Short head tubes - advantages & disadvantages

[olivertomberry]

Got offered a lovely steel frame from a friend - top tube geometry is bang on at 550mm, but the headtube seems very short - only 105mm (my other bike is 140mm).

Obviously this means it will require more spacers to bring it up to a more level riding position. Just wondering if there any advantages to having a lower cockpit other than for racer types - I just want a pretty relaxed ride for long distance.

Thanks

Oliver

 

[John_S]

Hi Oliver,

This is very much going to be a personal preference type of question. Also it's not that easy to make a complete judgment on the frame geometry based just on just the top tube and headtube because there are so many factors involved, angles, whether it's a slopping or fairly flat top tube etc etc.. But based solely on that to me my guess would be that it sounds like it could be a more race orientated bike which might be great if you want to race and get into aero positions but not so great if like you've mentioned you want a relaxed ride by which to you mean a more upright position rather that aggressively aero?

Just as a rough guide from some of my experience with bikes (and I'm not a frame or geometry expert and I'm sure others will have much more insightful advice to give) based on what has and hasn't worked for me I would not consider a bike with a head tube of only 105mm. I'm between 5'10" and 5'11" and I like a relaxed and comfortable long distance riding position and comparing two bikes I have one which according to the geometry chart has a 'horizontal / effective top tube length of 550mm' and it has a headtube length of 150mm and it has a fairly long reach and lowish (for my preferences anyway) stack and I don't find this bike particularly comfortable but it also has a seat angle of 74 degrees which I don't think helps. Having found this bike a bit of a pain on long distances I went in search of a bike with a more relaxed riding position and got a bike which according to the geometry charts has a top tube length of 565mm and a head tube length of 175mm and with everything else considered the reach is shorter than my other bike and the stack higher and I find it much more comfortable on long rides.

If you can find out the full frame geometry of the frame including the stack and reach measurements and then compare that to other bikes that you either have or haven't found comfortable that might help you.

For me geometry is now absolutely key when buying a bike having made mistakes in the past and learned my lesson. Rather than getting caught up in whether a bike is a good deal, if it has the right groupset, specs etc. first and foremost for me the geometry has to be right for me and then the other things can fall into place first of all.

But if the geometry isn't right then no matter how good a deal the bike is, how good it is or how nice the components are then it's not going to be a pleasure to ride over long distances. Yes you can tinker with things to adjust the set up of the bike to suit you which all of us have to do with off the shelf bikes that we buy which are mass produced as opposed to a nice bespoke frame built for us as a one off by a custom frame builder. It's perhaps best of thinking about tinkering with things like the set up of the bike just to get the very end bike fit set up just right for you rather than trying hard to overcome a geometry that isn't right for you by using loads of spacers or other options.

None of this is to say that the frame that you're being offered won't be right for you but I'd look at it carefully first before making a decision.

Hope that helps and good luck finding the right frame/ bike for you!

John

 

[SkipdiverJohn]

I have to agree with @John_S the whole geometry "package" is very important, although I do use the head tube length as an important visual rule of thumb when buying a secondhand bike. Likewise I want an upright, comfortable position, not cripple myself by breaking my back hunched over the front wheel. When looking at any potential purchase, I want to see plenty of daylight between the point where the top tube and down tube join the head tube. A minimum of three, and preferably four, tube diameters. That means even without being able to measure, I can tell the head tube will be north of six inches tall, and likely as much as seven inches.
It's not the whole story, because a short frame can have a taller head tube (if the shortness originates at the front, and not from a steep seat tube angle), and a frame with a long top tube can have a shorter head tube than it's size might suggest - but the general rule of thumb holds good is you will not get a relaxed upright riding position if the head tube is short in relation to the frame size.

 

[si_c]

Seems a bit short to me, my lower front end bike is 215mm with a 5" bar to saddle drop, which is fairly low.

Doesn't seem that the bike is conducive to a relaxed upright position. Unless the measurements are incorrect.

 

[kingrollo]

If the handle bar stem is a modern clamp - a more discreet way of adding a bit of height is riser handle bars.

 

[rogerzilla]

You're not supposed to have more than about the steerer diameter's worth of spacers under the stem (call it 30mm for nost bikes) for non-ferrous steerers. This is a big limitation. So you end up using a riser stem, which looks gawky on a road bike.

 

[SkipdiverJohn]

You're not supposed to have more than about the steerer diameter's worth of spacers under the stem (call it 30mm for nost bikes) for non-ferrous steerers. This is a big limitation. So you end up using a riser stem, which looks gawky on a road bike.

Or you can just ride old-school bikes with quill stems and you don't get all these silly problems in the first place....

 

[rogerzilla]

Or you can just ride old-school bikes with quill stems and you don't get all these silly problems in the first place....

Quills don't fully solve the problem, as most quills are quite short. There are a few long-quill stems around like Nitto Technomic but your average Cinelli quill has a tiny range of adjustment. Long quills don't do much for stiffness when climbing either, being only held at the bottom. You can see where the locknut lip chafes at the quill as it rocks about after only a few miles' use.

The main thing is to get the right frame size.