This week's blog post comes to us from Calgary native Geoff Mar, Geoff is connected to @MGridetoronto through fellow MG member Nick Aspros. Geoff is a wheel expert and has shared his thoughts with us about the debate over clincher vs tubular wheels.
The Silk Road: Tubular Tires - A Primer
The Tour de France is now in full-swing. Every day, TSN2 treats us to the best road racers in the world doing what they do best...in stunning HD. One of the things that makes cycling the glorious sport that it is and, in part, defines the place that ‘Le Grand Boucle’ has in France even today, is the inseparability of man and machine.
When the Tour was born, the bicycle was a new technology that symbolised freedom and promise of ‘La Belle Époque’ - man’s leap into the future. The Tour was a symbol of the primacy of France amongst industrialised nations. As it was at the infancy of modernity, bicycle technology today is front-and-centre at The Tour. Every manufacturer strives to have their latest wares on display, as the eyes of the cycling world are focussed there, seemingly unblinking, for the month of July. While the technology seems to become more and more amazing every season, only one thing has remained literally unchanged since Henri Desgrange first conceptualized the great race: the racer’s choice of tires.
By way of a brief introduction, I have spent most of my cycling life riding on bicycles shod with tubular tires. Back ‘in the day’, no-one had ever even heard of such a thing as a high-pressure clincher tire. Accordingly, the only choice I ever had was tubular tires for high-performance riding. That was just the way it was for both racing and training. When I started on tubular, I was as a wide-eyed Cadet. I became steeped in the traditions of ‘the old country’ by the many old road cyclists who came to our city in search of a better life. In our youth, were regaled with their stories, pictures and mementoes documenting their racing past in the service of some of the Legends of our sport. They seemed as pleased to find someone to pass that history and information to as I was to receive it. Today, well into the Masters category, I have over 20 years of experience with tubulars. I am a collector of professional racing bicycles that spans the Modern Era. I speak and correspond frequently with Pro tour riders, mechanics and Directors.
Due to my experiences, I frequently get asked for advice regarding many bicycle-related topics. Today, I would have to say that the single most-asked question that I get is regarding tubular tires, starting with a simple: ‘why’?
What is a tubular tire and how does it differ from the other available options? The tubular tire is the original form of pneumatic racing tire. Also euphemistically known as ‘sew-up’ tires, the basic structure of the tubular consists of a casing (basically a continuous ‘loop’ of fabric, originally silk or cotton, but today increasingly, blends of man-made fibres, too) to the exterior surface of which is adhered a tread and into which is placed an air-tight, inflatable tube. The fabric ‘loop’ of the casing with the tread attached is mechanically fastened around the tube. A basetape is then adhered over the stitching that joins the casing together, both to protect it and to give a secure mounting surface to the rim. The resulting tubular is essentially a one-piece, self-contained tire with the tube built-in.
The tubular tire and the rim are a true ‘system’, with neither functional without the other. The rim differs from a clincher rim in that it has a much simpler construction. Rather than a casting or extrusion in multiple layers (which construction is necessitated by the requirement of the clincher rim to accommodate the bead of the tire), the tubular rim is a simple ‘box’, the rim bed of which is a cavity matching the general curved shape of the base of the tire. While the clincher tire is held in place by the mechanical force of the inflated tube pressing the tire’s bead into a corresponding hook in the rim wall (the tubeless tire is essentially no different, other than the obvious, and relies upon the mechanical fastening of the bead of the tire to the hook in the rim by internal pressure), the tubular tire is fastened by an adhesive designed for the purpose.
The advantages of the tubular tire system are principally as follows:
For all of these reasons, the riders of the Grand Tours have been lining-up on tubular tires for over a hundred years. With all the advancements in science and technology, really very little has changed regarding the way power is best put to the ground on a bicycle.
The principal downsides of using tubular tires are down to the cost and inconvenience of punctures and the initial time invested in their installation.
Instead of carrying a spare tube, tire irons and a pump, the tubular tire rider has historically had to rely on a spare tire, which is definitely more cumbersome than the aforementioned clincher repair set-up. When a roadside repair is completed, the tubular tire relies on the glue left on the rim and the basetape of the spare, whereas the clincher is basically as good as it ever was. A replacement tubular is generally safe to complete the ride (taking care not to dive into corners in crit-like fashion) and requires re-gluing when back at home-base.
Once punctured (and unless the casing is cut), a tubular can be repaired. This involves either opening the casing at the puncture site, repairing the tube, re-stitching the casing and then re-gluing the basetape to the casing. Due to the time and experience required to complete such repairs, many employ the services of a third-party tire repair specialist.
If you haven’t been dissuaded from the tubular experience yet, there is a ‘silver lining’. In my experience, tubular tires rarely flat. In fact, in 20+ years of riding tubular, I have had two (2) cases of double-flats, about 15 years apart. In each case, the cause of the flat was invisible shards of metal strewn across the road.
In recent years, I have become lazy and stopped carrying a spare tubular. I had purchased a can of Vittoria’s ‘Pitstop’ tubular flat repair and a mini pump to test that. I have now been carrying the same can of Pittstop for so long that I am starting to get concerned that it might have a shelf life. Part of my ‘luck’ with tubular tires is obviously down to how I ride them (i.e., I avoid road debris where possible and, where impossible, brush the tires with my fingers to prevent punctures, etc.) I often wondered how much was me and how much was the tires. To be sure, I thought I would try an experiment.
My collection of professional racing bicycles also includes a wide range of other paraphernalia that people seem to keep sending me. Included are many sets of clincher wheels. Out of morbid curiosity, I decided to ‘test’ some modern clinchers for myself to see if there was any difference. I equalled my lifetime record of flats in a few months of riding clinchers. I did nothing differently in my riding style between the tubulars and the clinchers, including the periodic brushing of the tires, daily pre-ride checks and road debris avoidance. Maybe it still is just luck, but now I doubt it.
Perhaps the biggest barrier to entry into the tubular world is the mysticism surrounding the gluing of the tires themselves. Certainly, people have a fear of doing it wrong, resulting in an unsafe product.
There is no question that there is a lot of bad information about properly gluing a set of tubular tires. The following is my recommendation:
1) new rims, new tires -
1. Clean the rim with a mild solvent and then wipe well with a clean, damp cloth. Under no circumstances is it ever (nor has it ever been) necessary to 'scrape-up' the rim bed to receive the glue.
2. To the rim, apply a thin (THIN) layer of Vittoria Mastik One. I recommend a strip of poly or a heavy plastic bag wrapped around your finger (better than a glove, because you can just drop it when you need to). Let the rim dry (I always tell people that overnight is best, but if you are in a hurry, wait 4 or 5 hours at least for the solvents to flash-off).
Repeat this process at least 3 times (for the track or a track or crit-specific wheel, I use 5 coats). The secret is thin, even and complete coats (i.e. from rim edge to rim edge). Patience is a virtue here.
3. Concurrent with the rim applications, inflate the pre-stretched tire [we used to stretch tires by putting a foot into the 'stirrup' formed by a looped tire and pulling up hard, but this is discouraged nowadays by the manufacturers. Instead, put the tire on an old tubular rim (what good is an old Fiamme Red Label today anyway?) with no (or really old) glue on it, inflate to pressure and leave it for a week or more. As you inflate the tire, it will 'open-up' with the tread rolling-over so that you can lie it flat on the ground without getting the glue on the floor.
Taking your poly/bag applicator, apply a thin (again THIN) layer to the base tape (as you will have previously observed from your stretching of the tire, not the entire base tape contacts the rim. You only need to apply the glue to that component of the base tape contacting the rim. If you go over, don't worry, you can clean it up later, besides, the mounting of the tire will add some spots with glue on the sidewall anyway.
The base tape will absorb a fair amount of glue, so repeat this process at least twice.
4. Immediately before attaching the tire, apply one more layer to the base tape. This is to 'lubricate' the tire to make it easier to mount. Some guys say the rim, but this will make more of a mess on the floor when you push down on the wheel to mount the tire.
5. You need a surface to push-down on and protect your floor. I like a piece of sanded (i.e., not finished) cedar siding board about 60cm long that I have used for the purpose for 20+ years.
De-flate the tire and leave the valve partly open. Starting with the valve hole facing up toward you, place the wheel on its edge on your work surface (if you are doing the rear, it may help to take the cassette off first). Insert the valve stem through the valve hole and centre the stem in the wheel.
Work your way 'down' the rim, pressing with all of your weight (I say 'all', because I am 59 kg. I literally have to lift myself off the floor to get the tire as tight as possible around the rim). This is very important to the process. While you are doing this, make sure that you do it evenly and that the valve stem is not pulled one way or the other.
By the time you get down to the last bit of the wheel, flip the wheel over and, placing the tire tread on your lap with the remaining tire to be installed facing you, use your hands only to 'flip' the remaining tire onto the rim. If you have stretched the tire correctly and started to install it correctly (i.e., by stretching it down the rim as you go), even the 'hardest' tire to mount for stretching purposes (something like a Dugast Paris-Roubaix Seta 27) will go on like butter, with minimal glue mess.
6. Inflate the tire to 'round it out' (not too much pressure, you don't want to make it hard to move around on the rim). Holding the ends of the axle in each hand and looking down the tread (I recommend looking toward a white wall with no lines etc. on it so you don't get distracted), spin the wheel away from you slowly to watch the tread's trueness. Do not look at the base tape, but the tread. As you see imperfections in alignment, use your thumbs to poke and prod it into line. The tire does not have to be absolutely perfect, although you should be able to get it pretty close.
7. Inflate the tire to pressure. Some people say to de-flate the tire to allow the glue to adhere to a 'relaxed' tire (not mentioning Len Zinn's name), but I think that is crazy. The adhesion created by the internal pressure of a tire inflated to 100+ psi has to be more important to good adhesion.
8. There will sometimes be a bit of a mess on the sidewall or the rim. This is easily cleaned with a rag with a mild solvent. I would recommend more elbow grease and a less aggressive solvent (I use a household paint thinner). Wash-off the solvent from the tire and with water and a mild detergent. If you like, you can apply a layer of latex or Acquaseal or liquid latex now, but you don't need to.
9. Let the glue 'cure' at room temperature at full pressure for at least a full day. If you are using the wheel on the track or for a crit, I would leave it for two days at least.
2) new rims, pre glued tires
In my experience, not too much of the glue will adhere to the base tape, accordingly, I would follow precisely the same steps as above.
3) previously used rims, new tires
This is the trickiest of your scenarios, as it really depends upon the quality of the glue remaining on the rim. In the event that the glue is ‘fairly’ uniform and of good quality remaining on the rim (i.e., not covered with bits of basetape, not dry and crusty feeling, but soft when pressed with your fingernail and generally still tacky to the touch. I would typically recommend simply adding another couple of layers of fresh glue to the rim and dealing with the tire in the same fashion as above.
In the event that the glue is very patchy or is obviously dry and hard, then the removal of the glue is necessary. This can be a slow and laborious process and I have found no easy way to do it. It involves a pail of old terry cloth rags, your favourite solvent and a dull screwdriver. Not a lot of fun. You do not need to get all the glue off, just enough to start over with a good base layer of fresh glue. Once you are done, make sure you wipe the rim bed well again with acetone or denatured alcohol to clean it before starting the re-gluing process as before.
4) previously used rims, pre glued tires.
As I say, in my experience, not too much of the glue will adhere to the base tape, accordingly, I would follow precisely the same steps as above.
Of the ‘production’ tires, I like Continental Competition 22s. Admittedly, it is the least ‘tubular-like’ of the production tires, but it is very durable and the new ‘Black Chilli’ tread compound is very good. The Conti Competition has a classic ‘file’ tread pattern which adheres well to all but the slipperiest road surfaces. I have also had very good luck with the Vittoria All-Weather, which has sadly been dropped from their line-up. Fortunately, the tread pattern is making a comeback this season with the introduction of the Vittoria Evo SC (which is the modern incarnation of the Vittoria CG that we mounted as rear tires (with CXs up-front) for decades back ‘in the day’. Although I have not ridden the new tire, it appears to be the same as the CX, except with the ‘herringbone’ tread of the CG/All-Weather instead of the ‘file’ tread of the CX. The combination of a CX front and SC rear should be a potent combination for an all-weather tubular set-up.
I am a big believer in truly hand-made tires. While many (Vittoria, Challenge etc.) claim to be ‘hand-made’, there are many more processes actually completed by or with the assistance of machines. The single biggest difference is the use of heat in the manufacturing process. Truly hand-made tires, in my opinion, simply ‘feel’ better, they last longer and they do not flat easily. With truly hand-made tires (FMB, Dugast, Veloflex, etc.), part of the benefit comes at a cost (other than the obvious financial cost: they also benefit from being ‘aged’.
A real, hand-made tire is basically a natural, synthetic or ‘hybrid’ rubber tread adhered to a spun casing with an adhesive. The tires produced in this fashion use components that benefit from ‘aging’, where the exposure to ambient air oxidizes the tread and the glues to form a more puncture-resistant tire. There are physical changes to the appearance of these types of tires over time and they turn from a whitish-coloured side wall to a much more amber colour. The tread also shows obvious signs of aging, as well, often developing a brownish hue. Here is an interesting piece showing Julien Devries demonstrating the aging of hand-made tires: http://www.youtube.com/watch?v=DKfz0tkYin4
The hand-made tire features a spun casing that closely replicates many of the tires of the turn of the last century and may include silk as its principal ingredient. The silk tubular is the epitome of the racing tire. Supple and light, yet strong and durable, a silk tubular is used everywhere from record attempts on the track to the cobbles of Paris-Roubaix. There is no better riding, longer lasting tire on this earth. The following is a link to my friend, Richard Nieuwhuis, crafting his fabulous Andre Dugast tires entirely by hand, one by one: http://www.youtube.com/watch?v=CgcXTYbUhs8&feature=related
In stark contrast to the hand-made tires produced by Richard Nieuwhuis at Dugast or Francois Marie at FMB, most ‘modern’, manufactured tires are constructed utilising a ‘vulcanized’ construction, that is to say, the tread is compression-moulded to the casing by way of the application of heat and pressure in order to fuse it to the casing, as opposed to the use of a separate adhesive. In order to withstand the process ‘vulcanized’ tires require a synthetic rubber. It is said that synthetic rubber is not affected by ‘aging’, though I do not personally agree, but they are certainly much less affected.
In addition to the requirement for the use of a synthetic rubber tread, the mass-produced tubular tire also has a different casing design than a hand-made tire. Like the tread, in order that it withstand the heat and pressure of the ‘vulcanization’, the casing is necessarily stiffer and less compliant. Together, and while much better than any clincher, a mass-produced tire is a much less durable tire than its hand-made counterpart and misses some of the ride characteristics that make the tubular tire special. The following is a link to a video of the modern, mass-produced tire being constructed at Vittoria’s facility in Thailand: http://www.youtube.com/watch?v=jwrwbxPKjAI&feature=player_embedded
Aside from the durability and road ‘feel’ of a hand-made tubular, I can’t help but feel a kinship with the earliest racers and the machines they rode. Admittedly, my ride today (Davide Viganò’s Team Sky Dogma from last season with SRM PowerMeter and Shimano Di2) is nothing like the first bikes, but at least the tires are. My son is ‘helping’ me to prepare and glue tires now...and he is only three. I hope to pass-on the traditions and history of our great sport to him, too.