Road Cycling - Why Downtube Shifters??

I was looking at some huffy style "el cheapo" "road bikes" today, and i noticed that these bikes don't have downtube shifters, but rather the shifters are mounted at the head tube. This seems to me a much more convenient and efficient location to put the shifter than the downtube, but there must be something bad about it or else the REAL road bikes wouldn't be putting the shifter on the downtube.

Can anyone explain why my reasoning is wrong?

weight...cable stretch...

I used to have the problem that I would unintentionally upshift my rear gear when I peddled up hill and stood up - kicking the head tube mounted shift lever with my knee, just at the very worst time when I needed some good strength to keep up speed. So on top of the stretching and weight as mentioned above, for me that is not the ideal position for shift levers.

my mate bought his first road bike for 100bux NZD and shifted the shifters from the down tupe to the ends of the handlebars, on the drops there. He wrapped the cables and that under the bar tape like the brake cable and yer he reckons it is good

Brendon
:beer:

My wife had shifters mounted on the vertical part of the stem. Cable length was long so worked ok with friction, but I'm not so sure about indexed.

Big disadvantage is that when she had her accident last year (v nasty) she hit the stem and punched a small hole under her ribcage (not right through thankfully)

The stem is a really dangerous place for shifters.
DT shifters are very precise and quick to use, because of the short cable. When you change, you lean down, lowering your centre of gravity . For a stem shifter, you have to raise your centre of gravity, which makes shifting more difficult under some conditions.

My DT friction shifters are a lot quicker in the shift than my Campy integrated ones. There is no delay, just an instant movement of the chain.

I used to have downtube shifters on the 1992 Avanti Ultra that I had. On the beginners ride that I went on when I first started riding, I had the oldest and crappiest bike, but i could change gear MUCH quicker than anyone else, especially from like 1st to 6th (top) on the rear.

If you are riding in the drops the downtube shifter is much easier to reach than is one on the headtube/stem. Same with the integrated shifters. Less disruption of your riding position. Not sure the cable length/stretch makes much difference consider how much longer the cables are for the integrated shifters than they are for either the headtube/stem shifters or downtube shifters.

Like clipless pedals, I will never go back to any other style than the integrated shifter. I spend the great major of my riding "on the hoods" and everything is right at hand.

Hi Folks,

There is probably a slight weight saving - the integrated brake lever & shifter adds a bit of weight to the handlebars. Then there are all the unsightly cables sprouting from the 'bars and scraping the paint off the head tube.
Levers mounted on the stem are a bit dangerous - somewhere I heard them referred to as gut-rippers... I have an older bike with these and the process of shifting does make the bike feel less stable. Bar - end shifters are better in this respect.

Of my two most frequently ridden bikes one has integrated shifters and the other DT mounted levers. These are the same group-set (Shimano Sora) - and I enjoy both. If anything, the indexed DT shifters are easier to set up and have the cleanest shifting I have ever used. There is much to be said for the simplicity of downtube shifters :)

Cheers,

Ed


[edited - I got distracted by work halfway through my forst posting :) ]