Spoke question for JB...

[AndreZA]

JB, my two sets of boutique wheels are both 2 cross but:

 

on the road wheels the spokes running on the outside of the flange is no where near the spokes comming out of the inside of the flange.

 

 

 

om the MTB wheels the spokes running on the outside of the flange crosses on the inside of the spokes comming out of the inside of the flange.

 

 

 

Does this make any sense?

 

 

 

I do not have a problem, was just wondering why the one would build it the one way and the other, the other way.

 

 

 

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[Johan Bornman]

Hmmmm, I hope I understand the questions.

 

First, some terminology to help us both speak the same language.

 

1) Spokes with their heads on the inside of the flange are called outbound spokes and those with their heads visible on the outside of the flange are called inbound spokes.

 

2) Spokes that touch each other at the crossing are called interlaced spokes.

 

3) Spokes can cross each other without being interlaced.

 

If I understand correctly, you want to know the difference between interlaced and non-interlaced wheels.

 

If you look at the two wheels you'll see the spoke path from hub to nipple in the non-interlaced wheel is straight and that on the interlaced wheel is bent where the spokes cross. Park that for a moment.

 

Deep background time.  Assume a front wheel is lying on a table doing nothing. In that scenario, all the spokes have approximately the same tension. I say approximately because the tension in a perfectly round wheel cannot be perfectly equal, because the rim is imperfect. Carbon rims can be the exception.

 

On a rear wheel the right hand side has higher tension than the left for obvious reasons - dishing.

 

Now, that wheel is installed on the bicycle and loaded by you getting on the bike. The bottom few spokes in the load affected zone now lose some tension (just a little bit i.e. your weight divided by the number of spokes affected). Should you exceed the available tension in the spoke, they would go in compression and go slack. This could happen with a sudden bump or (very) fat rider.

 

Back to the interlaced and non-interlaced spokes.

 

Should the spokes temporarily loose all their tension the nipples can shake loose. If the wheel is interlaced, the adjacent spoke can take up some of the slack and prevent that from happening. If you look at the detour an interlaced spoke takes it'll become obvious to you how an adjacent spoke can help maintain ultimate tension.

 

As wheels start to have fewer and fewer spokes, interlacing becomes more important. This is not obvious to some manufacturers or, they consider the wheel's application to be outside any events where that could possibly happen.

 

Used in another application, interlacing could be strategically routed to move spokes to the left or right when heavily loaded. Picture two interlaced spokes. The one goes slack - you see the other slack spoke being moved laterally towards the one with tension - if the latter is behind it and away from the one with tension, if it is on the other side of it.

 

Interlacing is very important on Campagnolo-equipped bicycles. A Campag rear derailer is bent towards the wheel whereas a Shimano one is bent away from the wheel. There is thus less space between spokes and a Campag RD than spokes on a Shimano RD.

 

If the wheel is interlaced left-handed instead of right-handed (yes, I did just make up those two terms), then under load the spokes could move toward the RD and actually touch it.

 

Same story for disk brake wheels. If you brake, every second spoke slackens and every other one tightens. The spokes are interlaced and therefore move either right or left. The wheel designer must decide if there is enough clearance to allow for left-hand or right-hand interlacing and lace accordingly. For most 32-spoke wheels it does not matter if it interlaces over or under.

 

No torque is transmitted through the wheels on road bikes with calliper brakes so the interlacing handedness is irrelevant on road bike front wheels.

 

 

 

 

 

 

[AndreZA]

Okay, thanks.