Replacing SRAM red cassette to Force/Rival 11-32

j.w.hughes

I'm a complete newbie to road cycling and loving my new (second hand) Cube. My dad is doing similar and bought a second hand Felt F3 with SRAM red groupset, which he's struggling with uphills. I've been on it and the lowest gear on his 28 is his much harder than my 11-32 Ultegra.

What are his options? Obviously fitness plays a part, but he's currently not using his carbon and has reverted to a crappy hybrid because he's finding the hills so difficult. Sad and not nice to see his bike sitting there unused. I'm thinking changing the cassette is the most cost effective option and just wanted to see if this is the most sensible option!

If it is, is it possible to see from the photos whether changing to a 11-32 Force/Rival or even moving to a 105 cassette? The SRAM red's are ridiculously pricey. Any advice would be super! Thanks a lot

rafletcher

You can fit any Shimano or SRAM cassette as the splines are the same. The maximum rear cog size will be determined by the rear mechs maximum tooth number, and also it’s “capacity” - the difference in teeth between front chain rings added to the difference in teeth between the smallest and largest cassette cogs. If you fit a cassette with a larger big cog, then that number increases. You can find rear mech max cog size and capacity online, or others here will know.

sungod

what chainrings? if they are 53/39 then moving to a compact with 50/34 would be another way to get the same lowest gearing as going from 28 to 32 on the rear, while avoiding bigger steps between gears

diamonddog

The rear mech looks to be a short cage so you would need to change it for Sram medium cage for the 32 cassette.
As mentioned above a 50/34 chain set would give easier gearing than the one fitted if it is a 52 or 53/39

diamonddog

Just to add I use Red and Force cassettes with Sram Etap and both work equally well.

MidlandsGrimpeur2

Just get a rival cassette, no discernible shifting difference between that and red or force. I run sram on 3 bikes and just use rival cassettes now as they are far cheaper.

By the way, that looks like it is old sram 10spd so make sure you get the correct cassette if it is.

MattFalle

If you do end up going to a compact crankset that Red stuff is still worth a pretty penny on the 2nd hand market and 10 speed cranks work prfext with 11 speed groupsets.

Dependant on wear, the cassette is worth a decent amount as well.

joe_totale-2

IIRC a regular SRAM Red 10 speed rear mech can only accept up to a 28 tooth cassette.
There is a wi fli version that allows you to fit a 32, pretty expensive though:

https://www.chainreactioncycles.com/mobile/sram-red-wifli-10sp-rear-derailleur/rp-prod82885

Don't forget, you'll need a new chain as well.

As asked above, how big are the chainrings, could be a cheaper way of lowering the gearing.

darkhairedlord

Swap his back wheel for yours and see if it makes much difference. If not; get out more, ride longer and harder, it'll soon be easier on the 28.

j.w.hughes

Thanks a lot for the comments. Starting to understand!

To fill in some of the blanks, the bike is a 9 x 2 with 53/39 chainrings and a 12/28 cassette. If it looks like I'd have to replace the rear derailleur to fit a larger cog then this I think, as a few of you have said, is pushing me towards replacing the chainrings. Would it be so simple as to just replace his standard crankset with a 50/34 and, if so, do the same rules apply with moving to Shimano...Tiagra/105 aren't the worst value...

On an aside, and looking into Rafletcher's comment, the gear ratio on this current setup is giving him a ratio of 1.39 in his easiest gear...and dropping to a 34 a ratio of 1.21...a bit of a hypothetical and appreciate it's pretty subjective, but will that be a noticeable difference for him? It might be worth cutting his losses and buying a different second hand bike whilst he builds his fitness...?

Thanks a lot again. This is really appreciated

joe_totale-2

Well fitting a 32 tooth cassette with a 39 tooth inner chainring also drops you down to a ratio of 1.21.

I'd grab a 50/34 crankset, it'll make a big difference. You'll also have to adjust the front mech so it still shifts.

j.w.hughes

Good point!

sungod

as above, the red rear mech is 28t maximum, changing the crankset will be simpler overall

you haven't got all the info to do this yet...
i) bb type
ii) crank length

it might be bb30, if unsure, you can post a pic of the bb area viewed from underneath

ii) measure the crank length (centre to centre from spindle to pedal hole)

i suggest measuring the chain for wear...

if it is worn but not yet too far gone, replace it before it wears the cassette

but if it's too far gone, leave it as the cassette will have worn too and a new chain would probably slip

j.w.hughes

Thanks @sungod - I'm not entirely sure how to identify the bb, and so attach some photos in the hope that I can tap into superior knowledge (I will however show him how to clean his bike... ). Have asked him to measure crank length






Noted on the chain. Good advice. Will get him to check it before we fix

sungod

that looks like sram gxp, so the frame has a normal threaded bb shell (rather than bb30)

something like this should fit ok...

https://www.ebay.co.uk/itm/Chainset-Lovely-Sram-Force-Carbon-GXP-Bottom-Bracket-10-Speed-50-34-Red/265027593948

it includes a gxp bb, but no need to change the current one unless it's worn

but there'll be many other options, note that the seller of the above doesn't state what the crank length is

j.w.hughes

Thank you so much. Honestly, this is really helpful. I'll keep you posted on how we get on!

elbowloh

sungod said:

that looks like sram gxp, so the frame has a normal threaded bb shell (rather than bb30)

something like this should fit ok...

https://www.ebay.co.uk/itm/Chainset-Lovely-Sram-Force-Carbon-GXP-Bottom-Bracket-10-Speed-50-34-Red/265027593948

it includes a gxp bb, but no need to change the current one unless it's worn

but there'll be many other options, note that the seller of the above doesn't state what the crank length is

Is the GXP the same as a normal BSA threaded BB (that SRAM do also)? With it being an Felt F3 road bike frame, i'd imagine its BSA threaded like my Felt Z6.

sungod

elbowloh said:

sungod said:

that looks like sram gxp, so the frame has a normal threaded bb shell (rather than bb30)

something like this should fit ok...

https://www.ebay.co.uk/itm/Chainset-Lovely-Sram-Force-Carbon-GXP-Bottom-Bracket-10-Speed-50-34-Red/265027593948

it includes a gxp bb, but no need to change the current one unless it's worn

but there'll be many other options, note that the seller of the above doesn't state what the crank length is

Is the GXP the same as a normal BSA threaded BB (that SRAM do also)? With it being an Felt F3 road bike frame, i'd imagine its BSA threaded like my Felt Z6.

yes, gxp is a threaded bb, so it'll fit a bsa frame same as bsa shimano bb

but the inside diameter of the gxp bb is 24mm drive side and 22mm non-drive side, while shimano is 24mm all the way through

the matching gxp crankset spindle is 24mm most of the length but at the nds end there's a 'step' as it drops to 22mm

at the 22mm end, the inner race is clamped between the step and the inner face of the crank arm

MattFalle

Rember that when you come to take that crank off its self extracting - do a quick youtube on it and you'll see thats is as simple as. one allen key

And yup, standard gxp bottom bracket.

j.w.hughes

Alrighty chaps. Just to say thanks again for the help and that I've bought a gxp bb Force 50/34 - will update on how he gets on, which might help future searches/people with his problem

banditvic

I am a bit of a Sram fan boy, but think they seriously screwed up on GXP cranks, had a few GXP cranks with massive discrepancies on the 22mm side, see Hambini's You tube content, if you can stand the language.
engineering wise its pretty censored . i would suggest sticking a 105 or Ultegra set on.

arlowood

j.w.hughes said:

Alrighty chaps. Just to say thanks again for the help and that I've bought a gxp bb Force 50/34 - will update on how he gets on, which might help future searches/people with his problem

Bit late now you've bought the GXP 50/34 crankset but another approach would have been to remove the Red crankset and the GXP BB and replace it with a Shimano Hollowtech BB - you would then have the option of several 50/34 Shimano cranksets - Tiagra/105/Ultegra etc as well as the non-series ones eg FC-RS500 etc. All-in-all it might have worked out a bit cheaper. But Hey-Ho the die are now cast