Gearing Decisions...

[ChrisEyles]

I'm currently running the 48/38/28 crankset and 11-32 8 speed cassette that came with my current bike (11-13-15-18-21-24-28-32).

Mostly I get on with it very well - I love the "sensible" gearing for tackling some of the 15%ers around me, and I'm certainly never going to run out of gears at the top end.

However, there are two minor issues I'm currently having

1) The top gears are far, far too widely spaced - especially given you only use these when going pretty fast with a lot of wind resistance, it's hard to pick the perfect gear

2) The gears that see the most use in rolling rides and town commuting are the 38/15 and 38/18 cogs. When I'd like to up the pace a little, I've got the choice between 38/13 (which seems a bit of a small-small combination in terms of the number of teeth on each cog, and suffers from a bit of cross-chain on my set up), or 48/18 (only a small step up from 38/15, and then the next 48/13 gear is too big a jump, plus I'm constantly having to shift the front and rear together)

What I'd like to achieve is:

1) A closer spacing of gears at the top end (which needn't be anywhere near as high as it currently is - I think I could get by with 48/14 just fine)

2) Being able to stick in either the middle or top chain ring, using only the cassette to change gears, around my usual cruising speeds.

My first thought was a 14-32 (custom built) cassette - this would solve the spacing of the higher gears, but not the need to switch from 38 to 48 a lot when commuting...

Alternatively, I could look at changing the chain rings... I have a 53/42 crankset on my road bike, and love the 42 ring (but not the 42/26 low gear!), so maybe I could change the chain rings to something like 53/42/30 (assuming this is possible).

Any suggestions or ideas would be more than welcome

Cheers!

 

[mattobrien]

Could you try a compact chainset with a narrower ratio cassette?

Could you gave a 50/34 and then a 12-25? I appreciate this might be too much of a change though.

Equally, could you get a 12-25 cassette and run with the triple you have, hopefully still having enough gears for the steep stuff? Might mean more front changing though.

Caveat, I live in suffolk so know little about hills...

 

[ChrisEyles]

Good point - however, I thought carefully about compact double vs triple when buying the bike, and decided on the triple for the lower available gears... I've got to say that not only do I use my 28/28 and 28/32 combinations, I love them so much I'm never letting go!

I also suspect I'd have the same cross-chaining problems with a compact double as I'm experiencing now.

In terms of gear ratio, this happens around 2.5 - or ~17mph at 85rpm.

I'm a little bemused - since my bike is set up for touring, you'd have thought this would be right in the sweet spot for all day riding.... but there you are!

 

[ChrisEyles]

Hang on, you are absolutely right - the big 50t ring of the compact with a 12-27 cassette would actually be perfect for most of the riding I do..... but I would struggle with the steeper hills with 34/27!

There must be some touring afficionados out there who have cracked this...

 

[ChrisEyles]

Haha, just been fiddling around with a calculator, and d'you know what would work perfectly?

SUPER compact: 42/26 with a 12-28 cassette

But I've never heard of such a thing anywhere! Would probably suit rank amateurs like me quite nicely though...

 

[mickle]

Middleburn Duo.

 

[mattobrien]

You may find that as your fitness increase you don't need the escape gear as often. What is right now might not be right in the future. Just worth bearing in mind.

Ironically I couldn't really tell much difference between my double and compact. The double is 53/39 and 11-26 and the compact was 50/34 and 12-27 (I think, I have changed the cassette as it wore).

The double is lighter and better, so it is very possible that there is less weight to drag up the hills and more power goes into turning the wheels than on the compact.

 

[Rickshaw Phil]

Have you thought of changing the crankset to a MTB one with a closer ratio cassette? Almost certainly a cheaper option than changing to a double.

I've done this with my Raleigh so that the current spec is a 44/32/22 crankset and an 11-30 8 speed cassette. I've ended up with a sub 20 inch bottom gear which will get me up any hill I care to try, but at the other end of the scale, the 107 inch top gear means I'm still comfortable pedalling up around 30 mph (when conditions are right for it )

Like you I didn't want big jumps between the gears I use most often and the 11-30 cassette (spaced 11-13-15-17-20-23-26-30) works for me in this respect.

 

[ChrisEyles]

Agreed that the switch to a double is probably a little bit overkill, even if the ratios would be perfect for *right now* (and would be do-able with the middleburn rings - thanks for the tip).

The MTB triple with a closer spaced cassette wasn't something I'd considered - if I'm still having the same issues some months down the line, this is probably the way to go.

I've got to say, I still think an 11t small cog is complete overkill for the vast majority of riders out there, though! With a granny ring of 22, I could probably use a 12-26 or similar quite happily, which is a bit more of a stock option than the dream 14-34!

 

[themosquitoking]

Could you upgrade to a nine speed cassette and shifters?

 

[ChrisEyles]

I guess it would be perfectly possible... but would the extra gear make that much difference do you think?

 

[themosquitoking]

It would make for smaller ratios between shifts or a bigger range overall.