Cassette replacement

[Glyno]

Good morning!

I'm looking to replace my Shimano 105 CS-5800 11-28T cassette but notice most places seem only to have the 11-25T in stock - would this be a suitable replacement and would I notice the difference by dropping from 28T to 25T? Alternatively, could I replace with the Shimano 105 R7000 11-28T cassette, or would it be incompatible with my CS-5800 rear derailleur?

Many thanks, Glyn.

[roubaixtuesday]

All shimano cassettes for the same number of speeds are compatible.

So as long as they are both 11 or both 10 speed you'll be fine, but you can't swap 10 speed with 11 speed.

Whether the 25 is ok depends on how strong you are and how hilly your terrain is. If you want to test it out, try a ride not using your lowest gear.

[Mick F]

Got my 105 11-28 10sp from Chain Reaction but I see they're out of stock.
https://www.chainreactioncycles.com/shi ... -prod50454

They have the Ultegra in stock though.
https://www.chainreactioncycles.com/shi ... -prod39014

[Glyno]

All shimano cassettes for the same number of speeds are compatible.

So as long as they are both 11 or both 10 speed you'll be fine, but you can't swap 10 speed with 11 speed.

Whether the 25 is ok depends on how strong you are and how hilly your terrain is. If you want to test it out, try a ride not using your lowest gear.

Great. I'll be replacing 11sp for 11sp so no problems there. As I'm not getting any younger I was a bit apprehensive about dropping to 25T as I do encounter a few challenging hills at times. I guess opting for the R700 11-28 (or even 11-30) is my best bet then?

Thanks again,
Glyn

[Glyno]

Got my 105 11-28 10sp from Chain Reaction but I see they're out of stock.
https://www.chainreactioncycles.com/shi ... -prod50454

They have the Ultegra in stock though.
https://www.chainreactioncycles.com/shi ... -prod39014

Thanks Mick, didn't realise you could mix versions ie, 105 and Ultegra, that's very handy to know

[iandusud]

You'd definitely notice the difference between a 25t and 28t on the hills. I certainly would

[Glyno]

You'd definitely notice the difference between a 25t and 28t on the hills. I certainly would

Rightio, I won't be going down from 28 then. Is 30T a good choice, or would I be considered a bit of a wimp?

[chris_suffolk]

Depends on the hills and fitness I guess. I 'wimped' to x-32 when I went to the Alps, and at times may have wished for even lower! Even if not steep (by standards of some hills in parts of the UK), 15 miles of up hill needs a low gear IMO.

[iandusud]

You'd definitely notice the difference between a 25t and 28t on the hills. I certainly would

Rightio, I won't be going down from 28 then. Is 30T a good choice, or would I be considered a bit of a wimp?

It all depends on what rear mech you have, if it's std length or long, and also how fit you are. Personally I would always favour having lower gears and with an 11 speed cassette the spacing of the gears is such that you sacrifice very little in terms of how close the ratios are by going for a wider range.

I consider myself to be a pretty fit 60 year old regular cyclist and run a bottom gear of 34 front to 32 rear on my stripped down road bike and I can climb easier and faster with that than with a 28. But even when I was a lot fitter 30 years ago I discovered that lower gears are better for climbing regardless of how fit you are and even the pros have now come to the same conclusion.

[Mick F]

Someone on this forum once said ...........

Pick the highest gear you could ever imagine using down hill with the wind, and pick the lowest gear you can get so it's low enough to get you up the steepest of hills fully loaded and with a hangover, then stick as many ratios in between as you can afford.

[Glyno]

It all depends on what rear mech you have, if it's std length or long, and also how fit you are.

I assume I have a standard rear mech, this would be ok with 30T?

Thanks all for some great info, I've learned a lot in 20 mins

[reohn2]

It all depends on what rear mech you have, if it's std length or long, and also how fit you are.

I assume I have a standard rear mech, this would be ok with 30T?

Thanks all for some great info, I've learned a lot in 20 mins

Yes it would

[roubaixtuesday]

Got my 105 11-28 10sp from Chain Reaction but I see they're out of stock.
https://www.chainreactioncycles.com/shi ... -prod50454

They have the Ultegra in stock though.
https://www.chainreactioncycles.com/shi ... -prod39014

Thanks Mick, didn't realise you could mix versions ie, 105 and Ultegra, that's very handy to know

You can also use SRAM cassettes on Shimano, any variety of SRAM as long as it's the same number of speeds.

On the going to 30T, there you do need to be a bit more wary; it depends on the rear derailleur. It's also possible you might need a chain a link longer. It will probably work fine - it's not a huge change - but you can't be certain.

By the way, if you're changing the cassette it's sensible, and possibly essential, to change the chain at the same time. They wear together.

[philvantwo]

Mantel have everything in stock, delivered by UPS.

[Brucey]

FWIW shimano say that maximum sprocket sizes for 5800 series RDs are

32T for RD-5800-GS

https://bike.shimano.com/en-EU/product/component/105-5800/RD-5800-GS.html

and

28T for RD-5800-SS

https://bike.shimano.com/en-EU/product/component/105-5800/RD-5800-SS.html

in practice unless your frame has an unusually short gear hanger you can usually 'push' an SS mech to 30T without insurmountable difficulties.

cheers