j814wong

My area has quite a bit of hills that used to be impossible to climb without granny gears but after a few months of riding there, it has become a bit more manageable but eventually, I still ahve to shift back to my granny gear at times.

Currently, my crankset's gearing is 52/42/30T. I'm looking for a new 8 speed cassette and I've come upon the SRAM SRAM PG-850 8-speed Cassette which is compatible with Shimano 8speed drive trains. The rest of my components are Shimano Sora ones with 8 speed on teh back and a triple in the front.

My area is somewhere around Vestal and Binghamton, NY if you want to see what sort of terrain there is.

SRAM PG-850
https://www.amazon.com/SRAM-PG850-11-.../dp/B000NNX2P4
The gearing options are listed

caloso

The size of the cassette is limited by the capacity of the RD. I would get the most teeth your RD can take.

coasting 

up to 27. that seems to be good for me on steep hills and i am heavy.

j814wong

[HR][/HR]One set of gearing options says 11-28T. What does the T mean?

TrojanHorse

Teeth

j814wong

But why do some of them end in T while other's don't? Is this just naming inconsistency?

caloso

Probably.

30x28 is pretty low. I imagine low enough for any hill in your area.

TrojanHorse

It doesn't matter and doesn't affect the cassette in any meaningful way - 12-26T is the same as 12-26. Don't let the T distract you.

j814wong

[SUP][/SUP]would the 52x11 side be enough for me to go fast when I really need to? After all, if there are climbs, there are descents! (to which you all must unanimously say duh)

My original bike had a cassette with 12-25T and a crankset with 52/42/30T

52/42/30T + 11/28T should be enough for tough climbs and fast descents right?

coasting 

when you come downhill, your rolling speed will be faster than any pedaling speed so the 52 is well enough.

j814wong

Thanks for all teh advice everyone! I'm going with the 11-28T cassette,

caloso

52x11@100rpm=37mph

j814wong

How is that calculated? How would changing the 11 to a 12 affect the speed?

JonnyHK 

A few calculators will do this for you.

https://www.machars.net/bikecalc.htm
https://www.bikecalc.com/gear_speed


Yes, a change from 11 to 12 will have an effect on the speed, but probably not enough to worry you.

JimF22003

Might I suggest going with the 11-28 instead?

Homebrew01

Without a 't' it must weigh less.

expatbrit

I can hit over 45mph (downhill!!!)on a mountain bike with 44/11 before I spin out -- and I'm out of shape. I'd think 52/11 would get you up over that.

Is that fast enough

expatbrit

(Whups. Someone quoted maths. I guess I was spinning faster than I thought...)

RollCNY

I would suggest the 12-26, with or without the T. You still have the triple. Your area has short steep hills, and any of the long climbs are fairly shallow grade. I would rather have the closer spaced cassette, especially with only 8 cogs, than the 11-28.

hybridbkrdr

https://www.gear-calculator.com/#

This calculator can give you a visual idea of the difference between gears. So you can see how much of a difference you can have between the gears you use most often...

revchuck 

My first bike was a flat bar "fitness" bike with a triple and eight speed drivetrain. I converted it to drop bars and changed the cassette from 11-32 to 13-26. This gives me the same spacing between gears as my road bikes, and I don't miss the 11t cog. Unless your riding is mostly uphill and downhill with little or no flat, IMO this is a better choice than 11-28.

Phil_gretz

^^ This. It's an 8-speed. 30x26 is plenty low for climbing anything unless the OP is loaded touring. A tighter range with smaller jumps is preferable. He'll be in the middle ring most of the time anyway.

To the OP, the gear ratios are mathematical, with the number of teeth on the rear in the denominator. Going from 12 to 11 teeth is the removal of 1 part in 12. That's an increase of ~8% in pedaling resistance in your hightest gear. It can be a meaningful difference to some, and negligible to others. Stick with the 12-26T, as you'll have a smaller difference BETWEEN gears, which will give you the greatest opportunity to maintain a steady cadence over small variations in the terrain.

Good luck. PG

EDIT: Or the 13-26T recommended above...

Carloswithac

I rode a 30% grade climb last weekend in 30x28. 30% was the highest; it varied from 17-30% within 3/4 of a mile. It was painful, but I did it. I'd go with 11-28.

j814wong

Quoting RollCNY, " Your area has short steep hills, and any of the long climbs are fairly shallow grade"

j814wong

RollCNY, my current setup is 12-25T rear and 52/42/30T front. Even at the lowest possible gears, those shallow grade climbs are tricky. Just how much of a difference does a 12-26 provide over my current 12-25?