Tagesarchiv: 17. Juni 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

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Eingeordnet unter 2009, Mob

Tsurumigawa

Nagai-san has repaired my Cervelo and I could take a short spin along the Tsurumigawa close to my house. I was feeling pretty good, although I still could not brake with my left hand. After 20 kilometers or so something happened: Another flat rear tire.

I didn’t even curse. This has by now become such a regular experience that I just resign to my fate, go down to business, exchange the tube and repair the punctured one later at home. Is this some kind of divine intervention, giving me some hidden hints that I should stop riding my bike?

At least this time the cause was clear. A metal shard in the tire which I luckily found before exchanging the tube. Even a Continental GP7000 tire is not perfect

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Yabitsu Curry Chicken

On Sunday, before the official remounting permission came from the hospital, I decided to try Yabitsu Toge with my bad boy.

I had some objectives, first I decided to ride to the next station on the Yokohama line, Nakayama and take the train out to Hashimoto. That went relatively easily, however bad boy is pretty heavy and difficult to carry around.

New Train Company poster clamping down an illegal mama-chari riders in trains.

In Hashimoto I found out that I still need to ride 7 km around town before arriving at the Tuskui Ko North route which was silent and beautiful as ever. I proceeded to Miyagase Ko, but before I took a short break at a Family Mart.

Yes, you have read right, I was making purchases on a ride out at a Family Mart and not in the traditional 7-Eleven and I have to apologize profoundly as I am caught now red-handed in an orgy of evil.

However, in my defense I need to tell you, that Family Mart is not only selling the new COCA COLA PLUS with green tea whatever, but they also have launched a product line extension to their very tasty musubi line which is „Curry Chicken Onigiri„. That is in fact the best onigiri I have ever eaten and it gives awful power and stamina to bicycle riders.

Actually I could have never gotten up to Yabitsu Pass, if I wouldn’t have eaten Curry Chicken Onigiri and it was still in my mouth when I reached the top.Now, the Togebaka Time was not so impressive, around 67 minutes compared to my best of 51 to 52 minutes, but hey breathing is not so easy if one kilogram of sticky rice is slowly disintegrating into your breathing system.

And of course I had again a flat tire on the way up which needed to be fixed. The air was coming out only slowly and I had my small hand pump was me, so I thought I give it a try and press on. When I reached the top there was still enough air inside, so I pumped it up again before riding down.

I wanted to test another theory, which is that my bad boy is the better, safer and stable choice for going downhill. I was a little bit worried about the rear tire so I tried to play it safe in curves but right fast on straight stretches.

And indeed I was going over 70 km on the last straight stretch which leads into the first villages on the Southern approach to Yabitsu. The bad boy felt great, no bumps with the dampened front fork and going very straight and very stable.

The drawback is of course the nano-crank which doesn’t allow you to accelerate fast after braking in curves, so everything depends of gravity and momentum.

I took the train home from Hadano where I shopped at the Odakyu market which I guess is OK as I have seen other Positivo Espresso Riders doing so as well.

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Eingeordnet unter 2009, Mob