I bought a new bike a few days ago, Cannondale Bad Boy 3 2019 which gets delivered in a few days.


Buying the spares I'm at a complete loss on finding the right inner tube size, popped into Evans Cycles today and the guy wasn't much help at all.

Anyone able to tell me and possibly link me to the correct inner tube's required?


  • 1
    I understand the salesguy's difficulty with your request. From his POV you're "asking for a piece of string" but don't know how long.
    – Criggie
    Feb 27, 2019 at 19:33
  • Anecdotally, my Bad Boy 1 has presta valves. I don't know if that's a guarantee for you, but I think it's extremely likely. Feb 28, 2019 at 14:42

2 Answers 2


The required spec is on the page you link: Tyres: Schwalbe Kojak Performance, 650x35c. If you go into a bike shop and ask for 650x35 tubes they'll give you the right size (probably 650x32--38 as tubes fit a range of widths).

The only problem is that the valve type isn't specified there. It's almost certainly Presta, but there's a chance it's Schrader (car style). Strangely zooming way in to the photo, there's no sign of the valves at all. You might want to hang on until you can check what valve it's got.

  • Excellent point in that the bike will come with a tube per wheel, (unless its tubeless)
    – Criggie
    Feb 27, 2019 at 19:31
  • 1
    It's bizarre that Cannondale's official photos (which are used by all the online shops I saw, too) seem to have no valves. I found one site that reviewed the bike and their photos seemd to show Presta valves, as you predicted. Feb 28, 2019 at 10:05
  • @DavidRicherby I wonder if they actually are photos. Rendered models are so good these days that apparently some product photos aren't. Ikea for example. Either that or those tyres don't have tubes in and aren't taking the weight of the bike.
    – Chris H
    Feb 28, 2019 at 12:25

According to the specs, you need 650×35. In this case, they mean 650b, which is often also referred to as 27.5" and the 35 is the width in millimetres. Some brands will also list the width in inches as well. In that case, you'll need a 27.5×1.2 tube. Something like this is what you need (as long as it has the right valve).

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