Too high psi or bad tires?

Discussion in 'Cycling Equipment' started by southwind, May 22, 2006.

  1. gclark8

    gclark8 New Member

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    That may be just in the Northern Hemisphere. DownUnder, here in Aus, we use them the other way up. :D
     


  2. southwind

    southwind New Member

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    Tried them out tonight and they seemed slower than the TriComp. I took them on a hilly route, but tomorrow I'll take them on a relatively flat route and then I'll know for sure how they measure up. Would the difference in psi, 120 instead of 165, make that much difference in speed or is psi not that much of a factor? Don't mean to be premature in my comparison, but during the ride tonight my thought was...riding with the Tricomp felt like I was on crack...riding with the GP4000 felt like I was hauling concrete. We'll see how they do on a flat course when I go all out.
     
  3. wilmar13

    wilmar13 New Member

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    Ahh yes, I remember when I was a newbie riding and racing on 700x20 Conti GP’s pumped up to 160psi that the bike shop guys told me were faster. They sure were faster, I mean come on I could feel every bump in the road (a sure sign no energy was wasted on deflecting the tire), and when descending I always had to feather the brakes when drafting. Of course when it rained, I was hosed and on rough roads it was a bitch, but they were way faster :rolleyes: Funny thing is that I was not only uncomfortable, but they were slower…a super pliable casing with only about 110 psi is faster, more comfortable, and much better gripping. How little I knew then compared to now, and even now the only thing I do know for sure is that I don’t know for sure.

    My point is that whatever you believe to be true is influencing your perception of your ride… even though I pointed out the GP’s had higher rolling resistance, there is no way they take more than 10-15 watts than the Vred’s. Even if you rode with a power meter (which you obviously don’t) you would be hard pressed to tell the difference. GP4000 are good tires, pump them up to 110psi, and go out and enjoy your ride, content in the fact that you aren’t going to flat easily and they will last forever. If you are time trialing and worried about every second, ditch the GP 4000’s for that event, otherwise enjoy them as they are 99% as good as anything else out there. Lot’s of people race on them too.
     
  4. wilmar13

    wilmar13 New Member

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    I used them when I lived down under on the other side(Brazil), and they were much better there... before I "knew" how bad they were ;)
     
  5. southwind

    southwind New Member

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  6. wilmar13

    wilmar13 New Member

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    Sorry didn't mean to imply you were a newb, simply saying I used to be one, and we all learn more every day. The comment about the power meter, was not meant as a slam on you, merely a judgement I made based on how you are evaluating your equipment. Not trying to be a jerk, but apoligize for coming across as such... without nonverbal cues to go on, context makes it easy to misintepret.

    Anyway in response your original post, you see there is a series of compromises. Michelin P2R are faster and just as puncture resistant as you will find... but they suck in the rain and won't last as long as Conti G4K's Vred Fortezzas are fast, and good in rain, but not as punture resistant.... no such thing as a perfect tire... decide what is most important and choose accordingly.
     
  7. gclark8

    gclark8 New Member

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    I would like to suggest for trainig rides getting out and back safely should be the priority. We do not need side of the road tyre changing practice in the rain. My choices are based on what I can afford and what it costs to maintain the bike. My friend with the Michie Pro race, after buying 5 tubes in 24 hours, decided buying 2 conti ultra gator skins was better value, drop a few kph and save some down time and $$.

    I have GP 4000s on both bikes, the Tri bike also has a pair of Ultegra hub/deep V rims with a Conti ultra gator skin 2005 rib on the front and a 2006 slick on the rear for training and unknown bike paths. My friend above has the same rib/slick tyre combination.
     
  8. southwind

    southwind New Member

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    I must have unusually bad luck this spring with tires. Second time out with my new Conti GP 4000 tires and I have a chunk of rubber missing from the sidewall. I ride on paved roads in good condition and avoid debris in the road. Never had this kind of trouble until this spring. Below is a link to a photo of my newest gash. Going on a 70 mile training ride tomorrow...wonder what kind of tire misfortune will befall me??

    http://us.f13.yahoofs.com/bc/4415b25cmdded0355/bc/bike+photos/ContiGP4000.jpg?bfhB5dEBO38pKIxY
     
  9. gclark8

    gclark8 New Member

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    I can't get the link to work.. :eek:

    I tried to upload the pix, the file is way too large, reduce the size of the pix and try again.
     
  10. southwind

    southwind New Member

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    I tried to insert an image in my post and it asked for a url for it's location online. Instead it inserted a link. When I click on it, it works. I'll try to find another way to post it. I think from the main page on cyclingforums.com there is a place where people are posting pictures of their bikes, I may try that. I'll let you know if it works.
     
  11. southwind

    southwind New Member

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    The photo is loaded now. Go to photo gallery from the main page then go to the section titled "General". The photo of the tire will be there. Let me know what you think of the location of the splice, sort of an odd place for it to get damaged. Here is the direct link to the photo...hope it works.

    http://www.cyclingforums.com/gallery/showphoto.php?photo=398

     
  12. gclark8

    gclark8 New Member

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    Looks like you caught the edge of some glass. My bike is covered by insurance for such events. Ask the LBS about warranty claims. Meanwhile, I would contunue using it on the front, just for training, but at a much reduced pressure, 80-90psi. The time has come for a cheap second pair of wheels and another cassette. :)
     
  13. southwind

    southwind New Member

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    I'll drop the psi down for tomorrow's ride; I was running them at 120. Yeah time for a second pair. I'll put Gatorskins on them. Weird how this is all happening in just several months.
     
  14. gclark8

    gclark8 New Member

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    If you have had heavy rain after a long dry spell, up comes the glass. :( My friend with the Gator skins, 3 weeks today, no punctures. :cool:

    I run 85-90F/100R training, 100F/110R racing in my GP4000s. With carbon forks (Felt) it makes the ride just that little more comfortable.
     
  15. SpecializedWRX

    SpecializedWRX New Member

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    I started out riding on the specialized mondos and i flatted at least 5 or 6 times in the ~1000mile life of the tires...

    Over the past few months I have been riding an S-Works Mondo rear and have flatted 0 times in over 1500 miles of road...



    With that said I will probably flat tomorrow. :rolleyes:
     
  16. gclark8

    gclark8 New Member

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