Big ring vs little ring

[earlestownflya]

i never have my chain off the 53 ring.i can get all the range on the back with just a small amount of chain tinkle on front mech on the extreme crossover.i only have a short 100m ramp on my cycle to work,which i get out of the saddle for.try keeping it on the big ring all the time for a while it will transform your cycling experience...i believe...

 

[Lonestar]

Actually I've got a knee injury at the moment.Not sure if it's caused by high gears and the fact I had a hell of a lot of weight in the backpack on the last commute back.(including 2 bottles of Wine/2 bottles of Gin/Bike tools and three locks)...Im on holiday now so no commutes till next month.Out on the bike tomorrow (non fixie) for blood test tomorrow.

 

[slowmotion]

Recently, most of my miles have been in very flat parts of London. I lost the use of my front derailleur a month ago so the bike is stuck on the 34T small ring until I get round to fixing it. I've always been a bit of a gear masher, living on the big ring for most of the time. It's been quite an education to be riding with a much higher cadence, and I really quite like it. It's worth trying for a bit.

 

[Sharky]

Recently, most of my miles have been in very flat parts of London. I lost the use of my front derailleur a month ago so the bike is stuck on the 34T small ring until I get round to fixing it. I've always been a bit of a gear masher, living on the big ring for most of the time. It's been quite an education to be riding with a much higher cadence, and I really quite like it. It's worth trying for a bit.

Similar experiences. The front changer was playing up, plus was getting fed up with the wide spread between the 34 & 50, so ended up ditching the front changer and switching to a single 40t chainwheel. Now have range from 40" to 81" and I too enjoy the higher cadence you develop.

 

[berty bassett]

i run 50 36 on all bikes and find if i change from big to little then 2 clicks on cassette i am in a ery similar gear to what i was before i touched the gears , but if i was in the fens in big cog and do that , it does seem very slightly easier - quite willing to accept its all in my head but i just wondered if a bloke would jump up spouting calculus that would say there is 0.0000001 kj more effort due to friction on the ferlangee

 

[screenman]

i run 50 36 on all bikes and find if i change from big to little then 2 clicks on cassette i am in a ery similar gear to what i was before i touched the gears , but if i was in the fens in big cog and do that , it does seem very slightly easier - quite willing to accept its all in my head but i just wondered if a bloke would jump up spouting calculus that would say there is 0.0000001 kj more effort due to friction on the ferlangee

Very or in the case above ery being the big word in the post above, it is likely a lower gear.

 

[mustang1]

Actually I'm the opposite.

My head tells me its easier being in the large ring and large cog rather than small ring and small cog.

I've always wondered because if I ever bought a single speed, I wasn't sure if I should buy one with large ring plus small cog or smaller ring but larger cog. Mathematically I guess (I really don't know) that you're applying the same power and getting the same speed. I also wondering in terms of how quickly the chain and cog wear when they are of different sizes.

 

[bpsmith]

I would imagine that a 22 tooth sprocket would wear 50% less than an 11 tooth sprocket @mustang1.

 

[Dan B]

bigger cogs => less wear on each tooth, less chain friction (wider turn radius)
smaller cogs => lighter

Take your pick

(Also I think, but have not checked, that there is quite a high lower bound on the size of a freewheel, so if you wanted something you could flip to SS you would want to check there's a freewheel in the size you'd need)

 

[nickyboy]

try keeping it on the big ring all the time for a while it will transform your cycling experience...i believe...

I look forward to enjoying the "experience"of walking up the hills if I keep it in the big ring around here

 

[Cubist]

Anyone got any links to physics leverage calculations based on the length of the crank arms and the position of the chain relative to the fulcrum? Does it make a difference in two gears of the same tooth to tooth ratio? For instance, if a 70 inch gear combination is selected using small front and small rear, is the leverage force required to turn the cranks the same as a 70 inch gear using large front and large rear?

 

[Globalti]

This chart shows the overlap:

All you need to do is make sure the chain line isn't too "bent" by shifting the chainring in good time.

 

[nickyboy]

Anyone got any links to physics leverage calculations based on the length of the crank arms and the position of the chain relative to the fulcrum? Does it make a difference in two gears of the same tooth to tooth ratio? For instance, if a 70 inch gear combination is selected using small front and small rear, is the leverage force required to turn the cranks the same as a 70 inch gear using large front and large rear?

Putting to one side the fact that there may be different mechanical inefficiencies small/small v large/large there will be no difference in the force required for the same number of gear inches.

What you have to consider is the forces being overcome in moving the bicycle forward by 70 inches. You've got air resistance, rolling resistance, mechanical inefficiencies and gravity (if you're ascending). With the mechanical efficiencies proviso above, all these resistive forces are the same small/small or large/large. I suppose you could raise an argument that the air resistance may change very slightly but I can't believe the effect will be measurable

I don't know what work's been done on mechanical efficiencies but it feels that large/large will be more efficient as the angle of incidence between the chain link and the sprocket tooth is less acute

 

[earlestownflya]

I look forward to enjoying the "experience"of walking up the hills if I keep it in the big ring around here

don't walk..drop it to the small ring..obviously there are circumstances were you can't push a big ring. unless you've got legs like an ostrich,i used to use my smaller 39 ring all the time,until i switched to the 53,it's easier to get up good speed and maintain it and cycling to me,seems to take less effort than if you were switching between rings...similar to the enjoyment of riding a single speed bike,which are so popular now,and as we all know a single speed will smash most multi speed carbon bikes on the flat

 

[Drago]

I'm gonna sit on the fence. Obviously the big ring is harder but it also feels smoother, more natural, somehow easier to find a rhythm so where I can do so without having a hernia I tend to use the big.