Looking for a cassette

[Lycra Man]

Could the panel advise me? I have a Tiagra 9 speed on my (new to me) Genesis Day 06. The ratios are 12-25.

What I'd like is 11-27 or 11-28.

I have found a Shimano Deore HG61 cassette which is 11-28. Would that fit with my present Tiagra rear mech?

Thanks in advance.

Lycra Man

[MSeries]

What rear mech do you have ? Is it long cage ? Do you really need and 11 tooth sprocket ?

[MSeries]

Actually it will work. I use a Ultegra short cage with 12-27 and a triple chainset, it works. Well for the gears I use it does.

[Zoidburg]

What he said about 11 tooth sprockets.

You don't really need one, they exist because a lot of MTBs will only run an 11 tooth as the smallest sprocket, a 12 tooth won't fit.

[Lycra Man]

The rear mech is 'standard' ie not long cage.

The reason I need 11 is because my feet can't spin fast enough on the downhills, and I like going FAST.

I need a 27 or 28 becasue I'm old and heavy and can't get up the steepest  hills and hate having to get off and walk.

If I lived in Holland, the 12-25 would be fine, but I'm stuck in rural Buckinghamshire, and  like doing Audaxes.

Lycra Man

[Zoidburg]

The reason I need 11 is because my feet can't spin fast enough on the downhills, and I like going FAST.

What chainset are you using?

Something spinny perhaps like a MTB triple?

A 52/42 double will drive an 11 tooth faster than you can spin, going from a 12 to 11 is not going to make any huge difference, changing the chain ring is a better step, it makes a much bigger difference.

[MSeries]

YOu don't need gears that big. How big is your big chainring ? 53 ? A closer ratio cassette is better

[Polar Bear]

My only consideration would be can your mech cope with 28t.   Some Shimano road mechs are a bit limited.   I am betting that it will but don't take it for granted.  

[Zoidburg]

Mseries and myself are not convinced that changing the cassette is going to give the change in ratios that Lycraman is looking for.

Changing the chain set maybe, but not the cassette.

[Biggsy]

There comes a point where it's more aerodynamic, and therefore faster, to freewheel than pedal down hill.  But an 11t can be really useful if you have a smaller than "road" sized outer chainring, or for slipstreaming vans at 60 mph!

[Polar Bear]

I know you're not, but...

His bike

Unless I'm mistaken that's a standard Shimano triple, probably 30/42/52.  

He could slap a 53 ring on but that wouldn't solve his extra low end requirement.  A wider range on a cassette kills both birds.

[Zoidburg]

You still aren't going to get a particularly more usable gear from an 11 or a 28 at the other end IMHO.

It's linus blanket upgrading.

[Lycra Man]

Polar Bear is right, it's a 'standard' Tiagra triple, with 52/42/30 ratios. The same gearing on my previous bike, a Ridgeback Meteor flat bar road bike, or hybid to some. That has a 52/42/30 up front, and 11-32 at the back. So I know what it feels like when I'm going fast down a hill, and I like to still be able to push against the pedals.

I can't maintain that gear on the flat, but I don't like not being able to push down a hill with pressure against the drive chain. Anybody know what I'm talking about?

And then when I come to a hill going up, I know I need help. The Meteor has a long cage rear mech, with 32 lowest gear, and I know I can't copy that without changing the rear mech to a Deore, or LX or whatever it's called. So for now, I want to know if I can fit a 11-28 cassette. It's only £22.99, so it's not a fortune to find out the hard way.

Your vote is?
Polar Bar - probably


Lycra Man

[frankly frankie]

I've been using 11-28 for the last 12 years (was 8-speed, now 9-speed).  Works for me.  With a 'medium' cage.

[Polar Bear]

And if you find that you still need lower gears whack on a Deore rear mech which will work perfectly with your STI's, and an 11-32 cassette.   

[Biggsy]

I can't maintain that gear on the flat, but I don't like not being able to push down a hill with pressure against the drive chain. Anybody know what I'm talking about?

I do, but I also know you can often go just as fast or faster by freewheeling and getting into a bit of an aero tuck.

And then when I come to a hill going up, I know I need help. The Meteor has a long cage rear mech, with 32 lowest gear, and I know I can't copy that without changing the rear mech to a Deore, or LX or whatever it's called. So for now, I want to know if I can fit a 11-28 cassette. It's only £22.99, so it's not a fortune to find out the hard way.

I don't know the specs of that mech, but I would expect to able to push it by two to three teeth over what it's designed for.  It will help to have the chain as short as possible for the big-big combination.  A longer b-screw can help sometimes, too.

[Polar Bear]

A shimano road mech will definitely not stretch to a full 11-32 mtb cassette but should be ok with a 28 sprocket.

[Lycra Man]

Frankly Frankie and Polar Bear,

Thanks. Just what I wanted to hear. I'm off to the shops, tra la, tra la.

Lycra Man

[Lycra Man]

Just to close this one off - I purchased an 11-28 cassette and got it fitted (along with a new chain, which was needed) on Saturday. I couldn't ride on Sunday - it was my 60th birthday, and I was busy partying - so I commuted home last night and back in this morning, and the bike is now terriffic.

I can push all the way down the down hills, and achieve a steady climb up the up hills, so I'm a happy bunny.

Frankly Frankie and Polar Bear - thanks again for confirming it would all fit.

Lycra Man