18 hole front wheels

[fau1ty]

Hi Guys,

 

 

i have built so many rims over the years and never had a wheel failure. But this latest idea has me thinking as some guys say it wont hold.

 

i have taken a small flange AC micro 58 hub with a Mavic Open Pro rim and used double butted DT swiss spokes.

 

we all know this will work except that the rim is a 36 hole with every second hole left out.

 

the rim is laced radial and comes in at a low 630g.

 

will it be strong enough?

[MariusL]

I wouldn't take a chance with having my front wheel failing... and it will most likely fail under load... very much painful.

 

But good luck if you want to give it a "bash"

[Johan Bornman]

There are very few rimbuilders around and since you build your own rims, why not just build a 18-hole rim. That way your wheel won't have a rim with lots of empty holes where spiders and dust-bunnies can hide away.

[fau1ty]

Johan, i was hoping you of all people would respond to this post. as you are aware 18 hole rims are fairly scarce these days. since i could'nt find one and had a spare mavic open pro i built this wheel. it's very straight and came out very nice, It has amazing lateral strength. everyone that says it will break is not a wheel builder so i think they have a preconceived idea that it will be weak? i dont think a front wheel needs as much strength as a rear?

[Eldron]

I built one years ago for a TT bike - using bladed spokes nogal (I even filed the hub holes open a bit to get the DT bladed spokes through).

 

I used it maybe 10 times (~400km) then moved on to a more modern aero wheel.

 

It never gave me any trouble but it did feel A LOT more flexible than a 36 spoke wheel (the rim would rub on the brakes if I was out of the saddle - maybe I just didn't tension them enough??). I only used it on TT's and was a bit *** bang to sprint on it or give it real horns - not for any real reason other than there were only half the intended spokes...

 

If it's for a weight weenie bike or a trailer queen bike I'd say go for it. If it's gonna be your race bike or daily ride I'd stick to ye olde 32/36 - or compromise on a 24 or 28 spoke wheel?

 

Like Johan said - no holes for water and dust bunnies...

[Bat-ass]

I am totally unqualified in the wheel building game, but my engineering savy tells me that a 36 hole rim needs 36 spokes supporting those holes.... essentially where theres a hole, theres a week point. i would guess a rim designed for 18 spokes would be either deeper, or have slightly thicker walls to make up for the lack of spokes?

[fau1ty]

some thing to consider is that a Mavic Open Pro is double wall rim with eyelets. this is alot stronger than a standard rim.

[Johan Bornman]

Johan, i was hoping you of all people would respond to this post. as you are aware 18 hole rims are fairly scarce these days. since i could'nt find one and had a spare mavic open pro i built this wheel. it's very straight and came out very nice, It has amazing lateral strength. everyone that says it will break is not a wheel builder so i think they have a preconceived idea that it will be weak? i dont think a front wheel needs as much strength as a rear?

 

I was pulling your leg, playing with rims vs wheels. Let me spell it out. A rim is just one component of a wheel and most of us don't build rims.

 

 

What you are trying to do is perfectly acceptable and will work without any problems. However, 18 spokes is pushing it and although most people think rear wheels take the most strain, braking happens on the front wheel. I don't want poofter front wheels for that very reason.

 

Further, increasing the tension in a wheel (once the spokes are in tension), doesn't make the wheel stiffer. Spokes are made from a Hookean material and will flex the same for each given load applied. The only way to make a wheel stiffer is to either use a stiffer rim, thicker spokes or more spokes or a combo of these three factors.

 

As for rim weakness 'cause there are holes that are unused. A rim is weakest at the hole - the valve hole is in fact the weakest point. However, rims are strong enough and strong enough is strong enough. They never fail at one of these holes unless a bus happens to plow into the wheel exactly where the valve enters the rim.

 

Wheels have very little lateral strength. And they require little lateral strength since steering and balancing doesn't apply side forces to the wheel. You do apply a little side force to the wheel when sprinting and you may notice, like strong Edman here, that the wheels touch the brake pads under these conditions. However, we're talking about 1mm flex and in the overall scheme of things this is nothing.

 

If you think your wheel is very strong laterally, try this: lay the wheel flat on the floor after removing the skewer. Hold the wheel like a bus steering wheel and push down on it with your full weight. Come report back what happened.

[Johan Bornman]

some thing to consider is that a Mavic Open Pro is double wall rim with eyelets. this is alot stronger than a standard rim.

 

 

Nope. All sport bikes have double wall rims. I haven't seen a single wall rim since I worked on my Humber dikwiel in 1974.

 

Many rims have eyelets but that doesn't increase the rim's strength. The eyelets require even more material to be removed, making the rim stronger.

 

Open Pro rims have not only eyelets, but sockets that span two walls. The socket's entry point is huge, making the rim even weaker.

 

However, strong enough is strong enough and Open Pro rims are strong enough.

[Bike Mob]

I have just bought an 18 hole rim - Easton Ascent II front...and it's in stock at the local supplier

[Johan Bornman]

I have just bought an 18 hole rim - Easton Ascent II front...and it's in stock at the local supplier

 

Rim or wheel? Omnico doesn't sell loose rims AFIK.

[Bike Mob]

They offered me the rim only.

 

I was going to buy it there but it came stickerless. So I bought it on Chain reaction and it came all stickered up for R50 more

[fau1ty]

Johan, thanks for this little lesson for free. one can never learn enough. Rim vs Wheel building is a great conversation...... my bad. Know of any 18 hole rim i could purchase. will do the strength test later and report back.

[Bike Mob]

I have a used 18 hole Easton rim you can have for R200.

 

you just need to realign the join/seam in it and it's tip top. Lance (Epic) reckoned it can be repaired.

[mecheng89]

Resurrecting this thread.

 

Anyone have a 18 hole front hub for me? 

[TNT1]

Resurrecting this thread.

 

 

In the spirit of Easter?

 

(Was nice seeing JB and nipples though. The good old days)