New rear cassette for hills, numpty question
Discussion
I'm not very good with the technical side of bikes so apologies if I'm asking the obvious.
I'm doing the Cote de Holme Moss in a couple of weeks, 3,300m of ascent over 141km - http://app.strava.com/routes/2451748
My rear cassette is currently 25, so I'm looking to swap it for something to help me spin up the hills. My gearing is 9 speed Shimano Sora, is there any issue swapping the rear cassette for a Sram PG950 (http://www.wiggle.co.uk/sram-pg950-9-speed-cassette/)? And what size would you go for - it's available in 11-32 or 11-34, or should I be going for 30 or 28 from a different brand?
Bear in mind the reason I'm swapping the cog is that I've been injured for most of the year, so my fitness is suffering badly and would like to spin up the hills as I'm quite worried I won't make it to the end.
Any help appreciated.
I'm doing the Cote de Holme Moss in a couple of weeks, 3,300m of ascent over 141km - http://app.strava.com/routes/2451748
My rear cassette is currently 25, so I'm looking to swap it for something to help me spin up the hills. My gearing is 9 speed Shimano Sora, is there any issue swapping the rear cassette for a Sram PG950 (http://www.wiggle.co.uk/sram-pg950-9-speed-cassette/)? And what size would you go for - it's available in 11-32 or 11-34, or should I be going for 30 or 28 from a different brand?
Bear in mind the reason I'm swapping the cog is that I've been injured for most of the year, so my fitness is suffering badly and would like to spin up the hills as I'm quite worried I won't make it to the end.
Any help appreciated.
Do you know which version of Sora? It changed 2-3 years ago. The old style has little thumb shifters for changing to a smaller cog, the current style ("3500") has the same two lever style as the higher up groupsets.
The limitation on maximum teeth your cassette can have is your rear mech cage. If it's 3500, the standard cage should be able to handle up to 32 teeth IIRC. If you want a bigger cassette than that even - an MTB cassette, for example - it would be possible but you'd need to fit a long cage as well.
Edit - Assuming it's 3500, either that SRAM 11-32 or the Shimano HG50 11-32 would be good choices, I think. Neither are much more than a tenner. You could get one and go find some hills and see how you get on. If you then think you need more teeth still, you could look into changing the cage at that point.
The limitation on maximum teeth your cassette can have is your rear mech cage. If it's 3500, the standard cage should be able to handle up to 32 teeth IIRC. If you want a bigger cassette than that even - an MTB cassette, for example - it would be possible but you'd need to fit a long cage as well.
Edit - Assuming it's 3500, either that SRAM 11-32 or the Shimano HG50 11-32 would be good choices, I think. Neither are much more than a tenner. You could get one and go find some hills and see how you get on. If you then think you need more teeth still, you could look into changing the cage at that point.
Edited by SixPotBelly on Thursday 18th June 13:34
SixPotBelly said:
Do you know which version of Sora? It changed 2-3 years ago. The old style has little thumb shifters for changing to a smaller cog, the current style ("3500") has the same two lever style as the higher up groupsets.
The limitation on maximum teeth your cassette can have is your rear mech cage. If it's 3500, the standard cage should be able to handle up to 32 teeth IIRC. If you want a bigger cassette than that even - an MTB cassette, for example - it would be possible but you'd need to fit a long cage as well.
Edit - Assuming it's 3500, either that SRAM 11-32 or the Shimano HG50 11-32 would be good choices, I think. Neither are much more than a tenner. You could get one and go find some hills and see how you get on. If you then think you need more teeth still, you could look into changing the cage at that point.
Cheers - it's the newer version without the thumb shifters. Sounds like 11-32 is the way to go. I'll see if I can get one delivered before the weekend and get them swapped over. The limitation on maximum teeth your cassette can have is your rear mech cage. If it's 3500, the standard cage should be able to handle up to 32 teeth IIRC. If you want a bigger cassette than that even - an MTB cassette, for example - it would be possible but you'd need to fit a long cage as well.
Edit - Assuming it's 3500, either that SRAM 11-32 or the Shimano HG50 11-32 would be good choices, I think. Neither are much more than a tenner. You could get one and go find some hills and see how you get on. If you then think you need more teeth still, you could look into changing the cage at that point.
Edited by SixPotBelly on Thursday 18th June 13:34
JQ said:
Cheers - it's the newer version without the thumb shifters. Sounds like 11-32 is the way to go. I'll see if I can get one delivered before the weekend and get them swapped over.
I've just done some double checking and discovered Sora also has a short cage option I wasn't aware of. That has a design maximum capacity of only 27 teeth. If your bike came with a 25 it maybe you have that short cage. Sorry for the false information earlier.Cheers. Is there any way of me checking which I have? The bike's currently in the basement so I can do a visual check.
This is the bike : http://www.decathlon.co.uk/triban-500-road-bike-id...
and this is the description of the chainset : "Shimano SORA 50/39/30 triple chainset, 9-speed 12/25 cassette, SUNRACE 9 speed 12x25 (12/13/14/15/17/19/21/23/25)"
This is the bike : http://www.decathlon.co.uk/triban-500-road-bike-id...
and this is the description of the chainset : "Shimano SORA 50/39/30 triple chainset, 9-speed 12/25 cassette, SUNRACE 9 speed 12x25 (12/13/14/15/17/19/21/23/25)"
From the picture on the website, I'd say that is the longer cage one, so good for up to 32T. Obvious caveat being your bike may be different to the one in the press photo.
You can see for yourself the visual difference between the short cage (28T) and medium cage (32T) derailleurs on wiggle
http://www.wiggle.co.uk/shimano-sora-9-speed-rear-...
You can see for yourself the visual difference between the short cage (28T) and medium cage (32T) derailleurs on wiggle
http://www.wiggle.co.uk/shimano-sora-9-speed-rear-...
Cheers. Having phoned Decathlon they have confirmed it's the mid cage.
As for suitability, I honestly don't know, it was a suggestion from a cycling buddy - I'm no hill expert so I did some hill reps on Tuesday and was grinding my way up in the highest (lowest?) gear, I know Holme Moss is going to be a lot steeper, so am keen to have an extra couple of gears to go to. I'm not looking to win the event, crossing the finishing line without walking up the hills is my goal.
As for suitability, I honestly don't know, it was a suggestion from a cycling buddy - I'm no hill expert so I did some hill reps on Tuesday and was grinding my way up in the highest (lowest?) gear, I know Holme Moss is going to be a lot steeper, so am keen to have an extra couple of gears to go to. I'm not looking to win the event, crossing the finishing line without walking up the hills is my goal.
I may be reading some of the advise being given here incorrectly, but be careful with the terminology as you could put yourself in problems here by snapping a chain or breaking a derailleur.
A maximum "capacity" of 27 teeth doesn't mean the largest rear sprocket it can handle is a 27. The capacity is the range from the smallest chainring with the smallest sprocket to teh largest shainring with the largest sprocket.
So, if you are running an 11-25 cassette with 34-48 chainrings, the capacity is 14 teeth on the rear plus 14 on the front, so total capacity of 28 teeth. In this case, you could end up with a cage that can only take up 27 teeth of chain slack being asked to take up 28 teeth of slack.
The full specification will also tell you that there is a maximum size rear sprocket that the derailleur will handle, but as I've said, this is different to the maximum capacity of the unit.
For reference: http://sheldonbrown.com/derailleur.html
A maximum "capacity" of 27 teeth doesn't mean the largest rear sprocket it can handle is a 27. The capacity is the range from the smallest chainring with the smallest sprocket to teh largest shainring with the largest sprocket.
So, if you are running an 11-25 cassette with 34-48 chainrings, the capacity is 14 teeth on the rear plus 14 on the front, so total capacity of 28 teeth. In this case, you could end up with a cage that can only take up 27 teeth of chain slack being asked to take up 28 teeth of slack.
The full specification will also tell you that there is a maximum size rear sprocket that the derailleur will handle, but as I've said, this is different to the maximum capacity of the unit.
For reference: http://sheldonbrown.com/derailleur.html
Glad it was indeed the mid cage you have.
I have a triple Sora too. Like you I've signed up for a rather hilly ride - 4,000m climbing over 141km - and I'm also not used to climbing.
I went in search of some hills yesterday. Although my bike came with a 28 I'd since changed that to a 25. Until yesterday I'd never had cause to use the granny ring on the road. Yesterday I did. A lot. Gradient varied, 8-12% was common but Strava has the max gradient at 26%, or something stupid. Whilst I could climb everything in 30/25, I was standing above 12% and working hard. It was obvious I wouldn't be able to sustain that for a 20km up a mountain. Twice.
So today I've put the 28 back on and will try the same hills again next week. If that's not low enough I'll try the 32 from my MTB. There's less shame in gearing lower than you need than there is in walking up, in my book
I have a triple Sora too. Like you I've signed up for a rather hilly ride - 4,000m climbing over 141km - and I'm also not used to climbing.
I went in search of some hills yesterday. Although my bike came with a 28 I'd since changed that to a 25. Until yesterday I'd never had cause to use the granny ring on the road. Yesterday I did. A lot. Gradient varied, 8-12% was common but Strava has the max gradient at 26%, or something stupid. Whilst I could climb everything in 30/25, I was standing above 12% and working hard. It was obvious I wouldn't be able to sustain that for a 20km up a mountain. Twice.
So today I've put the 28 back on and will try the same hills again next week. If that's not low enough I'll try the 32 from my MTB. There's less shame in gearing lower than you need than there is in walking up, in my book
WRT the chain, I'd use a tool like this Chain Checker to see how much it has stretched.
If the 0.75 end doesn't drop into the link, it's under 0.75% stretched and I wouldn't change it, even if I was changing the cassette.
If the 0.75 does drop in, I'd change the chain anyway, regardless of whether I was changing the cassette or not.
And if the 1.0 drops in, it's over 1% stretched and I'd change both chain and cassette, even if I didn't want new gearing.
If you need/decide to change the chain as well, you can use KMC, SRAM or Shimano 9-speed chains. There's a lot of love for KMC because of the magic link that gives tool-less chain removal and installation. I'm using Shimano, but only because they were cheaper when I looked. No-one seems to like SRAM chains. If you go Shimano, the HG53, HG73 and HG93 all fit. They all weigh the same too, the difference is just in the coatings they have. The HG53 is £6 on Wiggle and the HG93 £10, so none are expensive.
If the 0.75 end doesn't drop into the link, it's under 0.75% stretched and I wouldn't change it, even if I was changing the cassette.
If the 0.75 does drop in, I'd change the chain anyway, regardless of whether I was changing the cassette or not.
And if the 1.0 drops in, it's over 1% stretched and I'd change both chain and cassette, even if I didn't want new gearing.
If you need/decide to change the chain as well, you can use KMC, SRAM or Shimano 9-speed chains. There's a lot of love for KMC because of the magic link that gives tool-less chain removal and installation. I'm using Shimano, but only because they were cheaper when I looked. No-one seems to like SRAM chains. If you go Shimano, the HG53, HG73 and HG93 all fit. They all weigh the same too, the difference is just in the coatings they have. The HG53 is £6 on Wiggle and the HG93 £10, so none are expensive.
Not a suggestion that particularly helpful now as you're close to the event but the long terms the best bet is to work on fitness so that you can make it up hills with the gears you currently have. Hills can frequently be a grind in bottom gear (my bike's lowest gear is 34-26) but with a lot of hard work it's a lot easier than it once was and I've yet to find a hill that I can't get up in bottom gear. This one gave me a bit of trouble at one point though.
http://clevelandwheelers.com/root/climbs/the-climb...
http://clevelandwheelers.com/root/climbs/the-climb...
I will be getting a 32t and new chain to go with my mid compact, whilst I love the chain set my compact and 30t on the other bike does allow progress to be quicker (well it feels like it)!
Going oop north in July and have these routes planned.
https://app.strava.com/routes/2608870
https://app.strava.com/routes/2611917
day three still to be planned, we are based in West Burton.
Going oop north in July and have these routes planned.
https://app.strava.com/routes/2608870
https://app.strava.com/routes/2611917
day three still to be planned, we are based in West Burton.
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