Geometry!

rukh

After some good advice on this forum, I'm looking for a bike with a drop bar (so road or cyclocross), 700x28c tyres, 105 or Veloce components... but bloody "geometry" is driving me crazy!

I want a relaxed upright ride. As you gathered, I'm leaning more towards comfort than speed :P So how do I tell what is what??

Ribble bikes talk about "Sloping top tube geometry" - does that mean comfy?

Thanks
Rukh

redddraggon

rukh wrote:

Ribble bikes talk about "Sloping top tube geometry" - does that mean comfy?

Nope, it means exactly what it says - the TT is sloping rather than horizontal.

For comfort, you'd probably want a bike with a longer headtube.

meagain

Compare if you can: headtube (as above), chainstay length, wheelbase and front-centre (b/b to front hub). By and large the longer the more relaxed. Seat and h'tube angles also worth considering.

And whatever the tendency to bias here, if you want "relaxed upright", WHY drops?

Bronzie

Used to be the case that "relaxed" geometry (ie more comfy) had a seat and/or head tube angle of 71° or so. Race geometry generally 73 or 74°. (This is the angle of the tube measured against the ground, so 90° is vertical).

Not sure if this still applies in the modern age of carbon everything, but certainly a steel frame with relaxed seat and head tube angles (and hence slightly longer chainstays and longer wheelbase) is more comfortable.

The downside is that relaxed geometry will respond slower (steering input) and will feel more sluggish when you push on the pedals.

rukh

meagain wrote:

And whatever the tendency to bias here, if you want "relaxed upright", WHY drops?

Because everyone here swore blind they were awesome, so I went and tried them and though they were okay... and perfect with the addition of frog legs

meagain wrote:

Compare if you can: headtube (as above), chainstay length, wheelbase and front-centre (b/b to front hub). By and large the longer the more relaxed. Seat and h'tube angles also worth considering.

<sigh> I think I'll just have to trust the pimply guy at my LBS...


Cheers,
Rukh

topdude

Have a look at the Giant SCR, It has a longer head tube, sloping top tube (compact geometry), Larger clearances for wider tyres / mudguards, overall a good looking bike with a more upright ride than most standard road bikes. Also available with different component levels.

Monty Dog

All of the big brands produce 'sportive' bikes, such as the Specialized Roubaix, aformentioned Giant SCR, Trek Pilot, Cannondale Synapse...plus countless others which offer a longer headtube, slightly more relaxed head/seat angles plus a longer wheelbase. apart from out and out racing, most cyclists would barely notice the difference in terms of performance.

iga

On the cyclocross front the the Kona Jake is quite relaxed (between 70 and 72 degrees for head/seat tube angles depending on frame size). The highly rated Focus Mares Cross is a bit racier (up to 74 degrees), Wiggle have geometry tables online.