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Clincher Tires / Beaded Edge Tyres. Pressures and Installation Tips

November 4, 2012

usco tires 

Not very many people today are riding old bikes with the early style tires.  They were called ‘clinchers’ in the US and ‘beaded edge’ in the UK, and both were replaced by drop center tires in the period of 1928-1930.  The were replaced for good reasons, the main one being that drop center tires stay in place better on their rims.  But the subtitle for this website is “Fun Stuff From 100 Years Ago” so I’ll write a bit about the early tires instead of the drop center type.

 

The big question among today’s enthusiasts is about tire pressures, and rightfully so.  The shape of the bead is such that the pressure from the inner tube forces the tire bead under the edge of the wheel rim.  This pressure then holds the tire on the rim.  So many people think that more pressure is better.  Which sounds good.  But more pressure also means more stress on that thin rubber inner tube.   This reminds me of a clown’s rubber balloon from a kid’s birthday party.  Blow it up just a little, and you can poke it with a stick and it will just bend and flex.  Blow it up to a higher pressure, and it will pop at the slightest touch against Madonna’s pointy sweater. 

 

Looking back at the information that was available in the old days, the tire pressures that were recommended were not extremely high.  Typically they were about 10psi higher than pressures that were recommended for drop center tires of the same size, with the same weight of bike.  Here is a snip from Victor Page’s book c1913: 

Victor Page tires

 

Those recommended pressures of 32-40psi are about half of what some guys are currently using.  But when they hit a rock, or a pothole in the road, then there is a loud noise, the tube pops, then the tire comes off the rim and the bike goes down.  Running a lower pressure seems to give less popped tubes, but too low is also a problem.  When my friend James crashed his 1920’s Sunbeam and sadly lost his life, the tire came off the rim, wrapped around the front forks and he fell down.  But the tube was not popped.  It was still holding air.  However the pressure was too low to hold the tire bead in the rim.  To get another reference, I checked Radco’s book, and found this table.  It gives very similar numbers to the Goodyear information from Victor Page, and Radco didn’t name his source, so it might be the same.

 

tire pressures

Note that for a typical single cylinder bike, the 26×2.5” tire would be run at 30 psi, give or take a few psi depending on your weight.  For a big American twin with 28×3” tires, it would be around the same.  The table doesn’t even list pressures above 36 psi, except for 3” tires with extremely heavy loads (440 pounds loaded onto each tire of a circa 1913 bike? wow.) 

An important aspect of these tire pressures is the weight of the vehicle, rider and luggage.  For a light vehicle (motorbike), less tire pressure is recommended.  For a heavy vehicle (car), more pressure is recommended.  The two sources shown above both deal with motorcycle tire pressures.  However, there are a lot more old and new books existing that recommend tire pressures for cars.  These seem to vary from 35-80 psi, depending on the car weight.  I wonder if the current practice of using such pressures on bikes is from those books?  (and possibly even from well meaning tire vendors who deal with car customers almost all of the time?).

 

Here is a similar table from the Veteran Car Owner’s Manual by Ernest F. Carter.  Motorcycle tires are about 65-75mm section, which gives a recommended pressure of 35-60psi for a car, while the same tire size gets 30-35psi for a voiturette (a very tiny car, analogous to our motorbikes).car tire pressure

 

Thinking about this mathematically, we can calculate the force that the tube puts onto the tire to hold it against the rim.  If the tire is 21”diameter at the bead, and say that the bead is 1/4” tall, that is an area of 16.3 square inches on each bead.  At 30 psi, there is 490 pounds of force on each tire bead.  A very interesting thought is that a drop center tire has about the same area and the same force, yet it doesn’t fall off the wheel nearly as easily…

 

That force is applied to force the tire under the “hook” of the rim.  Which leads us to a short discussion of the tire design.  Beaded edge tires have a thick bead of rubber to fit under the edge of the wheel rim,  Here is a view of the UK style Westwood rims.  The US style didn’t have the slight “V” at the center:

beaded rim westwood patternbeaded_info

In order for the tire to be installed on the rim, the beads are somewhat flexible.  Now if we compare that to the later drop center design, we’ll see the difference:

WIRED_ON

 

 

 

source for the image is here.

 

The drop center, or wired on tire has a metal wire around the lower portion of the sidewall, instead of a hooked bead.  An interesting side note is that the rims are called “drop center” due to the indentation of the rim at the center.  This was only needed because the metal wire of the tires was so strong and stiff.  It required that the tire be dropped down into the rim center during installation, otherwise the bead on the diametrically opposite side couldn’t be stretched enough to be forced over the rim.  (stay with me on this, we are getting somewhere). 

 

Recall that the hook of the beaded tire was forced under the hook of the rim, and yet those tires are famous for falling off the rim.  Yet they have about the same pressures and the same areas, therefore about the same forces forcing the tire to the rim.  If anything, that hook should make the beaded edge / clincher tires stay in place BETTER THAN THE DROP CENTER TIRES.  Yet we know that they don’t.  And the simple difference is that little bit of metal wire.  It has a huge circumferential strength that resists stretching, hence is was hard to fit them over the rim.  And the strength and stiffness keep that tire on the rim too.

 

Taking this back to that big question among today’s riders of 100 year old machines; “What tire pressure should we run?”  It must be more than the pressures for drop center/ wired on tires.   The reasoning behind the standard answer is now understood.  But how much more?  That is a harder question to answer.  Personally, I use 42 psi.  35-45 would be find I think, but 42 is an easy number to remember.  Lots of other guys that I’ve polled use similar pressures.  And 30 psi might be ok, based on the old books.  Some guys like 65 psi, but that scares me due to the party balloon analogy.  I’ve developed a few flats on early tires, and none of them were catastrophic in any way.  The tire went down slowly, the bike handled poorly, and I stopped to investigate why.  No blow outs yet, but I’ll keep my fingers crossed.  It does happen though, unfortunately our friends can tell us bad stories about subsequent crashes.  One friend runs higher pressures, and his tire blew with a spectacularly loud bang in the parking lot.  The bike wasn’t being ridden, in fact it was parked 20 feet from the nearest person when it popped without warning or provocation.

 

This could be the spot in the article for a speech about being safe, and fitting modern rims to old bikes.  Or the counterpoint that all old bikes are inherently unsafe, and that we should leave them stock and ride them with due caution.  But I’ll leave that alone.  However if you choose to run early tires on your early machine, here are a few tips.

 

  1. Check the air pressure often.  Know if you tube is developing a slow leak.
  2. Don’t bother with tire irons when fitting and removing clincher tires.  If they won’t go on using just your hands, then you should investigate why not.  Possibly the tires are not made well, or for your rim size.  There were a lot of different sizes in the old days, at least 39 different sizes!
  3. Use some French chalk (aka talc or talcum powder) when sliding the tire on if you have to.  It is a dry lubricant that will make the rubber slide over the rim easier.  I try not use anything to decrease the friction, as I want that tire to stay stuck to the rim when I’m done.   Using some talc on the tube to decrease chafing on the tire is recommended by many old books, but I’m not sure how to keep it off the beads.
  4. Warm the tire in the sunshine for a couple of hours before you fit it onto the rim.  It will soften the rubber a bit, and makes it easier to stretch into place.
  5. If you do use tire levers, they will bang up the rims, which were often painted in the old days.  You can protect the rims with plastic, cardboard, or try the neat Rim Protectors from Motion Pro.
  6. You don’t need a rubber rim strip with clincher tires, the tire itself fits down between the tube and the spoke nipples.  But you do need to trim a small half-circle into the two tire flaps for the Schrader valve stem to fit through.  Just use a box cutting knife, make the circles about 1/2” radius or less and make sure that you install one bead of the tire so that the circles are lined up with the hole in the rim before you put the tube in.
  7. Try using an adhesive if you like.  I’ve been putting belt dressing on one side of the Rudge tires with their funky rims and Dunlop tires.  It is a spray compound made to make rubber belts stick to steel pulleys, which seems appropriate for rubber tires and steel rims.  Putting it on the right bead, I can still remove the tube via the left bead.  When I need to replace the tire, a few good hits to the right tire sidewall with a big hammer loosens the belt dressing.  One 18 oz. can lasts a decade or more for $10.

food grade belt dressing

 

 

cat-nak

 

everyman's guide to motor effieciency - tire

From Everyman’s Guide to Motor Efficiency, 1920 edition. Also available for free on Google Books here.

 

Update Nov 9th, 2012:  Anton Dee sent in a link via the OcchioLungo page on Facebook.  (check it out if you’re on FB! lots of different stuff that isn’t on this website).   It shows the testing of a new clincher tire from a factory, with tests on a stand, and with the tire fitted to some old cars.  They wanted to really work the tire to see when it would fall off the rim, so they fitted it to a new Nissan pickup truck!  As they lowered the air pressure, and continued testing, they found that the tire would stay in place at lower and lower pressures, until they got to about 20-25psi.  Then the tire would come off the rim.  Very interesting.  Here is the link to Vintage Tires.

 

Update Nov, 6th, 2012:  Bevars sent in this note, which I thought covered some really good points:

Hi Pete – there have been many discussions on this topic over the years! And yet lots of people still believe that you need high pressures.

I have been riding early bikes with Beaded Edge tyres for the last 40 years. At first I listened to the guys who said that you had to have 60 psi or higher. That was until I had a rear tyre blow off the rim with a sound like a rifle shot. Not sure my heart has ever recovered.

So I investigated and found that it was way too high for the weight being carried. Nowdays I run 30 – 35 psi front and 35 – 40 psi rear. On the Baby Triumph (24 * 2 1/4 inch BE) I am at the lower end, and on the Power Plus (28 * 3 inch) at the higher end. I use modern motocross or heavy duty tubes that have thicker walls than the standard rubbish (2.75 * 21 tubes in 26 * 2 1/4 BE tyres, 2.75 * 19 in 28 * 3). If I ride the bike a lot I replace them each year as a precaution. If these tubes get a puncture they go down slowly. The cheaper tubes split when they get a puncture and deflate instantly. What the guys on the English “Red Dwarf” TV program used to call a “Brown Alert” – one worse than a red alert.

I leave the valve lock nut loose and keep an eye on the valve stem each time I stop. If it has developed a lean it means that the tyre has shifted. I let the tyre down, re-centre the valve stem and pump it up again – but I gotta say it don’t move often! To put this in perspective I weigh over 20 stone so my bikes are carrying a fair old load. As I have to lose some weight for a hip replacement they will get an easier time in the future :-)

The one thing you mention but don’t really emphasis is the importance of having a good fit – the right tyre on the right rim. As you say – originally there were many very similar size tyres, both imperial and metric sizes. Today we have only a few standard sized tyres available. We also have some oriental rims made for rickshaws which are slightly off size. If the fit is not good then the tyres will move. Higher pressures may help stop it revolving with respect to the rim, but that is fixing the symptom, not the problem. New good quality correct size rims is the only answer.

Most of the blow outs I have seen on BE tyres have the valve ripped clean out of the tube which suggests that the tyre rotated until it tore the valve out.

Bevars

12 Comments leave one →
  1. Monty Thompson permalink
    November 5, 2012 12:08 pm

    Thank you for this. I have some white Coker Baloon tires for my 20 Ex. I have been told that they fly off which worries me, The belt dressing is something I hadn’t heard of.
    Your buddy Phil Schack has my engine currently and I am getting excited that I might have the old girl on the road next year.
    Regards,
    Monty Thompson

    • November 5, 2012 12:16 pm

      Hi Monty. A few guys use the white Cokers, especially on show bikes. They look really good, but they don’t last as long as the black ones. One friend uses white tires on his c1915 Indian with a sidecar, and told me that the rear tire only lasts for one or maybe two three day pre16 tours. That would be less than 1000 miles. Tires were originally made from natural rubber, and had that off-white color. But around 1915, they found that by adding carbonblack to the rubber, it didn’t wear as quickly. But you can still see white tires in advertisements into the 1920s.

      Good luck with your Excelsior, I’d love to see it when you are done.

    • victor permalink
      November 5, 2012 6:16 pm

      Pete
      Enjoyable article, a little close to the bone at this time, but “we should know the truth” even if it hurts.
      For approximately 30 years I have been running clinchers on my 14 HD. with no problem—up to Sept 9th this year.
      I actually road in 2010 from New York to Dodge City whilst losing 10psi per day . I pumped it up each morning and finally chained the inner tube when I changed the worn out rear tyre in Dodge—–Bad boy. It had a small pin hole in the tube.
      Then, on the 2012 Cannonball Run, I finally had the grand daddy of blow outs — with little damage to the bike and to me.
      I was very very lucky.
      No warning, at 50mph the rear started fish tailing violently, the tyre wrapped itself around the frame ( we had to hacksaw the tyre apart in order top get it out the frame) and finally went down sliding about 60 feet whilst doing a 180 and facing the direction from which I had come from.
      When I got up off the road I said F–k that’s it, no more clinchers.
      I’ve witnessed three clinchers blowouts, I received the blast from the tyre that blew in the parking lot, the one you described in your article.
      In regards to air pressure I have always run 55 to 60 psi in my tyres, most of the time I am carrying saddlebags with lots of weight as well as a 2 gall. gas tank on the rear carrier.
      Always with out problems. I’ve hit pot hole at 40mph that I was sure would blow the tube, but no tube blows.
      I have tried come up with a reason for my blow out. The best I can think of is low pressure.
      I was 290 miles into a 320 mile day when it blew, I should have check the pressure 60 miles back when stopping fort gas. Crucial mistake.
      As you say. Check that air pressure–constantly.
      My thoughts are. I’ve been pushing my luck for a long time.
      Use drop center rims with modern tyres
      Still check the pressure constantly.
      Use the clinchers in museums and parking lots
      Do as I say not as I do. I picked the Cannon Ballers back up in Oregon and rode the last 3 days—on clinchers . My wheels are being converted as we speak.
      There are a lot of areas for discussion on this subject. I have a photo that is interesting, will try to post it later
      Victor

      • November 5, 2012 6:27 pm

        Sounds great Victor. I was thinking of you as I wrote some of that stuff, and I was glad that you accident didn’t hurt worse. Pressure that is too low will definetly cause problems. Usually it results in the bead being cut off the tire, then the tire comes off the rim. Could you see on yours if the bead was torn? Maybe not, it sound like the whole tire was a mess.

        I suppose that people can argue whether to use clinchers or not, but I don’t want to get into that. It is great to see bikes on the road, either with original equipment clinchers or with modern drop center rims.

  2. Bevars permalink
    November 6, 2012 3:20 am

    Hi Pete – there have been many discussions on this topic over the years! And yet lots of people still believe that you need high pressures.

    I have been riding early bikes with Beaded Edge tyres for the last 40 years. At first I listened to the guys who said that you had to have 60 psi or higher. That was until I had a rear tyre blow off the rim with a sound like a rifle shot. Not sure my heart has ever recovered.

    So I investigated and found that it was way too high for the weight being carried. Nowdays I run 30 – 35 psi front and 35 – 40 psi rear. On the Baby Triumph (24 * 2 1/4 inch BE) I am at the lower end, and on the Power Plus (28 * 3 inch) at the higher end. I use modern motocross or heavy duty tubes that have thicker walls than the standard rubbish (2.75 * 21 tubes in 26 * 2 1/4 BE tyres, 2.75 * 19 in 28 * 3). If I ride the bike a lot I replace them each year as a precaution. If these tubes get a puncture they go down slowly. The cheaper tubes split when they get a puncture and deflate instantly. What the guys on the English “Red Dwarf” TV program used to call a “Brown Alert” – one worse than a red alert.

    I leave the valve lock nut loose and keep an eye on the valve stem each time I stop. If it has developed a lean it means that the tyre has shifted. I let the tyre down, re-centre the valve stem and pump it up again – but I gotta say it don’t move often! To put this in perspective I weigh over 20 stone so my bikes are carrying a fair old load. As I have to lose some weight for a hip replacement they will get an easier time in the future🙂

    The one thing you mention but don’t really emphasis is the importance of having a good fit – the right tyre on the right rim. As you say – originally there were many very similar size tyres, both imperial and metric sizes. Today we have only a few standard sized tyres available. We also have some oriental rims made for rickshaws which are slightly off size. If the fit is not good then the tyres will move. Higher pressures may help stop it revolving with respect to the rim, but that is fixing the symptom, not the problem. New good quality correct size rims is the only answer.

    Most of the blow outs I have seen on BE tyres have the valve ripped clean out of the tube which suggests that the tyre rotated until it tore the valve out.

    Bevars

    • November 6, 2012 9:04 am

      Hello Bevars. You made some great points in your comment! I’m going to paste it into the bottom of the article, so that all readers will catch those details.

      cheers
      Pete

  3. Anonymous permalink
    November 7, 2012 8:28 am

    Hi Pete,

    Great info to consider, the age old debate of clincher VS drop centers will continue!

    I’ve been running 28 x 3 Coker clinchers on my 24 Chief w/ sidecar for 22 + years now. I’ve always run 50 psi and never had a problem. Keep in mind, this is a heavy machine and fully loaded with my 6’4″ frame and a 200 lb passenger it weighs in at about 1100 lbs. That works out to about 365 lbs per wheel, though not evenly distributed. I don’t thrash the machine, but I put it through it’s paces and often run 50 mph plus for long distances. I live near the mountains in Colorado, so lots of winding roads and fairly hard cornering with the usual tire scrubbing associated with a sidecar rig. Over the years, I’ve replaced 4 rears and one front, simply worn out. In fact, I’ve had more problems with rear spokes that tires! I’ve used the Excelsior brand tires, here is a link: http://www.cokertire.com/brass/28×3-excelsior-blackwall-tire.html These are a flat profie tire with very stiff sidewalls, a car tire in essence. There is NO WAY I can get these on without tire irons and even then, it’s a chore! For the 19 Excelsior with FLXI sidecar, I’m using a similar tire:
    http://www.cokertire.com/motorcycle/28×3-cl-coker-classic-all-black-rib.html
    Again, this is in essence a car tire, square profile and stiffer sidewall. These too are very difficult to get on and off. I think that is part of the reason I’ve had good luck with them.

    Looking ahead to the series 20 X with 3.85×20 clinchers, I’m concened about using them. Anybody have much experience with this size Coker?

    So far, I’ve had good luck with clinchers, knock on wood! Maybe I’m skating on thin ice….

    Gene Harper

    • November 7, 2012 9:55 am

      great info Gene. And good for you for keeping the X’s on the road! I’m sure that those stiff sidewalls help to keep the tires in shape, and the car-type tires must last longer too. The Coker motorcycle tires don’t last for a really long time. And running a sidecar is a severe test of rear tires, and spokes too. For our family Velocette rear wheel, (w/ drop center rims) I installed larger diameter spokes and two tire retainers when I installed the sidecar.

      What you are doing works, keep doing it. And I hope that when people read this article and comments, they’ll get an idea of where to start with their own tire setups.

  4. Dan emerson permalink
    November 10, 2012 5:42 am

    Rode a 3.85 x 20 on the rear of my 25 Deluxe in the 2012 Cannonball. Tire had fabric showing by the end. Started the run with 55 psi and a fairly heavy load in the bags and trunk. Tire wore significantly in the first four days. Reduced pressure to 35 and rode the remaining miles at a much lower wear rate and no issues at speeds exceeding 80 mph. Tire was new at the start. Basic 3.50 x 19 tube. Checked pressure often. My opinion based on my experience is clinchers can be used and have been used safely if mounted properly and carefully and used at moderate pressures (35 – 40). This tire was an NOS Universal not a repro.

  5. November 10, 2012 7:48 am

    morn n all, thank you for the great write up. hope you don t mind my getting in your conversation. i,m sure no authority on clinchers but i would like to share what little i experienced. after hearing and reading about clinchers and money being tight i too used them on the Cannonball. i had bought a bike from Ross Van Ettan and went thru it. the tires had 580 miles on the reset odometer, i put another 250 on them prior to disassembling the bike. after the rebuild i put another 750-800 miles on. 1630 miles +or-.
    while doing hub and spoke repairs i did drill the wheels opposite the valve stem and installed a wheel lock on each rim. every morning and mid day did check tire pressures i ran 32lbs in front and 34 in rear. i hit a number of pot holes frost heaves and a few wake up calls along the way. two of them being to the point i knew for sure i was screwed. but tires stayed on the rims and broke no parts thank goodness. had a call outside of Sturgis and collapsed the rear drum locking the tire up and did put a flat spot on it. and it did not pull the valve stem. only having one spare tire i eked out the miles to Mountain Home Id. before changing it. it was worn pretty good. sure had a time installing the new coker esp. the wheel lock.( i did install to 50 psi, let it set a while, drained air and loosend the tire lock sliped on the rim and re aired it again) so that rear tire had approx. 4500 miles on it. and the front is still on the bike at 5800 miles and change. one other thing i d like to comment on is the tire compound of the cokers i had on. i ride fairly hard and i enjoy the twisties. these tires are soft enough to put a smile on your face in line riding fast curves and side wall flex was manageable.
    Mr Victor, i am so glad you were not harmed when you went down.
    so knowing what i know now, being lucky enough to do what i got to do, would i have ran the clinchers if money for lacing drop centers and new style tires had been avalible.
    due to availability on the road, the amont of miles envolved and the peace of mind. probably not. but they are still on the bike and i do ride it.
    so, am i just lucky? gary

  6. Kaz permalink
    November 18, 2012 5:25 am

    Hello Pete

    I am happy to read your great essay!
    I love sharp handring of BE tyres with my triumph-P.

    I guess there are many factors to fit BE tyre to BE rim strongly.

    Before I had changed my BE Dunlopcord 26in 2 1/4 tyres with no rim tape thin wall tube,the pressure is about 30psi and almost maintenance free,of course no puncture for last 15years(but I rode only 2 tousands km).

    Last year ,after I had changed new Dunlopcord and set rim tape and hevy duty thick wall tube ,the charactor of Tyre & rim fitness is 180 digrees changed.
    I mean new charactor is very delicate,I don’t know the reason….

    I had 1 time rear tire tube bombing on my running 20mph,it happen just after change tyres and I guess it because low air pressure…

    Now,Before my running, I check air bulb position corect and 35 psi(front) 40 psi(rear) is enough.
    And I write “//” mark with white enamel paint from my BE rim to the BE tire for checking tyre is rotete or not,it’s easy to check it .

    I hope all vintage motorcyclist have safety riding.

    Best regards

    P.S.

    On the rainyday,My rear brake(dummy rim brake) is so poor……..

    Kaz

  7. John Andrew permalink
    December 15, 2012 4:49 am

    On my ’20s H-Ds I’ve settled on 35 front, 45 rear solo or sidecar and have had no problems in 30 years, bar one event on my 2800 mile round trip to Poland in 1986 on the ’20F. In this case the side wall of the rear tyre started to separate from the bead, I think due to excessive flexing with the excessive load on the rear carrier over very rough roads and long days at 50-55mph. With reduced baggage it held out for another 400 miles to Prague…

    My first year of b/e was a bastard! I was using 50 front and rear with Betco covers (Beaded Edge Tyre Co of Australia). I had about 6 rear blow-outs before I established that the beads on the covers when fitted left a very small gap between. My diagnosis was that the air pressure forced the tube between this narrow gap really stretching it on this centre line, which would then split spontanteously. Each time the tyre came loose from the rim with the tube in a knot round the axle, fortunately without dire consequences. Since using other covers I’ve had no problems, other than fitting which definitely needs levers! Tyres that can be fitted by hand can too easily come off if pressure is lost.

    I would add that some of the repro rims available are rubbish, and no tyre could ever be a good fit! So far I have always found decent original rims. I have bought quality repros for my ’29 JD from an old firm, Richards of Cardiff (since 1937) http://www.richards-bros.com/beaded_edge_rims.htm . They cold-roll heavy gauge on hard tooling for correct form. The late (’27-up?) beaded edge balloon tyres had lower recommended pressures, (about 28psi from memory) which certainly gives a better ride. When the ’29 is complete I’ll give an up-to-date report.

    Over the years I have hit some spectacular pot-holes, including at Brooklands, but never suffered a failure due to that.

    Despite pretty good experience of b/e, for myfaster ’28 JDH (which I use solo and with Goulding sidecar) I decided on wired-on rim / tyre combination for greater peace of mind rather than originality.

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