garage sale GT

As a 210lb rider I have bent a few freewheel axles.

Every bike I ever bought used with a multispeed freewheel hub had a bent axle.

I have seen a few new solid-axle freewheel-hub wheels in shops and they all have fairly firm cone adjustment.

What if the hub is designed to put a slight bit of pressure on the cones, so that the right hand cone, spacer, and locknut would become more resistant to bending? That way, you'd have to stretch a tensioned axle and bend the hub shell before you got any bending.

I tried my theory with the same axle on two different bikes, although I was also pretty good about unweighting the saddle. It was a solid CrMo axle from Niagara cycle-same one for both bikes, going about 600 miles total.

Sure, the slight pressure contributes to fatigue failure but in my limited testing it seems not to contribute nearly as much to fatigue failure as bending the axle and causing the cones to be severely misaligned.

Thoughts?

Mike Mills

As a 200+ lb rider, I can say I have never bent a freewheel axle. Ever!

What's up with you?

garage sale GT

Well, maybe you are better about unweighting before hitting potholes.

BTW are you saying you run your cones loose enough that the axle gets NO support from the hub shell? If not, how is what you said a counterpoint?

Cone adjustment loosens up, too. The surface finish can be less than ideal on an unground cup or cone, and then the balls swage a path into the surface which produces clearance. In the freewheel days people used to sand their cones or lap the bearings into place with polishing compound.

vettefrc2000

Go to a cassette hub.

karmat

I've bent 3 in the last 2 years of commuting and I'm a good rider, and I do unload before bumps. But then I weight 230lbs, so that might account for it. My commuter is about to get Phil Wood freewheel hubs, so we'll see if that helps.

Karl

LWaB

QR axles are stronger/less likely to bend than solid.

TheDL

And you can convert a solid axle freewheel hub to QR, yes?

garage sale GT

I disagree. What do you base your assumption on?

MOST solid axles are weak due to poor material, but you can buy chrome moly ones which I have found to be strong. I believe if they are made from equal material, the solid ones will be better.

garage sale GT

That's the obvious solution, I guess. I got a Velocity 27" cassette wheel for a World Sport, in fact, and it's still good after three years, but I'd just like to be able to keep it old school if there was a way not to break the axle.

Wouldn't you prefer to keep your next c&v find original except maybe for a few service replacement parts like axles, cones, and bearing balls?

I'm telling you, I've done it, if only for about six hundred miles. (I then stopped using freewheel hubs; I did not get a bent axle while using my program.)

vettefrc2000

You may disagree. However. he is correct. Generally Q/R axles are made out of better materials. Also, a tube resist stress risers better than a solid cylinder.

garage sale GT

If you have a point, please state it. You don't have to buy the crummy ones. niagaracycle.com and harriscyclery.net both have good ones (niagara sells all kinds; not saying anything you get from them is heat treated cromoly.)

Why do you feel a "tube resist (sic) stress risers better than a solid cylinder?" Please state either your reason or quote your reference. You're just wrong.

dbakl

I don't know.

I'm heavier than anything I've read here and never had any axle problems. And I'm riding 60s-70s stuff, always have...

roccobike

+1, I weigh in at about 210, been as high as 220 and have never bent a rear axle. Just to make it interesting, I'm not just referring to road bikes, I'm talking about a MTB that's been ridden on technical trails. On the other hand, I have a freind and fellow BF member who is lighter than I am, and has bent several. I have to admit, I have no clue why some bend axles and some don't.
As for solid VS QR axles, of the bikes I've flipped two have had badly bent axles. Both were solid.

garage sale GT

Would you share your setup with us?

My point is that what you said ought to be perfectly possible with the correct preparation.

garage sale GT

I posted to tell my theory that part of the reason is the cone adjustment. A cone which is snugly adjusted against the bearings and cup will not be able to twist unless it 1)bends the axle and 2)deforms the hub shell. A cone which has clearance only has to 1) bend the axle.

Part of that theory is that cheaper cones can have a pretty rough finish and the adjustment loosens considerably as they acquire a wear track.

I am sure stock solid axles will more likely be bent than QR. Solid axles typically come on cheaper bikes and so are usually made of cheaper stuff; however, that's not really relevant to a discussion about what kind of axle to buy and install on your next c&v project.

vettefrc2000

Are you an engineer? It is your BS theory to prove. Have you conducted a design of experiments? Do you have a background in material science. If you understood wtf you were saying you would realize how ignorant you really are.

"The strength of a tube, or hollow cylinder, is to the strength of a solid one as the difference between the fourth powers of the exterior and interior diameters of the tube, divided by the exterior diameter, is to the cube of the diameter of a solid cylinder, - the quantity of matter in each being the same. Hence, from this it will be found, that a hollow cylinder is one-half stronger than a solid one having the same weight of material."

FYI...it is chromoly not cromoly?

garage sale GT

What you're saying is you turn your solid axles down on a lathe until they weigh as much as a hollow one? No wonder you think solid axles are weak!!!

I don't think you understand what you're reading. They are comparing two rods with the same cross sectional area. They are not comparing two rods, one hollow and one not hollow, with the same external dimensions.

and I can abbreviate chromium and molybdenum any way I please, btw.

vettefrc2000

You can't be that stupid? Are you pulling my chain? You really got me going

karmat

Err, this thread turned kind of ugly. What's the point insulting each other? In any case Garage Sale is right... a solid axle is stronger than a hollow one if the same metallurgy is used in both. That quote you have there vettfrc2000 is referring two shapes using the same amount of material: "the quantity of matter in each being the same". Think about it this way: if you took a solid steel rod 1 inch in diameter and 2 feet long and a tube the same diameter and length, but with a wall thickness of .1mm, which would be stronger? That's just an extreme version of the comparison you're making here.

Hope that sheds some light... and chill out people.

Karl

dbakl

Setup? I've ridden Campagnolo Record/Nuovo Record hubs exclusively since 1972 and never had an axle problem. I keep the hubs adjusted and lubed if required and keep the QR tight. I watch where I'm going, avoid potholes if possible and don't ride up or down curbs. My current main rider I've ridden for 25 years and only recently trued up the rear wheel though it has been through at least 3 sets of tires. I'll admit I haven't repacked the hubs, they still feel fine, but I also don't ride in the rain.

BTW, I build my own wheels: not that I think I'm an expert, but they work for me.

I'm not sure what could cause an axle to fail except excessive force.

dbakl

In my experience, the cones need to be adjusted a hair loose; when they're compressed by the quick release some slack is removed. On the other hand, my experience is almost exclusively with 60s-70s Campagnolo components; maybe other brands function differently; I don't know.

vettefrc2000

With regard to withstanding a compression / tension load, a hollow tube wins.

"A hollow tube
has significantly higher compressive strength than
a solid bar using the same amount of material."

Bam42685

This is true. My work builds conveyor systems and we deal with this all the time. It's a generally accepted fact in industry.

garage sale GT

It is my understanding that campagnolo freewheels incorporate an extra bearing which regular freewheels do not have. The only bearings on a typical 5-7 speed freewheel hub are at either end of the hub shell. There is no additional bearing transmitting load from the right end of the freewheel to the spacer which goes between cone and locknut.

Edit: No, my mistake. I misunderstood an illustration and thought there was a bearing which went in between the inside of the freewheel and the outside of the axle spacer.

garage sale GT

First of all, are you using your axles for table legs or some other application where they face a COMPRESSIVE load? Are you saying the compression of the skewer makes them fail?

Second, and more importantly, and for the second time, we are not discussing two axles with the SAME AMOUNT OF MATERIAL(or the same cross sectional area, to take out the effect of the additional length). We are discussing two axles with the SAME EXTERNAL DIAMETER. If your columns were failing, could you make them stronger by drilling a hole down the middle?