which cassette?

by ta2dwez   July 23, 2014  

Now I know this question has probably been asked many times before but I'm sure each rider has a different circumstances so ill ask anyway. I have a shimano sg 52/39 front crank/cogs, 8 speed on the back and in my little group I'm the stronger climber, but what cassette would benefit me more for the hills as they have a compact cranks and can spin the legs up the climb where as I have to grind to get there.

If you need more details I'll try to help as much as I can. I have looked around but all the options/variations are quite overwhelming.

Thanks in advance

17 user comments

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What do you have on the back at the moment?

posted by ajmarshal1 [293 posts]
23rd July 2014 - 21:02

3 Likes

Hmm good question... I'm not entirely sure, the groupset is a shimano 2300 which came on the bike (2x2 worldwide Race).

posted by ta2dwez [18 posts]
23rd July 2014 - 21:10

1 Like

If you have to grind to get up hills, my answer would be... a substantially larger cassette! 28 is a popular choice and often the largest cog size that will work with a standard derailleur. With 39x28 you can do a decent bit of climbing - maybe not everything though. 30 or 32 are also available options. You'll need a new chain to go with a new cassette, measured to the right length for the big cog.

posted by chokofingrz [286 posts]
23rd July 2014 - 23:25

1 Like

To put things in perspective, a 39/28 is generally a pro's lowest gear - at least in current fashion - so providing there aren't any serious climbs around where you live, you might be able to get by without changing the front cogs or the rear dérailleur. Something easier would certainly be a good precaution for anyone not earning six figure sums for riding bikes. A compact (50/34) set at the front would also be another option in taming the gears.

But really, if you're sticking with the full-size front rings, go as easy as you can on the back. Which as someone has said, is going to max out at 28 teeth on a standard derailleur.

posted by Quince [146 posts]
23rd July 2014 - 23:58

2 Likes

The 30 or 32 teeth options usually require a Shimano derailleur with a longer cage.

39x28 will get a decent climber up pretty much anything. If you're a bigger built chap you might struggle to reach a good cadence on this combo on double digit gradients.

posted by giobox [284 posts]
24th July 2014 - 0:23

1 Like

Thanks for all the advice.

Ill have to sit and count what i have on the bike already as to what size i have at the moment.

I think a 11/28 would be a good option as my cadence does drop considerably when climbing (meaning i have to grind and dig deep) but im managing so far. My sparrows legs get me up the hills before the rest of the group so i cant be too bad!

Im in East Devon and the hills are mainly cat 4 (according to Strava).

I was really hoping not to change the front rings or derailleur (cash is tight)

Thanks again.

posted by ta2dwez [18 posts]
24th July 2014 - 9:29

1 Like

If this is your gear set, you may be limited to 26 on the cassette.

posted by truffy [311 posts]
24th July 2014 - 9:42

2 Likes

Ahhh yes it is, nice find. Limited to 26T then Worried Not really sure where to go from here then. I was hoping to just change the cassette and chain and that was that! Might have to rethink, or just continue with what i have. I can only get stronger with what i have now.

thanks again

posted by ta2dwez [18 posts]
24th July 2014 - 10:04

1 Like

ta2dwez wrote:
Ahhh yes it is, nice find. Limited to 26T then Worried Not really sure where to go from here then. I was hoping to just change the cassette and chain and that was that! Might have to rethink, or just continue with what i have. I can only get stronger with what i have now.

thanks again


New Chain Cassette and get a claris mech, 8 speed and does up to 32T.
Can pick up a Claris for around £15-£20.

glynr36's picture

posted by glynr36 [397 posts]
24th July 2014 - 10:16

2 Likes

I've just got into the shed to check the cassette it's a 25t so would an extra tooth really benefit me?

posted by ta2dwez [18 posts]
24th July 2014 - 10:37

1 Like

I have agonised on this for the last 2 years. I had a 53/39 and 12/27, and really struggled on the hills, on both events and group runs. On the flat or downhill life was great. Have swapped the crank for a full compact (was tempted with the new 52/36) and have not looked back. Generally have a spare cog or 2 on the hills now- which gets used up towards the end of an event. That said, it was not a cheap option (but just cheaper than a new cassette and long cage mech).

posted by NickK123 [70 posts]
24th July 2014 - 11:02

2 Likes

Use the Sheldon Brown Gear calculator seeing what your GI is for them.

glynr36's picture

posted by glynr36 [397 posts]
24th July 2014 - 11:15

1 Like

You often find that running a cassette with a couple of extra teeth compared to shimano's spec. will be fine, particuarally if you don't cross-gear. Maybe speak to your LBS about what you can get away with and if there are any risks in operating outside of the spec. but I wouldn't be surprised to learn that a 27t or even 28t works fine.

I'm prepared to be shot down on this if anyone has knowledge of a reason not to do this.

posted by Matt eaton [395 posts]
24th July 2014 - 11:46

1 Like

ta2dwez wrote:
I've just got into the shed to check the cassette it's a 25t so would an extra tooth really benefit me?

An extra three would. I'd seriously contemplate a compact.

As an aside, you can run a 30 on the rear of a standard Tiagra / 105 shimano ten speed derailleur, no problems. Tried, tested, works.

posted by ajmarshal1 [293 posts]
25th July 2014 - 9:19

1 Like

Well it looks like I'm going to leave swapping out the cassette for now. I rode this morning and took nearly 4 minutes off my pb. So maybe the 39/25 is making me stronger in the hills. Would you all say a new wheelset is the best first upgrade in terms of improving my rides.

posted by ta2dwez [18 posts]
25th July 2014 - 14:53

1 Like

The question is, do you race or ride competitivly? If the answer is no then there's really no reason to upgrade anything, at least until something is broken or worn out. The most important thing to upgrade is your engine and that only comes through training, rest and nutrition.

If you are serious about racing and being as competitive as possible then wheels and tyres are a good thing to look at. A lot of folks have a race wheelset with tubs and a training wheelset with clinchers. Some guys have different wheels for different conditions too - it all gets a bit complicated.

On the other hand, if you've got money burning a hole in your pocket and you fancy some shiny new bike gear there's no shame in that, get wheels if that's what you fancy.

posted by Matt eaton [395 posts]
25th July 2014 - 15:19

2 Likes

It says 26 max at the rear, but you can almost certainly go to a 27, Shimano are conservative. They used to say 27 max for Ultegra 6600, but you can run a 28 without probs.

posted by drmatthewhardy [311 posts]
25th July 2014 - 23:28

1 Like