Viewing 16 posts - 1 through 16 (of 16 total)
  • real road tyre widths
  • Premier Icon mrmo
    Free Member

    Is there anywhere online you can find out how wide/tall a tyre is really? if my frame says it will take a 25mm, and i can see some 25’s are bigger than others. i can also see my frame has a fair amount of clearance. Just wondering if there is a way of finding out what tyres i can fit without buying first.

    Which i assume once fitted can’t be returned??

    Premier Icon cynic-al
    Full Member

    There was once a site with details of this for MTB tyres, no idea re road.

    There’s a lot of knowledge here if you have some tyres in mind.

    LBS should fit them and refund if no go?

    Premier Icon trailwagger
    Free Member

    Too many variables.

    Premier Icon 13thfloormonk
    Full Member

    You’re better searching for specific tyres, the better reviewers state real world widths on specific rims.

    For what it’s worth, 25mm Specialized Espoir and 25mm Continental GP 4Seasons on 19mm internal DT R460 rims both measure 27mm at widest point.

    This means Specialized are technically correct when they say the latest Allez can take 28mm tyres, but try fitting an ACTUAL 28mm Conti GP4season tyre and there’s virtually no clearance. I sent them back as you couldn’t tell they had been fitted, I even preserved the little bit of packing tape stuff they use to keep them rolled up in the box.

    Premier Icon n0b0dy0ftheg0at
    Free Member

    GP5000s are supposed to run a lot truer to size than GP4000S IIs, 700×25 variant is approx 25.5mm (max) vs 27mm.

    Premier Icon mrmo
    Free Member

    currently i have a trek ALR with campag potenza calipers, campag c17 rims and gatorskin 25mm tyres. It looks like i can get a bigger tyre on, it is just trying to get an idea of how much bigger a bigger tyre actually is.

    Just thinking if i can get something bigger that will cope with potholes etc.

    Premier Icon 13thfloormonk
    Full Member

    Next size up Conti tyre would be a 28mm which in my experience measures up 31mm. That’s on a 19mm internal rim though, so perhaps 30mm on a 17mm internal?

    How much extra space do you have?

    Premier Icon MoreCashThanDash
    Full Member

    Avoid 28mm Conti 4 Seasons – like trying to fit a fat bike tyre in!

    Premier Icon mrmo
    Free Member

    How much extra space do you have?

    I can just about getting a 6mm allen key around the tyre on the back and a 5mm on the front.

    Premier Icon thisisnotaspoon
    Full Member

    Old Schwalbe Pro one’s were about +3mm, new ones are true to size.

    It depends on the rim apparently, the old ones must have been measured on some seriously narrow rims though! Which is weird as my old Ultremo’s and Blizzards were both true to size as well. just the Pro One’s that are massive (even on relatively conservative rims).

    Premier Icon bluebird
    Free Member

    http://www.bicyclerollingresistance.com/road-bike-reviews has some real world tyre width info. I think it’s based on a 17mm internal rim and 100psi.

    Premier Icon mrmo
    Free Member

    in case anyone does a search in future, the following works fine, Conti gp5000 28mm on c17 Campagnolo rims, a trek emonda ALR frame, and Campagnolo potenza calipers.

    Premier Icon boombang
    Full Member

    Schwalbe One 25mm on 17mm rim is ~27mm
    Schwable One 28mm on 19mm rim is 30.5mm (but noticeably less tall so fits under a Shimano caliper)

    Premier Icon simondbarnes
    Full Member

    My 28mm Conti GP5000TL measure exactly 28mm on DtSwiss PR1600 spline disc with an 18mm internal rim width.

    Premier Icon scotroutes
    Full Member

    My 28mm Conti GP5000TL measure exactly 28mm on DtSwiss PR1600 spline disc with an 18mm internal rim width.

    I took from an earlier thread that new 28mm GP5000s were slightly narrower (i.e. actually 28mm) than older ones.

    Premier Icon jkomo
    Free Member

    The wheel rim width means it will differ. A 25 on a wide rim might rub when it wouldn’t on a narrow one.

Viewing 16 posts - 1 through 16 (of 16 total)

You must be logged in to reply to this topic.