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Building a Cyclo Cross bike


Meerkat82

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Two tech related questions:

How important are thruaxle for cyclocross frames or are QR axles ok as what is found in lower spec frames?

Secondly, if you use tubeless which rims are better, mtb or road? If mtb is the max psi good enough for road usage and if road rims, do they work at lower psi for off road conditions?

I can't comment on the first question, but suspect that the lateral forces for my kind of riding would come nowhere near what the road pros put on their wheels in the highspeed descents down mountain passes or on the cobbles of the classics.

 

They all use QR axles, so I suspect that they are OK.

 

I had road wheels on my bike before, but always felt vulnerable on highspeed rocky sections. I now have a set of MTB Hope Hoops; the weight penalty on the rims is not significant, but I the benefits to me are :

 

Stronger wheels - I am not sure I would have been happy bombing down Breedts yesterday during the van Gaalens gravel grind on road rims. But then again, I am almost 100 kg;

I know that I can run them tubeless at low pressures without an issue;

I run 28mm Conti GP4000s at about 4 Bar on the road and can go up to 7. More than enough;

They look better as they do not have a machined brake surface and I have disks. I suppose one could use track rims but i'm not sure that they will take the pounding.

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I can't comment on the first question, but suspect that the lateral forces for my kind of riding would come nowhere near what the road pros put on their wheels in the highspeed descents down mountain passes or on the cobbles of the classics.

 

They all use QR axles, so I suspect that they are OK.

 

I had road wheels on my bike before, but always felt vulnerable on highspeed rocky sections. I now have a set of MTB Hope Hoops; the weight penalty on the rims is not significant, but I the benefits to me are :

 

Stronger wheels - I am not sure I would have been happy bombing down Breedts yesterday during the van Gaalens gravel grind on road rims. But then again, I am almost 100 kg;

I know that I can run them tubeless at low pressures without an issue;

I run 28mm Conti GP4000s at about 4 Bar on the road and can go up to 7. More than enough;

They look better as they do not have a machined brake surface and I have disks. I suppose one could use track rims but i'm not sure that they will take the pounding.

Good questions. I use QR but would like 

 

Two tech related questions:

 

How important are thruaxle for cyclocross frames or are QR axles ok as what is found in lower spec frames?

 

Secondly, if you use tubeless which rims are better, mtb or road? If mtb is the max psi good enough for road usage and if road rims, do they work at lower psi for off road conditions?

Good questions.

 

If you can get through axle then take it - it is laterally quite a bit stiffer. But its not absolutely necessary unless you are planning on some serious cornering.

 

Second question wrt rims - I am using Carbon MTB rims (i got a set of Dark Horse wheels second hand on the hub) running Conti CX 35 mm tyres. Clincher and Tubeless. I run them at about 4 to 5 bars.

 

A road rim with a deeper section will work well for strength. Not your wheenie lightweight road rims, but a slightly heavier rim.

 

Tubeless works well for reduced spun mass. I have broken spokes on the wheels but I am a big guy and I think hey weren't well built but now I have completely rebuilt the rear and hopefully the problem goes away.

 

It totally depends on what you plan to ride (what sort of terrain).

 

You can also go much more aggressive on the tires. I have some 42mm tyres that are really a mission to pedal on tar but great offroad. Larger tires = more volume and therefore also a better ride and less smashing the rims.

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Chaps I am looking for Avid Shorty Ultimates for my Cotic... please let me know if you have any for sale.

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all this talk about tubeless, through axles and disc brakes. We're still talking about Cross right?

That's what I was thinking!...

 

Pump up the tubes. Tighten the QRs. Straighten the cantis. And ride!

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  • 2 weeks later...

whats the actual measurement of those? Precision vernier please :)

 

40mm wide, Precisely. 38mm high - measured off the rim to surface rubber.

 

Might pop up a little more with some more pressure?...

 

These are the 40C versions...

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