Shimano 9sp 12-30 cassette

winjim

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Does such a thing exist?

I'm getting the CdF ready for winter so I've got some spiked tyres, but I think I need to lower my gearing a bit. Currently running a compact 50-34 with a 12-25 cassette and a Sora 3400 GS (I think) mech. I reckon a 12-30 cassette would do but I can't find one.

I can find an 11-30, but that would leave me with a high gear I'm unlikely to use with spikes, and questionable capacity on the mech, and a 12-27 which I think would not be quite low enough. So any ideas? And does 34/30 seem low enough for icy weather in a hilly area? I'm not sure if my mech could handle a 32.
 

Banjo

Fuelled with Jelly Babies
Location
South Wales
Cant help with sourcing the cassette but re your gearing question i have 34 / 30 on my Synapse , dont use ice tyres but can get up almost any hill provided I can keep the back wheel from spinning on the road and the front one from lifting.

Sat in the saddle I can plod up hills at speeds right down to 4 mph on times.
 
OP
winjim

winjim

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Well the only one I found was this http://harriscyclery.net/m/product/harris-custom-century-12-12-30-9-speed-cassette-2369.htm
Which at $115 is a bit out of my range. I thought I'd give an 11-30 a go and hope that my mech could handle it. I visited five shops today and none of them had one! Am I just trying to use a really weird range of sprockets or something? Anyway, all that traipsing around used up the time I was gonna spend fitting the thing, and I'm gonna have to order one online anyway, which I could have done to start with. :banghead:
 
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winjim

winjim

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Righto, all fitted and it was pretty much a straight swap. Mech looks like it's right on the limit of capacity. Looking at it again I think it's actually an SS so it's working four or five teeth over spec. The chain length seems to be the critical factor but I reckon it's spot on. I actually reused the old one which was just right.

It's all working fine on the stand but I won't get to ride it till Monday.
 

SteCenturion

I am your Father
Righto, all fitted and it was pretty much a straight swap. Mech looks like it's right on the limit of capacity. Looking at it again I think it's actually an SS so it's working four or five teeth over spec. The chain length seems to be the critical factor but I reckon it's spot on. I actually reused the old one which was just right.

It's all working fine on the stand but I won't get to ride it till Monday.
Careful there @winjim with that cassette/derailleur combo.

I speak from experience having ordered & fitted the 12-30 to my mates Giant Defy.

It caused issues, including chain shipping & he was sure the mech was going to snap too.

SS is Shimano's short cage mech & not designed for this large spread.

Good news is that a new Shimano Tiagra 9 speed derailleur in long/medium cage does the job & doesn't cost the Earth.
 
OP
winjim

winjim

✊🏻✊🏾 🌈 😷
Careful there @winjim with that cassette/derailleur combo.

I speak from experience having ordered & fitted the 12-30 to my mates Giant Defy.

It caused issues, including chain shipping & he was sure the mech was going to snap too.

SS is Shimano's short cage mech & not designed for this large spread.

Good news is that a new Shimano Tiagra 9 speed derailleur in long/medium cage does the job & doesn't cost the Earth.
Well having had a couple of tentative rides it seems ok. Mech travel is from here:
20141220_122109.jpg
To here:
20141220_122027.jpg
So it looks right on the limits of its capability although this is obviously at the extremes of chainring / sprocket combinations. I'll keep a close eye on it but you're right, a new mech wouldn't break the bank.
 
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