lxs602

Hi,

I am building a wheel for the first time. I bought everything a long time ago, with triple-butted spokes and a Mavic rim, but have since found the hub to be defective.

The hub, a solid-axle Marin Rockstar, appears to be an odd, rare one with uncommon dimensions (centre flange distance L 46.3mm, R 19.2mm; flange pitch circle diameter L 45.5mm, R 45.5mm). The closest replacement I could find on the kstoerz hub database which I am now using is a Shimano FH-T610 (flange offsets 35mm L, 19.5mm R and flange diameter 45.5mm).

On starting to thread the spokes through the new hub, I notice a big gap between the spoke elbow and body and the flange of the hub. I tried using 3mm washers, but it didn't really help as the elbows are so fat.

Sheldon Brown's page on wheel-building says "Flange thicknesses vary, but the spoke's elbow should be snug against the flange. If it is not, the spoke's tension will try to bend the spoke at the elbow -- a frequent cause of spoke breakage."

I know that on the path of the spoke will bend towards the flange on raising tension, but it seems like a large gap to me.

What do you think?

[EDIT: I have tried uploading images, but it won't let me as a new user... perhaps a mod or another use might kindly help, if I send them to someone?

I have added some photos as links on my profile page in the mean-time... if you navigate to my profile and select 'Visitor Messages', they are listed there)

canopus 

That will be fine. rarely will inward radiating spokes snug up to the hub flange.

Pic Assist​​​​​​​

cxwrench

I'll second the above post.

Bill Kapaun

The holes in Shimano lower end hubs tend to be "generous" in diameter @ 2.6mm.
15 gauge spokes look a lot worse.

cyccommute 

This article explains what is meant by “snug against the hub” and why it’s good to form the spokes against the hub. I use an old crank arm to do the bending. The crank arm works well because it is soft and doesn’t damage the spoke.

ClydeClydeson

From the picture, that looks about as snug as your gonna get. You can see that the radius of the elbow basically starts inside the flange - there is no straight bit of spoke below the elbow visible.
You would get problems if the hub flange was narrower than normal, which might be likely with a steel or some other oddball hub, but with a standard spoke and normal modernish aluminum hub there won't be an issue. Be sure you pre-stress the spokes as discussed above and in every wheel building guide as this relieves much the cyclical stresses at the elbow that happen when riding.

mpetry912 

there was a time when DT spokes had a revised radius at the elbow "to make automated wheelbuilding easier". Spokes of that era required washers under the head.

Stuart's pic showing how he "works" the spokes close to the hub flange is a great technique. I also use a tool (crank arm, big screwdriver) at the outer spoke crossing, go around a couple times.

Phil Wood hubs had an extra - thick flange that supports the bend radius better than most other hubs.

/markp

lxs602

Thanks for the replies.

I did wonder if this gap introduced a weakness. Especially given that I had spent more on triple-butted spokes and a good rim, I wondered if it was better to find another hub (with wider spoke holes). I was hoping to build a strong wheel for loaded touring (not that I am very solidly built... 10 stone, or in American, 140 pounds...)

L

ThermionicScott 

The only place on my wheels where the heads-out spokes actually do snug up to the hub flange is the drive-side rear. Look at the path the spokes take anywhere else, and I don't know why you would expect them to.

cyccommute 

If you don’t form the spokes to the hub, they will eventually form to the hub anyway. The problem is that letting them from over miles of riding will change the wheel dynamics. The tension with change. I have used Eric Hjertberg’s wheel building method since his articles appeared in Bicycling magazine in 1986. You can find a link to the original articles here. He has this to say on why it is good to preform the spokes

The other article I linked to explains the reasoning in a bit more depth.

As a heavy rider who carries fairly heavy loads on tour and uses triple butted spokes, I can tell you that it does work.

79pmooney

Are you building this wheel for yourself? If yes, don't sweat it. Build it, ride it, look at the tensions and true in a couple hundred miles. (Tension will be a little less anyway because the inflated tire does that.) Tweak the tensions and true if necessary. Simply not a big deal. Now if your wheel is leaving tomorrow on a year long tour or your wheel building reputation and income source is on the line, that's another matter,

lxs602

Wheel built. I followed all the tips for pre-stressing the spokes. It has been fine for 50 miles or so. Thank you all.

ign1te

If you want the flat of the spoke head to fit more flush with the flange surface, consider using a spoke where the stock diameter of elbow is smaller. What diameter does the elbow have in this photo? 2.3 mm? Then a 2 mm alternative would be next.