Gearing help for hills !!

ballbag

I have entered the Sheff100 this year and feel I need to change my gearing.

I currently have a standard Shimano Ultegra 9 speed 12-25 cassette and 39-53 double chainset, and although I haven't needed to get off the bike and walk up a hill yet this maybe due to riding in my area (nottinghamshire/leicestershier) with gradients not much more than 15%. The Sheff100 is going to be a little different.

Anyway. I am pretty sure I am going to change to a 34-50 compact chainset but wonder if it is also worth switching the cassette to maybe a 12-27. Will I really get much benefit with the extra 2 teeth on the large cog? Any help on this may save me £40 or not.

Thanks in advance.

LeighB

Before replacing your chain set I would try a 12-27 first as 39 x 27 is quite low gearing and may be ok for what you need.A couple of years ago I swaped a 25 tooth for 28 and it was like a mountain bike wheelieing up hills!

onthefells

see below gear ratios

39/25..... 42.1
39/27......39.0
34/25......36.7


depends what riding you do. if you are going to be doing long, hilly sportives and no time trials I'd get the compact chainset as what you lose on the big cog won't count for as much as you'll gain going up the 20%ers!!

Anonymous

I have a 53-39 and 12-27 on the back, runs well, got me through the forest of dean sportive nicely, even the 25% climb after the 2nd feed stop that wasn't on the profile, sods.

maddog 2

I think 34/50 and 12-27 is ideal for hilly conditions. Nice to have a decent low gear so that you can get up steep climbs at a decent cadence, or when you're tired. If you prefer to grind/honk that's fine, you don't have to use the low gears.

note that 12-27 is the same as 12-25 except for the biggest two sprockets:

21-24-27 vs 21-23-25

...so there's very little in it in terms of shifting

see http://www.sheldonbrown.com/gears/ for all you need to know

sheffsimon

ballbag wrote:

I have entered the Sheff100 this year and feel I need to change my gearing.

I currently have a standard Shimano Ultegra 9 speed 12-25 cassette and 39-53 double chainset, and although I haven't needed to get off the bike and walk up a hill yet this maybe due to riding in my area (nottinghamshire/leicestershier) with gradients not much more than 15%. The Sheff100 is going to be a little different.

Anyway. I am pretty sure I am going to change to a 34-50 compact chainset but wonder if it is also worth switching the cassette to maybe a 12-27. Will I really get much benefit with the extra 2 teeth on the large cog? Any help on this may save me £40 or not.

Thanks in advance.

Sheffield 100, hardest climb there is out of Edale up to Mam Nick, which I train on fairly regularly on, and Ive got 39-53 and 12-25. 1:6 gradient in places so you might be OK with what you have.

Im assuming it goes anticlockwise round the route, was trying towork it out from the profile!!

Might enter it myself.

MatthewBulmer

I run a 9 speed SRAM 11-28 cassette with a compact and I find it ideal for the terrain I train on (south pennines.) There are some largish jumps in gear ratios between the bigger cogs, but I reckon the ability to get up the hills at a decent cadence more than compensates for this.

ballbag

Thanks all very much for your help. I think I will take the plunge. I will try the cassette first, then maybe the chainset.

SheffSimon - Looking at the profile would suggest there are several 20%+ gradients with one 30% right at the start, but I don't think any are particularly long. So yes you maybe right with my existing setup, but I don't want to take the chance.

rickhotrod

If the 12-27 isn't low enough, try 49/36 rather than 50/34.

When double shifting, the 49/36 feels just like the 53/39 as there is the same percentage difference between the 49/36 rings and the 53/39 rings (36% jump in both cases).

With a 50/34 you will be messing about in the 15 and 16 sprocket before changing up, whereas with a 49/36 (as with a 53/39) you can change up to the big ring when on the 17 sprocket. Also, it's easy to spot the 17 sprocket as it's bang in the middle of the cassette (12,13,14,15,17,19,21,24,27).

sheffsimon

ballbag wrote:

Thanks all very much for your help. I think I will take the plunge. I will try the cassette first, then maybe the chainset.

SheffSimon - Looking at the profile would suggest there are several 20%+ gradients with one 30% right at the start, but I don't think any are particularly long. So yes you maybe right with my existing setup, but I don't want to take the chance.

I live about a mile from the start, deffo no 30% gradients around there. Not sure of the hills the far side of the Buxton/Ashbourne road but I would think any 20%+ will be short enough to power up on the gears you have. Other than that Shutts Lane near Over Haddon has a steep bend.

Feed station seems in a strange place, only one after 30km with another 130 to go??

Tough day out all in all!

onthefells

looking at the map, the hill near the start you are talking about looks to be Long Line which is 1 mile long but nowhere near 20% gradient. It makes for a tough start to the ride though as you turn left at Ringinglow and ride up to Stanage immediately after that so there are a couple of steep hills in the first 3-4 miles before you will have warmed up.

as Simon says the real big climb looks to be up to Mam Nick from Edale. I used to live in Edale and have been up there loads of times. Its roughly 1.3 miles long with no respite and a very steep bit in the middle. Tom Simpson won a hill climb race up there in 1957 a short while before competitng in the British Hill Climbing Championship up Winnats Pass a few weeks later (which mercifully isn't part of the route!!)

everyone in the ride will get up it with few problems I'd think but its fair to say those hills near the start of the ride will be taking their toll 70 miles in!!

sheffsimon

onthefells wrote:

looking at the map, the hill near the start you are talking about looks to be Long Line which is 1 mile long but nowhere near 20% gradient. It makes for a tough start to the ride though as you turn left at Ringinglow and ride up to Stanage immediately after that so there are a couple of steep hills in the first 3-4 miles before you will have warmed up.

as Simon says the real big climb looks to be up to Mam Nick from Edale. I used to live in Edale and have been up there loads of times. Its roughly 1.3 miles long with no respite and a very steep bit in the middle. Tom Simpson won a hill climb race up there in 1957 a short while before competitng in the British Hill Climbing Championship up Winnats Pass a few weeks later (which mercifully isn't part of the route!!)

everyone in the ride will get up it with few problems I'd think but its fair to say those hills near the start of the ride will be taking their toll 70 miles in!!

Dont think riding back up Frogatt Edge is gonna much fun right near the end of the ride either. Its my favourite climb when I'm coming back into Sheffield from the Peak, always try to nail it in big ring, not with 100 miles in the legs though!!

onthefells

Simon, hadn't twigged we came up there at the end...mmmm.....lets hope the weather is ok as it could be pretty miserable riding that distance over those hills in bad weather!!

sheffsimon

onthefells wrote:

Simon, hadn't twigged we came up there at the end...mmmm.....lets hope the weather is ok as it could be pretty miserable riding that distance over those hills in bad weather!!

Rode Spud Riley last year in torrential downpour, part of it on similar roads to this one, south of Buxton. Was a hard day out with endless short, steepish climbs and I didnt really know the roads. I dont mind the rain so much, once you are soaked through a bit more makes no difference.

At least with this one, up to Peak Forest, and heading back from Youlgreave, they are part of my regular training ride areas so at least I know whats coming, and it will feel like I'm heading home at the end. I also like the fact that I can ride to the start and ride home from the finish, bit of a novelty!