Sizing on a traditional road bike

[pawl]

I’m looking at a couple of vintage road bikes on EBay with a 21” frame. Both are resto projects and would need some work to be usable so not looking at paying much. They are on 27” wheels, steel frame.

Just wondering if they might not be a little small for me as I’m 5’10” with 32 inside leg. The sizing charts I’ve looked at seem to put me on a slightly larger frame but how important is this on vintage bike I would use on sunny occasions?

I have the same measurements as you.Back in the day I rode either 221/2 or 23 inch frames.

 

[Illaveago]

It is a bit of a dilemma ! I was in a similar situation many years ago with my old Sun Mist . I now wish that I had kept it . Like a few people on here I am a similar height as you. I measured my Flying Scot which is 22 1/2 last night as a guide , which I find is a bit on the smallish side, but with a bit of component change could be sorted.
I was wondering if you were to use a longer seat post and a longer handlebar stem you may be able to find a solution . It was these options I hadn't considered all of those years ago, plus fitting 27 inch wheels instead of 26 inch would also have helped .
It seems as though you fancy a project of restoration and are a bit taken by them .

 

[SkipdiverJohn]

was wondering if you were to use a longer seat post and a longer handlebar stem you may be able to find a solution .

I would try to avoid doing things like stem swaps if possible, as it could start to push the costs up as well as being a bit of a sticking plaster solution. It's better to hold out for a bike whose size will accommodate your dimensions within it's in-built adjustment range. There is no shortage of secondhand classic steel bikes with 22 1/2" or 23" frames at modest prices if you are happy with a basic hi-tensile model. If you specifically want Reynolds 501 or 531 and don't wish to pay much or travel too far, then you might have to compromise a little. I think a 21" is a bit small for a 32" leg though, unless the top tube centres are close to 22" long. A 21" bike is really only intended for someone of up to average mens height - 5' 9" . Anyone taller than average really needs a bigger bike. Also consider a too-small size with a short TT might cause toe overlap issues with the front wheel, depending on how "racy" the geometry of the frame is.

 

[biggs682]

Rule of thumb used to be inside leg less 9" as a starting point. 11 for MTB.

Never heard that before

i always use the can i touch the floor without squashing the crown jewels test or if its a small one how much seat post is exposed trying to get the saddle up to 39" from the floor as any more than 6" looks like the bike is too small for the rider

 

[mjr]

Never heard that before

i always use the can i touch the floor without squashing the crown jewels test or if its a small one how much seat post is exposed trying to get the saddle up to 39" from the floor as any more than 6" looks like the bike is too small for the rider

I've heard the standover approach before but it's not as good as sitting on it properly because I've at least one very comfortable bike I have to lean to stand over. Stand over is as much to do with bottom bracket height as frame size.

 

[GuyBoden]

Putting 700c wheels on a 27inch vintage lowers the bike too.....

 

[amedias]

very much depends on your proportions too, not all frames are 'square'* and reach is just as important as height. I'm 5'7 but with short legs, and I generally go for ~52-53cm (20.5-21in) frames, but I've been happy on anything down to 50cm, and up to 55cm depending on exact geometry and vintage as the trend for smaller or larger has changed over the years and some bikes look better with more or less post.


* I think I've only ever had one square bike, various frames at the moment as follows (STxTT)
50x51.5
55X56
54x56
54x53
53x54
49x52
52x53

And they all fit me just fine, some have longer stems or longer reach bars, others shorter, all appropriate to the type of bike and period.

 

[mikeymustard]

I think 22.5-23.5 is more like the ideal (I'm pretty much the same height/inside leg as you), I can go to 24" at a push but 21" is way too small for me, I feel really cramped on that size of frame.
This is what happens when you try increasing stem and post size:

This is my partner's bike, she's only 5' 8" but has a 32"+ inside leg. I think the stem looks a little silly IIH, but she loves the colour so much. If it was a frame you already had then it might be worth the faffage but it would be a lot easier to buy the right size in the 1st place

 

[Tim330]

Thanks for all the advice. The owner has been quite honest with me and the frame sounds in poor condition, letting me think it may be corroded inside too. As it’s as small size, I’m going to pass and wait for a larger frame to come on the market, which I’m sure one will crop up. This one won’t be worth the work and parts.

I’ve always needed the leg length more so the frame size needs to be right.

 

[woodbutcher]

Thanks for all the advice. The owner has been quite honest with me and the frame sounds in poor condition, letting me think it may be corroded inside too. As it’s as small size, I’m going to pass and wait for a larger frame to come on the market, which I’m sure one will crop up. This one won’t be worth the work and parts.

I’ve always needed the leg length more so the frame size needs to be right.

Tim 330, if you really want to get into the fine details of bike fit and loads of other stuff related to bikes and riders check out BIKE FIT ADVISER on youtube if you haven't come across him yet. The guy gives very detailed info .... l find it all highly addictive even if l don't understand all of it