Wheel building

[ianganderton]

So within 1 either side on the gauge?

I'm currently looking at a 650b mountain bike wheel (giant xc-2 rim, giant disc hubs and butted spokes (1.8mm))

I have 26" mountain bike wheels and 700c road wheels to check through too

[ianganderton]

Ok. Here is what the park tool website says

Relative tension is the tension of a spoke in comparison to the tension of one or more other spokes. A wheel with spokes that are within plus or minus 20% of the wheel’s average spoke tension is generally considered to have acceptable relative tension.

So thats acceptable. What's good and what's realistcally best

[ianganderton]

Info came from http://www.parktool.com/blog/repair-hel ... -section-6" onclick="window.open(this.href);return false;

It also has a table of manufacturer recommended spoke tensions but what to do where specs aren't available? Hmmmmm

[Duck!]

The main cause of inconsistent readings is the manner in which you release the handle to take the reading; if you just let the handle go you'll get a lower reading than if you release the handle in a more controlled manner. So be consistent in your action.

As pointed out, the scale readings are at best an approximation of actual tension due to the wide range of spoke types around. Don't get too hung up on whether an indicated 100 kgf is exactly 100 kgf or a bit off, it's close enough. Even readings around each side of the wheel are more critical. I generally build alloy rims to 100kgf, and carbon to 120 kgf. These tensions are high enough give a good stiff wheel, but not right up to the maximum the rims will take, except the lightest aluminium rims, where I'll drop back to about 90.

[ianganderton]

Cool

I'm very conscious of the way I release the handle to help.with consistency

I've just found this very useful web based app http://www.parktool.com/wta/" onclick="window.open(this.href);return false;

I can choose my level of accuracy with 20% as a minimum. I'd like to try to see if I can get 10% or better with practice

I'll see how 100 Kgf feels.

[ianganderton]

Here is an interesting article showing the results of computer modelling testing various lacing patterns inc 3x, 2x, radial/3x and 3x/ radial

http://www.williamscycling.com/assets/i ... Lacing.pdf" onclick="window.open(this.href);return false;

It won't conclude in anything you probably didn't know already but it's interesting none the less

[human909]

So thats acceptable. What's good and what's realistcally best

Consistency of tension is far and away a tertiary concern. What the primary concerns is having enough tension along with appropriate trueness and roundnesss.

Consistency of tension is not a goal in of itself. Which is why +-20% is acceptable. (Though unless your rim is not round or has other issues, you should be able to achieve close to consistent tension while also achieving the primary goals.)

[find_bruce]

Interesting article. What he actually tested comes as no surprise. was however surprised to see this recommendation in the conclusion

4x lacing should be used with 32 spokes or greater.

I suspect he has never built or attempted to build a 4x lacing with 32 spokes - IIRC the spoke will get interference from the head of the next spoke.

What is easily forgotten is the trigonometry underlying the cross pattern The spoke angle at hub and rim will be identical in a 4x 40 spoke wheel as a 2x 20 spoke wheel - try this mental experiment, you lace a 40 spoke wheel 4x, remove every second spoke & you have a 20 spoke 2x & the length or angles of the spokes haven't changed.

Usual recommendation is 36, 32 or 28 laced 3x. As duck says, 28 is a crossover point as you can also lace 28 2x.

[ianganderton]

I found the info on what happened to the non drive spokes interesting and exactly how much they unweight under load.

[Duck!]

Interesting article. What he actually tested comes as no surprise. was however surprised to see this recommendation in the conclusion

4x lacing should be used with 32 spokes or greater.

I suspect he has never built or attempted to build a 4x lacing with 32 spokes - IIRC the spoke will get interference from the head of the next spoke.

What is easily forgotten is the trigonometry underlying the cross pattern The spoke angle at hub and rim will be identical in a 4x 40 spoke wheel as a 2x 20 spoke wheel - try this mental experiment, you lace a 40 spoke wheel 4x, remove every second spoke & you have a 20 spoke 2x & the length or angles of the spokes haven't changed.

Gerd Schraner suggests that 4x lacing should only be used on hubs with a flange PCD of 70mm or greater; the bigger flanges space the holes further apart & allow the spokes to seat properly.

[hedgehog]

i built a set of rims for my mtb quite a while ago.it originally came with a set of rigida taurus rims 1.8mm 32 stainless steel spokes disk brakes.
i bought a set of 36h hubs.the front wheel has an alloy alesa rim and steel spokes,the rear a steel ukai rim and steel spokes both 4x.
weight and tire are not a problem for me.
i purposely misaligned the wheels to the frame.the front wheel is 3mm more to the left and rear wheel is 3mm more to the right.
are there any negative aspects to this set up?

[ianganderton]

What size rim? 26", 650b or 29"

Out of interest why did you set the wheels up off centre?

And why 4x and not the 3x 'norm'?

[hedgehog]

rim size 26 inch
wheels of centre to increase the spoke angle on the rear drive side
and increase the spoke angle on the front disk side
4x was not a choice i used the original old spokes

[hedgehog]

the front wheel is 3mm more to the (right) and the rear wheel 3mm more to the (left).correction

[eeksll]

the front wheel is 3mm more to the (right) and the rear wheel 3mm more to the (left).correction

does it work that way? I would have thought same offset to the same side.

[hugh stone]

Here is an interesting article showing the results of computer modelling testing various lacing patterns inc 3x, 2x, radial/3x and 3x/ radial

http://www.williamscycling.com/assets/i ... Lacing.pdf" onclick="window.open(this.href);return false;

It won't conclude in anything you probably didn't know already but it's interesting none the less

Nice article - I was particularly interested in the results for the radial drive side pattern which is used by Zipp. The larger change in tensions might explain some of the problems they've had with hub flange failures.

Also relieved to see 3x being a winner as I'm building some wheels with this pattern at the moment.

[ianganderton]

My wife's Specialized Alias has a radial/3x pattern too but the drive side is 3x. She is light and doesn't really honk when she's climbing so doesn't put the wheel under lots of stress so shouldn't cause problems so no need to change it but I will keep a watchful eye on it now.

The problem is now I know it's not an ideal set up it will bug the hell out of me [emoji19]

[hugh stone]

My wife's Specialized Alias has a radial/3x pattern too but the drive side is 3x. She is light and doesn't really honk when she's climbing so doesn't put the wheel under lots of stress so shouldn't cause problems so no need to change it but I will keep a watchful eye on it now.

The problem is now I know it's not an ideal set up it will bug the hell out of me [emoji19]

Radial non-drive side is pretty common - I wouldn't worry about it.

[Duck!]

the front wheel is 3mm more to the (right) and the rear wheel 3mm more to the (left).correction

does it work that way? I would have thought same offset to the same side.

His idea is reducing wheel dish, hence the rear off to the left (away from cassette) and front off to the right (away from brake disc). In theory, cornering would be whoopsed due to the wheels not tracking centrally, and indeed the tracking axis between the tyres' contact points being at an angle to the frame, but in reality it's probably too subtle to notice.

[hedgehog]

what was meant to be spare set of wheels has become an experiment ,not to contradict gerd schraner 4x on 70mm flange or greater,the wheels have got 4x on pcd 45mm hubs
but the hubs are made out of alluminium not steel.
does it work that way? im finding the ride better than before,more solid,but wheels are still under observation
mostly in the spoke elbows.

thanks duck,

[ianganderton]

Help!

I seem to have got the spoke length wrong (too long) and I'm not sure why

I'm building a SP PD-8 into a SR300 rim

The ERD that I've previously calculated and used is 583mm

Here is the DT spoke calculation



I'm guessing I've got the wrong hub dimensions.

Does anyone have PD-8 specs they have successfully used?

Can anyone spot something else it is

Thanks

Ian

[Duck!]

Your flange distances are out by a considerable margin. Unless you're building a fatbike wheel.

[ianganderton]

Your flange distances are out by a considerable margin. Unless you're building a fatbike wheel.

Ok. Cool. I'll look into it

[ianganderton]

Your flange distances are out by a considerable margin. Unless you're building a fatbike wheel.

Ok. So I can't find the right info for the DT Swiss calculator and it's difficult to measure from the centre

But it's even both sides (AT) 25mm to the flange as per this image



The flange thickness is 2mm

So from the centre of the hub to the centre of the flange = 25mm - 1mm = 24mm each side



282mm spokes.

Does this look correct?

Thanks

Ian

[Duck!]

Looks a lot better, but that hub diagram is whoopsed - the hub is clearly asymmetric, yet still somehow gives equal measurements from the locknuts to flanges.