Advertise on Bikeforums.net



User Tag List

Page 1 of 2 12 LastLast
Results 1 to 25 of 29
  1. #1
    Senior Member
    Join Date
    Jul 2008
    My Bikes
    Brompton, Dahon Vitesse D5
    Posts
    1,800
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)

    Kojaks - opinions

    I recently installed a folding bead Kojak on my Brompton front wheel. Whilst putting it on I couldn't help but be amazed by how elastic the side walls are and I figured that despite the lower volume of air the tyre might prove to be just as comfortable as larger volume ones. However, for the time being I can't really assess the tyre as I'm using a Pantour hub which is soaking up bumps very efficiently.

    I'm considering putting one on the rear and thought I'd fish for opinions before deciding whether or not to do so.

  2. #2
    Senior Member
    Join Date
    Oct 2007
    Location
    Phoenix, AZ USA
    My Bikes
    2010 Brompton M6R, 2011 Felt F5, 2013 BMC Team Machine
    Posts
    106
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I loved the way they rode on my Brompton and I got lots of flats with them. I eventually went back to the green label Brompton brand tires. If I didn't have thorns to contend with I would still be using the Kojaks. Such a nice ride.

  3. #3
    Senior Member Foldable Two's Avatar
    Join Date
    Aug 2005
    Location
    Vancouver, Washington and Ocean Shores, Washington, USA
    My Bikes
    2 - 2007 Custom Bike Fridays, 2 - 2009 Bike Friday Pocket 8's, Gravity 29'er SS, 2 - 8-spd Windsor City Bikes, 1973 Raleigh 20
    Posts
    1,306
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by chagzuki View Post
    I recently installed a folding bead Kojak on my Brompton front wheel. Whilst putting it on I couldn't help but be amazed by how elastic the side walls are and I figured that despite the lower volume of air the tyre might prove to be just as comfortable as larger volume ones. However, for the time being I can't really assess the tyre as I'm using a Pantour hub which is soaking up bumps very efficiently.

    I'm considering putting one on the rear and thought I'd fish for opinions before deciding whether or not to do so.
    We have 1.35" Kojacks on both our custom Fridays. They more comfortable and faster than the stock 1.50" Marathons, IMO.

    Lou

  4. #4
    jur
    jur is offline
    Senior Member
    Join Date
    May 2005
    Posts
    6,151
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    I wonder what the relative contribution of tyre construction is to rider comfort... I am just thinking of 50kg or so on the rear tyre, with the air holding the wheel up with say 80psi, about just how much a sidewall matters in this scenario...? I suspect very little. So if I think back on tyres I have had on my various bikes, the only one that really sucked was a Marathon Plus, it wallowed terribly unless pumper very hard. But as for the others... I had a Kojak, followed by a Scorcher, and now a Primo on my Brommie back wheel. IfI am brutally honest, then I will admit I can't feel a difference. Even the fatter Scorcher didn't feel particularly different.

    (I got very few miles out of the scorcher due to my Zefal tyre liner cutting the tyre casing threads. Slime liners rule.)
    My folding bike photo essays www.dekter.net/

  5. #5
    Senior Member bhkyte's Avatar
    Join Date
    Sep 2008
    Location
    York UK
    My Bikes
    2X dualdrive Mezzo folder,plus others
    Posts
    2,219
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Like my Kojacks, much smoother than marthans due to tread pattern. Not had many flats with them. About 3 in 3 years. Carefull in the wet and loose stuff!
    Dual drive Mezzo (GOLD), Dual Drive Mezzo with bullbars (black), White Brompton thingy with Dahon Androes stem and bull bars. Birdie (old sytle) 7 speed. Downtube NS8. Birdie red.

  6. #6
    Senior Member
    Join Date
    Jul 2008
    My Bikes
    Brompton, Dahon Vitesse D5
    Posts
    1,800
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Jur, in switching tyres did you notice any change in the folded geometry of the Brompton? I don't suppose it would make any practical difference to most people whether the front wheel drops slightly lower due to the rear tyre allowing the main frame to fold a fraction further etc., or vice versa . . it might to me though with the way I have my 5 speed IGH arranged.

  7. #7
    Senior Member
    Join Date
    Jul 2008
    My Bikes
    Brompton, Dahon Vitesse D5
    Posts
    1,800
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I'm wondering if the rolling resistance of Kojaks ought to be higher than Comets or Scorchers due to the form factor? I.e. fatter tyres deform less . . . with Comets weighing only a shade more perhaps thinking Kojaks = speed is a mistake?

  8. #8
    weirdo
    Join Date
    Jan 2008
    Location
    Reno, NV
    Posts
    1,956
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by chagzuki View Post
    However, for the time being I can't really assess the tyre as I'm using a Pantour hub which is soaking up bumps very efficiently.

    I'm considering putting one on the rear and thought I'd fish for opinions before deciding whether or not to do so.
    Can you swap tires front to rear to see how you like the kojak in back with whatever else on the front Pantour wheel?

    Quote Originally Posted by jur View Post
    I wonder what the relative contribution of tyre construction is to rider comfort... I am just thinking of 50kg or so on the rear tyre, with the air holding the wheel up with say 80psi, about just how much a sidewall matters in this scenario...? I suspect very little. So if I think back on tyres I have had on my various bikes, the only one that really sucked was a Marathon Plus, it wallowed terribly unless pumper very hard. But as for the others... I had a Kojak, followed by a Scorcher, and now a Primo on my Brommie back wheel. IfI am brutally honest, then I will admit I can't feel a difference. Even the fatter Scorcher didn't feel particularly different.
    With no way to really measure, I guess it`s one of those judgement calls, but I definitely feel a difference between stiff and soft sidewalls. Never used Kojaks, but I`ve ridden a lot on Paselas and a bit now on Primo Comets, and much prefer the ride to stiff tires- in my case, the stiffest have been studded Marathon Winters (brutal!) folowed by Maxxis Overdrives (rough). Unfortunately, I get a lot more flats with Paselas than with tougher tires. Haven`t flatted my Primos yet, which might either be because they aren`t so prone to it or just good luck, as I have less than 1000 miles on them.
    Last edited by rodar y rodar; 11-05-12 at 02:38 PM.

  9. #9
    jur
    jur is offline
    Senior Member
    Join Date
    May 2005
    Posts
    6,151
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by chagzuki View Post
    Jur, in switching tyres did you notice any change in the folded geometry of the Brompton? I don't suppose it would make any practical difference to most people whether the front wheel drops slightly lower due to the rear tyre allowing the main frame to fold a fraction further etc., or vice versa . . it might to me though with the way I have my 5 speed IGH arranged.
    The Scorcher was bad for geometry. The wheel pressed in hard on the bottom bracket shell when folded (I added helicopter tape for its protection) and against the top tube. The front wheel was much further from ground, so it would not stand at all. The Primo Comet is much better, does not touch the BB shell and the bike can still stand although it still has to lean over a bit and is a bit precarious.
    My folding bike photo essays www.dekter.net/

  10. #10
    Senior Member bargainguy's Avatar
    Join Date
    Sep 2012
    Posts
    556
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Wow, I'm getting a bit nostalgic for the Primo Comets. Legend has it that Vision, the recumbent maker (long gone), enlisted Cheng Shin to help develop this tire, and suddenly, we had a wonderful tire with flexible sidewalls that actually made riding a folding bike fun and enjoyable instead of brutal. There are still many devotees of the Comet. My experiences with them are somewhat limited, running a hodgepodge of tires on all my folders, but I generally liked them. Sometimes not very grippy in the wet with the relative lack of tread, but an overall fine tire.

    Don

  11. #11
    Thread Killer
    Join Date
    Aug 2008
    Location
    Ann Arbor, MI
    Posts
    3,643
    Mentioned
    7 Post(s)
    Tagged
    0 Thread(s)
    Kojaks look bad assed.
    Chaad--'95 DeKerf Team SL, '02 Lemond Buenos Aires, '05 Novara Buzz, '73 Schwinn Collegiate, '06 Mountain Cycle Rumble, '09 Dahon Mariner D7, '12 Mercier Nano, '12 Breezer Venturi

  12. #12
    Senior Member smallwheeler's Avatar
    Join Date
    Aug 2012
    Location
    NYC
    Posts
    1,690
    Mentioned
    7 Post(s)
    Tagged
    0 Thread(s)
    are kojaks similar to stelvios? anyone have experience with both?

  13. #13
    Senior Member bhkyte's Avatar
    Join Date
    Sep 2008
    Location
    York UK
    My Bikes
    2X dualdrive Mezzo folder,plus others
    Posts
    2,219
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by smallwheeler View Post
    are kojaks similar to stelvios? anyone have experience with both?
    Stelvio no longer availalbe 16" ?
    Ride very harshly, punture very easily. get damaged easily, and are very difficult to fit.
    Kojacks ride smoothly and quickly,( as quick?),but seem to cushion out bumps that rattle with stelvios even with 100+ psi, and can be pretty durable.
    Dual drive Mezzo (GOLD), Dual Drive Mezzo with bullbars (black), White Brompton thingy with Dahon Androes stem and bull bars. Birdie (old sytle) 7 speed. Downtube NS8. Birdie red.

  14. #14
    Senior Member smallwheeler's Avatar
    Join Date
    Aug 2012
    Location
    NYC
    Posts
    1,690
    Mentioned
    7 Post(s)
    Tagged
    0 Thread(s)
    ugh that sucks.. i just bought a pair of stelvios..

  15. #15
    Senior Member
    Join Date
    Feb 2011
    My Bikes
    86 Nishiki Olympic Sport, 87 KHS Montana Team, 06 Dahon Mariner
    Posts
    156
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I too find the Kojaks to have a smoother-than-expected ride, even at 95 PSI front and rear. The steel-beaded versions are an especially good bargain, I think.

    I've gotten two flats in almost two years.

    I will buy when these are worn out.

    -Warr

  16. #16
    Senior Member
    Join Date
    Aug 2011
    Location
    Seattle
    My Bikes
    Spec. Roubaix, Cannondale RT2, BF NWT, BF tandem
    Posts
    201
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I tried Kojacs when I wore out my Stelvios. They rode a little better with slightly more rolling resistance--really not really noticeable. I removed the Kojacs since I was getting deep cuts in the tires and did not trust them. Finally fitted Duranos which are theoretically the replacement for the Stelvio. They are very close to the Stelvio with better cut resistance along with better rolling resistance than the Kojac.

  17. #17
    Senior Member Sangetsu's Avatar
    Join Date
    Jun 2008
    Posts
    363
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I have been commuting almost daily on a pair of Kojaks for more than a year, and I have been happy with them. I keep them at 110 psi, the suspension on my Birdy folder keeps the ride smooth. The tires are showing some cuts and cracks, but I have had only one puncture since I installed them. I will be replacing them shortly, as they are nearly worn through. I wanted to fit a new set of Panasonic Minits, but I love the durability and long life I have gotten from my Kojaks.

  18. #18
    Senior Member
    Join Date
    Jan 2009
    Location
    Bay Area, SF California
    My Bikes
    Citizen Tokyo, A-Bike, Dahon Boardwalk D6, Dahon Boardwalk D7, Dahon Curve D3, Dahon Mu XL, BF Tikit2, Dahon Speed TR, Dahon Curve SL.
    Posts
    1,487
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    have kojaks on my speed tr and like it better than the stock big apple. ride is smooth and faster than stock tires. i set the pressure at 100psi. i like the feel of the tiny stones when i am riding on it...

  19. #19
    Member
    Join Date
    Sep 2011
    Location
    SE Asia
    My Bikes
    Dahon Curve P9, Smooth Hound 08, BF Tikit
    Posts
    30
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Just put on a pair of Kojak on my Curve, I like it better than the previous tires (Marathon Original). Not really much of a difference with comfort, only faster. I pumped them to 100psi.


  20. #20
    Senior Member bhkyte's Avatar
    Join Date
    Sep 2008
    Location
    York UK
    My Bikes
    2X dualdrive Mezzo folder,plus others
    Posts
    2,219
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by rain13 View Post
    Just put on a pair of Kojak on my Curve, I like it better than the previous tires (Marathon Original). Not really much of a difference with comfort, only faster. I pumped them to 100psi.

    Can i just pouint out the elephat in the room.

    Slick tyres are grippy in dry but not in the wet or loose, just in case someone wants kojacks on a commuter bike remember winter. This is the reason I run two Mezzos, one with kojacks and one with marathons.
    Dual drive Mezzo (GOLD), Dual Drive Mezzo with bullbars (black), White Brompton thingy with Dahon Androes stem and bull bars. Birdie (old sytle) 7 speed. Downtube NS8. Birdie red.

  21. #21
    Member
    Join Date
    Sep 2011
    Location
    SE Asia
    My Bikes
    Dahon Curve P9, Smooth Hound 08, BF Tikit
    Posts
    30
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by bhkyte View Post
    Can i just pouint out the elephat in the room.

    Slick tyres are grippy in dry but not in the wet or loose, just in case someone wants kojacks on a commuter bike remember winter. This is the reason I run two Mezzos, one with kojacks and one with marathons.
    You are so right, last night it was raining, I had to put more attention to the road, lost a bit of traction on some road surface.. kinda scary really.

  22. #22
    New usename ThorUSA brakemeister's Avatar
    Join Date
    Nov 2004
    Location
    Southern Illinois USA
    Posts
    2,469
    Mentioned
    0 Post(s)
    Tagged
    1 Thread(s)
    profile on the tire is a lot of marketing hype... SUre in deep snow, sand or mud ... it will help to get you trough it.... but remember that your contact point is the size of a quarter... ( very large penny for our Int friends)
    the rubber compound, different layers of construction, make much more difference....

    I sometimes wonder if somebody who says it was slippery in the rain on Kojaks ( or other slick tires) would have had the same slippery feeling on a different tire .....of course its hard to do... switching tires and ride exacly the same spot, same speed, same angle ..

    just sayin ..... maybe cause I love the Kojaks so much ..... the Supremes are my next choice ...:-)

    thor

  23. #23
    Senior Member
    Join Date
    Feb 2011
    My Bikes
    86 Nishiki Olympic Sport, 87 KHS Montana Team, 06 Dahon Mariner
    Posts
    156
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by bhkyte View Post
    Can i just pouint out the elephat in the room.

    Slick tyres are grippy in dry but not in the wet or loose, just in case someone wants kojacks on a commuter bike remember winter. This is the reason I run two Mezzos, one with kojacks and one with marathons.
    While I agree while riding on the loose stuff, it is simply not true that treadless tires like Kojaks fare any worse on wet pavement than treaded tires.

    Tread exists on tires for two main reasons: to "bite" into soft surfaces (like dirt, gravel, snow, soft ice, etc.) and to prevent hydroplaning by giving standing water a path to "get out of the way" of the tire's contact patch.

    When riding on wet pavement, even with standing water, bicycle tires are too thin and curved to hydroplane, which is rather unlike like a treadless car tire, so there's one "benefit" gone. Pavement also doesn't give, so there's nothing for tread blocks to "bite" into, so there's another one gone.

    Then factor in that pavement is never glass-smooth; it is always irregular and therefore has both spaces for water to "get out of the way" through, and the irregularities act like tread "biting" into the smooth surface of the treadless tire, providing more grip than it would on a treaded tire because there's more surface area for the "tread" of the pavement to "bite" into.

    Now riding over wet metal plates and wet painted road stripes is very tricky on treadless tires, but it also is on treaded tires; both are slicker-than-snot and hazardous regardless of your tire.

    I've been riding on "slick" treadless tires since they became popular in the late 80's in all sorts of weather. I commute rain-or-shine on Kojaks on my folder. There is nothing to the myth that "slick" tires are not suited to wet weather if you limit your riding to paved surfaces.

    -Warr

  24. #24
    Senior Member smallwheeler's Avatar
    Join Date
    Aug 2012
    Location
    NYC
    Posts
    1,690
    Mentioned
    7 Post(s)
    Tagged
    0 Thread(s)
    my primo comets agree wholeheartedly with your well-worded defense of slick tires..

  25. #25
    lowlife bottom feeder BassNotBass's Avatar
    Join Date
    Apr 2008
    Location
    Lou-evil, Canned-Turkey USA
    Posts
    1,851
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by wernst View Post
    ... When riding on wet pavement, even with standing water, bicycle tires are too thin and curved to hydroplane,..
    Not to mention that the speeds at which most people ride a bike is too slow to induce hydroplaning. Rubber compound and carcass construction are more important concerning traction.
    I plan on living forever... so far so good.

Page 1 of 2 12 LastLast

Posting Permissions

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