Straight pull or J bend dose it matter ??

Everything about building wheels, glueing tubs, etc.
Post Reply
Allen254
Posts: 142
Joined: Sun Feb 07, 2016 3:05 am

by Allen254

I have a question, basically are straight pull wheels sets stiffer than J bend wheels. ive only ridden j bend wheels sets before and i have ridden a friends straight pulled wheelsset which honestly did feel very stiff (fulcrum speed 40T). but iIDK if it was just a psychological thing???

alcatraz
Posts: 859
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

I don't have a scientific answer to your question. I'm sure someone else does have it. I'm very curious though and if I were given the question I would say this. (But wait for the real wheelbuilders reply)

My memory tells me straightpull was introduced for this reason. To help stiffen wheels up a bit.

But it's not that a J-bend spoke is weaker, because the material is the same. It's simply in the design where the bend creates a weak spot prone to fatigue. A straight pull spoke can withstand more than a J-bend without breaking.

Maybe this increase in reliability helps to increase the total tension in a wheel a bit.

Also straightpull spokes solve a problem with the hubs and it's the one of flex in the flanges (some straightpull hubs still have flexy designs). With the heads directly in the hub body there is very little flex there. Also flex at the J-bend is eliminated.

SP also helps hubs to have their flanges positioned wider which improves lateral stiffness in the wheel.

Does any SP wheelset out-stiff a J-bend one? No. It's in the design of the wheel.

Is a wheel with same hubs/spokes/rims stiffer with SP instead of j-bend. Yes.

Can a wheel be built similarly stiff at lower weight with SP compared to J-bend. Yes.

Is an SP wheel more reliable than it's J-bend counterpart. Yes.

Again, these are the answers of an amateur.

/a
Last edited by alcatraz on Wed May 02, 2018 10:48 am, edited 2 times in total.

Allen254
Posts: 142
Joined: Sun Feb 07, 2016 3:05 am

by Allen254

Thanks man I think you’ve answered my question, and I’ve had problems with j bend spokes before not recently but I have had spokes brake on a very low tiered wheel. Yeah my main concern is stiffness I like a very stiff ride. But I think you’re right the straight pull seems to be where its at. Thanks again.

Post Reply
  • Similar Topics
    Replies
    Views
    Last post