Gear ratios...Advis appreciated

The Noble Nudge

Have been on the bike a few years now never investigated gearing at all always happy to plod along,
As far as I know I'm on 50/34 compact me thinks.....mostly do hills and at 95kg I wouldn't be the quickest but get up them....
I'm due a change of cassette, chain and crankshaft bearings as advised by LBS.....I have a 53/39 in the attic I think, so was thinking of changing it now...Have an adventure race the end of this month one section around Lough Tay and Sally gap...
Changed back to ordinary pedals did Shay Elliott and Sleeve Mann Saturday got up them but found changing back odd.....
Anyways am I mad to change the gear ratio now front and back???
Intend doing the evil 200 too so would like to change now in preparation,
Any advice appreciated.
Thanks

quozl

I think you're mad That's a big change and you don't seem to have any reason in mind for why to do it? Higher gears may also make it harder to run in your adventure race afterwards if I was guessing.

Do you never use your lowest gear now? Because you're definitely losing it if you change from a 34 to a 39. If you have a tightly spaced rear cassette then you may be losing your bottom 2 gears. The move from 34 to 39 is slightly more than changing from a 28 to a 25 on the back, or a 25 to a 22.

What you'd gain is higher top speed without having to shift from your small ring to your big, as you'd now have a 39-11 or 39-12 instead of a 34-11 or 12. Plus a higher top speed in the big ring but do you really spin out a 50-11? That's a higher gear than the old 53-12s. I really doubt you need it!

I saw a piece of advice somewhere which struck me as likely true. It was something like, if you don't know that you need a standard double then you'd be better off on a compact!

Lumen

Doing the Evil 200 on a 53/39 is a great idea.

To give yourself the best choice of gears, pick a nice close-spaced cassette like a 12-23. Big gaps between gears can really mess with your rhythm.

The Noble Nudge

quozl wrote: »

I think you're mad That's a big change and you don't seem to have any reason in mind for why to do it? Higher gears may also make it harder to run in your adventure race afterwards if I was guessing.

Do you never use your lowest gear now? Because you're definitely losing it if you change from a 34 to a 39. If you have a tightly spaced rear cassette then you may be losing your bottom 2 gears. The move from 34 to 39 is slightly more than changing from a 28 to a 25 on the back, or a 25 to a 22.

What you'd gain is higher top speed without having to shift from your small ring to your big, as you'd now have a 39-11 or 39-12 instead of a 34-11 or 12. Plus a higher top speed in the big ring but do you really spin out a 50-11? That's a higher gear than the old 53-12s. I really doubt you need it!

I saw a piece of advice somewhere which struck me as likely true. It was something like, if you don't know that you need a standard double then you'd be better off on a compact!

Haven't a clue to be honest in saying that I feel I maybe missing out lad I'm with seems to be pissing uphills and im slogging it....excluding weight differences I cant see how he has so much of an advantage...led me to gear ratio....
I could do with a bit more torque for down hills as don't seem to have enough gears for going downhill....
All in all more downhill speed while not affecting my uphill....clear as mud

The Noble Nudge

Lumen wrote: »

Doing the Evil 200 on a 53/39 is a great idea.

To give yourself the best choice of gears, pick a nice close-spaced cassette like a 12-23. Big gaps between gears can really mess with your rhythm.

I'll have to read the evil thread to see if you're taking the wazz Lumen...I don't know whats making me doubt you though...:cool:
Maybe its all in the name of the spin......:eek:

mossym

The Noble Nudge wrote: »

.excluding weight differences I cant see how he has so much of an advantage...led me to gear ratio....

so you;re discounting the biggest factor in hill climbing and arriving at gear ratio.

not being smart, but lighter riders are going to get up hills significantly easier than heavier riders. even small weight loss will make a big difference

The Noble Nudge

mossym wrote: »

so you;re discounting the biggest factor in hill climbing and arriving at gear ratio.

not being smart, but lighter riders are going to get up hills significantly easier than heavier riders. even small weight loss will make a big difference

No smartness taken....
Ah I know the weight is a major factor for uphill
Its not just climbing downhill I cant seem to get any faster either
The process of elimination....not in any specific order that I am investigating at present.
Fitness
Persons weight
Bike
Wheels
Gear ratio...know nothing about it and as I'm getting new stuff is it time to put another ratio on the bike....

smacl

The Noble Nudge wrote: »

Gear ratio...know nothing about it and as I'm getting new stuff is it time to put another ratio on the bike....

As usual, Sheldon is worth a read; http://sheldonbrown.com/gain.html

Basically moving from 50/34 to 53/39 will make cycling uphill more strenuous, and give you a theoretically higher top speed going downhill when your spinning as fast as your legs can manage. Probably better to get a wide ranging cassette such as an 11/28 or 11/30 on your existing set-up, which should give you all the gears you need for much less hassle.

The Noble Nudge

smacl wrote: »

As usual, Sheldon is worth a read; http://sheldonbrown.com/gain.html

Basically moving from 50/34 to 53/39 will make cycling uphill more strenuous, and give you a theoretically higher top speed going downhill when your spinning as fast as your legs can manage. Probably better to get a wide ranging cassette such as an 11/28 or 11/30 on your existing set-up, which should give you all the gears you need for much less hassle.

11/30-possibly more power than 11/28 for downhill

mossym

The Noble Nudge wrote: »

11/30-possibly more power than 11/28 for downhill

the same, as you're not going to be using the biggest cog, the 30 or the 28, while going downhill. you;re more likely to be in the 11 or one of the other smaller cogs.

The Noble Nudge

mossym wrote: »

the same, as you're not going to be using the biggest cog, the 30 or the 28, while going downhill. you;re more likely to be in the 11 or one of the other smaller cogs.

ah right with you now....:o
The 30/28 for climbing....I better check what the existing one is on the rear....

dragratchet

if its war glendalough you're lining up, your legs will be pretty fatigued off each of the runs, so a handier gear is always welcome. last year a lot of the competitors got off their bikes and walked the loch tay climb, its one thing smashing climbs when you're just out on spin, another thing when you've just run the spinc. pedal wise, i changed to cages and really regretted it as my giant feet didnt fit in right, id have saved more time and hassle bringing my cycling shoes and changing each time tbh. that or use v. basic flat pedals