guy who taught me how to build on my cytec had a little pinpoint scar on his forehead from a similar incident, I always keep my head to the side if there's no tape on and some tension.

I stand by relatively low risk, as opposed to posting on LFGSS.

I used longer nipples for my own wheel that I messed up measuring. It's holding fine.
Wouldn't do that for anyone else, see @mdcc_tester tester diagram up there, hollowed just where it meets the rim.

Given these wheels are both for @PhilDAS and not for myself I'll build them with the correct lengths. Not worth risking sorry dude. Lesson learnt: don't assume any wheels were originally built correctly. I just measured the existing spokes instead of my usual rule of measuring the hubs and rims that you have in hand. Thanks for the help all

Theres a reason why they are cheaper now. Utter shit. Suitable for front wheels only.for single speed builds they are o.k.

Yes never assume anything.

Yeah, they couldn't take the tension they were rated at.
What was the final tension on your 16:8 sl23/Royce ti build; are they still running?

Very much so. 1200N DS I think or was it 1150N average. NdS is about 74% of that. I use them every day. The bike is my daily commutor and audax bike. The front wheel with matching hub is about to get it third rim as I keep wearing them out. Lots of use and now they carry loaded panniers often.

Which is people’s go to online spoke length calculator?

And is it a bad idea to use the built in presets for hubs and rims? If so, is there a reliable database of things like ERD, Flange distance etc? Thanks

I use the Edd spoke calculator for normal stuff and the DT Swiss one for more offbeat stuff like straight pull hubs. Hub manufacturers are usually pretty accurate with their dimensions, rim manufacturers less so. I always measure just in case. I've yet to find a major discrepancy with hub dimensions (where they've been available) but rim ERDs have been a few mm off sometimes.

The Edd calculator has a database of dimensions, but it's very hit and miss and I don't trust it.

Might be a yes and No, I've been riding my beater with the spokes too short. It's done loads of miles but had a side on impact and the nipple heads broke right off. If the spoke isn't going into the wheel far enough, the nipple head is going to be a weak point

Edit:ignore me, just realised I chimed in late and didn't add anything 🤷🏽‍♂️

Great. I’ve used the DT one and will compare the numbers Edd spits out and hopefully they’ll match up

Spokecalc is the most versatile spoke calculator as it alow fractional crossing. The dt swiss calculator is great for straight pull hubs.

I need to create a sheet for spoke calc so it can handle straight pull spokes.

I have worked it out. Use spoke calc and enter 2.5 or 3.5 cross and add the spoke hole offset from centreline. That not easily measured and varies between hubs

This document gives a value for offset left and right - is this the same as flange distance?

https://www.hopetech.com/_repository/1/documents/2016-UPDATED-HOPE-HUBS-SPOKE-OFFSET-AND-PCD-1-1.pdf

Yes.

Much appreciated

My go to spoke length calculator is my own of course. Always measure the ERD if you can. Some rims actually state the ERD on the side but more often than not when I've measured it's been a few mm off as @danstuff has mentioned. The ERD and number of holes has the largest effect on the output. Try changing the values of the hub dimensions and you'll see that it doesn't effect the output that much but even a 2mm change in the ERD and you'll see a noticeable difference.

On the topic of ERD:
What is the best tool/way to measure it?
Right now I'm using two spokes cut to a specific length and joined together with an elastic band.
Pulling the spokes and the elastic band through the spoke holes multiple times per rim is kind of a pain though. If I use too much electric tape on the joint it doesn't fit through the spokes holes, not enough and it rips apart when pulling it through.

I've found a specific tool called "Rim Rods" made by Wheelsmith but it seems to be discontinued and only available from US online shops.
Are there any alternatives? Or does someone know where I can get the Rim Rods without ordering them from overseas?

the elastic band method is pretty good but your method above sounds slightly different and more complicated than the one i've used. I did this (from Sheldon):

1. Insert two old spokes into holes exactly opposite each other on the rim. Count holes to be sure.
   
2. Screw some nipples onto the spokes.
   
3. Pull them tight and measure dimension A in the figure (the diameter to the edge of the nipples, where the spokes disappears into them). Do this at several spots around the rim and average the measurements.
   
4. Measure the length of a nipple (dimension B in the figure) and add it twice (once for each nipple).
   
5. The result is Effective Rim Diameter (ERD). Thus,
   ERD = A + 2B.
   

Are there any alternatives?

I have to confess that I haven't directly measured an ERD since I stopped using tubulars nearly 30 years ago. Since the bead seat diameter of clincher rims is easily within 0.5mm of nominal, I just use a depth gauge to measure from bead seat to the desired end point of the spoke and subtract twice that value from the nominal BSD to get ERD. This method also completely eliminates the need to take multiple measurements and adjust for the rim being oval.

Thanks for the replies!

@fizzy.bleach
Thanks for sharing your method. You're right, it seems a little less complicated than dealing with the rubber band. But you still have to take multiple measurements and pulling the spokes together and taking an accurate measurement at the same time sounds a little tricky.

@mdcc_tester
Haven't thought or read about this method before! Thanks for sharing it. It sounds a lot easier and you only have to take one measurement per rim. I'll give both a try and see if there's any difference.

Get 2 spokes of known length, put the nipples on them to where you want them to finish, one in opposite holes on rim, verniers on the gap in the middle, do the math (spoke x2 +gap). I've got a big DT poster somewhere with some proddy things but haven't used that in years.

I forgot to mention that I do use a rubber band. I didn't find it that complicated. You've got two spokes (of any length) held in tension across a rim. You measure across them to the ends of the nipples. Then you measure a nipple and add that (x2) to the total spoke distance. I repeat twice more to account for a rim being out of round. It maybe takes 10 mins max for two rims. If you're feeling lucky, you can assume that your rims have an identical ERD and are sufficiently round to warrant one measurement.