April 01, 2015 8 Comments
Clinchers are the primary pneumatic wheel system of our time. Cars, planes, high speed trains all use forms of this proven approach to suspension and travel. In cycling as well, clinchers are the bedrock tire system. Today’s topic concerns the high pressure clincher (HPC) for road racing and performance pavement riding. Who would question The System??
When did HPC’s arise?
Before the ’70’s, bicycle clinchers had maximum pressures of 80psi and most depended on 30-65psi. They served the needs of everyday riding from commuting, to commercial delivery, to touring and recreation. Racing to win was another form of cycling. Competitors used narrow (18-25mm) tires at high pressures (7 bar/100psi+) to make wheels light, yet resistant to dents, and hopefully win races. Since the dawn of pneumatic tires, racing needs were not met by clinchers but, instead, by tubular (sew up) tires.
The mass of riders on modest pressure clinchers were well served and racers had little problem gluing sew ups or hiring mechanics to do it. For both systems, rims and tires were simple to design and flats were rare and easily fixed. What ended this happy, stable era?
In the mid-1970’s, America experienced a sudden bicycle boom, fueled by alternative thinking and, especially, a nationwide gas shortage with soaring prices. Suddenly mobs of young Americans wanted to ride bikes. Cycling didn’t have much of a role in the US besides besides grade school commuting and news boys. To get out on the roads with cars was intimidating, but less so if you rode fast. Going fast was fun and the boom focused on speed. European racing was inspiring.
Unexpected Boom Crisis
Importers found supplies of racing bikes and soon everyone was hunched over skinny tire racing bikes, riding as fast as they could. Despite some problems (neck pain, sore butts, safety, etc), one threat loomed largest: better racing bikes from Europe came with tubular tires. Few in the US knew what to do with them, no old timers in the neighborhood to mentor beginners. Tubulars were misunderstood, miss used, and became the bane of lightweight riding. They weren’t, after all, intended for general use.
An alternative to the tubular was needed quickly or the biggest American bike boom of the century faced an untimely end. Mountain bikes were still 10 years away so a new machine was not an option.
Enter the HPC. The dawn of tires and rims attempting to hold high pressures, for example IRC High Racer tires on Araya rims, was scary and loud. Tires could be mounted crooked, rims could expand with pressure, standards for fit were inadequate, tire levers bent and broke, pumps were not strong enough. HPC’s, the bastard child of an awkward historic moment?
However, the goal was clear: a system to equal the performance (pressure, weight, speed) of racing tubulars but be easier and cheaper for the masses to maintain.
40 Years Later
Where do we stand with high pressure clinchers?
(1) They are heavier and less strong by weight than tubulars.
(2) They are not cheaper, rather equal or more expensive than tubulars.
(3) They get more flats, especially pinch flats, than tubulars.
(4) Rim-to-tire fit standards are so vague one can buy a top-of-the-line tire and be unable to mount it to a top-of-the-line wheel. I would estimate 70% of riders of HPC’s do not repair their own flats. They call home. Prying off the tire and making the patch or tube insertion is complicated, requires too much hand strength, and often fails. Mechanics, like the readers of this piece, have noticed the difficulty but are not in the 70% helpless category. We are busy helping our less-able customers and riding companions. Fact is, more tubular riders with punctures ride home than their HPC counterparts.
(5) “Tubeless” systems aim to fix this but is it worth the trouble? True, fewer flats, but the rim interior is often invaded with sealant that can NEVER be removed. Bead fit is so tight that only experts can mount them. Tires cannot be inflated without compressed air. And the suggestion you can insert a tube if you flat during a ride is bogus. Putting tubes in a road tubeless system is a task virtually no one can accomplish.
(6) Making light rims in any material for HPC’s is complicated. Outward pressure of tire beads is gigantic. To withstand this force carbon rims add mass to equal the weight of aluminum rims. Huh? The circumferential pressure of HPC’s (tube or tubeless) on rims is 10X that of tubulars due to the different physics. Tons of constricting force shrinks light rims, lowers spoke tension, and deprives wheels of much strength. Is it worth it?
High pressure clinchers have had 40 years to accomplish the goal: equivalent performance, improved convenience, and lower price than tubulars. They have failed. It’s over. Good try but no win. 40 years is long enough. Believe me, I’m not alone among industry veterans puzzling over this situation.
This is not a call to return to tubulars. That’s the system that needs replacing. A new system is needed for the narrow, high pressure, racing pneumatic. Don't stop using HPC wheels. Until there is a better alternative, it’s the best we can do.
Nor does this apply to moderate pressure clinchers as in BMX, MTB, utility, and randonneur riding. Larger casings, lower pressures, and a wide variety of rims are delivering great function and value. It's also important to note that efficiencies of narrow, high pressure tires have been exaggerated. Fast, competitive riding is often better with lower pressure and larger cross sections. Jan Heine's Bicycle Quarterly (among others) has really driven this point.
Here is also not a criticism of the modern HPC tire. Taken alone, todays’s HPC’s are remarkable technology and quality. Complex and refined, tough and impressive. Same with rims. It is the system that is at a dead end for high pressure.
What to do?
(1) Separate yourself from deniers who claim HPC systems (especially tubeless) are perfect. They’re not.
(2) Think hard about alternatives. Study tubulars. Study HPC’s, both tube and tubeless. Cycling innovation begins with you.
(3) Don’t hold your breath. Innovation requires motivation (we have plenty), technology (it’s out there), and courage (well...). Structural obstacles also seem insurmountable. Tire companies are some of the largest corporate entities in cycling. Michelin, Hutchinson, Continental, Innova, Cheng Shin, Kenda, these are global chemical giants. Cycling products are trivial for them.
Why does this spill from the mouth of a wheel person? We are über proud of wheels. Anything seriously limiting their beauty and usefulness gets our attention.
Rest assured, a fearless young bicycle thinker is reading this and in due time will engineer the needed solution. I'll bet it's a wheel builder.
If my tongue-in-cheek leaves you confused or annoyed, make a comment. Then hug your bike and take a ride!
November 02, 2021
To Murray – My response to a few people who said they couldn’t fit 25 or 28mm tires to their frame or fork is that they had been sold the wrong bike for their needs. IMO the day of bikes just built for 23mm tires has to end. They’re ok for sub 140lb (or so) people but just silly for the average person (160-240lb?). ALL pro riders are sub 180lbs and even the lighter pros are going to fatter tires. I blame the makers and the bike shops. The poor customer probably doesn’t have the experience to know better. People like me try to educate on forums but it gets frustrating.
November 02, 2021
Ric this is your best blog piece ever. High pressure (100psi+) clinchers are at the dead of the wrong path. Tubeless, as you say, with its terrible tire fitting and messy liquids isn’t the route. They’re trying to fix a bad idea.
The way is for wide rims (which allow lower pressures) with tubes and easy-fit tires. Almost every rim now is “tubeless ready” and what we really need is a NON tubeless-ready rim with pressures of 70-90psi and a tire width that will allow those pressures for our weight (25? 28? 32mm?)
And tubulars will only ever be for racers. They’re really the perfect high pressure tire but not ideal for every day riding. I did that for 24 years and don’t want to go back to them. I’ve found the perfect tire, rim and pressure combo.
November 02, 2021
Regarding the future bringing back foam technology, the tire and rim would be an integrated system (one piece) and would quick connect to a wheel spoke or blade set-up. Tom
November 02, 2021
Ric, I’m not sure that I agree with everything in this post (I think your blog is absolutely superb and I have learnt a huge amount from you BTW). Tubeless is, I agree trying to fix a broken system, and I agree that a return to tubulars is clearly not the answer for the average cyclis . I’m average, I tried tubs and I failed just 100%.
I also agree with Mike T that wider rims and lower pressures are the answer but the problem really with that solution is that clinchers tend to come up wider and then you experience frame clearance issues. I can just about run 25mm GP4000S tires on Pacenti SL23 rims on my Pinarello. Anything bigger, no dice.
The solution? That’s anyone’s guess. Although I do run narrow rims, wide rims, tubed and tubeless and would say that using the Stans no tubes system, that tubeless isn’t as bad as it appears you portray here. Tubeless is not the answer, its a stop gap.
The answer is, and I challenge the engineers here, clearly a combination of rim/wheel friendly (from a physics perspective) tubulars with the easy of repair / mounting of a clincher. The solution is also in education. People need to realise that 25mm tires are faster and more comfortable (surely the holy grail for bicycles?) than 23mm.
Thanks for your wisdom, long may it continue.
November 02, 2021
I never gave much thought to this topic. Actually I’ve been impressed with the high quality of tires and tubes I buy these days. They seem great to me although I don’t race but at times ride pretty hard. If I had to guess, there may be a foam type tire system adjusted by varying tension. I know foam has been tried but it will be back in the future. Foam as a high tech material is being considered more and more in the arena of engineering material selection – this is growing. Just like my cylindrical pen, I’m pretty happy with the way things are regarding this topic. Tom
November 02, 2021
Your assessment of HPC’s are right on.
I agree that tubulars do have problems for the average rider but some of the the problems have been addressed.
TUFO a tire company in the Czech Republic has a tubeless tubular with a sealant that I have used from the mid 90’s with great success eliminating flats.
A few years ago TUFO developed a double sided tape that removed the other obstacle, the dreaded glueing process. Velox also has a the tape now.
November 02, 2021
Wholly agree with Mike T.‘s comment: most people riding skinny HPCs have been sold (or insisted on) the wrong bike. I’m 120 lbs soaking wet and I got rid of my traditional road bike with 28s because even they weren’t big enough; my road rides are seldom exclusively on pavement. The sweet spot IMHO for ISO622 tires is about 32mm, right about where true tubeless systems become a viable option for the home mechanic without a compressor.
I think we’re finally seeing the road bikes for the everyman. Unfortunately they’re being marketed as gravel bikes (and they usually come with atrocious wheels).
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November 02, 2021
The answer came and went without a shot fired,. Sad really because I was really into tire design and rode everything ….and I mean everything . The best I loved was a rare Tufo 22mm tubular for track, Then a 110 gram paper thin tread , early light, 17mm Conti Olympic for timed events ( Kevlar in them and they always wore out but did not flat.,even at 250 psi and helium. Gran Bois impressed me, Vittorias economy tubular in 25c, and the real sleeper of them all for real practical riding, and the gold standard of clincher design- the bottom end Panaracer.-the humble wire bead, non belted, Panaracer Pacela.
So tire obsession has been a Love of mine and I’ve enjoyed pink Dugast tires and Clement Pista Setas,but nothing came close to how the invention of, and first attempt at a functional radial tire Panasonic made in 1982’! I hunted for them in 2010 and found different styles . Remember Clinchers were just getting better at that time and here comes a radial tire with incredible longevity and a ride at 28c width that outdoes any tire today for compliance. I rode these old tires and wore the tread off even to test them. I tried to get a couple companies interested because it was obvious to me that the first attempt was not a failure many claim( lateral flex complaints and the tire was very low pressure.
The mistakes were simple, too tall and too square. But the casing made the width change lightning fast at the contact patch. Also I learned how latex and vinegar, and a scrub brush can work wonders on ss
seemingly shot tires.
A radial made sense. I gave up. Crosses and truck like ride was and is norm – relatively speaking.
Until a brilliant move by Vittoria. The wide Diamante Radial tire is the best tire going by far and totally missed by the market. The sucker rides like a 32c fast tire ( not the heavy junk Schwalbe and others make , minus G. B. And Pasela wire bead). So look a little,closer and it’s already discontinued but don’t just follow the heard. The engineer tofold me Vittoria went whole hog on Graphine. Reminds me of old carbon, or the next Corn shell or Chile gimmick.
They dumped the best thing since the wheel. Only cycling still uses bias ply. It’s light and insane fast in real time use. Wider rims better. It’s not perfect, 28c would have been and spec.ed for wide rims only, but it’s damn good.
I’m telling you, you missed it. Mount carefully and the sucker matches a corsa cx tubular of days past, better than today’s..
Radial tire, with wide rim, and a large air volume rim ( seems all forget this too), with low aspect and rising sun curve is where It (the Love) is located “at”.