Conference noted::bicycle

    
    First of all, punctures often come in bunches, for some reason
    (alpha rhythms, zodiacal, or wet weather that makes glass more
    apt to stick to tires).  So don't despair yet.
    
    Second, are all your punctures caused by the same thing?  Do you
    know what caused them?  The three principal reasons are
    
       - snake-bite (rim pinching the tube, e.g., by running over an obstacle)
    
       - external puncture (glass, nail, staple, etc.)
    
       - spokes braking through the rim tape (can start as a slow leak).
    
    Some people really like Kevlar belted tires, despite their stiffer
    ride.  But first, analyze the cause of the punctures.
    You say you are on the heavy side, so that would make punctures
    more likely ... a bit unfair, but I guess that would justify bigger
    tires (though 25mm should be sufficient).
    
    -john

    Cause was glass every time - The first time, in fact, it gouged the
    tire badly enough that it had to be replaced as well as the tube.  And
    I DO make an effort to avoid the stuff, but there's just SO much of it
    around  . . . 
    
    	Actually, my reason for wanting a larger tire is mainly to protect
    the rims.  I bent one my first day out with this bike - hit a RR
    crossing kinda fast - and the fellow at the bike store who straightened 
    it suggested going to a larger tire would help prevent rim damage.  It
    sounded plausable, considering that some mountain bikes use pretty
    narrow rims with fat tires.  

    
    I have Kevlar belted tyres on one of my bikes and have found them
    to provide excellent protection against glass, thorns, sharp stones
    etc , albeit at the cost of a slightly harder ride. The puncture
    resistant tubes that I have used were on the market here a couple
    of years ago and the resistance was provided by increasing the wall
    thickness. I found these to be practically worthless, hard to insert
    in the tyre, the ride was terrible, and the puncture resistance
    was hardly increased at all. I know that some latex tubes are also
    supposed to provide increased resistance to punctures but also require
    frequent doses of air to keep them topped up as they are slightly
    more porous than butyl tubes, they are also very expensive.
    
    I ride 20mm tyres and weigh 194lbs, my rules for steering clear of the 
    dreaded hissing sound are:
    
    1) Keep the tyre pumped up to around 110 PSI
    2) Check the tyre frequently after rides for signs of splitting
       or embedded foreign objects.
    3) Liberal doses of talc between tyre and tube.
    4) Check rim tape for wear/splitting
    5) Keep clear of potholes, broken glass, freshly cut hedgerows etc
       etc
                                                               
    Hope this helps
                    Regards Richard.

A 700-28c might all you need a 32c tire is taller and on some bikes it rubs the
break caliper. 


If I were you I'd take a day off from riding Saturday and sweep all the glass
off the road on your commute. Heck, it's only 5 miles ;-)

Maybe a call to the town department to request a street sweeper hit those
streets...??? I on one occation did call to have a street swept, two days later
it was done. Worth a try.

Tom

    Thanks for the tips -
    	Talc between tire and tube? what does that do?
    
    	I do believe that I'm going to go for the kevlar tires and stick
    with normal tubes for now.  
    
    	re [-1] - > take a day off from riding Saturday and sweep...
 	Well, I'd do that but I've been taking a longer scenic route (8.3
    in & 12 or so back, so that kinda rules that out - I DO like the broom
    on front of the bike idea - sort of like the cow catcher on the old
    trains.  Add a few spikes and it could take care of dogs too!  Gee, I
    bet that could be marketable - take out an ad in "bicycle" magazine &
    who knows . . .
    
    Any advice as to brands?  Also, all the ads
    I've seen have been for 20-25mm tires.  Anyone know if anybody makes a
    slightly Kevlar belted tire in 28 or so?  thanks.
    						Joe
    

I have been using Kevlar tires, Avocet K20 in 700x19, for some time now with
excellent results.  I have only flatted once in the last 2k miles.  I tend to
run my gloved over the tires if I run through some glass and I keep them 
inflated to 125 psi.  I just replaced the rear tire at 1350 miles because the
tire had worn through to the casing.  Even worn that far I didn't flat.

Mark

     I'll vote for the K20's too, plus a down vote on the uselessness
    of the "puncture-resistant" tubes.
    
     I've had pretty good luck with my K20's. Ran into a few flats this
    year, but none last year at all. And I ride over a lot of junk. In
    fact, my front tire flatted last week (staple). I've got over 10K
    on that sucker. Yup, it is getting a little flat in the center and it's
    even starting to crack. I have the back-up hanging in the cellar to
    replace it, but I just can't seem to bring myself to do it.
    
      Chip

    RE [.6 & .7] - Any idea if these come in other widths than 19?  What
    should I expect to pay for them?  Thanks.
    
    							Joe

     If I remember correctly (and I know I'll be corrected if I don't)
    they run about $19.00. I know you can't get any thinner than a
    700cx20 in the K20. They do offer a 700x25 at the same price.
    
      BTW - That's a Performance catalogue pricing w/o shipping
    
           Chip
    

    That sounds pretty reasonable.  I'll have to give them a call tonight. 
    Thank you.  

    I've had  very  good  luck with the Specialized K4 kevlar tires. I
    have no idea what they cost, as I haven't changed them in a couple
    of years now. The come in 27X1 1/4, so I suspect that they come in
    wider 700C sizes as well.

--David

    
      I switched from Specialized touring II's to Matrix CD3K's Earlier
    this year and have had a lot of luck with them.  They ride nicer
    than the Specialized and have a smoother more solid feel to them.
      The "K" suffix means Kevlar and you can get them in a non Kevlar
    version as well.  I have only gotten one flat in these tires and
    that was a staple.  Kevlar will not help much against sharp punctures
    but will help prevent larger slices from happening.  I paid 18.00
    at Bicycle Alley in Worcester.
    
    John C.
    

    This year I've put over 4000 miles on my Trek 1200's front stock CD3,
    and changed the rear at 2500 miles cuz it was getting thin.  One flat,
    at the start of the year on the front, from a rock snakebite.  They're
    700x25's at 110-115psi.  I used to be happy with a thousand miles from
    IRC's, but that was on a heavier bike (and owner).
    
    Can anybody top 4000 miles on a tire?  -kratz  

    Well, I just spoke to Lincoln guide & they say they have the
    Specialized  Kevlars in 28 and 32 mm widths for $19.95.  Since they're
    concenient to my location, I suppose that's where I'll be going
    tonight.  Thanks for all the info folks.

    I bought a pair of Specialized kevlar tires once about two years
    ago.  I put them on and went less than three blocks and got a flat.
    Not just a puncture but a slice that rendered the tire useless.
    I threw them out and have never used kevlar since.

    re [-1] -  Not too encouraging, but I suppose that whatever did that to
    the tire probably would even have sliced through a car tire.

    John, the tendency for flats to occur in close coincidence to each
    other is similar to the tendency for traffic to suddenly become heavy
    when you want to make a left turn (or right turn as here in Aus. or in
    GB) it's called Hyper Coincidental Juxtaposition Syndrome and was
    discussed in net.bicycle some years ago.
    
    ed

    
    RE: HCJS
    
    Ahhh... that explains a lot!
    
    -john

    I don't know who makes the Schwinn VR Select, but I have a set that I
    bought last year for $8.95 each.  They are Kevlar belted, have about
    2000 miles on them, and have NEVER had a flat.  When I got the C'Dale
    it came with Michelin Selects.  Two flats in two days, one from glass -
    the other from a spoke nipple, and I pulled the Kevlars from the Trek
    and put them on the C'Dale.  I liked the feel of the Michelins, but I
    REALLY like the security of reduced likelihood of flats.  
    
    Tonight I was on a ride with approximately 50 other people.  There were
    no less than 6 flats that I saw.  I'll take the slightly harsher ride.

     As stated, I have over 10k on my front tire (Avocet K20). I
    got over 5k last season and I am over 5k this season. 
    

    Talk about timing - my Nashbar catalog came yesterday, so I decided to
    delay buying anything until my wife (who works in Needham) can see what
    they have in stock.  I've gathered from their charts that I
    can't/shouldn't put anything wider than a  28mm tire on my 25mm rims -
    just as well, now that I see how the max inflation pressure decreases
    with size.  The three tires I'm considering are the Avocet K20, in
    28mm, the IRC Triathelete in 25mm, or the IRC road II (I think) in
    28mm.  The 25mm has a max inflation of 125psi, while the 28s are
    105psi.  How much of a difference in efficiency does the 20psi pressure
    difference represent, all else being equal?  One of my main motivations
    for going Kevlar right now is that I'd hate to try my first Century &
    end up with a flat, but on the other hand, I figure I'm going to need
    all the help I can get & I don't want to end up feeling like I'm riding
    on silly putty (I'll probably feel like that by the end anyway).
    
    'nuther question - I noticed in Nashbar's catalog, a gizmo called a
    "Mr. Tuffy tire strip".  Apparently, it's a puncture-resistant strip
    that goes between the tube and the tire.  Anyone have any
    experience/opinions on this?  Does it work, or does it just add weight?
    
    
    							Joe

    I ride the Avocet's (700 x 25), I've had no problems with flats since I
    switched from rubber rim strips (which has nothing to do with the tire
    anyway).  That said, isn't the Kevlar in these tires in the bead?  I
    don't believe the Avocets' (or most of the others discussed so far)
    have Kevlar belts under the rolling surface.  Someone please correct
    me, if I'm wrong.  FWIW, I like the Avocet tires, they are the closest
    thing to a tubular I've tried since switching to clinchers.  They are
    lousy for going up gravel embankments, however, but that's another
    story.
    
    re: Mr. Tuffy; They were popular with the not-so-serious recreational
    riders In the California desert, where I used to live.  Thorns were a
    major problem there.  The real serious riders avoided them because of
    the weight (and lived with the flats).
    
    Barry

>>    have Kevlar belts under the rolling surface.  Someone please correct
>>    me, if I'm wrong.

Both are available, Kevlar belts and beads. The beads allow for folding the
tire.
    
    re: Mr. Tuffy; They work but are not worth it (IMHO). They add weight that
is noticeable and they cause a harsh ride and are a pain to mount. Do a 
SEARCH/NOTE=1-* TUFFY and see what other replies are in this conf. Typing
SEARCH again after a it finds the word will continue the search.

Tom

    From the description in the catalog, the Avocet foldable tires are
    advertised as having kevlar beads.  The ones I'm talking about state
    that they have kevlar belts for puncture resistance.

    
        I've been riding Kevlar belted tires for about a year now.
    I've only flatted twice in the ~2000 miles since I mounted them,
    and both flats ocurred after collisions (curb,snakebite - my fault;
    truck,blew off rim - his fault). In the 500 miles previous to
    mounting them I had to fix & pump on three separate occasions. I
    know this is only anecdotal evidence at best, but I'll continue to
    use the kevlars on rides where a sense of security has a higher
    priority than performance. I would, however, love to have a light,
    narrow set of wheels with silk tubs for when I feel decadent. I
    doubt that this would actually make me go any faster, but at the
    speeds that I average (low), illusion can be everything. 8^)
    
     Joe,
    
         I ride 28mm wide tires and haven't had any problems finding
     them in kevlar. The label on the tire says "Discovery", but I
     can't recall for certain who makes them (IRC?). I paid about
     $20 at the local bike shop, and about $12 at Nashbar. I don't
     think that they were advertised in the catalog, I found them
     hanging on the rack at the Needham store.
    
    
                                                     Steve
    

    re [.23] thanks for the tip - always nice to learn a new feature of
    NOTES!
    
    re [-1] Actually, I have located 28mm kevlar belted tires from several
    manufacturers.  Now my question is how much harder are they to turn
    than 25s, considering the difference in pressure?

    re [-1] Actually, I have located 28mm kevlar belted tires from several
    manufacturers.  Now my question is how much harder are they to turn
    than 25s, considering the difference in pressure?

28c tires have a nice soft ride to them no matter how high they are inflated.
Much like the ride of a cheap tubular tire. They do have a higher rolling
restistance due to the contact patch to the ground is larger. Plus they are
heavier, that means they accelerate slower.

So on the plus side; A softer ride, more traction for braking and rain, usually
	 	     has a thicker tread, and are taller so they resist pinch 
		     flats. All the reasons for touring cyclist to use this 
		     tire.

Negative side; Slower rolling, Heavier and they aren't "aero". All good reasons 
	       why racers don't use them.


Tom

>>    GB) it's called Hyper Coincidental Juxtaposition Syndrome and was
>>    discussed in net.bicycle some years ago.
  
    	Gee Ed, and I thought you couldn't even spell Fisher :)
    
    	I use the Specialized Kevlar Belted tires and love them.
    I have been relucant to enter a note here stating that I haven't
    had a flat all year on them because I'm sure that now that I have
    stated it both my front and rear tires will be deflated the next 
    time I mount my machine :(  The only problem with Specialized 
    is the hard time you have putting them on, but considering that
    I sometimes exceed 50 mph on the down hills, I like the confident
    feeling that gives me, knowing that the tire isn't going to blow
    off the rim at 125 psi.  Re. -1, I use the 28's for normal training
    and use to keep a set of 25's for short faster rides mounted on
    a spare set of rims.  A good thing to have on hand anyway since 
    sooner or later you'll probably come up with a broken spoke, rim
    or hub and wish you had a spare wheel on hand.  In Ed's case he has
    complete bicycles for backups :)  This way you *can* have your
    cake and eat it.  Right Alice?
    						_Jerry
    BTW - A Specialized 700x28 is about the same size and weight as
    a Michelen 700x25 so depending on the manufacturer tire size
    can mean entirely different performance features.

I run 28mm Specialized Turbo/S on my tandem, inflated to 120-130 lbs (as 
recommended by the tandem maker) with no problems due to the pressure.  Total 
rider weight is about 275.  This tire has a kevlar bead, but no belts, and we 
have had few flats, so far.  The tire performs pretty well, at least on the 
tandem, where we average around 21mph for short (20-30m) rides.

Kevin

>>I run 28mm Specialized Turbo/S on my tandem, inflated to 120-130 lbs (as 
>>recommended by the tandem maker) with no problems due to the pressure.  Total 
>>rider weight is about 275.  This tire has a kevlar bead, but no belts, and we 
>>have had few flats, so far.  The tire performs pretty well, at least on the 
>>tandem, where we average around 21mph for short (20-30m) rides.
    
    	Thanks Kevin,
    			We have a lot in common!  We both run 28mm Turbo's,
    inflated to 125 psi at about the same rider weight....but I don't
    own a *tandem*.
    						_Jerry

    re: .21 "One of my main motivations
    for going Kevlar right now is that I'd hate to try my first Century &
    end up with a flat, "
    
    Heck, that would just serve to complete the experience.
    
    ed

    Wound up getting a pair of IRC Road-II Kevlar belteds in 700-28C last
    friday (because that's the only matching pair I could find at
    Nahsbar), and so far so good.  No flats, and the 28C width is certainly
    a lot more comfortable than the 25s.

    Just got into this notes file today.  I used Specialized K-4's for the
    past 5+ years. 700/28 for touring and 700/25 for my racing bikes.  I
    really have liked them over the years until recently I started having
    big chunks come out of the tread (delamination) two other riders I ride
    with have had the same problem.  I sent the last two back to
    Specialized with the big chunks and received two replacements....at
    about  500 miles a big (.38" dia.) came out of the rear tire.  This
    makes 4 total tires with delamination.  It could be the high
    temperatures here but two of these never saw days higher than 90
    degrees F.  I have since switched to IRC triathalons...no flats or
    chunks so far.

    Having used IRCs on my motorcycles in the past, with good luck, I
    felt pretty secure trying them on the cycle, and they were considerably
    less expensive than most others ($12.99 at Nashbars in Needham -
    however, you have to rummage through their stock to find two matching
    tires.

    
    Thought this might be of some value to those considering kevlar.
    
    Performance is having a SALE on their high performance Kevlar
    beaded (foldable) tire.  An excellent all-purpose tire.
    Performance Nova ST/K
    Size: 27 x 13/16.  Will fit 27 x 1.  
    For the unbelievable price of  $3.95   reg. $12.95
    order number: 44-5020   source number: 20796
    phone number: 1800-pbs-bike
    
    I have had a race version of this tire, Nova EX/K, 700 x 20 on my front 
    for three years with much luck! approx 3500 miles. (knock on wood!)  
    
    Good Luck,
    Steve G.
    

    
    What a deal!  But is this only the 27-inch size?
    
    -john

    
    Yes.  The 27" is the only one advertised.  Definitly worth a call
    though.