17 June 2009

Ask Dr. Evil


Dear Readers, the following piece of correspondence from a desperate fellow rider has reach my desk in the afternoon (obviously it has been written during work):

Sate, I was plodding up Wada last Sunday (on my own) and realized again, as I slowly turned the wheels up the hill, that my big dura ace 52 crank is not designed for me! I bought my bike 8 years ago and so it only has a cassette of 9 gears on the back so I am very behind the times.

So, I am wondering what to do without buying a whole new bike (which is delayed until my wife thinks there is no chance of me being laid off at work).
  • Option 1. Buy a new dura ace compact crank only. If I do this, will all the other dura ace bits on the bike work with this new crank without me buying anything else?

  • Option 2. Do option 1 and also buy a nice new 10 gear cassette. If so, will I need to change gear levers and all?? (If so, this is probably not cost effective for one more gear.)
Any thoughts much appreciated. Good to hear that you are back cycling again.

First I would like to write that I am glad that your problem are not punctured rear tires because I should be considered the last person on earth to give advise on this problem. Now, I think you have given the answer to your problem already. As any decent 40 year plus amateur rider from Positivo Espresso will tell you, you need a new bike, preferably with Shimano Dura Ace Di2 and an investment cost close to the defense budget of Mozambique. It should have however one small flaw on which you can blame any lack in performance, for example that the handle bar tape is not matching with the saddle leather. But this is probably not the answer you would like to hear.

Also, the other reasonable advice, that you should leave everything on your bike just as it is and get up your butt, finally do more training and loose some weight so you can fly up Wada like a mini car driven by two gays
would only be honored by your lovely wife and not by your good self.

OK, let's try something unreasonable :

It would be my educated guess that you can combine Dura Ace 9 speed components only with other Shimano 9 speed components, such as Ultegra and 105.

You can probably not combine them with any components from the newer Dura Ace with 10 speed (7800 series) (different chain width) and also not with the new 2009 Dura Ace (7900 series) (one way chain). The same is true for the newer 10 speed Ultegra and 105.

So if you are looking for an economic solution which would give you more choices on steep climbs my advise would be to upgrade with older 9 speed dura ace components, which are still plentiful available as they were replaced only in 2004.

CRANK

Obviously you would like to exchange your standard crank with a compact one. Perhaps there are also other options in the market, not only from Shimano. Check also the crank length; all lengths in 2.5 mm steps from 165 mm to 180 mm are available. I am using a 175 mm crank, so perhaps a 172.5 or 170 mm should work well for you.

Of course you can also consider a very uncool triple in the front, not sure if there is one with dura ace specs although.

REAR CASSETTE

I do not know what you are using now, my guess would be 11/23 or 12/25? If you just change the standard crank into a compact one I don't think you will need a new rear cassette if the biggest sprocket is 25 or bigger. Anyway, the biggest one available from Shimano for road bikes is 27. But I believe that in order not to loose too much on your maximum speed in the flats or downhills, the smallest sprocket should be 12; 11would be better.

12/21, 12/23, 12/25 and 12/27 9 speed cassettes are available here.
The alternative would be 11/21 or 11/23, but that's nonsense for climbs.

Don't laugh, my first pro bike had a default 10/21 9 speed - I was suffering in the mountains and I had no idea why.

If you have a standard crank and a 11/21 rear cassette mounted on your bike, I would guess that just changing the rear cassette to 12/27 would be good enough.

I am not convinced that a 10 speed offers so much more advantage over a 9 speed system. In most cases it seems to me that the smallest and biggest sprocket mounted are the same, so you have more variety in between with a 10 speed system. But you also need to do more shifting when you want to move from a climb in a low gear to a downhill stretch in a fast gear.

If you desperately want to move to 10 speed, my suggestion would be to change to Shimano 105. In this case you would need no control levers, new front derailleur, new crank, new chain and a new rear cassette. With 105 compared to dura ace this is somewhat affordable and I don't believe that this will have any substantial impact on the performance of your bike. Except for the weight, perhaps 300 gram more. So take less coins with you in your wallet if you decide for this solution.

If you have tons of time, you can also take a look on what the authority is saying:

http://www.sheldonbrown.com/dura-ace.html

3 comments:

andy said...

Mob, yes you can mix and match nine speed components.

For steeper climbs using the 9 speed set up, I would recommend a 27 cassette. I have dura-ace on my bike but the 27 cassette is 9 speed Ultegra (if I remember rightly, I don't think you can get it in Dura Ace or maybe I just thought Ultegra would be good enough).

To get the range of gears you want, you can mix and match your new cassette with your existing cassette. (mine came as a 13 - 27 9 speed cassette, but I mixed them up a bit to get 12 - 27)

Also don't forget you can go smaller on the front without going compact or triple.

If your crank is 52/39 (39 is usually the standard), you can change the inner ring to a 38. Sugino make good and reasonably priced rings (1 or 2000 yen?)

http://www.suginoltd.co.jp/chainrings_standard_e.html

Riding 2 bikes, I find the difference between a 39 and 38 toothed chain ring on the front to be really big on climbs.

As for crank arm lengths, you can go as far as 180mm. I use these but I'm tall. Shorter riders tend to use shorter crank arms. However, I have a friend who swears by them and he's not tall at all. Also, Tom Boonen likes them so much that he uses Dura Ace 180mm depite the rest of fancy carbon crank set up.

Hope this helps,

Andy

mob said...

Hi Andy,

Thanks for your comment, I hope we can go out riding together soon. This was really a question by a fellow biker, not myself. I have different problems as I want to upgrade from Ultegra 10 speed 2008 to the new Ultegra 10 speed 2009 which will require to exchange any single Shimano component except for the brakes.

Yes, you can mix Dura Ace, Ultegra and 105 components, provided that they all are 9 speed. Or all are 10 speed, but mixing 9 and 10 speed components seems to be difficult.

Otherwise it is exactly as you wrote: Crank, or rings in the front, making one's own combination of rear sprockets (but careful, you might require to change the rear derailleur from short arm to long arm if the difference between the smallest and biggest sprocket becoming to big), crank length.

Otherwise: training.

mob said...

Hi Andy,

Thanks for your comment, I hope we can go out riding together soon. This was really a question by a fellow biker, not myself. I have different problems as I want to upgrade from Ultegra 10 speed 2008 to the new Ultegra 10 speed 2009 which will require to exchange any single Shimano component except for the brakes.

Yes, you can mix Dura Ace, Ultegra and 105 components, provided that they all are 9 speed. Or all are 10 speed, but mixing 9 and 10 speed components seems to be difficult.

Otherwise it is exactly as you wrote: Crank, or rings in the front, making one's own combination of rear sprockets (but careful, you might require to change the rear derailleur from short arm to long arm if the difference between the smallest and biggest sprocket becoming to big), crank length.

Otherwise: training.