Geometry?

funkyg

Hi guys,
I'm new to road biking. I currently have a mtb but have just ordered my first proper road bike. (Ridley R6 http://www.merlincycles.com/ridley-r6-el-road-bike-61377.html )
I've been browsing many forums while waiting for my cycle scheme voucher to arrive and lots mention the geometry of a bike saying its sporty or racy or relaxed. Can anyone please explain what this means exactly? I'm guessing it's something to do with how low you are on the bike. On my bike it's listed as 'traditional' whatever that means!

kajjal

If you look up reach and stack this will give you an idea. The difference is roughly between a stretched out head down racing biking and a less stretched out more upright bike with less drop from the saddle to the handle bars. There is no right answer , it is just down to personal preference.

If you read up on bike setup this will give you an idea of bike setup options. My road bike is setup with only and inch of drop from saddle to handle bars as I prefer being more upright, others have quite a few inches of drop as they prefer a more head down position.

owenlars

It also determines the relationship between height, wheelbase and things like length of chain and seat stays and hence handling.

For example a longer seat post will put the saddle further from the handlebars than a shorter seat post ( all other things being equal) therefore things like seat and chain stays will be longer and hence probably less stiff and hence more comfortable. The wheelbase will also be longer with less twitchy handling.

In short the geometry determines handling, comfort and stiffness and how you need to design the tubing to achieve it.

In general racing bikes have a short wheelbase and hence shorter and stiffer tubing for quicker handling and less power loss through flex. Touring bikes have longer wheelbases and hence longer more comfortable tubing with more forgiving handling. There are a load of other variables involved in this as well of course.

This all has to be achieved whilst still making a bike that fits the rider so all things are a trade off.

team47b

Look at the angles in the frame description.

Seat tube angles vary from about 70-75 degrees, steeper angle moves the saddle forward while a shallower angle moves it back. Steep is fine an aero crouch, as the more open hip angle doesn't constrain breathing or power transfer. It's not so good for more relaxed riding as it transfers more of your weight from your ar5e to your hands, which can cause hand aches and numbness.

Monty Dog

'Traditional' means horizontal toptube and fairly short headtube in comparison to 'relaxed' geometry which will likely feature an extended headtube, a sloping toptube and a slightly longer wheelbase. Set-up is just as important - reduced saddle to bar drop, slightly shorter stem and shallow drop bars also help on the comfort stakes. As you're new to road bike, be conservative with your position and give your body time to adapt - deep-drop bars and your ar$e in the air might look cool but you'll likely suffer in the comfort stakes.