How to choose Crank - Rear Cogs combination
 

Well Hi all !

Need Help and sugestion ....
Although i drive bike for long time last year i have spent lots of time exploring bike mecanics so my biggest problem atm is how to choose combination front cogs and casett ....
I have some ideas but like to hear you opinions and how you drive your bike .... double or tripple ..... 7 or 9 speed .... small casett - 11-22 or MTB 12-34....
Most i dirve road of road 60-40 % and atm 70% flat

tnx :-)

to narrow it down.. do you intend to buy a bike or just gears ?

If you're relatively fit and don't have to climb much, you can go with higher gearing.

Do you have a bicycle now? What's the current gearing, and how does it feel? Do you want something a little higher, or lower, larger range, etc?

Sram makes an 11-32, so you don't need to give up your high end. I bought one monday. I forgot to ask what sizes he had, I just said I wanted a shiny one! Haha. I think the chrome plating makes it last a little longer, and it's easier to tell if it needs cleaning as opposed to a black cogset. I haul a large trailer, so I need the low gears, but I like having the eleven, too ("This one goes to eleven!" ~ Spinal Tap). Especially because my large chainring is only a 44 on that bike (a mountain bike that stays on pavement 95% of the time).

I like triples, and wide ranging cogsets. With eight cogs, there seems to always be one that is just right, but some people prefer their gears more closely spaced and don't want or need the very low gears.

Depends on how you like your current gearing. If you never use your lowest gears, you might go with a smaller cogset, and/or larger chainrings. If you find yourself sometimes wanting a lower gear than what you have, you might want to get a cassette with bigger cogs and a triple crankset.

On my modified 7.FX I have a 30/39/52 triple crank, and a very narrowly spaced 12-23 10-speed cassette. I like the triple because it gives me the really low set of gears while still allowing me to have a closely-spaced cassette that gives a wide range of "fine tuning" gears when I am riding on the 39 or 52 front chainrings. I place a lot of value on the ability to "fine tune" what gear I'm in. I'm sure I shift a lot more often than most people as a result. If I didn't have a triple I'd have to have a wider range cassette with a climbing gear. I don't ride in a very hilly area, so I haven't met a climb that the 30/23 combination couldn't solve. Truth be told, it is extremely rare that I use the 30 chainring up front. I don't think I've ever gone to 30/23 but I know eventually I'll go for a ride somewhere it is required, so I like the peace of mind! Cheers, Matt.

I have Surly LHT 24/36/48 chain rings and a 9 speed 11-34t cassette.

My riding is 60% flat, 40% hilly, mostly on road, but some gravel. A lot of the flat and most of the hill miles are with 30 to 45 lbs loaded on the bike. The low granny gear (18 gear inches) is more important to me than a real high end, or even closely spaced gearing.

I ride 80% hills because of living in a canyon... but don't like the gearing gaps of large heavy rear cassettes, so I run this...
http://i17.photobucket.com/albums/b9...e/IMG_3063.jpg

It's a 24-34-46 "mountainbike" crankset with an ultra close ratio 12-13-14-15-16-17-19-21 8 speed "Time Trials" cassette. It yields seamlessly spaced non-chaincrossed ratios from 31 to 104 inches.



Greg

I really like come to work and with my first coffe read about bike ..... so you have make me nice morning :)

old and new - well im still considering redesign my 6 year old bike (TREK 7100) so im looking for best combination atm i have Shimano Mega cassette and M151 .... (but buying a new bike is option-
although recession have hit my bike too :notamused: )

I actually like idea of Triple with long range cassette because it give me feeling that you can drive
everywhere in right gear ... something like MattyA said you have fine tune all time (i m shifting gears on every change of angle or base .....)
Im not shure do i need to go so low 24-34-46 because im more on flat than hill .....

qmscd15 i also like your idea of chrome plating so you can see if they need cleaning but they are not looking nice to me .... so will consider beauty over use .... :lol:

Tnx all ... little more material to think :D

P.S. sorry for my english not best one :innocent:

True... You don't need that, especially with Megarange rear gears. The only reason I do is that I live in an extremely steep canyon.

(your English is fine... :thumb: )

When I got my first ten-speed in the 1970's, I believe the smallest cogs available were 13 and there were only five cogs on a freewheel. Your bike with nine cogs, and an 48x11 high gear has both a higher top end than my first ten speed (52x13), a much, much lower low, and more closely spaced gears! :thumb:

Interestingly, oldpedalpusher with his "corn cob" freewheel doesn't have the top end that you have despite your big cogset and extremely wide range of gears. His compact triple still allows a wide range of gears. He has given up a little top end and doesn't have a super low granny, but he has lots of gears in the range he needs and the very closely spaced gears he likes.

Both well reasoned gearing choices, but quite different, which illustrates how gearing can be tailored to meet a rider's needs and preferences.

A 31 inch low gear gets me up the hills just fine... but I can't push anything higher than 104 inches... because I'm old. :roflmao2: