Rim width question

lemonenema
lemonenema Posts: 216
edited June 2019 in MTB workshop & tech
Need to change my front wheel as its quite old (and cheap) 16mm internal width rim and 40mm tubeless tyres.

Rear wheel is a bit newer and runs nicely, 17mm internal width.

Should I just replace the front wheel for similar or change both wheels to a wider rim like 21mm?

Will I gain much benefit in terms of stability and handling?

Comments

  • steve_sordy
    steve_sordy Posts: 2,446
    This link will take you to a Schwalbe website that will tell you which tyre fits which rim.
    https://www.schwalbe.com/en/reifenmasse.html

    The 17mm rim will fit tyres from 25mm to 52mm wide (1" to 2")
    I'm not sure about your 16mm front rim. A 15mm will only fit 23 to 32mm (0.9" to 1.25"). You could make an estimate about what a 16mm will fit by looking at what the 15 and the 17 fit, but that could be dodgy.

    If you fit a tyre too large for the rim, the tyre will be more balloon-like and you risk it coming off in hard corners. Also the ride could be unpredictable.

    Do you have the clearance on the frame to fit larger tyres? I'm not just talking about will it fit in when the bike is just stood there. When using the bike the wheel flexes, the frame distorts and you might end up with the tyre rubbing on the frame in various places. In addition, tyres have a habit of picking up stones and mud which make a very efficient abrasive wheel when presented to an alloy frame!

    Front wheels normally have much more clearance than the rear, so if your 17mm rear wit its tyre fits OK without any of the mentioned problems, then you can certainly fit another to the front.

    If you go to 21mm internal rim widths, then the tyre you can fit increases dramatically (up to 2.4"). But as I mentioned earlier, do you have the frame clearance?

    New wheels can be had quite cheaply, but beware! You can have cheap, light and strong. Pick which two you want!
  • lemonenema
    lemonenema Posts: 216
    Hi Steve, I know the tyres/ rims fit because ive already been riding them for a few years!
    Yep clearance is fine on both ends, just wondering if its worth the upgrade
  • steve_sordy
    steve_sordy Posts: 2,446
    lemonenema wrote:
    Hi Steve, I know the tyres/ rims fit because ive already been riding them for a few years!
    Yep clearance is fine on both ends, just wondering if its worth the upgrade

    Your question implied to me that you were thinking of going for wider tyres.

    If you have tyres that fit the capability of the rim, and you are happy with the performance, why change the spec? Go with what you already have again, if you can get it.

    A wider rim will help give the wheel more stability and allow you to have a wider tyre that will give you more grip and a more comfortable ride.
  • robertpb
    robertpb Posts: 1,866
    On my gravel bike I have 23.5mm internal width rims with a Nano 40c onthe back and a resolute 42c on the front. Both of them are around 44mm on the rim, the wider rim gives more volume so more air, lower pressure and a better shape to the tyre, if that helps.
    Now where's that "Get Out of Crash Free Card"
  • billycool
    billycool Posts: 833
    You don't run very wide tyres, so 19 to 21mm should be fine.

    I run 2.1's on 19mm rims and 2.25's on 23mm.
    "Ride, crash, replace"

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