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What is a Standard Bike? #19   BackToList   Print
Written: 2020.06.09   Review Date:2020.06.09    LastUpdate: 2020.06.09
"Standard" is a relative term. All bikes can argue they are "standard" so we need a criteria to define what we are talking about. In considering any bike, it could be evaluated on the basis of the following:

  1. Available Parts
  2. Published specs
  3. Simple to maintain

To evaluate a bike, you should be able to look at the specs and determine availability and cost of the main components. For purposes of this study I am aiming at touring bikes in the $1000-$2500 price range.

In thinking about a standard bike, it is a useful exercise to imagine having the bike assembled with the parts you want. Eg: I'd like a frame with a standard 68mm BSD bottom bracket and 135mm rear dropouts. I'd then pick Spyre C disk brakes, probably go for a square taper crank (or Hollowtech).

The exercise of building up the bike is useful even if no packaged bike model has exactly the parts you'd want. For example, a Surly Long Haul Trucker comes with a standard "build kit" which is close to what I'd want, but some things are not quite as low maintenance cost as I'd like. Eg: From the factory, Surly comes with 9 speed cassette and chain, but an 8 speed would be cheaper to maintain. So if I was having one built up for me by somebody like Mighty Riders, I'd be looking for an 8 speed drive train because the chain and cassettes are less expensive.

Here is the list of interfaces you want to check on any frame:

  Bottom bracket shell 68BSA
  Dropout width 10x135
  Rim Diameter BSD 622 (700c)
  Steerer Stem diameter Always 28.6
  Brake Mount Flat,Post or ISO

  Beyond the frame interface, it is desirable to look at the "build kit", which is what parts come with the bike. The two most important are drive train and brake components.

So let's go thru those criteria one by one. We can imagine assigning each item a standards level of 2 points, 1 point or 0.

  1. Bottom Bracket shell
     The most standard frames still have the familiar 68mm BSA threaded bottom bracket shell. It's been standard for 30 years, and likely to continue because there is no other shell size that is clearly better. This is still by far the most common bottom bracket shell size. It is what is found on the majority of new bikes the world over. It will accommodate a variety of bottom bracket bearing units: either Square taper or something with outboard bearings like Shimano Hollowtech II.
      68BSA 2 points

  2. Hub Spacing
     The most standard way to attach wheels is still the dropout system: On the front, the standard hub spacing is 100mm with a 9mm diameter axle, and on the rear a 135mm hub spacing with 10mm. I think they are the same. Second most common is a 12x142 mm thru axle, and 12x100. Replacement wheels for this standard tend to be twice as expensive, and there are not as many choices. And the threading of the thru axle seems to not be standard. Therefore in our "standards criteria" such a bike would get 1 point.
      Dr9x100 2 points
      Th12x100 1 point

  3. Rim Diameter
     The most standard rim diameter is BSD 622mm, also known as 700C, 29ers, etc. The second most common is BSD 559 (26") or BSD 584 (So called 650B). With disk brake bikes, you can sometimes interchange either 650B or 700c wheels.
      622 2 points
      559 1 point
      650 1 point

  4. Drive Train
     For low cost I'd still go with the 3x drive trains. With 3 cogs on the front, you can use more common cassettes and still have the low gears you want. These days there are lots of 2x systems that also have adequate low gears, when using the new Shimano 36 tooth cassettes. However you are then into the 9 speed cassettes and chains which are more expensive. If the bike is rarely going to be used in harsh conditions, the extra cost isn't as significant. What we are trying to avoid are the $600 tuneup bills I've seen, entirely due to drive train adjustments.
      3x8 2 points
      2x9 1 point
      2x11 expensive

  5. Steerer Stem Diameter
     These days almost all touring and commuter bikes come with a 28.6 steerer tube. There are lots of stem sizes available for that. At the handlebar end 31.8 is almost universal in the bikes we are looking at.

  6. Brake Interface
     There are three standard ways that disk brake calipers attach to the frame: Post mount, Flat mount and ISO. With any scheme, replacement parts are equally available.

Now we can discuss the level of standardization of components:

  1. Brakes
     Rim brakes: 2 points

  2. Crank

  3. Cassette
     8 speed 2 points


So now with this criteria, we can look at some typical bikes: