I've recently mounted new Maxxis Raze tires on Mavic OP rims and was really surprised by their actual width. While they are advertised and marked as 35, they measured slightly less than 31 in fact. Is this normal?

Companies measure however they want. My Conti 700x35 are skinnier than my Michelin Muds 700x30.

I can't find any consistencies either. Michelin, Bontrager, WTB - all of them are all over the place. I'm just glad the Cross Crusade in Portland isn't UCI, or at least not in the lower categories!

Thanks, guys.
I just didn't expect the differences to be THAT big. Can you recommend any good wider (around 35 mm) clinchers? Is the situation as bad with tubulars or are they more consistent with claimed width?

Tire width from most companies do not comply to what they indicate. Generally these are Taiwanese or Chinese made tires.
The reason for this is that they follow ETRTO rules that in this case (from our point of view) are not correct.

The rule states that tires above 24mm should be mounted on normal touring rims that are wider but in the Cross side we mount
them on standard road wheels and the size from hook to hook is smaller. Therefore the end result is that the tire market 35 is
now 30.

We come from the road racing and cross world so we know what the athletes want and our sizes are quite true. There is a tolerance
that is in the +1/-1mm .

Here are 2 reviews made on our tires with more detailed explanation:

http://www.londoncyclesport.com/index.p ... Itemid=104

http://www.londoncyclesport.com/index.p ... Itemid=104


Another reason is because lot of people are interested in weights (this is the right site to say this ) so what to these companies do? Make a smaller tire
so that the weight goes down and sell it as a bigger tire. Our Open Grifo is quite light and is 32 but if you compare it to a 35 of other brands which in the end
is not a correct size we end up being heavier.

I found this site and this guy hit the spot. check it out: http://sheldonbrown.com/tire-sizing.html

Thanks for the detailed answer. I remember similar issues with MTB XC tires where measures are not consistent across different manufacturers either. They also have a strange standard of measuring tire width on some 30 mm wide rims while common XC rims are around 20 mm wide (on the inside).

It is quite a difficult also for us as tire manufacturers to make the correct size.
Now wheel manufacturers are playing with internal width size with no information or standards
for us to follow. There should be more information amongst the industry but this does not occur.
Both clincher and tubular wheels are changing specs and each manufactures has different designs
and spec.

Standard tubulars have a base tape of 23mm but now Zipp has taken the tubular wheel to over 25. This will cause issues to tubulars
and users will complain to us and not to Zipp!

A lot of interesting thoughts here. Makes me wonder why UCI has gone to 33 as a standard. Or, more specifically, why there's a maximum at all. Kind of difficult to know how wide your tire will be once it's mounted until you've already bought it. (not that I do a lot of UCI races)

I agree that limiting the size has no meaning at all. We have talked to UCI and expressed our thoughts but we got nothing in return.
The only explanation was to help young athletes entering the sport and limiting the wheels they had to use. did not need to have wheels with 32 and other wheels with 34 but this is not correct. I understand that Fidea guys like Bart Wellens, Stybar or Nys to mention other teams also have a truck load of wheels but now they still have the same amount and just mount them with different profiles and different compounds so you have not resolved the problem.

Introducing disk brakes has caused huge problems to frames, forks and wheels and adding additional weight to the bike with not technical advantage.
Cross does not need disk brakes. Wheel manufacturers now have to change spokes, hubs reinforce head tube, reinforce forks. Disk brakes are an offset braking power so the entire bike needs a totally new construction. The best disk brake in the bike world is the brake on the wheel. The wheel diameter is 28” and now you’re putting all on a little disk on one side of the bike? Sure it is cool but technically no meaning. other issues like the brake needs to warm up to give a good performance or adjusting the brake force is much more difficult. You can go to no braking to locking your front wheel. Downhill is a different story and has a more valid application.

Going back to your questions on size we slightly undersize the tire to avoid exceeding 33. the new generation of tires sizing has been changed but in any case our old 34 inflated at 2bars = 29psi will measure 33. Generally this is the max pressure to be used in cross. Pressures used in UCI racing are from 1.5 bars =22psi to 2bars = 29psi

Too much politics behind guys....I can’t say more

Sorry, but personally I think such a statement is a bit conservative...

Apparently a lot of people "complain" about disc brakes being legalized for CX. I don't really see why. If you look at mountain bikes, no one uses rim brakes anymore (except for weight weenies that aren't racing). Give it some time, let Shimano or Sram make a shifter/brake unit that allows for hydraulic disc brakes. You can reduce the disc size to shave weight. I think most people will prefer (hydraulic) disc brakes... As for mechanical disc brakes or "ghetto-hydraulic" systems I understand the scepticism, but for proper hydraulic discs I wouldn't hesitate getting a disc-equipped CX bike the next time around.

I get that it's a pain in the ... for the manufacturers of forks and frames, but without evolution, where would we be now?

I don't see how the change in tire width has anything to do with disc brakes

Sorry, I meant to copy the last quote and agree with it. Saves rims, works in the wet, eliminates shudder, etc. Once they come up with a small diameter hydro road lever, I'm interested.

Me too.

I've tried cable operated discs and was disappointed in their performance, but I'd still give proper hydraulics a go in cross.

Disk brakes are a great invention and I am not against technology. You got the wrong impression or I did not explain myself well.
It was an example. Analyse how a disk brake work and you will see that is not suitable for cross. If you want to use it, fine. Nothing against
that. Making disk brakes lighter to compensate the increase in weight of frame head tube, fork and wheel? It can’t happen. How can you take
off 1kg of extra material from something that has a weight of 350grams? the extra weight is not the issue anyway. It is fine if you like it. Same thing with soft and hard
tail bikes. Great invention but then the MTB guys went back to hard tail. The advantage was not enough to compensate the weight (one reason and
loss of power is the second reason).
Great for Downhill but not for cross country. What I am saying is you have to see what discipline you are doing and gear up the best way for it.
Again, if you want full suspension bike in cross country fine. Up to you.
Disk brakes are fine in certain applications and technically valid but no advantage in cross. If you want to use them fine but you are not getting advantage
and losing competitiveness. I am sure you have seen Nascar and for us Euro guys F1. Are the brakes flaming hot when they hit the brakes? Yes, because
when a disk brake is cold.....no braking. The disk brakes works damn good at high temperatures. Road racing going downhill at 90km//h or 50m/h
fantastic. Do you have the same braking in cross? Do your wheels get to 85-100 degrees C like on road or Down Hill? Final decision on how to gear up your
bike is up to you. I have used and tested disk brakes more than 15 years ago. As you can see they have been around for some time and in the end they
found the right application in certain disciplines. Smaller disk = non braking to locking. Hydraulic is a better force and calibrate better but once the brake gets
to temp. Don’t forget that the disk is on one side so asymmetrical backing more ability needed in controlling. Anyway this is a discussion for my friend
Lance at TRP. They have some cool stuff and probably with the new disk brake for cross has overcome some of the issues.

I am talking of something else. If someone has a warehouse full of product and they are not selling but have the power to influence the cycling rules
this, is politics, nothing to do with technology and this happens in the industry. There are many examples out there just need to understand why
certain rules are change, made, introduced and it is not always the way it seems for the end users.

Spinaci (Cinelli) handle bars used by Pro’s at the Giro Tour.... suddenly became not legal. Is it better to see the rider going downhill at speed holding cables?
These were made to help riders keep control of the bike. Sram new Crono bar shifters are not legal if mount strait, considered an extension to the aero bars
but if bent up 15 degrees they are ok. Now what advantage will half a centimetre give you? Cant competition do the same? Yes, but would have lost a season
and products in stock to be thrown away.

Back to tire size what is the technical reason behind it?.....there is not one! So here it is ok to limit technology because we are probably disturbing some
big company which has the power to influence ...... My point is politics in the bike industry and nothing against technology.
Politics is damaging technology.

Check out TRP Cross brakes released at Taipei 2011 show (pics attached)