Seeking advice on bike sizing.

[vishalpallikonda]

I'm 6'1" with a 36 inseam and I am thinking of taking an 19.5" L size hybrid bike because that's a vastly available frame size for my height. I've done huge research and checked various forums and online size calculator sites and according to the charts they provide, they all seem to follow a standard relation between overall height and inseam length. And I understood that my body proportions are off those standards. According to that standard if taken the overall height, the 19.5 inch frame should fit me. But when I take the inseam, things get strange. According to the inseam length suggested size I need to go for a 21" frame at least, because my inseam length falls in range of a 6'3 or 6;4" person. Now this is really confusing and it would really help if someone clears me of this. Unfortunately I'm far away from any major city to test the bike physically in a shop and I'm buying online. So please help me if i should go for a 21" XL size, if so will it be too big? Or I can fit the 19.5" frame with some major adjustments which seem unavoidable considering my abnormally long inseam for my height? Thanks in advance.

 

[SkipdiverJohn]

Since when was a 19 1/2" frame size classed as Large?? My inside leg is about 33 1/2" and I ride 23" frames!
I had a 19 1/2" frame when I was about 10 years old!

 

[Cavalol]

As Skipdiver has said, 19.5 isn't really large. I'm about the same size as you (though possibly with slightly longer legs) and a 19.5 would give you cramp on even a short-ish run, imho.
It has been said that older bikes such as 1970's/80's racers frame sizes were different, even some 23s have felt too small for example, but I'd certainly suggest as 21 inch frame for you if you get a hybrid.

Could you post up on here somewhere to see if anyone local to you has a bike you could try for size?

 

[Milkfloat]

Skipdiver is talking about retro frames where the sizing is very different. Each manufacturer is different, so looking at a chart for one manufacturer and assuming that it will be relevant to another is not wise. Trying the bike is the way to work it out, but failing that you can try other bikes by the same brand to get a rough idea. Worse case just remember it is a lot easier to make make a bike that is too small fit you than a bike that is too large.

 

[SkipdiverJohn]

Worse case just remember it is a lot easier to make make a bike that is too small fit you than a bike that is too large.

There's still a limit though. When you ride a frame that is a bit small you tend to find yourself perched too far forward, because the TT is normally shorter so you end up over the front wheel more and it also affects the weight distribution. I find undersize frames feel odd to ride and don't seem as predictable or stable. The other issue is the bar height, because small frames tend to have shorter head tubes, so although it may not be a problem to get the saddle high enough you may well find yourself having to suffer low bars and use an unusually long stem. Personally, I tend to size bikes by the length of the head tube more than anything, and I want to see plenty of daylight between the junction of the TT anf the DT.

 

[ColinJ]

A person with very long legs who is only 6' 1" tall must have a relatively short torso so bike fit is always going to be tricky!

I am the same height but my legs are only 32-33" long. I have quite a long torso so I choose bike size and stem length to fit that and adjust the saddle height to suit me.

My mountain bike is supposedly a 19" frame but that has a sloping top tube. (Pause to whip out tape measure ...) Okay, it DOES have a 19" seat tube measured to that sloping top tube, but the top tube (actual) length is about 22" and the length of a virtual horizontal top tube is 23.5". So the fact that the hybrid bike in question is quoted as having only a 19" frame doesn't mean that it is small, unless it has a horizontal top tube, in which case it probably is!

One thing is certain - the saddle on the bike will have to be very high, so there is likely to be a huge drop to the bars. Leave plenty of spacers under the stem and be prepared to experiment with stem length and rise!

 

[Cycleops]

Since when was a 19 1/2" frame size classed as Large?? My inside leg is about 33 1/2" and I ride 23" frames!
I had a 19 1/2" frame when I was about 10 years old!

Mountain bike sizing is very different to road bikes, MTBs tend to have a higher BB so the seat tube is shorter. Hybrids have frame which are MTB derived so sizing is similar. They also have sloping top tubes.
As suggested above the OP doesn't have "standard" dimensions so a bit of fine tuning is required. I like to ride a frame that is slightly big for me so go larger if given the choice. I'd say he would be fine on either, if he wants a more upright stance I'd say go for the XL.

 

[SkipdiverJohn]

Mountain bike sizing is very different to road bikes.

Not necessarily that different sized. here's three of my Raleighs, one Road, one Hybrid, one MTB:-

Raleigh Royal Tourer, 23 1/2" frame, built 1985.

Raleigh Pioneer Hybrid, 23" frame, built 1997.

Raleigh Sabre MTB, 23" frame, built 1994.

The MTB is seen in "as acquired" condition and both the saddle and bars are too low, and were adjusted before being ridden. The other two are set up as I ride them, pedal to top of saddle approx. 36 1/2", measured in line with the seat tube.

As you say, the main difference is MTB frame has a higher BB, but the difference is 1 1/4", but the standover height is not that much different due in part to the slacker angles and also being welded not lugged & brazed.
The most nimble overall is the MTB, the Hybrid feels the most stable, and the Tourer is the fastest (if you want to ride it fast).

 

[Levo-Lon]

My wife and me both have 30" inside leg.
We both have medium levo bikes.
Im 5'8 she's 5'3 bar stem and seat heights are very different.
Bikes would be classed as 17.5 frames.

I think you really need to go ride a few to gauge true sizing

 

[ColinJ]

Not necessarily that different sized.

Here is one that IS ... My mountain bike with its 19 inch/22 inch/23.5 inch frame, depending on how you measure it!

 

[SkipdiverJohn]

A rider with a 36"inside leg is going to exert an awful lot of load on a small frame with a tall seat post sticking right out. Unless you want to risk issues with the seat tube cracking or the clamp failing, the frame needs to be as big as possible and the amount of seat post sticking out kept to a minimum. The heavier the rider, the worse the problem.

 

[ColinJ]

@vishalpallikonda seems to effectively be a 6' 3"" person with a short torso whereas I am effectively a 6' 3" person with short legs. I think vishal's solution will probably involve a very short stem. I go the other way and use a 13-14 cm stem to help stretch my long torso out.

 

[Rando]

I feel the OP pain ! I too am only 6ft 1" tall but with 36.5" inseam. This makes it extremely tricky getting bikes to fit. My current road bike is a Trek Domane size 60cm with a shorter stem - 100mm. As much as I want a more race orientated bike rather than an endurance type one I have resigned myself that I need a taller head tube length and so this is most endurance bikes. Even some of those are a bit short at the front like the Giant Defy Advanced. Only solution is to have a huge stack of spacers and ignore how it looks !