Vireo

Hello Everyone,

It has been awhile since I have posted on the forums. I am not ashamed to ask for advice on things I'm not that familiar about. I have a 2007 Pinarello tandem. I've done some long distance riding on it and some climbing centuries and doubles as well. I am looking to lighten it up before RAAM June 2015. We are doing 4X tandem relay.

One thing in particular I need advice is in converting the triple to a double. Currently I ride a triple with a 55/39/28 Sugino and 11-28 cassette. I hate the triple and since this hasn't been my primary bike I only had to deal with it every few months. But I will be riding this bike more regularly between now and June.

So my questions are:

how much lighter are 2X cranksets than 3X?

What brands make quality light 2X cranksets?

Does someone have a link to a chart with verified weights of these cranksets?

There are more questions I want to ask but let's start with the crankset.

barkersoldbean

To be honest I was a bit in "shock and horror" as I read your post. Unless you are a 120kg/500 watt output uber competitive team, I can't see how the loss of 50g in a chainring is going to make a heap of difference? Lose the breakfast 3 days running before the comp and this will have more of an impact.

Vireo

It's got to be more than 50g to go from 3X to 2X. The chainring, and its spider weigh more than 50g. Additionally, I bet they have some crappy and heavy square taper BB hidden in there (two BB's actually.) And it is a Sugino aluminum crankset, 4 aluminum crank arms, so I was wondering how much lighter a carbon 2X would be with a more "standard" bottom bracket. The combination of these should yield more than 50g weight savings.

Lastly, I hate the way it shifts and I prefer 2X and want to explore the option of Di2 like on my single bikes.

So barkersoldbean unless you have something positive to contribute please stay off the thread.

akexpress 

one of the lightest carbon tandem cranks are the Lightening cranks. You can configure them for standard or compact. We have had them for two years now and they have worked well. We use them with Ultegra DI2 and would never go back to mechanical shifting again.

Vireo

Thank you akexpress - would you happen to have weight you verified yourself?

akexpress 

I will weight them when I return home on Tuesday as they are off the bike right now while I have some framework done. I will weight them with BB's so you have a true weight complete. Lightening uses their own BB's

Vireo

Thank you akepress!

barkersoldbean

Apologies - was not meant to be offensive - just a bit of a light hearted comment that went awry. T

merlinextraligh

take a look at how Paketa sets up their one sided drive trains.

If you can use a belt, the lightest setup is likely to be a single side drive, with a 2x10 (or 11), and the belt in place of the third ring.

You might need to run the belt on the outside of the crankset for chainstay clearence.


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waynesulak

In the unlikely event that you are just concerned about shifting then the inner stop screw can instantly make your triple into a double and you can loose the inner ring too. Then you can just shift all the way in or out for front shifting your "double".

There is definitely some weight to save with a crankset upgrade, especially of you are willing to spend money on a whole new drive train. If you are going to spend a lot of money, then consider upgrading the wheels and tires. That is often a relatively good way to go to save weight and/or make aero gains.

For us I doubt it would make much difference as long as the drive train is shifting well but if you want to go that route then my vote is for wheels then cranks.

On a pure weight saving side, dummy stoker hoods usually run 1/2 pound or so. Lighter stoker bars without hoods is a cheap way to save weight IF the stoker agrees.

Carbonello

I'll echo what was said above about the belt drive conversion. We saved half a pound.