Spoke Lacing

[Joel Klavins]

G'day all, I'm after some advice on spoke lacing. I am doing a radial lace for the front, but unsure of the rear. The rear is a 20H Circus Monkey HRW2 hub and a 50mm carbon rim. I have sketched some quick lacing options but I'm not sure if these are possible. Cross the drive side but radial lace the non-drive side. I prefer the look of the second option.

 

[CAMPYBOB]

First option.

 

[danfoz]

Originally Posted by Joel Klavins
Cross the drive side but radial lace the non-drive side.

Good to at least avoid radially spoking the drive side of the rear wheel, doesn't transfer torque well. No problem on the front as that's just along for the ride.

From Boyd Cycling...
"On the rear wheel you are putting a lot of torque to the hub and this has to transfer to the rim to get the wheel to spin. By crossing the spokes on both sides of the wheel, we have up to 15% better torque transfer compared to a wheel that has radially laced spokes on the rear wheel. This makes for a better responding wheel that will accelerate faster, especially in sprinting or climbing situations."

 

[Joel Klavins]

Good to at least avoid radially spoking the drive side of the rear wheel, doesn't transfer torque well. No problem on the front as that's just along for the ride. From Boyd Cycling... "On the rear wheel you are putting a lot of torque to the hub and this has to transfer to the rim to get the wheel to spin. By crossing the spokes on both sides of the wheel, we have up to 15% better torque transfer compared to a wheel that has radially laced spokes on the rear wheel. This makes for a better responding wheel that will accelerate faster, especially in sprinting or climbing situations."

I noticed that some wheels are like that, such as some of the Fulcrum'. Does that mean they're bad for sprinting and climbing? I'm still a newbie to wheel building...

 

[danfoz]

Originally Posted by Joel Klavins


I noticed that some wheels are like that, such as some of the Fulcrum'. Does that mean they're bad for sprinting and climbing? I'm still a newbie to wheel building...

It's interesting you mention Fulcrum, at one time they actually touted their unique lacing pattern as delivering good stiffness, the website doesn't seem to carry that particular copy anymore.

You'll see they adhere to the non-drive side radial paradigm on their rims - Here's the Racing Zero.



I haven't ridden any Fulcrums, but I hear they are pretty stiff wheels.

Interestingly that while the Mavic Ksyriums did run a drive side radial lacing, I raced them for a season, they were quite stiff sprinting wheels which may also partially be a function of their proprietary spoke's thickness and hub design. But the Zipp101's that I used to run which also had radial drive side lacing were the noodliest accelerating wheels I ever rode by far, possibly due to the thinner Sapim CX-Ray spokes, but it was probably a combination of the low spoke count, lacing, and hub design. Don't quote me on this but I believe Zipp uses their particular spoke pattern to maximize flange width and gain an extra mm or so on the drive side which would contribute to lateral stiffness. Just a point to note, rotational stiffness and lateral stiffness are different things imo. While I imagine lateral stiffness would be an asset to cornering and descending, rotational stiffness would be and asset to torque delivery i.e. for sprinting/accelerating. Surprisingly I don't see the differentiation in print much but it should be obvious to anyone with a rudimentary understanding of high school level physics i.e. force vectors. That's just my opinion.

 

[CAMPYBOB]

Mavic is FUBAR.

Some of their rear wheels are crossed on the drive side and radial on the off-drive side. Most are radial on the drive side and crossed on the off-drive side.

It's almost as if they don't have a clue or just decided to cover all bases.

I am using their crossed drive side wheels and they are wet spaghetti compared to a quality build job using 32H / 3X. Agree with Dan, Hub flange width, spoke count, spoke tension (I'll argue the point until they shovel me into a hole in the ground), spoke gauge/cross section and rim design all factor into what makes a wheel 'stiff', responsive, smooth riding, etc.

 

[Joel Klavins]

I had some Fulcrum Racing Quattro's a while back and I really liked them and even regretted the sale... They had one side laced radially and the drive side crossed, that's where I got the idea from. However, they use straight pull spokes, not J-bend. I wonder if this could be the difference in having a better radial laced rear wheel?

On my wheels I will be using CN Aero424 spokes which are esssentially DT Swiss Aerolite or Sapim CX-RAY spokes.

 

[danfoz]

Originally Posted by CAMPYBOB
Spoke tension (I'll argue the point until they shovel me into a hole in the ground)

I once had me a wheel builder at Roy Sheepshead Cycles build me up a set of sweet tubbies (a colleague actually as I was selling bikes on the floor of the same store): GP4 on the rear, GL 330 on the front on some hub du jour titanium numbers (which compressed bearings on the first time I accidentally overtightened the rear QR btw, and which promptly sent me back to tried-and-true Shimano DA) who pontificated high spoke tension. Anyways, with my cats and all was one day riding home from the pet food store with a bag full of fancy feast cat food cans dangling off the handlelbar and absentmindedly let the bag fall a bit low and it ran through the space on the front wheel between the fork blade and the spokes (on my brand new set of wheels!!!) and I almost tipped over! Low and behold, the can of Fancy feast was MANGLED! but the wheel remained perfectly true. What a stunning set of wheels until that rear hub compressed it's bearings the night before my A-race, and me, coming from friction derailleurs and just getting back into riding/racing, caught hanging with my **** in the wind not knowing how to adjust the new fangled "indexed" rear derailleur against my old set of wheels...

...before then it was just upper and lower limit screws!!!

 

[CAMPYBOB]

Quote by Dan:
"Low and behold, the can of Fancy feast was MANGLED! but the wheel remained perfectly true."

...It slices! IT dices! It makes mounds of Juliennes fries in just seconds!

Too bad it doesn't work on duffel bags stuffed full of race clothes...I built a pair for a friend. Riding from the motel to the start, his duffel slipped around his shoulder and into the front wheel. The face plant was not pretty and his wheel DID require truing.

 

[Joel Klavins]

I found a review of a custom wheel set that used radial lacing on the rear non drive side and they're meant to be very good. Also, I'll be using a stiff 50mm deep, 23mm wide carbon rim on the rear. http://www.bikerumor.com/2010/06/07/stans-notubes-alpha-340-ztr-pro-road-tubeless-wheels-unboxed-weighed-and-first-rides/