larger cassette

[paulmad]

• hi, i have a revolution cross sport with 36/46 chainrings and shimano 3400. im wanting a larger cassette. im only able to get out once a week, for a couple of hours and its going to take me longer to get fit than i thought and cant think of going up hills at the moment. planning on buying the following SRAM PG970 9 Speed MTB Cassette Each - 11-32 SRAM PC991 9 Speed Chain Each - 114 Links Shimano Sora 3500 9 Speed Rear Mech GS - Medium Cage. do these seem compatable?. im mid 50s just started cycling so go easy on me

 

[black'n'yellow]

Assuming the problem is gearing-related, the easiest - and cheapest - thing to do would be to swap the 36 ring for a 34. The only other thing you need to do is get fitter, and spending money is not a shortcut. In the meantime, just avoid hilly routes.

 

[addictfreak]

What size cassette do you have on at the moment?

 

[Brommyboy]

If changing to a larger rear sprocket, you need to confirm the maximum capacity of the derailleur. As black'nyellow says, just change the smaller chain ring. You would not need to make any other change.

 

[Manonabike]

• hi, i have a revolution cross sport with 36/46 chainrings and shimano 3400. im wanting a larger cassette. im only able to get out once a week, for a couple of hours and its going to take me longer to get fit than i thought and cant think of going up hills at the moment. planning on buying the following SRAM PG970 9 Speed MTB Cassette Each - 11-32 SRAM PC991 9 Speed Chain Each - 114 Links Shimano Sora 3500 9 Speed Rear Mech GS - Medium Cage. do these seem compatable?. im mid 50s just started cycling so go easy on me

With most Shimano medium cage it would be enough for a 32T cassette. The Sora can handle the 32T too so you should be OK. You will need a longer chain too.

I have a 105 medium cage with a 32 speed cassette in one of the bikes and works fine.

 

[Cycleops]

Seems a lot of expense just to get a lower gearing. Just fit a smaller chainring as already suggested. You could also consider a triple chainset but that may involved a new bb as well, plus more expense.

 

[lulubel]

Personally (and this is what I actually did), I'd get a wider range cassette that goes up to 34 or even 36 teeth and a long cage rear mech. Shimano mountain bike rear mechs are compatible with road levers - the front mechs aren't - so you won't have any compatibility issues. With that kind of setup, you'll be able to get up practically anything, even if you are unfit and tired towards the end of a ride.

I've got an 11-34 cassette with a small ring (on a triple chainset) of 30 teeth, and I've used the 30x34 combination several times.

 

[paulmad]

thanks everyone, i did think about changing the chainring to 34 but didnt think it would make enough difference. will 2 teeth be noticable ? think it will only cost about £10. if i need more perhaps change cassette to 11 28 and hopefully keep the same derailleur. does that sound more sensible. thanks again for your help currently have 11 25 cassette

 

[addictfreak]

thanks everyone, i did think about changing the chainring to 34 but didnt think it would make enough difference. will 2 teeth be noticable ? think it will only cost about £10. if i need more perhaps change cassette to 11 28 and hopefully keep the same derailleur. does that sound more sensible. thanks again for your help currently have 11 25 cassette

That's the way to go IMHO, try the 34 chainring first. Depending on the hills in your area and your fitness level a 34/25 should be fine. Build up to the steeper climbs, don't try and climb 'Everest' in your first week. The fitness will come.

 

[raindog]

thanks everyone, i did think about changing the chainring to 34 but didnt think it would make enough difference. will 2 teeth be noticable ? think it will only cost about £10. if i need more perhaps change cassette to 11 28 and hopefully keep the same derailleur. does that sound more sensible. thanks again for your help currently have 11 25 cassette

Your current lowest gear with 36x25 is 40inch
Your lowest gear just changing the chainwheel to 34 and keeping the 25 would be 37inch
Your lowest gear keeping the 36 up front and changing to 28 at the back would be 35inch
Not much difference really, so the chainwheel might be the best option, but make sure your existing crank will accept a smaller ring before you spend your quids.

 

[Nigelnaturist]

What I did was change the front chainset from 52/40/30 to 48/38/26 and the cassette from 26/23/21/19/17/15/13 to 28/24/21/19/17/15/13 with an acera mtb mech. chain and bb (I can change the 28 for a 32 but it upsets the near 10-15% ratio I have on the back) total cost £80
Chain set http://www.spacycles.co.uk/products.php?plid=m2b0s109p2000
Cassette is an 8 sp HG41 11-32 9.99 from chainreaction I think, rear mech was 17 from spa cycles, chain KMC 8sp £8 bb JP400 110mm £10, might not be the best kit in the world, but I havent been defeated by any hills, not that we have too many, and my view is if I get up them I will keep going out, if I could never get up them I might have given up.
I managed this p.b. today ok not great by many I am sure, the point is I kept going and now I finally feel I have some improvements.
http://app.strava.com/activities/28637531#509383251

 

[Brommyboy]

One gear change is about 10% or more: to change from 36T to 34T chainring is about 6% or half a gear change, so 32T would make a full gear lower, if the cranks would accept that.

 

[Nigelnaturist]

One gear change is about 10% or more: to change from 36T to 34T chainring is about 6% or half a gear change, so 32T would make a full gear lower, if the cranks would accept that.

I know from 13T up to 28T I go 15/13/12/11/10/12/14 % with out a wider range of gears I cant get it much smoother and still have the range of gears I have 99.7" to 25.1", when I have enough to get some 9sp shifters I will put a 32T and a 11T on giving me 117.8" to 21.9" it originally went from 108" to 31.2" which to be honest is lower than I really use these days unless it's long or steep. I dont really miss the 8" on the high end at the mo apart from down hill, and as I am not a speed freak I am not that bothered, its more about getting up.
One question what have the cranks go to do with it, I always thought it was about if the rear mech could cope with the number of teeth change. i.e. in my case at the mo front 48-26=22 rear 28-13=15, total 15+22=37, with a 32/11 rear it would be 22+21=43T which the acera will do, my understanding is that the rear mech, is controlled by the shifter and as long as there is enough travel on the unit it should work with a 9sp cassette, though I will need to check this as I just read the acera is for 7/8 sp.

 

[Widge]

Hi Nigel..........this setup; Spa cycles touring chainset (seems very good for the money) and a slightly larger cogged cassette (28 teeth?) is exactly what I had in mind for my Triban 3 one day soon...........figuring it might make Dartmoors hills more doable for me. I presume I would need the 110 mm bb but wonder whether a new (mtb style) rear mech would be absolutely necessary. Does this combo really make the difference in your opinion? Part of me is just tempted to stick with what I have (50-39-30 and 12-25) and man-up to the occasional grind............but my God it's still hard around my neck of the woods..........plus....next year I would like to get into a bit of 'light' touring, (few days maybe with tiny-tent and panniers) and reckon the spacycles options would be really good for the job. what would you recommend?

Best

w

 

[Nigelnaturist]

Hi Nigel..........this setup; Spa cycles touring chainset (seems very good for the money) and a slightly larger cogged cassette (28 teeth?) is exactly what I had in mind for my Triban 3 one day soon...........figuring it might make Dartmoors hills more doable for me. I presume I would need the 110 mm bb but wonder whether a new (mtb style) rear mech would be absolutely necessary. Does this combo really make the difference in your opinion? Part of me is just tempted to stick with what I have (50-39-30 and 12-25) and man-up to the occasional grind............but my God it's still hard around my neck of the woods..........plus....next year I would like to get into a bit of 'light' touring, (few days maybe with tiny-tent and panniers) and reckon the spacycles options would be really good for the job. what would you recommend?

Best

w

If you are going touring, then you need low gearing its not really about speed, the thing about changing the chain set you will need to lower the front mech down the tube (no big deal really), when I first started messing about with the gears I got a 12/14/16/18/21/24/34 cassette of ebay (I caught a bungee hook in it and it bent), the 34 on the 30T front made a huge difference to me, that equated to 23.8" gain as opposed to my current low (26T-28T) of 25.1" so it is actually lower, but there was a massive jump from 2nd to 1st (29%, thats like 2-3 gears, my current is 14%). Most road Dérailleurs wont cope with such a large range, so I got an Acera M.T.B. Dérailleur since you have an 8sp I believe one option would be to replace the rear cassette with an 11/13/15/18/21/24/28/32 (there three Shimano cassettes that I know of that cover this range HG31/41/51 teeth cominations vary slighty) the 30/32 combination would give you 25.3" gain almost the same as my 26/28 @ 25.1"
I suspect the 12-25 is an HG50 12/13/15/17/19/21/23/25, so you would gain extra at the top and bottom, but you will lose the smooth stepping between gears, thought to be fair I didn't notice, though some combinations I tried just didn't work for me at the time (I make up my own ratios from stripped cassettes).
So your HG51 Cassette is currently £15 http://www.wiggle.co.uk/shimano-cs-..._campaign=uk&gclid=CIiS59KV47MCFczHtAodejQAaw
A rear mech from £18 http://www.wiggle.co.uk/shimano/cycle/mtb/rear-derailleurs/?o=2
and a new chain.
It will give you 122.7" to 25.3" gain range, sacrificing the smoother transition of a road cassette.

Hope this helps