Cyclocross, It's a funny/weird old game. No more so than when it comes to Rubber. For new-comers to the sport the options can be mind boggling and packed full of Jargon, for example who would know that an 'Open tubular' is not a Tubular at all but a very pliable clincher? Not I cried my good friend and ex DH MTB pro who has joined us on the start line this year (therefore depriving me of yet another point ).
To help clear up any confusion here's my round up of all things Rubbery in the world of 'Cross, CX, Cyclocross, Gravel etc...
Tubular : The pro's choice.
Tubulars or Tubs as they get called are basically a tyre and latex tube stitched together into a big sausage, this then gets attached (I'll come back to how in a minute) to a special Tubular rim. Tubular rims have a different profile from normal (Clincher) rims and cannot take normal open tyres as they have no bead socket.
The advantages are that Tubular tyres can be run at low pressures without fear of pinch flats, they give masses of grip because they can be run at 20psi, the tyre wheel combination is lighter and because of the way they are fixed to the rim the transfer of power is actually better than with normal rims.
There are disadvantages though and this is why Tubs are found mainly on Pro and 'serious' (not that serious it is 'Cross after all) riders bikes. The Tubs themselves are expensive roughly twice the cost of a clincher (read on and I'll explain). Fixing tubs for 'Cross to rims is a messy and time consuming job. If it's done correctly Tubs require a combination of glue and special adhesive fabric tape (often known as belgian tape) built up layer by layer over a period of a few days, then some poor soul has to wrestle these sticky rubbery things onto the other sticky carbon or aluminium things then tug and pull them into alignment and then put sealant in them. God forbid you make a mistake like putting the tyre on the wrong way (Sorry Steven) as the rim and the Tub are not parting company in a hurry and the mess is horrendous. [I know you can use tape only but I've seen quite a few riders carrying their bikes back to the pits when a Tub that was taped has let go of the rim] Having different tyres for different conditions means having multiple wheelsets with you, tyre choice is critical in Scotland where we can go from sand to thick mud in 24 hours, but you can run really low pressures so your intermediates can be suitable for mud, but they're still not mud tyres. They do puncture and they are not easy or cheap to repair. I for one do not like the Schwalbe Tubs as I have ripped them open so often it's not funny. On the other hand the Challenge Tubs are excellent.
In conclusion : Tubs are the Pro's choice for a reason, once you've ridden them you'll understand why, but they are not cheap and they are not home mechanic friendly unless you're significant other has no objection to the smell of solvents and glue invading the living room while you try to keep the glue warm to stop it from setting instantly during the depths of winter. Tub rims start at about £50 for Velocity Major Tom's and go upwards rapidly from there into the £000's, Tubular tyres are roughly £80+, Glueing and sticking costs £25 a wheel.
Clinchers : Normal tyres and tubes
You may not know it but you're probably riding clinchers already. Normal vulcanized tyres (ones that have shape when you take them off the rim), butyl rubber inner tubes and traditional rims are what most bikes will be equipped with. The advantage of this combination of tyres, tubes and rims is the endless combinations that can be put together and the cost. The disadvantage is the lack of puncture resistance, the pressure required to improve this and the weight. Pinch flats are what happens when the rim and the tube get 'pinched' together on impact with an obstacle or hard landing, this results in a 'snake bite' puncture, so called because of the twin holes like the bite of a snake. To minimise the risk of the Pinch flat you can do 3 things:
- Run higher pressures. This then looses you grip and makes the bike handle poorly.
- Use super supple tyres such as the Challenge Open Pro. These are awesome tyres and do add a good amount of puncture resistance, and with a Latex tube don't weigh too much, this is a very common setup at CX races.
- Use sealant such as Stans No Tubes inside your tubes just in case you puncture. Again this adds weight and is not fool proof as sometimes the holes in the tube will be too big for the sealant to cope with. Also you need tubes with removable cores to allow you to pump sealant in.
In conclusion: Most people will have ridden and raced on Clinchers and for the majority of people that aren't concerned about weight or grip they will be ideal due to the cost and readily available tyres, tubes and rims for all conditions. But there are better options out there in the form of Tubeless ...
Tubeless : Tyres that fit like Clinchers but as the name suggests no Tubes .
People will tell you that Tubeless is a new thing and unproven. Not True. Myself and Andy Kyffin were succesfully running Tubeless on a certain Sheffield DH'ers bikes in 2002. Tubeless involves the use of a few specialist ingredients and has many versions, for 'Cross I've used both the 'Rim Strip' method and the 'Tape' method. There is also UST - Universal System Tubless (UST) rims that require no sealant or rim strips but I've not used them for cyclocross, yet. If you take a standard clincher rim it is possible to make it Tubeless using a rubber Rim Strip, this basically seals the rim and provides an air tight seal for a standard Clincher tyre. Chuck in a bit of sealant and Bob's your Auntie. BUT I have found when using the combination of the narrow profile of most road rims ( 19mm ish ) and the wider tyres ( roughly 32mm ) that tyres do sometimes 'Burp' (leak air and sealant in corners) or even roll off the rim. This is not a problem with MTB wheels where the width of the rim and the tyres is much closer and the tyres tend to be stiffer, i've succesfully run this style of Tubeless on my Mountain bike for years with no problems.
If you invest in some Tubeless specific rims then it's a different story. Tubeless rims from the likes of Stans No Tubes, H+ Son or Velocity have a different profile and include a 'Hook' in the rim to provide more grip to the bead of the tyre to stop burping or rolling off, no need for rim strips just some light tape also means the weight saving is impressive especially when you consider the weight is saved at the outside of the rotational mass where it counts most. Combine these rims with one of the emerging Tubeless specific 'Cross tyres such as the WTB CrossWolf or the 120tpi Challenge Grifo and your good to go, almost...
The advantages of Tubeless are numerous:
Low tyre pressures so more grip, more feel and more speed. Lighter weight than Clinchers so more speed. No pinch flats so much better puncture resistance. You can use standard tyres and rims if you want so you can have tyres for every occasion and condition. The Tubeless specific tyres are half the price of tubulars and don't need messy glue to attach them. In some cases if you pick you're wheel components carefully you can go Tubeless for less money and less weight than Tubular. If you do get a puncture just bung a tube in, no problem.
There are some lessons to be learned though, it's not all a bed of roses:
Not all tyre and rim combinations work, even the Tubeless specific ones. You will get covered in sealant changing tyres if you're not careful. You might want to invest in a small compressor to seat the tyres properly, a garden spray with soapy water helps too.
In Conclusion: Tubeless is the way forward for those riders that want the grip and weight advantage of Tubulars without their cost and their technically awkward fitting, and riders that want the benefits of the ease of use and cost of Clinchers without their disadvantages; punctures, weight and lack of feel & grip. Setup can be a bit hit and miss. You don't want to be changing tyres the night before a race, but get everything done in time and the results are impressive.
This should go some way to helping understand the jargon and hyperbole surrounding the subject of Tyres and Wheels for 'Cross, if i've missed anything, you have any questions, or want to discuss what would suit you best then get in touch.