No idea about the type of cassette, gears and drive train that I need. Decent ground clearance. The build it guy looked at me like a fool (probably realised I know zilch) and said, have a look around & let me know. I felt so silly not knowing the basics (I did tell him I just like to cycle and go on long rides involving some steep climbing).
How do I avoid this situation ?
PS : Feel silly asking here but I rather be silly in here ( at least no one is judging me).
Some people like the simplicity of a "1x" - single chainring at the front and only a derailleur at the rear, but unless you go for a big number of sprockets on the cassette (I'd say more than 10), then if you have a large range of gears (low to high), you get bigger steps between gears - or you have a smaller range and smaller steps. But when you go for big numbers of sprockets on the cassette, the price goes up.
As time has gone by, sprockets on cassettes have gone smaller at the high end and bigger at the low end, and the number of sprockets has gone - doubled - so nowadays it is easier to find a wide range cassette with smaller steps. In the past, if you wanted a wide range with reasonable steps between gears, you had to go for a "3x" (three chainwheels at the front and a front derailleur to shift the chain).
Gear ratios are usually expressed in "gear inches" - basically the diameter of the wheel of a direct drive to achieve the same rate of progression as the gear. This has an historical context - Penny Farthing bikes were sold by front (direct drive) wheel diameter and when the safety bicycle was invented, people wanted to know what the gear was equivalent to in a penny farthing. It is worth becoming familiar with gear inches - it makes it easier to discuss gears.
There is debate and personal preference as to what the sweet spot is for range, increment and cost. Personally, I think that a 2x9 might be your sweet spot.
To get a better understanding of gearing choices, take a look at
this website. The link gives two bikes - the top one is the Voodoo Marasa linked to in a previous post and the bottom one is my drop bar touring bike. You can change the labels, the pedal cadence, tyre size, slide the cogs up and down the scales etc and see the results of different gearing set-ups.
For what it's worth, I like low gears and wouldn't like to go much higher than 24" for a bottom gear and I prefer a lot less - my usual bike has a bottom gear of 19". I also don't make use of high gears and I rarely go above about 85". A 100" gear with a pedal cadence of 90rpm will give you a speed of about 27mph (you can get this information from the website I linked to). Going downhill, you waste energy pedalling hell for leather and are better off tucking in to reduce air resistance and not pedalling, if you're not a racer. On the hills of north Warwickshire, I usually reach over 30mph without pedalling.
Most people when choosing a drivetrain, go for Shimano or Shimano compatible. Be aware that anything above 9spd will have different cable pull requirements for gear shifting, and road systems can differ from MTB/hybrid systems - so it's not a case of anything Shimano is always compatible.
And unless you're looking at hydraulic brakes or electronic shifting, a bicycle is made up of parts that use basic mechanical principles. Things may look complicated, but usually they end up being more straightforward.
