Mountains, 36T cogs, cassettes and what have you

daniel_b

Afternoon all,

I'm off to France for 3 days soon, and then onto Italy for a week to spend some time with my brother.
I'm taking a bike, and my brothers CAAD 3 as it happens.

I'm reasonably fit at the moment, but never tackled a proper mountain on a roadbike.

Both the bikes I would likely take are running a smallest front cog of 36 with an 11-28 rear cassette.

I can get up most hills over here with that setup with no real struggle - Streately was a bit more of a mission, but wasn't a huge deal at the end of the day.

My CR1 has Ultegra 6800, with (I am fairly certain) a bog standard rear cage - easy way to tell?
I am contemplating changing the chain and rear cassette, and popping an Ultegra R8000 11-30 on there instead.
Not convinced it will take a 32 to be honest.

I can get said cassette with discounts for around £40, and already have the chain.

I tend to average about 88-90rpm cadence, though am happy to drop to 70ish for climbs if required, ie it doesn't cause me to blow up\wreck the rest of the ride etc.

Worth doing?

N0bodyOfTheGoat

Especially with a 36t small chainring, get an 11-34 cassette and a gs rear mech along with a new chain. If you have plans to tackle a big French climb and like me you have never tackled anything bigger than a Strava cat3, you want a gear or more that will allow you to ride below your estimated FTP... Especially if your estimate is not based on a 60min MAP.

I'm out of cycling shape at the mo, but at a push, I reckon I could hold ~275W for 20mins, but even when in better shape I think my best 60mins was ~255W (perhaps not helped by having to climb and descend multiple categorised hills around Butser to do that, rather than a single steady climb). I'd be surprised if I could hold more than ~230W at the mo and it doesn't take much of a gradient to hit 230W+ with my easiest 34/32 gear.

arlowood

If you want to confirm what your 6800 derailleur is you can do so quickly by measuring the length between the jockey wheel pivots. 50mm and it's a short cage. 74mm and you have a medium cage.

I think I've seen some people report that they have managed to run an 11-32 with a short cage RD. Bit of B-screw tweaking required I think - even maybe fitting a longer than standard B-screw. Might be worth a try.

If you're not sure it's always better to have one too many bale out gears than one too few,

joe_totale-2

It depends on how steep these mountain climbs are. For example 36-28 on a hire bike was fine for me in Mallorca where the climbs are quite long but not too steep, there were plenty of gears which allowed me to get into a nice rhythm and spin away. Typically mountain roads don't kick up too steeply but there are definitely exceptions and if you're riding one of those then you'll want some smaller gears.

craigus89

You can run a 32 tooth on a short cage, just don't cross chain big to big. I've been doing it for years on a couple of my bikes.

Have you considered fitting a compact chainset?

daniel_b

Thanks all, not worked out where I will be riding yet, hope to have a look this weekend, and will decide after that.
My bro is mapping out some routes and will send them over too, so that will give me some data.

IIRC, they should be lower averages then over here, although of course WAY longer than the short sharp punchy ones we have here.

I think I am at around that same power potential NO, and am just tipping over 4w\kg.

Bizarrely, or otherwise, on the turbo, when it comes to higher power outputs, at or above FTP, I tend to naturally slip into a lower cadence, perhaps 80, and that seems to work pretty well.
Not really had the opportunity to try that out on the road, but I guess a monutain or two will be the place to try!

That reminds me, I need to change the tyres on the CR1 as well, have some GP4000's to fit.

@Craigus - it's a family holiday where I happen to be taking the bike, so I'll probably be doing 3-4 days at the very most, so not worth the expense imho of changing to a 50\34.
If I was going away on aspecific training camp, then perhaps I would, although you could argue a long cage rear derailleur and an 11-34 would make more economical sense, unless my front cogs were nearly on the way out, which they are not.

Interesting you have no issues with 32 on the rear and a standard RD.

Midlands Grimpeur

To be honest you should be okay with a 36-28, as suggested you may just have to lower cadence a little so as not to blow up on the climbs. Proper mountains are an entirely different prospect to any UK climb as most people state so having an extra gear just for peace of mind never hurts but I think you would get by without the 30 if you chose to stick with a 28.

N0bodyOfTheGoat

Just a thought, you could doing some testing on your turbo if you have time to do the odd 1-2 hour session, to see how you cope with the gearing...

https://www.rgtcycling.com/ is still in free open beta, it has Stelvio Pass (~8% over ~9 miles) and Mont Ventoux (~6% over ~15 miles or ~7% over ~13 miles from Malaucene) routes

Zwift has 25Km of free trial each month, which with a new account you could climb Wattopia Mountain/Mountain8 cat2s (~7% over ~4.5/4 miles), plus Alpe Du Zwift if you already have an account with "level 12"

They won't simulate the wind or the heat you will probably experience on the real thing, but it should give you an idea of what pace you can hold over longer climbs and what your current gearing will offer you.

pblakeney

As a benchmark, I was happy with 34x29 in the Pyrenees. Guy with me said the 34x32 on the hire bikes was too spinny. I am taking the 34x29 to the Alps and expect it to be fine.
The virtual test seems like the best idea. PS - I am only 3.4 w/kg.

daniel_b

Thanks NO, alas I have an aging laptop from circa 2011 that I use for trainerroad, but I am virtually (swidt?) certain that it would not handle zwift.

I do have a rarely used bigringvr subscription, but have my old felt on there with a compact and probably a 9spd 11-25, could probably figure out what the equivalent is though.
Both other bikes are 11spd, and as it's a dd trainer, don't really want to faff with moving cassettes around.

PBlakeney wrote:

As a benchmark, I was happy with 34x29 in the Pyrenees. Guy with me said the 34x32 on the hire bikes was too spinny. I am taking the 34x29 to the Alps and expect it to be fine.
The virtual test seems like the best idea. PS - I am only 3.4 w/kg.

Thanks for that, without working it out, suspect 34/29 can't be far off a 36/30 really can it.

I do dislike the gaping casms on an 11-32, so something less gappy would reduce my annoyance.

This is also meant to be morphing into my 'climbing bike' so it would kind of make sense.
Would give me the excuse to fit my black and yellow chain too 8)

N0bodyOfTheGoat

Daniel B wrote:

Thanks NO, alas I have an aging laptop from circa 2011 that I use for trainerroad, but I am virtually (swidt?) certain that it would not handle zwift.

I do have a rarely used bigringvr subscription, but have my old felt on there with a compact and probably a 9spd 11-25, could probably figure out what the equivalent is though.
Both other bikes are 11spd, and as it's a dd trainer, don't really want to faff with moving cassettes around.

It doesn't get around your bike on the DD turbo issue, but as regards hardware to run Zwift, there is an open beta Android app that I've used most times I've run Zwift since the spring (because my better half has been using her Surface Pro 4 more often) https://play.google.com/store/apps/deta ... e&hl=en_GB

If your mobile is an iPhone, I think there might be an iOS Zwift app.

pblakeney

Daniel B wrote:

Thanks NO, alas I have an aging laptop from circa 2011 that I use for trainerroad, but I am virtually (swidt?) certain that it would not handle zwift.

In that case, go out onto the steepest road you have access to, hopefully 15%+.
If you feel you need an additional gear, or two, or more, then that is a decent guide.
Alpine climbs are long but not too steep (I hope) so you should be able to spin up on anything that you are comfortable with at 15%. Again, I hope.

daniel_b

PBlakeney wrote:

Daniel B wrote:

Thanks NO, alas I have an aging laptop from circa 2011 that I use for trainerroad, but I am virtually (swidt?) certain that it would not handle zwift.

In that case, go out onto the steepest road you have access to, hopefully 15%+.
If you feel you need an additional gear, or two, or more, then that is a decent guide.
Alpine climbs are long but not too steep (I hope) so you should be able to spin up on anything that you are comfortable with at 15%. Again, I hope.

Nothing like that to my knowledge in the immediate vicinity, and I've left it all a bit too late.

For a safety net I have reserved an R8000 11-30 from Halfords, to collect Saturday or Sunday.
Assuming all my previous indexing should be fine, and also that I may need one extra link on the chain to cater for the 30 versus the 28?
If memory serves, I have always used the wrap it around big / big (Ignore rear derailleur) and add two links - has worked for me so far.

pblakeney

Daniel B wrote:

If memory serves, I have always used the wrap it around big / big (Ignore rear derailleur) and add two links - has worked for me so far.

You could be all right as I thought it was +1 link, or +0 and a quick link. I'd check once fitted before use as I swapped cassettes once, didn't check and accidentally crossed. The results were disastrous.

itboffin

For European mountains its always a 50/34 and 30 on the back with the standard rear mech.

"Oh this gearing is too easy" said NO one ever when riding up yet another Col. Map says avg 5% be prepared for something more like 8% for an hour maybe two at a time, thats what i generally have found.

Now if only you knew someone who's recently gone the otherway and swapped from a 50 to 52, if only ......

mercia_man

When you are riding up an Alpine pass, gaping chasms between ratios are not a big concern. But your ultimate bottom gear is. Nothing in the UK can prepare you for the length of those big passes. An average gradient of 8% doesn’t sound too bad. When you are climbing at 8% for mile after mile, you will be pleased to have a low bottom gear. Of course, you will always get show-offs boasting that an 11-32 is too spinny but there is no shame in being able to ride up big passes without walking.

I manage OK with a 34/29 bottom in the Alps and Pyrenees although I have to confess that the French chap I rode alongside the last time I climbed Ventoux found it much less of a struggle with his 32 big cog. The OP’s potential gearing of 36/30 is a slightly higher bottom than my 34/29. I would say go for it. I’ve never come across anyone complaining that they would prefer a higher bottom gear in the Alps.

pblakeney

itboffin wrote:

"Oh this gearing is too easy" said NO one ever when riding up yet another Col. Map says avg 5% be prepared for something more like 8% for an hour maybe two at a time.....

My friend said exactly that about the 34x32 combination.
Proves you are right about the 34x30 though.

mrb123

The altitude can be a factor too. Once you're above 2000m it can make the difference of a gear or two, so slopes that would normally be spinnable in 34-28 definitely require 34-32 if you've got it.

On a recent trip one of the cols had a 3km section into the wind, all around or above 2000m and with a gradient that was a constant 10-11%. Even in 34-32 it was a real grind.

Not all the cols get that steep though, plenty max out at 8 or 9%.

thistle_

For some reason I decided to give hill climbing a go last year and found I wasn't that good at it.
I left the cassette as 11-28 but dropped the small front cog from 36 to 34. This was fine for the Horeshoe Pass (long climb, not too steep) but too big for shorter, steeper climbs (e.g. Bank Road) where a higher cadence would have helped a lot. YMMV.
I didn't change derailleur and the chain was slack on 34/11 but if I'd taken out a link or two it would've been too tight on 52/11 so just don't shift into 34/11.
I'm not sure whether I could fit a 32T ring on my crank, but that would be a 20T jump from big to small which seemed like too much to me.

pilot_pete

Anyone who says a bottom gear is too spinney simply needs to change gear to solve the problem... :roll:

PP

pblakeney

Better to have it and not need it than need it but not have it. Just sharing experiences though.

alanparsons

PBlakeney wrote:

itboffin wrote:

"Oh this gearing is too easy" said NO one ever when riding up yet another Col. Map says avg 5% be prepared for something more like 8% for an hour maybe two at a time.....

My friend said exactly that about the 34x32 combination.
Proves you are right about the 34x30 though.

Not "too easy" but I found that 34x32 was too low and I was bouncing on the saddle, have now changed to 52/36 front and find it much better than previous gearing.
I only put the 32 on for Big alpine stuff as it requires a change of RD, I find 36x28 OK for anything else.

poptart242

52/36 and 11/28 has seen me fine on bigger euro climbs but I wouldn't have complained about a 30 on the back - if you end up not needing it just change up.

I'd miss a 52 front ring though, descents are fun.

Dorset_Boy

Just back from 10 days in the Alps including the Etape. Rode 750 kms and climbed 16,000 m. Used 52/36 front and 11/28 rear and was fine.
Have on earlier trips had an 11/32 but never got beyond the 28, even on previous Etapes.

I find that an 8% french alpine climb feels like a 6-7% UK climb because of the less grippy roads.

That all said, stick the 11-30 on the back and I'm sure you'll be fine given your FTP. Key is to pace yourself, find a comfortable rythym and don't go out hard at the bottom.

thegreatdivide

Where in France and Italy are you going to?

Matthewfalle

currently on a 1x in Abruzzo mountains - 42 on the front, 11-32 on the back. tend to sit in the 26/28/30 tbh but my knee is in bits and I'm not (my personal level of) bike fit so the 32 is handy to have.

you could ride up on Everest on that gearing and it spins out far too easily on the way down. 72kph is as fast as it will do, flat out, tucked in, legs spinning - 20kph slower than my other holiday bike with a 53/28 on.

my perfect gearing would be a double, 42/53 on the front, same rear, but we are all different.


#spinny

daniel_b

thegreatdivide wrote:

Where in France and Italy are you going to?

Nowhere that exciting in France, as it's just a stop off camping point - south east of Dijon, near Dole.
I have spied some mountain looking objects about 10-15 miles south east of the camp site though, so hoping to try a couple.
Also found a 16% average short climb with peaks of 25%.

Italy will be more interesting, Ski Resort called Champoluc, think there are some mountains used in the Giro not that far away.

Picked up the 11-30 yesterday for just under £40, will fit today or tomorrow along with new chain.

Matthewfalle

36/30 - you could go up anything on that no problems.

enjoy the holibobs and send pics.

#holibobs
#riding

naylor343

You could swap your inner ring for a 34, leave the 52 as is. It's cheaper than a new cassette.

daniel_b

naylor343 wrote:

You could swap your inner ring for a 34, leave the 52 as is. It's cheaper than a new cassette.

True, but I would have to reverse it upon my return, and shifts at the front may be pushing it a bit.

I think the bike is due a new cassette and chain, so this should be a fit and forget until it needs replacing. Will probably be rather useful the next time I try Streatley hill too.

Oh and I also have an absolute black 36T which I want to fit at some point in the future to see if it works for me or not.

FatTed

You could try the pseudoscience approach.
If you know your combined weight of you and the Bike and kit, the gradient you wish to climb, say 8% and the power you can sustain for an hour or so and your preferred cadence, then you can work out the best gear ratios for you, mainly a lower gear will allow you to maintain a higher cadence.
If you and the bike where 90Kg on an 8% slope at a cadence of 80 on a 34X27 would require 290W @ 34X29 = 270W
If you and the bike are 81KG the the numbers are for 34X29 @ 8% 226W for the same cadence, if you dropped your leg speed to 70 the power required would be 196W, of course your speed would decrease.
ignoring wind and assuming a certain rolling resistance (which I have forgotten)