Continental Grand Prix 4000S II 28mm

vegas76
vegas76 Posts: 278
edited July 2018 in Road buying advice
Has anyone tried fitting these in 28mm to a Giant TCR Advanced Disc 1 bike? Is there enough clearance?

Comments

  • donboogie
    donboogie Posts: 75
    I too would like a definitive answer to this. For a 2018 rim brake version not disc. Think there may be a thread about it already. And there is a durianrider video about it IIRC. If I can summarize from memory, it comes down to the rims. With a modern wide-ish rim these balloon to 30+ mm and there is not enough clearance. Comments are welcome, thanks
  • vegas76
    vegas76 Posts: 278
    Would a Mavic Ksyrium Elite be a modern wide rim? Or CERO ARD23?
  • ericbayarea
    ericbayarea Posts: 16
    My riding buddy has a Giant TCR Advanced Disc 0 in size M/L and he runs 28 Schwalbe tubeless with no issues
  • bungle73
    bungle73 Posts: 758
    ericbayarea wrote:
    My riding buddy has a Giant TCR Advanced Disc 0 in size M/L and he runs 28 Schwalbe tubeless with no issues

    Not all 28s are created equal though (as is the case with other sizes too). Some tyres measure up to a different width than the manufacturer's stated one. Apparently Conti Grand Prix 4000S II 28s come out at 31 mm, according to Bicyclerollingresistance.com.
  • cycleclinic
    cycleclinic Posts: 6,865
    Tyre width and height depends on the internal width of the rim. IT not that some 28 GP4000sII tyres come up at 31mm all will on wider rims.

    Also tyres gain height on wider rims.

    The internal bead to bead distance tells you how big the tyre is going to be.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • donboogie
    donboogie Posts: 75
    How can a tire gain height on a wider rim? If the bead-to-bead width of a tire is a fixed number, shouldn't a narrower rim result in greater height, as compared to a wider rim? Thanks in advance.
  • ericbayarea
    ericbayarea Posts: 16
    Bungle73 wrote:
    ericbayarea wrote:
    My riding buddy has a Giant TCR Advanced Disc 0 in size M/L and he runs 28 Schwalbe tubeless with no issues

    Not all 28s are created equal though (as is the case with other sizes too). Some tyres measure up to a different width than the manufacturer's stated one. Apparently Conti Grand Prix 4000S II 28s come out at 31 mm, according to Bicyclerollingresistance.com.

    True. I was providing a comparison as best I could. It's worth noting that the tire hairs/nubs on his Schwalbe 28s, located on the TOP of the tire, brush the underside of the front fork. I think they've since warn off but it is CLOSE. Didn't see any issues on the sides either front or back (I rode with him this morning).
  • vegas76
    vegas76 Posts: 278
    So I read a review which said that there was space for 28mms so I have put them on. But holy moly it is tight. 1-2mm of clearance and as was aid above the bur at the top seems to brush on the frame in certain places.

    But how friggin awesome are the tyres!
  • thegreatdivide
    thegreatdivide Posts: 5,807
    Vegas76 wrote:
    But how friggin awesome are the tyres!

    Smash those KOMs dude!!!!!!!!!!!!!
  • donboogie
    donboogie Posts: 75
    I have a 2018 TCR Advanced Pro 1. Wheels are Fulcrum Racing 3, the new ones with 17mm internal width. Tires are 28mm Vittoria Corsa G+. They fit with a good amount of clearance.
  • vegasfoster
    vegasfoster Posts: 59
    DonBoogie wrote:
    How can a tire gain height on a wider rim? If the bead-to-bead width of a tire is a fixed number, shouldn't a narrower rim result in greater height, as compared to a wider rim? Thanks in advance.

    The sidewalls will be taller the more parallel they are to wheel. They angle in more on narrower rims pulling the top of the tire closer to the rim.
  • ROAD_MAVEN
    ROAD_MAVEN Posts: 1
    Late contribution here but I'm keen on this topic. I've been on a mission to ride 28mm GP4K's on my 2012 Giant TCR SL (recent frame buy) and they do fit at 80psi or less. Mine measure 30.5mm wide and around 29mm tall mounted on 25mm wide carbon rims with 19mm internal width. They didnt fit good too tall using 21mm outside 16.5 inside alloy rims, maybe below 70psi they would. With the wide carbon rims the tire side clearances on the TCR SL are good front and back, but the height is a hair clear front and two hairs clear rear. There is some minor top of tire contact initially which I am okay with as this creates the clearance I need maybe less than 0.2mm and I don't mind taking small risks with my sports equipment (I'm also a composites engineer). No rub along sides. I've been road riding and triathlon for 30 years mostly flat and semi smooth roads occasionally bumpy I've owned several roads bikes and have tried many combos of wheels and tires its a bit of an obsession. I have to say that switching to the 2012 TCR SL is like switching from an avg sports car to an exotic sports car and with the conti 28mm at 80psi makes it feel like your floating over the road surface. Its by far the best upgrade I have experienced. And for contribution clarity my goals are road ride speed and ultimate comfort bump absorption. I typically do 1-2 hour rides (I stay busy) with some intervals, occasional fast group rides. All flat no climbing or descending. Hope this helps and cheers to bikeradar!
    EDIT: Very important edit I switched to SRAM APEX brake calipers because the Ultegra 6800's are pinched at the pivots and wont allow the tires to clear. Any quality brake calipers with a broad open U shape should work.

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