3 ring to 2 ring comparison

tc20

Hi folks,

please excuse my lack of knowledge on gear ratios but i'd appreciate some advice from the learned folk here.
I'm a daily commuter and my current BTW is due for replacing.
The daily hack is a Lapierre cross (hybrid) which has a 48/36/26 set on the front, and a 11-34T on the rear (9 speed) - this is taken from the spec sheet of the bike when I bought it - as attached.
Whilst the bike is used for a 8k each way commute, I've done a couple of WW200s and like to get up in the hills in the summer - I live in north Wicklow so i'm lucky that they're on my doorstep.
Apart from the lack of stock in the local stores, it also would appear that "granny ring" bikes are falling out of fashion and the majority of the type i'm looking for are 2 ring. I've only ever ridden 3 ring bikes (as an adult), and my question is what groupset (if that's the correct terminology) on a 2 ring would be equivalent to my current 3 ring, and allow me to climb the steeper local sections.

Thanks

CantGetNoSleep

Do you ever need the 26-34 gear? That is very low. On gravel / touring bikes these days, the lowest 2x on the front tends to be 46-30, then on the back you can get an 11-24 or 11-36 cassette, which wouldn't give you as low a gear but should get you up a lot of hills

tc20

CantGetNoSleep wrote: »

Do you ever need the 26-34 gear? That is very low.

Where I would need the low gearing would be going up the likes of Red Lane in Glen of the Downs, Slieve Maan/Shay Elliott etc, where iirc the gradient can be apx 12%.
In the normal daily usage, no, but I don't want to go up in the hills and find myself banjaxed

mh_cork

If you do use the lowest gear, then the ratio is 26:34, i.e. 0.77.

If you had a new bike with a 46-30 on the front and a 11-36 on the back, then the lowest gear would be 30:36, i.e. 0.83, which would not be too far from what you are used to. (I'm ignoring slight differences due to wheel size).

Triple cogs in the front are being phased out because modern drive trains can take bigger cassettes at the back. If you are looking at a "racing" bike instead of a hybrid, then I'd suggest looking at "gravel" bikes - they allow for wider tyres (which you are used to on the hybrid) and have lower gears than traditional "racing" bikes.

tc20

thanks mh.
it is a hybrid i'm after rather than a racing/road bike but i'm opting for solid front forks this time around as I would have little use for the front suspension.
Thanks for simplifying the maths behind gear ratios - I think I understand it a bit better now

benneca1

Google Sheldon Brown gear calculator this will give you a great idea how different cassette chaining combinations compare. Alternatively if you have time there is a way using a slide rule but is a bit more complicated

alentejo

I went from a 3 ring to 2 ring some years ago. Never looked back 50/34 - 28 cassette. Didn't feel any difference.
If you have done the WW200, you will have no issues.

smacl

tc20 wrote: »

thanks mh.
it is a hybrid i'm after rather than a racing/road bike but i'm opting for solid front forks this time around as I would have little use for the front suspension.
Thanks for simplifying the maths behind gear ratios - I think I understand it a bit better now

Dropping the front forks and having a better new bike will also reduce the weight, make climbing a bit easier and hence mean you can get away with a slightly harder lowest gear for the same effort. FWIW having come from a similar hybrid some years back and also liking a low low gear, I run 50/34 up front and 11/34 rear giving me a lowest gear of 34:34 or 1.0 which is fine for most road climbs. It's a CX bike setup for gravel and I'd actually like a slightly lower gear for the tougher off road bits.

tc20

thanks folks for the replies, I think you have eased any fears I had of losing the "granny ring".
Now to get me a bike!

smacl

tc20 wrote: »

thanks folks for the replies, I think you have eased any fears I had of losing the "granny ring".
Now to get me a bike!

My old road bike is a triple with a low gear of 30/28, my CX is double has 34/34 which is actually lower geared.

ED E

tc20 wrote: »

Where I would need the low gearing would be going up the likes of Red Lane in Glen of the Downs, Slieve Maan/Shay Elliott etc, where iirc the gradient can be apx 12%.
In the normal daily usage, no, but I don't want to go up in the hills and find myself banjaxed

Single speeds can do Stocking Ln, I've seen late 70s do Red Lane on 2x. You'll be fine


FYI the current trend is 1x, 3x is kinda like dial-up internet.

smacl

ED E wrote: »

Single speeds can do Stocking Ln, I've seen late 70s do Red Lane on 2x. You'll be fine


FYI the current trend is 1x, 3x is kinda like dial-up internet.

Depends on the style of riding. I was out on an audax training spin a couple of years ago and most of the bikes were triples. Main gripe I'd have with triples, apart from availability of parts, is that keeping the front mech in good adjustment is way more finicky. From a cycling perspective, my old bike with Veloce 53/44/30 and 12/28 is a lovely setup for long days on the bike and very versatile.

benneca1

smacl wrote: »

Depends on the style of riding. I was out on an audax training spin a couple of years ago and most of the bikes were triples. Main gripe I'd have with triples, apart from availability of parts, is that keeping the front mech in good adjustment is way more finicky. From a cycling perspective, my old bike with Veloce 53/44/30 and 12/28 is a lovely setup for long days on the bike and very versatile.

By the way the new SRAm Force AXS has more or less the same range but at a huge price premium

tc20

ED E wrote: »

Single speeds can do Stocking Ln, I've seen late 70s do Red Lane on 2x. You'll be fine

thanks for the vote of confidence ED E - though I haven't mentioned how old I am but if people in their 70s can do it, I should be able to too