Gearing for alpine climbs

[bobbyp]

I'm off to the Alps for a few days and have managed to find room in the car for my bike. Whilst I'm there I fancy trying a few climbs, probably Col De Joux Plane and Col de la ramaz.

At the moment I go down as far as 39x25. Is it worth trying to dig up a 27 sprocket from somewhere? Currently I ride mostly round the Chilterns so do steep but not long climbs, only usually hit the 25 sprocket above 20% incline. Long local climbs I can manage seated in 39x21 but there's no not many above 5-10 minutes.

 

[Dave Davenport]

You'll be fine with 39x25, have a good time.

 

[HLaB]

Depends if you want the challenge. On my trainer I've got a 38x25 and it will get up things but is hard work (for me anyway) but with my compact a 36x25 I feel like I can go up the hill in that gear forever (I couldn't ), I term it the 'Nirvana' gear. Last year on a trip to the southern Spanish mountains, I hired a 34-27 and it just cruised up the mountains and made it very enjoyable. I've found mountains abroad are generally less steep than Scottish hills but 10x longer and for me anyway that where you see the benefit of the 'Nirvana' gear.

Just my 2p Enjoy your trip whatever you do

 

[bobbyp]

Thanks for the advice. I think I'll go with dave though, it saves me trying to find a cassette remover or fit my rather nasty and heavy compact chainset to my beautiful DA equipped bike.

In the words of Nietzsche what doesn't kill us makes us stronger - I'll let you know how I get on if I get back :-)

 

[ASC1951]

You'll be fine with 39x25, have a good time.

I would have struggled on the Joux Plane with that. OK, I had done 80 miles over the Col de Morgins, Martigny, Chamonix, Sallanches and Cluses by then, but I was very glad of a triple with 30 x 23.

You are no doubt younger, fitter and stronger than me - who isn't? - but if you are doing rides with more than one big climb, I would go for a 27. [39 x 25 sounds like a standard Campag set up. Their cassettes are a doddle to swap.]

 

[Dave Davenport]

If he's managing 5 - 10 minute UK climbs in 39x21 without struggling i don't think he'll have any problem. Granted if your doing something like the etap with multible cols and a cut off time a lower gear would be a very good idea but for recreational riding i'd be happy with the set up he's got.

 

[TheDoctor]

My gut reaction would be that if you think you might need it, fit it.
Actually, my reaction would be to fit the widest cassette I could, and a triple...

 

[Tynan]

24x26!

 

[TheDoctor]

Yes. Problem?
I sit down and spin on hills. Especially ones as long as that.

 

[davidg]

based on what you are already doing, I would say fine as well, although I wouldnt be!

 

[Tynan]

Yes. Problem?
I sit down and spin on hills. Especially ones as long as that.

not at all, I honestly didn't know gears went that low, in my ignorance

I barely got up Ditchling, I struggle to imagine a hill longer/steeper than that

 

[TheDoctor]

Well, MTB gearing goes lower, but I was pushing the limits of what road bike gearing will do.
Frankly, I'm not all that good at mountains, hence the ridiculously low gearing.
6km of 1 in 10 was ruddy awful. I needed the lowest gear for that, especially as I'd already been climbing for 20 km!!

 

[jimboalee]

Pop in a local gym and ask about Free trial days.

If yes, get on the gym bike, get warmed up and then crank it up to 250 - 300 Watts ish.
Alternate between sitting and standing for half an hour or so.

Assess how easy that was.

Crank it up to 325 Watts and stand up on the pedals for another 20 minutes or so.

If you get through this, you'll be OK on your 39 x 25.

 

[DaveP]

I done Lons-Le-Saunier to Genève (via Gex) last year on a standard front end with a 11-28 cassette, and boy after the climb up the col de la Faucille was I glad of it!

Mind you, I am getting on a bit!

Some of the best riding I have done, enjoy fella!

 

[rustychisel]

work out what you think you might need in gearing and then find something at least one full gear step lower.

ie if you think you'll be okay on 39 x 25 then get a 39 x 26 or 39 x 27 at the very least. It's called insurance. (have done Ventoux and col de Lauteret/Briancon etc on 39 x 25).