Thru axle versus QR

[Johan Bornman]

 

The most common excuse is that if you do not feel the difference..you're not riding hard enough....I think that correct spoke tension will make a far bigger noticeable difference...

 

 

Sorry, no. A spoke is made from a hookean material. This means that once they are in tension (even low tension), each un it of weight added will create exactly the same stretch as the previous weight. E.g. 1kg will stretch the spokes 1mm. 2kg will stretch them and 3kg will stretch them...you guessed it....3mm.

 

Therefore, no matter how tight you make the spokes, the wheel flex will always be the same.

 

The only way to create stiffer wheel is to use a heavier rim, more spokes, thicker spokes or all three options.

 

Marketing will tell you otherwise. All they have to do is to make the spokes from Zircon (yes, it is true, ask Mavic) or the rims from "aerospace aluminium" or the spokes from 18-8 stainless steel. Then miraculously the wheels are faster, stiffer, smoother and...wait for it, more compliant.

 

Only in the marketing department can you have your cake and eat it.

[LOOK695]

Hi Johan. Sorry off topic.

You would not maybe have 2 white ztr arch rims available for sale?

[Motard660]

Can somebody please tell me what de hack is that numbers on the FOX fork where the TA screws in. Looks like one or other advanced setting. After staring at this a few times, decided that it must be a setting that I don't really need and left it like the way I got it.

Please tell me it makes the bike faster and easier on the hills!

[GoLefty!!]

what numbers? thread is useless without pics

[Johan Bornman]

Can somebody please tell me what de hack is that numbers on the FOX fork where the TA screws in. Looks like one or other advanced setting. After staring at this a few times, decided that it must be a setting that I don't really need and left it like the way I got it.

Please tell me it makes the bike faster and easier on the hills!

The numbers themselves are irrelevant. However, that gadget allows you to "tune" the resting position of the QR lever on the axle. Lets say you prefer to have your lever pointing forward but right now the correct position with the desired tightness is in the upright position, you would use that gadget to change it.

 

Here's how. Undo the little screw (can't remember if it is hex or philips) that holds the little plate over that round thing with the numers. Now push the round ratchet ring thing out and turn it a few notches. Redo the locking plate screw and install the wheel and check where you axle now rests in the locked position. If you have my luck, it is now completely opposite to what you actually want and you can go back and change it to the other direction.

 

The numbers are meaningless but I suppose if you work with these forks often (like assembling them in a factory), a certain number would be your sweet spot to be memorised.

 

On the udder hand, maybe they're the lever's position in degrees. I don't have one handy to check.

[Johan Bornman]

Hi Johan. Sorry off topic.

You would not maybe have 2 white ztr arch rims available for sale?

johanatyellowsaddledotceeodotzeda

[Johan Bornman]

Will a tapered steerer make a noticable difference in the same way a TA supposedly does/does not?

 

Tapered steerer is another of those post-rationalised items on a bike.

 

The primary reason for tapered steerer is to make manufacturing of frames easier.

 

I'll give you an example. Modern bikes, through fashion and necessessity, have large diameter downtubes - much much fatter than 20 years ago. To join that downtube to an old-fashioned straight head tube, is very difficult. The downtube's front end would have to be tapered in a shape difficult to manufacture. It would also look silly - a thin head tube on a fat downtube. My old Cannondale CAAD4 suffers from that problem. You can actually see how they had to make the downtube narrow at the head end.

 

With a tapered head tube, the joints are cleaner and the look more integrated. Especially with modern organically-shaped hydroformed and carbon frame parts.

 

They didn't take the fat bit right through for legacy reasons. To make the top end fat as well, would require a new fork standard that would render all 1 1/8th forks completely incompatible (at least now, with an adapter they can be fitted to a tapered frame) and it would render all stems useless. For once they tried to advance the standard in a sensible way.

 

Once they created all this, they decided to add "stiffer" to the marketing blurbs. Technically it may be stiffer, but current 1 1/8th forks are plenty stiff - most downhill bikes bomb down hills very successfully with 1 1/8th steerers.

[eddy]

 

 

 

 

A test on this is very, very easy. We stay away from the subjective "feel."

 

We take two exact forks and the same wheel, with a Hope hub. We clamp the fork in a jig and hang a weight from the wheel in two or three different positions. We measure the deflection. We clamp the idential QR fork in a jig, convert the wheel to QR and repeat the experiment.

 

 

Johan

 

What is the role of tyre side wall flexing on "front end stability" ?

 

I can't get my mind around making the axle area as stiff as a honeymoon p1el as then have a nice flexible, compliant piece of air filled rubber on the part of the wheel through which the forces are transmitted.

 

Or have i got it wrong?

Edited October 20, 2012 by eddy

[GoLefty!!]

spot on

[Motard660]

The numbers themselves are irrelevant. However, that gadget allows you to "tune" the resting position of the QR lever on the axle. Lets say you prefer to have your lever pointing forward but right now the correct position with the desired tightness is in the upright position, you would use that gadget to change it.

 

Here's how. Undo the little screw (can't remember if it is hex or philips) that holds the little plate over that round thing with the numers. Now push the round ratchet ring thing out and turn it a few notches. Redo the locking plate screw and install the wheel and check where you axle now rests in the locked position. If you have my luck, it is now completely opposite to what you actually want and you can go back and change it to the other direction.

 

The numbers are meaningless but I suppose if you work with these forks often (like assembling them in a factory), a certain number would be your sweet spot to be memorised.

 

On the udder hand, maybe they're the lever's position in degrees. I don't have one handy to check.

 

Thank you Johan, your explanation make perfect sense!

[RED1408]

54

 

WHAHAHAHA!!!!!!

 

Dude that made me spill my coffee