40 tooth 10 speed Cassette question

I have a shimano 105 5700 medium cage rear mech on my caad8, the chainset is a compact 105 5700 series also. Because I have multiple Sclerosis I can't push full tilt like I did before diagnosis. I've ridden up 18-20% percent gradients using a 32 tooth rear cassette but my cadence drops to 60rpm and my body heat rises dramatically, not good for me. I watched Katie Kookaburra youtube videos and she went the 40 tooth cassette route with absolutely no regrets as it just made the real hard climbs accessible for her.
Could I ask please, with 50/34 compact and a medium size rear mech, could I simply fit a 10 speed 40 tooth cassette and go ? If I could, would 2 extra chain links suffice ?

Many thanks.
 
Location
Cheshire
I'm sorry to hear about your MS but no need to worry about going beyond 34/32. Just stay on the flatter stuff. You will be fine.
 

Buck

Guru
Location
Yorkshire
You’ll most likely need a wolf tooth (I think that’s what KK uses) to get the larger cassette. And yes, a longer chain.

if you are going from 32 to 40 then that’s 8 teeth more that you need to accommodate with the longer chain.


ETA: it’s the wolf Tooth Road Link. They do a few versions to match the differing Shimano series
https://www.wiggle.co.uk/wolf-tooth-roadlink
 
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You can get the same first gear by shrinking your chainring by 6 to 44/28.
If you go the route then you may need to change the BB and front derailleur.

Luck .......... ^_^
 
Thanks for the encouraging words folks. It's such a pain in the backside having MS as I used to push for all I'm worth in the past. Now if I give it full welly I run the risk of a relapse. Is the change from 32 to a 40 THAT noticeable on demanding climbs in excess of say 12% and upwards ?
 

Buck

Guru
Location
Yorkshire
I would say it will be a definite improvement for you albeit it’s will feel strange the first few times as you will spin away in comparison.
In basic terms if you go from a 32 to a 40 that’s a similar step change to going from your 12 tooth cog to your 19/21 or whichever you have.

Sometimes, even if you don’t actually use it, having the 40 there as your bail out gear is a good thing and will allow you to keep your effort in check as you need to.

Also, I wasn’t clear from your first post about your chain query. You will need a longer chain and “sucking eggs” I wouldn’t advise adding links to an existing chain if that is what you meant?

Let us know what you decide and how you get on
 
I would say it will be a definite improvement for you albeit it’s will feel strange the first few times as you will spin away in comparison.
In basic terms if you go from a 32 to a 40 that’s a similar step change to going from your 12 tooth cog to your 19/21 or whichever you have.

Sometimes, even if you don’t actually use it, having the 40 there as your bail out gear is a good thing and will allow you to keep your effort in check as you need to.

Also, I wasn’t clear from your first post about your chain query. You will need a longer chain and “sucking eggs” I wouldn’t advise adding links to an existing chain if that is what you meant?

Let us know what you decide and how you get on
That sounds like a step in the right direction. A particular climb I like tops out at 18% and its tough going for me. I ride it in zig zag fashion and cadence is painfully slow 60rpm, I ride on the flats 90-92rpm by comparison . With a 40 cassette I'd be happy to ride that hill at 75rpm+ if possible without feeling like I am having a coronary .
 
Go for the 40. Lots of queries on the 40 in cycling forums. Noticed its popularity about 3 years ago. It took a long while to move past 28. And when Froome did, Armstrong made fun of him. With the 40, you continue to ride the terrain and the landscape that you enjoy with little less effort.

Haven't tried it but read that you need a RoadLink.
 
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Spiderweb

Not So Special One
Location
North Yorkshire
You can get the same first gear by shrinking your chainring by 6 to 44/28.
If you go the route then you may need to change the BB and front derailleur.

Luck .......... ^_^
Can you actually go down to a 28t front chainring on the OP’s set up, he is currently running 50/34 (standard compact) so 110 BCD, I understand the smallest you can fit is a 33t?
I could be wrong.
I would be looking at a longer cage rear mech and a longer chain to suit.
 
Can you actually go down to a 28t front chainring on the OP’s set up, he is currently running 50/34 (standard compact) so 110 BCD, I understand the smallest you can fit is a 33t?
I could be wrong.
I would be looking at a longer cage rear mech and a longer chain to suit.
I should have said go for a sub-compact crankset, hence the 44/28 chainrings.
Something like -> https://www.spacycles.co.uk/m8b0s109p3383/SPA-CYCLES-Super-Compact-Chainset-with-Zicral-Rings

It's a question of gear spacings and how much use does the OP gets out of a 50/11 top gear ??
Going 11-42 opens up the gear range while keeps the same number of sprockets. You need to check which steps alter with the new cassette and do you suddenly get a big step in your most commonly used gears. Some riders hate the new cassette when this happens.
Going for a sub-compact crankset keeps the same gear range/steps but biases all gears down. Main downside I can think of is with a max cadence of ~80rpm you'll spinout around 25 mph vs 30 mph with a 50/11 top gear. You will need to check that you can move the front derailleur down by 12mm for this to work.

Luck ............. ^_^
 

Ming the Merciless

There is no mercy
Location
Inside my skull
Go for the 40. Lots of queries on the 40 in cycling forums. Noticed its popularity about 3 years ago. It took a long while to move past 28. And when Froome did, Armstrong made fun of him. With the 40, you continue to ride the terrain and the landscape that you enjoy with little less effort.

Haven't tried it but read that you need a RoadLink.
I moved past 28 in 2003. Can’t have been the only one.
 
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