06 January 2009

Gear inches and advice


11 12 13 14 15 16 17 19 21 23 25 27













53 127 116 107 100 93 87 82 73 66 61 56 52
39 93 85 79 73 68 64 60 54 49 45 41 38













50 120 110 101 94 88 82 77 69 63 57 53 49
34 81 75 69 64 60 56 53 47 43 39 36 33













52 124 114 105 98 91 85 80 72 65 59 55 51
39 93 85 79 73 68 64 60 54 49 45 41 38
30 72 66 61 56 53 49 46 42 38 34 32 29


I am continually going backwards and forwards about what to do with my gearing. So I decided to post something and maybe get your opinions and in that way help myself make some decisions.

Trek - Triple (52/39/30) with a 12-25 cassette
Cervelo - Double (53/39) with a 12-25 cassette
Klein - Compact (50/34) with a 12-27 cassette

I will leave the Trek alone.
I intend to sell the Klein in the spring but before that I need to give myself some lower gearing on the Cervelo and might want to use parts from the Klein.
My options are to swap over cranks, or change cassettes, or both.
Obviously the 50-34 gives me a few more low gear options, but I am tempted to stay with the 53-39 from a 'purist' perspective. Silly?
I liken this to getting carving skis. I learned on normal straight alpine skis and eschewed the use of the 'new' carving skis for a number of years. When I finally got 'carvers', they were a revelation. The carving skis are a compact crank. I really like it on the Klein.

Also, given that I will swap the wheels over too (Mavic Ksyrium SL for Zipp 808), I was thinking that the Klein might be more 'saleable' (as a triathlon bike without the aggressive geometry) with a 53/39 on board and the Zipp wheels.

Any thoughts or suggestions gratefully accepted. Yes, I am extremely fortunate to have these 'problems' :)

21 comments:

mob said...

Wonderful post, could have been written by myself as I am standing exactly at the same crossroad in my [cycling] life: will I have th guts to mount a compact crank on my Cervelo? Yes, some people are saying that a compact crank is uncool or strange, but I could never figure out exactly why. As an engineer I would logically say that this is only a question of gear ratio and I cannnot imagine any other factors involved.

Looking at the gear ratio, to exchange a 53/39 standard crank with a 12/25 cassette with a compact 50/34 and 12-27 would result in your highest gear:

before 116, then 110, but still better than 107 in your second highest standard gear. So basically you will loose your highest gear which is rarely used anyway.

So perhaps you will be a little bit slower going down some roads, instead of 70 km/hr you manage 65 or so.

But the lowest gear will come down from 41 to 33, so 20% more opportunities here.

If you keep your speed up and do more spinning, that should be less exhausting up the hills.

I think the comparison with carving skis is a very good one. I could add even more examples from my life were I postponed a decision for months or years on the basis of the same reasoning and after I did it I could not figure out why I have waited for that long:

I used clips instead of cleats, I bought my first mobile phone only in 2000 - clearly I am not an early adopter.

My suggestion would be to go for the compact crank. Once you have done that I will finally have the guts to do it myself.

Manfred von Holstein said...

Couldn't agree more with mob. I had to decide what combination I wanted when I bought my bike in September. Also did some tables back then (showing gear ratio, e.g. 12 on 53 gives 4.4 - I'm not sure what your numbers show?). They showed me that:

- I would never need a 12 on 53 because I wasn't going to accelerate at break-neck speeds of 55 km/h plus

- I wouldn't need a triple (on a standard crank) either because the lowest ratio was 1.2 vs a 1.3 with a compact - that bit of difference one can manage with force

- A compact crank would save me a lot of shifting gears on the crank

I'm glad to report I did not regret my choice and always pitty mob and others when I see them labouring up steep hills.

On Sunday I did 14 degrees uphill and with a standard combination this would have been physically impossible for someone as light as me (and very exhausting for those that can put more mass onto the pedals!).

I don't see the parallels to learning on the real stuff. Actually, if you still want to go uphills at 39 on 25, you can still do that with a compact crank and cassette: just go in the third gear - same gear ratio of 1.6 to 1. I bet though you will find 1.3 to 1 often healthier.

But if you want a real challenge and continue practicing on less advanced gear, why not put the gear shifters back onto the frame, like in the good old days...

David L. said...

James:

I am accustomed to seeing you ride with a very high cadence, using a relatively small gear -- just what the experts recommend for better recovery/less muscle damage on a multi-day effort. Given your style, I would think a compact crank makes a lot of sense. As noted by Manfred, it extends your riding capability onto steeper hills.

As for me, I went several years with a 53/39 on my Airborne Ti and a 50/34 on my Giant (then Cervelo), both with 12/27 cassette. I could not make it up Wada and a few other very steep hills on the 53/39, and when I have the lower gear available I always use it on climbs. I struggled some when my FSA compact crank gave out (recall?) and I rode for 2 weekends in the hills with a 53/39 in October/Novembe. But it is partly a question of what one is used to. I'm going to go back to a 53/39 for my training over the next few months, when my powermeter arrives (no choice, since the Quarq is not yet available for a 50/34 crank), and I hope it will be a useful exercise from a training perspective.

Meanwhile, I need to get my Mavic Ksyrium SSC SL's back to Nagai-san and repaired once more, and consider some new all-around wheels. Mavic R-sys? Topolino? Fulcrum Racing 1 or 3?

TOM said...

JAMES:
Normal vs. Compact? If your favorite field is hillclimbs then the Compact is the safest option, no doubt.

The problem is, as you are gaining strength and nearing peak condition after several months of attacking nothing but steep hills, you will long to reach back to a normal crank! Believe me!! Almost all of the top-finishers in amateur hillclimb races like Norikura, use normal cranks not just the "standard normal" of 52/39 but even one size bigger, i.e. 53/39. And yes Manfred, almost all of those top finishers weigh less than 60 kilograms!

Personally, I am now perfectly happy with a Normal 52/39. Depending on the occasion, I just swap the cassette. For races that include 20%+ gradients, I'd put on 12/27. For a flat enduro, I'd change to 11/23. I just don't like to use a compact crank for the flat road...pedaling like crazy coffee grinder-style is nothing for me.

DAVID:
Those Topolino look awfully sturdy and shock-absorbent at the same time and might fit you extremely well. I find the Fulcrum 3 lacking in suppleness, they are fast though. How about experimenting with the PBO zylon-spoked Synergies? Maybe Nagai-san has a pair for test riding?

Manfred von Holstein said...

Tom, you are obviously playing in a different league from us. Coffee grinding in the flat? One must go at over 55 km/h with a compact crank to get to that. I find that tough even drafting behind a truck.

James said...

Thanks guys, exactly what I wanted, viewpoints from all of you. I'm leaning towards a crank swap. I just need to go down to Shimoda to get the bike it is on!

David, I like the look of the Mavics, but I do not have too much experience with regard to wheels.

MvH, the numbers above denote gear inches, best explained here http://en.wikipedia.org/wiki/Gear_inches

David Jacob said...

Hello matey, felt the urge to comment on gears!

The compact crank will go nicely with your new skirt and blouse...

I struggled in the steep hills on 53/29 and 11/23 - switching to 12/27 gave plenty of room without losing too much on the downhills - spinning out is a pain the butt. Giving in to the lower ratios ultimately saps your strength! Also think about longer cranks and lowering your saddle - gives a bit more gearing effect.

Next you'll be suggesting a compact frame!

Happy New Year,

David J.
HSBC Spring Fashion Co-ordinator

TOM said...

Well put david & happy New Year to you too!

TOM said...

MvH...that's exactly my point, it would be very tough to do with a compact crank! The coffee mill problem gets even more annoying on long downhills...a pain in the butt indeed.

Manfred von Holstein said...

I have yet to find a down-hill which is too fast for me to run out of gears. And this is despite mob thinking I'm going downhill at break-neck speeds. I also managed to do 67 km/h somewhere on Doshimichi while peddling, and don't remember peddling at crazy frequency.

This thing about standard cranks and 11-23 cassettes is for people whose heart bumps in the thirties when they sleep and who otherwise wreck their lives with speed and drugs. And maybe those that want to be like them?

mob said...

Wow, a lot of comments, even from far Britain, where everything is going well we all hope?

After the first question is answered and yes, a compact crank it will be, there is now the second one: Which one is recommended?

Surely it should look well and have some carbon parts on it.

dj said...

hidehi mob, yes, all well in chilly UK tks!

Had a fun new year in Berlin and visited Jena, Dresden and Weimar. Would have loved to try some German christmas cake but it was all stolen (its a play on words :-)

back to gears - 50/12 gives a cadence of 126 at 67 kph - not impossible but not comfortable for any length of time. So descending even at this sedate speed is difficult. Descending at manly speeds of 80 kph and higher you would be spinning out - Man Up!!

This is not to say compact cranks don't have their place - my dad got one for his 70th birthday and is very comfortable on it.

Best wishes to all for a healthy and happy 2009 - come visit us in the land of advanced domestic plumbing and we'll take you for a ride in the English Alps...
David

James said...

If I go compact the option is to fit the Shimano R700 that is currently on the Klein, or to purchase an FSA SLK Carbon Lite Compact.

Anonymous said...

How about a normal crank (53/39, I mean BCD 130 mm), then you change the chainrings for 51/38. FSA offers different sizes: http://www.glorycycles.com/fsaroch.html


Thierry

James said...

Thanks for the idea Thierry.
I emailed FSA a few weeks ago. 50/34 rings are only available in BCD 110mm. A shame as this would have been the perfect solution.. change the chainrings over as and when required with a quick adjustment of the front derailleur.

mob said...

Yesterday Ludwig and me did a long ride in the mountains, climbing up from Kosuge to Tsuru Toge. Some stretches of the road are steep, but I am sure than they are many more even steeper stretches somewhere out there. I was going up at turtle-like speeds at extremely low cadence with my 39 front 27 rear gear ratio and I wished I would have more options.

I always find it some kind of personal defeat to climb up the hill in the outer front gear and then shift to the inner one. And every time I shift down on the rear. So I try not to do it.

But I started going to Okutama with my 11/25 cassette in 2003 and only after I have bought the 12/27 I started to have fun.

On an ordinary ride out, I believe I could cover 80% of the time with standard or compact crank (including resting time) and the remaining 19 to 20% I would fare better in the hills with a compact crank.

Is it very, very rare that I go faster than 60 km/hr, perhaps once or twice during a ride. And if I do, i normally do not pedal.

So, yes, one may loose out here, but the argument I feel is similar to the argument that was made against the introduction of seatbelts: You might not get fast enough out of your car in case of a fire. True, but the likelihood of this occurence is far lower than a crash in the first place.

I agree that it looks much more manly, to have a standard crank on a bike, provided somebody notice that. In case of James a compact crank is anyway an improvement, as he has a triple on his Trek bike, which I would believe, is the ultimate statement of uncoolness in the hills [provided someone notices]. Now James has this very nice Cervelo in the garage and is using his Trek instead, one reason being the standard crank?

At the end one more word to David's father:

1. He is not the average 70 year old gentlemen, but he was an extraodinary racer during his youth, probably he will still beat some of us going up to Hakone.

2. Actually he owns Tom's old Trek bike now. Does that mean that Tom is ridig like a 70 year old? Obviously not, the same is true for the compact crank.

3. In the English alps a standard crank might be sufficient.

I am checking out the available compact cranks on the market ... Campa is not an options for many reasons, Shimano would offer the best performance /price level but looks so bulky and ugly, which will leave FSA, Ritchey, Truvatic, Race Face, Look, Time, Miche, SRAM .... any other suggestions?

Manfred von Holstein said...

Well spoken mob! And I am really praying for the day you have a compact crank and we can go up the hills together a little faster!! You made me save all my energy for Otarumi reverse side yesterday, where 17min40 looks rather passable after 130kms and 1,200m climbing. BTW, I did that mostly in the third gear, so a standard crank would have been fine - but then Otarumi is rather flat.

Anonymous said...

I just bought this carbon compact from ChainReaction in the UK, The ControlTech Carbon Shield:

http://www.controltechbikes.com/test/prod/product.asp?pro_id=26

Includes hollow-tech-style BB; haven`t installed it yet but in my research for it I found nothing but good reviews for it and ControlTech`s other products.
-Davad

mob said...

There is only one post in the long history of Positivo Espresso with more comments than this one:

http://positivo-espresso.blogspot.com/2008/07/riding-out-weekend-july-1213.html

Soon I will issue a complete review of available compact cranks

Manfred von Holstein said...

Wow, yes, and incidentally that was the first one on which I was mentioned without knowing it and it was all about the ride that eventually got me to buy a bike and join this group. I think this alone justifies the length!

David L. said...

Well, Nagai-san recommended a Shimano Ultegra SL compact crank for me last fall, and I'm very happy with it. A good combination of cost/performance/weight/appearance. From the Excel Sports (Boulder CO) web page blurb:

Shimano narrows the gap between its 10-speed Ultegra and Dura-Ace groups with the new Ultegra SL components. The new Hollowtech II design crankset with new BB spindle and alloy bolts help shave weight over standard Ultegra cranksets.

# Features 34-50 chainrings
# High-polish gray SL finish
# 717 grams