Advertise on Bikeforums.net



User Tag List

Results 1 to 12 of 12

Thread: Tire question

  1. #1
    Do I use too many commas?
    Join Date
    Aug 2006
    Location
    Central New York
    My Bikes
    Giant Yukon SE
    Posts
    621
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Tire question

    The rubber on my Miyata is pretty old. I intend to replace the tires ASAP. They are currently 700C28's. Would there be any real advantage/disadvantage to going with 700C25's? The ride is quite comfy with the 28's. Will it be harsher with 25"s?

    Thanks!

  2. #2
    Small Member maddmaxx's Avatar
    Join Date
    Nov 2003
    My Bikes
    Leader home built hardtail, Diamondback Response
    Posts
    7,126
    Mentioned
    5 Post(s)
    Tagged
    1 Thread(s)
    The general rule of thumb is..the smaller the tire, the lower the air volumn will be and the less flexable the sidewall will be. This equates to less comfort. The other half of the "general" rule is...smaller is faster due to less rolling resistance (not always absolutely true) and less air drag.

    Unless you are in a position to do an A-B comparison on the same bike you have to make some assumptions based on the general rules.

    http://www.velonews.com/tech/report/...s/13059.0.html

    The link above has an interesting short analysis of rolling resistance and some possible myths in the paragraph about tire pressure.

  3. #3
    Senior Member DnvrFox's Avatar
    Join Date
    Aug 2001
    Posts
    20,898
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I doubt you will notice a lot of difference for the same tire, but give it a try and find out. I have found that the make and model of the particular tire makes for more variation (i.e., Conti 2000 ultra vs. Specialized Armadillo, etc.).

  4. #4
    Senior Member
    Join Date
    Feb 2007
    Location
    S.E. Pennsylvania, USA
    Posts
    1,737
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    A lot of the comfort issue also has to do with the amount of weight the tires are carrying. Someone weighing 130 lbs is going to be much less concerned with 25s vs. 28s than someone weighing 220 lbs. I hover around the 195 to 205 range. I have a touring bike with 28s, two road bikes with 23s and one road bike with 25s. The 25s seem just as comfortable to me as the 28s on all but the most rough road surfaces.
    Oh I used to be disgusted and now I try to be amused. But since their wings have got rusted, you know, the angels wanna wear my red shoes. But when they told me 'bout their side of the bargain, that's when I knew that I could not refuse. And I won't get any older, now the angels wanna wear my red shoes.

  5. #5
    Ride Daddy Ride Jet Travis's Avatar
    Join Date
    Feb 2007
    Location
    Villa Incognito
    My Bikes
    1983 Trek 720; 1983 Trek 620; 1989 Gi Cannondale Bad Boy Ultra; LeMond Victoire; Bike Friday Pocket Rocket Pro
    Posts
    2,648
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Maybe it's all in my head, but for most riding I prefer the 25s to 28s. Seems a little less cushy a little more speedy.
    "Light it up, Popo." --Levi Leipheimer

  6. #6
    Time for a change. stapfam's Avatar
    Join Date
    Jan 2004
    Location
    6 miles inland from the coast of Sussex, in the South East of England
    My Bikes
    Dale MT2000. Bianchi FS920 Kona Explosif. Giant TCR C. Boreas Ignis. Pinarello Fp Uno.
    Posts
    19,915
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Don't think there will be a great deal of difference from a 28 to a 25 but down to a 23 and WOW. Get a Michelin or Conti in 23 and pump em up to 120 psi and ride. Rolling resistance wil be less, speed will be up but Comfort might be a bit lacking.

    Or failing that- Just put 140 psi into the 28's.
    How long was I in the army? Five foot seven.


    Spike Milligan

  7. #7
    His Brain is Gone! Tom Bombadil's Avatar
    Join Date
    Sep 2006
    Location
    Paoli, Wisconsin
    My Bikes
    RANS Stratus, Bridgestone CB-1, Trek 7600, Sun EZ-Rider AX, Fuji Absolute 1.0, Cayne Rambler 3
    Posts
    9,980
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Rivendell usually has interesting opinions on bicycle topics, and tires are no exception.

    http://www.rivbike.com/node/18

  8. #8
    Do I use too many commas?
    Join Date
    Aug 2006
    Location
    Central New York
    My Bikes
    Giant Yukon SE
    Posts
    621
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thanks for the input everyone!

    I wanted something with puncture resistance to replace the 18 yr old tires on the bike. An LBs had some Bontrager Race Lite Hardcase tires for $10 off. I went with the 25s. While not as smooth riding as the original tires I feel a lot better with the new rubber between me and the road. They are only a little harsher than the originals.

  9. #9
    Senior Member Terrierman's Avatar
    Join Date
    Oct 2006
    Location
    SWMO
    Posts
    3,177
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Now that I won't be influencing you, I can reveal that I just ordered a set of Continental Ultra Gatorskins in 700 x 25 for my Coda Elite, to replace the worn out in 1300 miles 700 x 28 Vittoria Zaffiros that came on it. From LBS for $30.00 each!!
    It's all downhill from here. Except the parts that are uphill.

  10. #10
    Senior Member roadiespinner's Avatar
    Join Date
    Mar 2007
    Location
    Reno Nv
    My Bikes
    Della Santa, Bike Friday Air Glide, 1974 Schwinn Paramount, Cannondale t2000 Touring, Cannondale r500 Road Silk, LeMond Buenos Aires, Trek 7000 mtn bike, Sears and Roebuck[ made by Puch. I have had up to 36 bikes at one time. I am a sick person.
    Posts
    145
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The next time I need tires, I am going to look at the Armadillo 25/23[or23/25?] It has a 25 casing and 23 tread and the Armadillo flat resistance.

  11. #11
    Senior Member
    Join Date
    Sep 2004
    Location
    Cushing, Oklahoma
    My Bikes
    1969 Peugeot U08, unknown MTB circa 1980, '93? Merckx MX-Leader
    Posts
    628
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    You asked this just to cause controversy on this forum didn't you?

    I find 700x23's are worlds faster than the original equipment 28 inch x 1.25's on my Peugeot U08. I even noticed a speed difference vis 700x25's. Other's here have not.

    Remember, though, and I don't think there would be any controversy over this point, that even with tires with the same published measurements, there are actual differences in the size. AND, even if they are the same size, some of the 'racing-type" tires are much faster than the all-weather or more puncture resistant tires.

    Play around with several different types. In the big scheme of things, tires are not all that expensive.

    IMHO
    Tyson

  12. #12
    Small Member maddmaxx's Avatar
    Join Date
    Nov 2003
    My Bikes
    Leader home built hardtail, Diamondback Response
    Posts
    7,126
    Mentioned
    5 Post(s)
    Tagged
    1 Thread(s)
    Racing tire manufacturers tend to fudge the numbers slightly to gain the impression of additional performance over rivals. Racers tend to pay a lot of attention to weight and perceived rolling resistance. My favorite Kenda Kalliente Iron Cloak 23mm road tires are in no way as wide as most other 23's so because there is less tire there, they are lighter. Marketing or just another way to make a measurement......you make the call.

    There are almost as many different tires out there as there are saddles. Everyone likes one of them.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •