Stem Length

Hmm, fraid I am indeed a new-fangled kind of guy, thanks though!

stem length is only part of the equation (unless you use flat bars or only ride the tops) you have to consider the bar dimensions in as well. A compact bar might be about 80mm from the centre to the apex of the bend, a more traditional drop bar could be over 100mm.

FWIW - road 100mm stem + 80mm reach , cx 100/70, mtb 80/0. me=5'10 long back, shortish arms.

Mark Cavendish's stem is probably wider than it is long.

It used to be said that to get the correct stem length you should sight down towards the front hub when sitting in the saddle with hands on the bars (can't remember whether it was tops or drops, maybe it's all the same). If it's right the hub should be hidden from your sight behind the bar tops.
Maybe that method has gone out of fashion? Maybe because everyone is so different in their preferences? I always go on calculating around 100mm stem for traditional frames, 110 or 115 for current style compact frames. I think that means I've got the right size frame for me.

Bike racers favor an aero riding style which may not be the best position for recreational cyclists. Race bikes are generally as small as possible, as racers don't need tall head tubes and want the frames to be light and stiff, not necessarily comfortable. Over the years I've gone to a bigger bike. I like the feel of being "between the wheels" that a longer top tube gives me, as opposed to being "over" them. The stems I use are shorter, around 100MM or so. I don't need to put a bunch of dorky looking spacers under my stem, either. A bigger bike means I have a taller head tube, another reason I don't need dorky spacers. To each his own -but- I do believe one's riding setup should reflect the actual riding style, not some fantasy of racing like a Tour rider.

Double post....

Started on a 90mm stem (XS frame Ribble- I believe is 44cm/ slope top tube) ended up with a 110mm it
is a lot better. On my Kona(47cm) it's a 90mm stem, seen no reason to change..bar is a wee bit narrow mind you...only 400mm

To further confuse the issue, as you get older you become shorter, I used to be 5ft 9 now 40yrs on I am 5ft 7 1/2 I think it has something to do with one's spine, so that being correct it would be the upper body and reach affected, so by the time I am 100 perhaps I will be riding a bike with a 50mm stem instead of 100mm

For anybody who is interested, I just read on the internet that Mark Cavendish uses a 49cm bike. I thought that was small.

So many variables. Everybody's different, I for example have long legs in proportion to my upperbody and arms, so ride small frames 44cm tcr's and 50cm other bikes, with 110mm stems, saddle setback and handlebar type can also have a part to play some bars have less forward "throw" than others. I prefer Ritchey less throw but a good width on the tops. Not to mention the type of riding engaged in, racing,touring or commuting? Vive la difference.

130mm usually. 120mm if the top tube is a bit long.

30mm on a road bike? Or hybrid?

Just to add some more data:

The stems on my bikes are:

90mm and 110mm

Out of interest, how are you using a 30mm stem, as I thought that the miminum length stem you could have was 30.2mm, and that would be with the bars directly touching the steerer (assuming you are using OS bars with a 1-1/8" steerer), as I believe stems are measured Centre-to-Centre. Is it a custom stem that you are using?

I run a 100mm stem on all my bikes by the way, although about to change one to a 120mm.

various bikes have varying stems, the longest is 110mm and the shortest 80mm

110mm, just in process of being changed to 100mm. It's my poor old back, see.