RollCNY

Not saying it was sustainable, but it was quite the hoot doing that in a pack of guys with compact and standard cranks, holding on for dear life. Really makes me believe I will never need a 53x11 again.

cerealkilla

Tru'dat tiz when I switch over to the jet-pack and line my cape with the suns magnetic pulse.

cali_axela

Try that on a fixed gear bike... I've done 35mph sustained down fairly long descents in 46x16. When continuing to pedal becomes a matter of life or death (or at least serious injury), you quickly adapt to 150+ RPM being a sustainable cadence

Campag4life

That's what I'm talkin about.

martymc

Thanks for all the replies...

I pulled my bike out and counted the current cassette. It's an 11-25 (..12,13,14,15,17,19,21,23..). As someone said, that 15-17 and 17-19 hole is my chief complaint, as it seems it is a complaint of many.

Went and bought a cheap, used Chorus 13-26 cassette (..14,15,16,17,18,19,21,23..) and will give it a try tomorrow to get more granularity.

As for the spinning technique on the downhills, I probably should have been clearer. I usually cruise at 95-100rpm as a comfort zone. I don't know the exact cadence where I keep wanting another gear and started to bounce, but it's well above my comfort zone of 100rpm. As for the bike setup, I sprung for a Retul computer fitting a few years back and it made a world of difference in comfort and slight increase in speed. I'm by no means am as serious and technically tuned-in as many here, but I feel my bike setup is a 9/10 and my cadence & ride technique is fairly sound... My desire for speed was primarily to get some free climbing by killing the downhill and using the momentum to make the next climb easier.

That brings up a Q: Can I take the last cog from my previous cassette (the 11 tooth) and replace the last cog on the new cassette (the 13 tooth) -- so as to have an "overdrive" gear, should I want it? i.e an 11-14-15-16-17-18-19-21-23-26? Any big no-no's in doing so?

Thanks again in advance for all the replies. This forum is wonderful.

Fox Farm

10 speed Campy and you have a 26 on the cassette? Hum... I would have said to install an 11/25 Campy cassette. But, from what you are saying, do you need a compact crank where you live?

merlinextraligh

One place I'd like to have bigger gears is on the tandem, but even then it would only be for really rare circumstances.

At Masters Nationals in the tandem road race, the race started with a 10 mile descent down Mt Bachelor. Knowing we were going to be outclimbed on the climb backup Mt Bachelor, our one hope was to attack on the downhill.

We jumped at 50+ mph, got in the mid 50's and got a couple hundred yard gap, but we're also spinning 140 rpm plus in 53/11. As a team, we weren't smooth enough to sustain that without the bike shaking unacceptably, so discretion lead us to sit up and go back to the pack. 56/11 would have helped a bit.

We've hit 65mph, but that was due to gravity, not pedaling.

Campag4life

Crazy fast. Long wheelbase of tandem help stability at that speed?...compared to a std. road bike?. I am no expert on the TdF but they likely hit these speeds or close to when descending the mountains at times.

Campag4life

I haven't tried what you propose..not sure how the downshift i.e. shift from 11t to 14t would go...with 3 tooth jump. May work. Up top the cassette a 3 tooth jump is 50% less due to twice the teeth and much larger cog diameter so more sustainable.
I can tell you that Campy smallest cogs are lockring specific...lockring has to match the no. of teeth...but you likely know that.

merlinextraligh

Tandem is definitely more stable than a single due to the wheelbase. Only disadvantage is that 2 people have to coordinate, which usually isn't an issue until something bad happens like a blow out. Fortunately my stocker is very good at following my lead.

rm -rf

Here's a chart (from Mike Sherman's gear calculator)

It's for 50/34 chainrings, and 13-26 10 speed cassette, with the 12 cog added as the 11th gear. The 12 adds about 2 mph at the top end. When I hit about 33-34 mph on downhills with my 50-13 top gear, I'm spinning but not adding much more speed. So I just coast on steeper descents.

50 chainring is black, 34 chainring is red. RPM from 85 to 105.





Speeds at 95 rpm. 50/12 is 30.9 mph, 50/13 is 28.5

The 18 cog that is added on the 13-26 cassette is 20.6 mph at 95 rpm. The 17 and 19 cogs are only 1 mph up or down from there. That's a good place to have close gears for me.



EDIT -- I accidentally set the small chainring to 35 instead of 34. But it doesn't matter here.

brianmcg123

Did I miss something. Is granularity the word of the day?

Campag4life

Having close gears in the 17-18-19 range has been discussed many times on this forum including this thread.
I have addressed the counterpoint of this. Where does not having a 18t really matter? When running a 34t small ring in front. So why is this?
It is because of virtually no overlap i.e. redundant gear inches between front chainrings with a 16t gap between 50 and 34. So what's the alternative if you still like a compact but want to climb. A 50-38 with bigger cassette in back. Why does this work out better for the elusive 18t cog? Because a 38t small ring in front allows running on the small ring with say 28-12 cassette...down where there is 1 tooth difference on most cassettes which is in the smaller cogs. So the 34t compact ring is a liability to a wider spacing in the middle to higher tooth count cassette. Another example is...on a std crankset which is 53/39. Not having a 18t cog in back isn't a liability for the simple reason that you can easy pass the 20mph mark in the small ring where you are lower on the cassette and can tune your cadence in 1 tooth increments. Same for a compact with 50/38 combination. I can ride 38-12 to 25 mph if I want and can dial my cadence precisely in the 20 mph range with 38-13 or 38-14.

Campag4life

To me, a misnomer really. I believe incremental or close gear spacing is more appropriate.
Ahhh words...but an imperfect metaphor for the truth.

martymc

I road 30 miles this morning with the 13-26 Chorus cassette on the back -- and it was much, much better for dialing in the cadence for commonly used gears. Felt like a different bike. It really highlights how annoying the 15-17 and 17-19 jumps are once those jumps are eliminated.

However, I definitely need something bigger than a 13t as my smallest gear. It's rolling hills around here with lots of 100-200ft climbs, 100' drops, another 100' or so climb. Getting speed on those downhills really slices my course times and preserves energy by using momentum up the next hill. So... swap the 13th cog for an 11t (to at least get me back where I was / can live with) -- or / and replace the outer chainring on the front to a 53 so as to achieve a 53/34 instead of a 50/34? Is that even possible?

Many thanks...

gsa103

That will be a pretty big jump from 53->34, so you'll want a chain catcher. The other issue is that's a lot of gear spread (34 teeth), your RD may not have enough take-up. Do Campy make a mountain bike RD that you could use?

rpenmanparker 

C4L can chime in here, but I think it is highly unlikely you can shift acceptably over a 19 tooth gap from 53 to 34 or back. The 50-34 combination of front rings is for a reason, that is the capability of the FD. In the days of 5 speed freewheels it was common to have a two tooth gap at the high gear end of the freewheel, e.g 13, 15, 17,19, 21 or some such thing. So we know two tooth jumps at the small cog end are possible. The jump from 12 to 14 is a little bit more difficult but your RD should be able to handle it, much more likely than the three tooth jump from 11 to 14. Besides that puts your high end back where it was, and you still get the mid-range gear density (better than granularity?) you were looking for. Many go to the semi-compact crank for this reason such as 36-52. Same 16 tooth gap as 34-50, but with a higher top end.

merlinextraligh

I get back to the better answer being raise your comfort zone to where you can spin 120 rpm or higher. It's not tha big of deal to do that for a minute on the rollers you describe.

Additionally, as stated before if you're getting in the mid 30's or above, you can often tuck and go as fast, or faster, with less energy expenditure than continuing to pedal.

The fastest way to ride the terrain you're talking about is push over the top of the roller with some effort, spin up quickly, as you approach spinning out, tuck, coast, recover, then pound the next roller.

A few hard pedal strokes at the top, then coast, ends up being faster than trying to pedal moderately contiously, and with less energy expenditure.

This really is a matter of technique more than gearing.

Campag4life

Campy offers three cage lengths...long cage designed for a triple will work.

cyclezen

simplest - you already have the 11 cog - try it with the lockring from the old cassette.

next option is the larger big chainring - many riders already are using the 52 - This might require a little more judicious shifting, especially on the downshift to the smaller ring, becuase of the big gap and the looseness of the chain when it comes free - chain catcher fer sure...

if you really like the current gearing with the included 16 & 18, then making that 11 work should seal the deal. A 3 tooth jump at the rear should only be a problem if you're Tee Jay VanGarderen, riding off the front in the TDF and using Shimano DI...

rpenmanparker 

OP has already spoken that he appreciates the higher gearing density of his new cassette, and I have no argument with that. Nevertheless, I was just thinking that a one tooth difference over the range of cogs from 15 to 19 teeth is always in the range of 5-7%. So just adjusting cadence by that amount, say 90 instead of 95 or so or vice versa would obviate the need for the missing 16 and or 18 tooth cogs. How hard is that for an experienced cyclist?

Drew Eckhardt 

It's too hard for Lance Armstrong. He didn't feel the jump from the 21 to 23 cog was acceptable for attacking hors categorie Tour climbs like l'Alpe d'Huez, the Tourmalet, and Luz Ardiden so he ran 12-13-14-15-17-19-21-22-23 cassettes.

When a 9.5% jump is too hard for an alleged drug using mutant whose day job is riding, tolerating 13% from 15 to 17 is too much to expect of duffers.

To be a little less snide it's mostly about what's most pleasant not what's possible. Otherwise I'd still be riding 52-42 x 14-16-18-21-24-28 and have spent thousands less on bike parts.

I did notice at the same stress balance I could do 3x10 or 40 minutes at a threshold pace on consecutive days keeping my cadence over 90 RPM but not either side of the 85 average I naturally preferred. In decent shape shifting at 120-130 RPM feels good sprinting; around VO2max 105-110 RPM works good; but at threshold somewhere under 100 feels better. No missing cogs though the 19 makes a 90-100 RPM range work or work without ADHD-like shifting.

I notice a small difference with a 20 between 19 and 21 but would take a smaller starting cog instead to defer shifting up from my 39 ring. I don't notice a 22 between 21 and 23 (I've been riding a 14-23 straight block as an experiment).

Drew Eckhardt 

With 10 speed parts:

Short (55mm between pulley centers) is officially for doubles and all cogs except 13-29; 52-34x13-26 is just two teeth off from the official limit which accommodates variations in derailleur hanger geometry and people have succesfully used short derailleurs with doubles and 13-29. Definitely worth trying.

Medium (72.5) is officially for doubles with all cogs and triples with all cogs except 13-29. 52-42-30 x 13-26 is 35T of wrap. Officially ample. In the 9 speed era the Racing Triple was a medium not a long.

Long (89) is officially for anything with a claimed 39T capacity. Over kill for a wider range double.

martymc

No claim here to be some awesome or even competitive rider. Just a 41 yr old riding about 450-500 miles / month, riding for 20 years / just doing it for fun and fitness. For casual rides, recovery rides, even group rides, I'd agree the 2-tooth holes in the cassette are no big deal. However, I frequently ride solo and push myself to effectively do time-trials on set courses, typically 25-40 miles long. In those cases where I am giving it my all with no benefit of drafting / taking a break, I really notice the gaps. I can spin higher in the smaller gear but feel I'm "leaving something on the table" in terms of overall course time, so I do the jump to the harder gear but can only take it 5-10 minutes before I need a break. Being able to finely tune-in an acceptable level of pain and ride just a little faster so as to set a new PR is what I'm after, why that fine density on the cassette is much appreciated.... Even this morning with the denser cassette, the change and feel was immediate and very welcomed.... Reminds me of the benefit of constant speed props in airplanes...

Campag4life

Good stuff Drew.
I just picked up a Campy 10s medium cage derailleur with goal of running:
Typical: 50--38 and 12-29
Hill climb days: 50-34 and 12-29

Cheers.