My Wheel Building Guide

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My Wheel Building Guide
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flag peeldog
Posted: Mar 23, 2020 at 9:01 Quote
R-M-R wrote:
peeldog wrote:
What end tension should i aim for?

Look up the maximum tension rating for the rim. Spokes on the side with less flange offset should be at, or a little below, this value. Let's say definitely within 20%, and within 10% would be ideal.

Ok cool. Thanks.

Go for max tension value as stipulated by the rim specs? Or is there a sweet spot before that? I’ve only built up a few wheel sets and generally just try and hold within the range as stated on spoke tension gauge chart (I use park tool).
flag ajax-ripper
Posted: Mar 23, 2020 at 9:11 Quote
peeldog wrote:
R-M-R wrote:
peeldog wrote:
What end tension should i aim for?

Look up the maximum tension rating for the rim. Spokes on the side with less flange offset should be at, or a little below, this value. Let's say definitely within 20%, and within 10% would be ideal.

Ok cool. Thanks.

Go for max tension value as stipulated by the rim specs? Or is there a sweet spot before that? I’ve only built up a few wheel sets and generally just try and hold within the range as stated on spoke tension gauge chart (I use park tool).
I usually aim for 120kg-force on mountain wheels
flag peeldog
Posted: Mar 23, 2020 at 9:37 Quote
Great. Thanks for the advice R-M-R and ajax!
flag R-M-R
Posted: Mar 23, 2020 at 10:56 Quote
peeldog wrote:
Go for max tension value as stipulated by the rim specs? Or is there a sweet spot before that? I’ve only built up a few wheel sets and generally just try and hold within the range as stated on spoke tension gauge chart (I use park tool).

It's not absolutely critical to hit a particular value. It's also good to know the "maximum" tension isn't actually the maximum. That's just static tension; when riding, the peak forces will be a lot higher, so it's just a guideline.

Spokes stretch and act as springs. The higher the tension, the more the springs are stretched and the less likely they are to ever go slack. The thicker the spokes, the higher the tension has to be to ensure you stretch them enough to keep them tight. This is why it's better to design a wheel with a greater number of thin spokes, rather than a lesser number of thick spokes.

There is not necessarily a clearly defined local maximum in performance, i.e. a tension above and below which performance is decreased. Too low and the wheel can be weak and will come loose. Too high and the rim may crack at the holes. More tension is typically better, which is why I give the basic guideline to build them near the rim's maximum recommended tension. This is often a practical limit, too, as nipples may become difficult to turn beyond about 1.2 kN.

You may have heard about World Cup DH mechanics building wheels "loose" to reduce deflection of the bike. It's true a more flexible wheel can help the bike track better, but this would be better accomplished with thinner spokes at proper tension than thick spokes at low tension. It's also helpful to select a rim with some flexibility. Modern rims are trending toward shallow cross-section heights, with some even going to single-wall designs.
flag robnj
Posted: Apr 1, 2020 at 16:12 Quote
I'm trying to find the ERD of my rim . It's a 2019 Giant TRX1 29 wheelset. I've E-mailed Giant a few times with no response. My local bike shop can't find the info. I'm going to replace the Giant hubs with Hope Pro 4. Any ideas? Thanks Rob
flag stymiecat
Posted: Apr 1, 2020 at 17:51 Quote
robnj wrote:
I'm trying to find the ERD of my rim . It's a 2019 Giant TRX1 29 wheelset. I've E-mailed Giant a few times with no response. My local bike shop can't find the info. I'm going to replace the Giant hubs with Hope Pro 4. Any ideas? Thanks Rob


Simple... measure the freakin' rim.
flag R-M-R
Posted: Apr 1, 2020 at 17:59 Quote
stymiecat wrote:
robnj wrote:
I'm trying to find the ERD of my rim . It's a 2019 Giant TRX1 29 wheelset. I've E-mailed Giant a few times with no response. My local bike shop can't find the info. I'm going to replace the Giant hubs with Hope Pro 4. Any ideas? Thanks Rob
Simple... measure the freakin' rim.

You're not wrong, but you could be a little more descriptive!

Best results with the bare rim. Take something that doesn't stretch - stiff string with a knot at the end, for example - and measure from where the spoke nipple rests on the rim to the equivalent spot on the opposite side of the rim.
flag potato
Posted: Apr 1, 2020 at 18:25 Quote
You need to measure to the head of the nipple.
I use 2 spokes with known length, thread them in until they are flush with the nipple slot.
Then use a caliper to bridge the gap.

https://www.parktool.com/blog/calvins-corner/measuring-effective-rim-diameter
flag R-M-R
Posted: Apr 1, 2020 at 18:34 Quote
Some ERDs account for this, some don't. It's been the cause of unreliable measurements since the dawn of ERD.

In the hope of standardizing it once and for all, we might as well go with the Park method.
flag stymiecat
Posted: Apr 1, 2020 at 18:41 Quote
I have an old metal yard stick with MM's marked off. Measure the rim from where the nope rests in the rim to the opposite side.
Depending on Rim profile I will measure from edge to edge inside and have used a toothpick and a marker to measure the nipple depth.
Sounds rudimentary... but has never failed me
flag clkdecember14
Posted: Apr 19, 2020 at 21:54 Quote
Okay I'm kinda new to this thing. I have yet to do a wheel. How easy is it really? Like, everyone says it's so easy but it seems hard to me.
flag seraph
Posted: Apr 19, 2020 at 22:20 Quote
clkdecember14 wrote:
Okay I'm kinda new to this thing. I have yet to do a wheel. How easy is it really? Like, everyone says it's so easy but it seems hard to me.

It's easy but it's also hard. If you have all the correct numbers and you can get the exact spoke lengths that you want, it's pretty straightforward. It gets complicated when you have to figure out if you can round up or down, or change lacing patterns to accommodate what spoke lengths are available. Then you're going to need a tension gauge, or else you run the risk of under-tensioning or over-tensioning your spokes and damaging your wheel, or your wheel failing mid-ride and causing personal injury.
flag clkdecember14
Posted: Apr 20, 2020 at 13:39 Quote
Thank you! I have some old wheels maybe I'll practice with.
flag R-M-R
Posted: Apr 20, 2020 at 13:45 Quote
That's a good idea. For me, lacing is where I'm clumsiest, so I suggest practicing that several times - it also produces less wear-and-tear than doing several full tensionings.
flag bernan11
Posted: May 30, 2020 at 18:05 Quote
Does anyone have any good recommendations for some am/enduro rims for under $100?

 


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