Mountain bike sizing for a short female

Question

This is similar to this question on frame size, however that is addressing it from a road bike standpoint.

My wife is 4' 9", and I am interested in getting her a mountain bike, as she has expressed interest in hauling the kids back and forth to local parks, etc, in a trailer. We had a child's bike previously, that was...clunky at best. It doesn't need to be full suspension (Truthfully doesn't need to be front suspension either, although I suspect there aren't any of those around any more).

The frame size charts that I've seen all stop at 4'11" for the shortest, with a recommended frame size of 13-15". Will that be sufficient, or will I need to possibly look at kid sized mountain bikes? Her body morphology is normal (No overly short legs with larger torso, etc), so everything is in proportion.

Answer 1

Proper bikes do exist in kids sizes, in essentially all types. 24" wheels are now common, which makes things easier. Some examples:

• Ridgeback dimension 24" (hybrid as you said you don't really need suspension)
• Specialized Hotrock 24" (hardtail)

Many of the major brands offer equivalents. This is something where sticking to the big brands probably makes sense, as there's plenty of junk out there too. These tend to be entry-to-midrange bikes (though there are exceptions) but unless the park is up a mountain or 10s of km away hey'd be more than adequate. Compared to the full-size equivalents you probably get slightly lower-spec gearing, but that can usually be upgraded quite easily/cheaply especially if done when the bike is being serviced anyway. They're often in stock in big bike shops so test rides should be easy to arrange.

Compared to squeezing onto a slightly too-large bike (at a similar price point) you should get a lighter frame, and if you go for suspension it should be capable of being set up for someone of that weight.

A test ride is essential whether you go down this route or try for the smallest bike marketed for adults.

And a tip: getting moving with a trailer is harder than without; jumping up onto the saddle every start isn't going to make it easy.

Answer 2

I would tend to think you would be better off with a smaller frame than trying to squeeze onto the smallest 'adult' bike.

Depending on the level of quality you are looking for, there should be some 24" wheel mountain or hybrid bikes available that are just fine for casual use on paved or flat unpaved surfaces.

Bike stores are generally willing to let you test ride bikes, so make use of that. Try both 24" and adult XS sizes and see what works and feels good to ride.

If you buy from a dedicated bike store you should get good advice and a properly set up and adjusted bike, something not guaranteed from a larger store such as Target or Walmart.

Many kids bikes - even from the bigger names such as Trek or Specialized - come with Shimano's lowest level Tourney groupsets. If you find that still feels 'clunky' to you then you can ask the store if they would upgrade to Alivio, Altus or Acera. If your wife has been riding a used low end bike that has been poorly maintained you might find that even a Tourney equipped bike feels significantly better.