Does anyone here regularly ride a bike that is a size too small? I am in the process of rebuilding a 1969 Hercules 3-speed, 19” frame that is “beat”. It works OK but has been used hard, has some rust and looks like it was maintained by someone that owned very few tools. So yesterday while walking the dog I saw a Raleigh Sport girls bike that looked like it has about 100 miles on it but was stored in a shed so there is some rust and oxidation on it but will serve as a good donor bike. Problem is I should be riding a 21” frame. Does anyone here ride a smaller frame like this, I was thinking of using a longer seat post and handlebar stem to adjust the bike for the difference in size?

I have a Raliegh mixte that is 1" too small for me and that is exactly what I plan to do with it. A longer reach on the stem and a little extra setback on the saddle should extend the reach enough to be comfortable. I don't see it as a problem, but I intend to use it as a city bike and not any all day tours.

Do it all the time. I really need a 25" frame on a Raleigh Sports type bike, but have regularly ridden a 21" with a long stem and seat post.

Aaron

As long as you'll be comfortable with the top tube length on a smaller frame, there's no reason not to adapt it. Neither the stem nor the seatpost presents an insuperable problem -- both are available with long shafts. For the seatpost, lots of old MTBs (newer ones tend to have fatter tubes) came with really long shafts, and these are regularly available on eBay. For stems, I'd try Nitto, either the Technomic (7-shape, comes in multiple extensions, the "regular" one is longer than the more expensive "deluxe" version) or the Dirtdrop (MTB-style, but beautiful shape and finish, 80 mm extension only). See Rivbike.com to view/purchase either one. My own opinion is that it's harder to find a nice longer seatpost than a stem, because you're close to stuck with whatever diameter you need (can use a shim for undersize post), while stems have fewer variables.

The way you adjust the top tube length to suit you are: saddle fore-aft adjustment (somewhat variable, within a small range), stem extension (need to know which one you need and buy it), and handlebar design (where are your hands most of the time).

All that being said, it's arguably better to start with a bike frame that's close to fitting you; however, that's often not possible for the models you're talking about (3-speed "black bikes") because they didn't come in that many sizes to start with. There's probably a 21" or 23" frame out there, though, with your name on it in invisible ink -- you just have to find it!

This is what you need for you Hercules:

https://www.wallbike.com/seatposts/kalloy200.html

Been there, done that.



And then I bought a frame in my size.



It's a very doable thing. I wish I had a longer steerer on the old bike though, so I could raise the fork up by a cm or two. Overall, just get a longer seat post, longer/taller quill stem, and it will be a pretty good ride. I had a horrendous amount of toe overlap on the white bike (Trek 760), and it was awesome . I could corner like crazy, and it was a very downhill rider.

Here is a picture of my beauty

This bike was my only form of transportation from 1982-1986 and then used by my brother and others for a few more years. Best $25 I ever spent!

The second bike is a ~50cm step through that I use as a grocery getter, thanks to MTB seat posts I can ride it.

Aaron

The longer stem and saddle setback are pretty normal on my bikes. I have a long torso and arms, but fairly short legs, so most bikes are a comromise.

My riding style has changed a bit, I'm taking longer rides but I'm not as concerned with outright speed. So I now prefer a more upright position, and a couple of my bikes are getting switched back to shorter stems, which is the unexpected advantage of a too short bike.

A frame that's too small is easier to make fit (within reason) than one that's too big.

Ken.

Thanks for the replies. I have been riding the other two Raleigh 3-speeds I have which are the smaller frames but I have not tried them for my longer (20 mile round trip) commuting distance. I will go ahead with the restoration of the Hercules.