I will soon start to build my new Caad 9. I have most of the parts, but I need a crank.
Hollowgram would be the natural choice. But there are two versions to choose; SI Alu and SI SL Alu. Some who know the weight difference between these two crank arms? (Or know the actual weight of any of them)?
Edit: I'm a jackass. The SIs are ~ 660 grams and the SISLs are 580 grams (all in) so it's like 80-90 grams lighter depending on BCD. Considering a 7900 crank is ~660 and the BB is 90 grams, they're friggin' light.
This was at the end of 2007, when Cannondale was just rolling out the first Super 6's, and looking at the SI SL vs. the SI, I couldn't see a difference.
Anyway, here's an SI
Notice the crank bolts are solid...............
while these are hollow.......... yes I am fully aware those are mountain cranks. They are however, the same crank bolts and crank arms used on the road bikes.
Here's an SISL
here's the spider to arm interface. The SI is silver and the SISL is black. Notice the SL are missing the material.
Like on MTV cribs, this is where the magic happens
Since the pic was taken by a D-bag at a 100mph it's 'kinda blurry. For those that are less visually inclined, here's a pretty cartoon to illustrate the CNC wizardry at work on the SISL.
Edit: some of these pics really suck but you get the idea.
LegalizeMyCAAD9 wrote:Also the lockring on the SI SL is lighter than on the SI ones!
Yep, that's what I said. Along with the crank bolts. The Mark V rings were lighter than the Mark IV also but thats a bit thin for this discussion.
where'd you get that pic??
I bet the next generation of the SISL will be a DS or NDS spindle integrated into one of the arms and made from one piece of Mg or Al. I'd think what's holding them back currently is the inherent upside(s) of the current SISL. I know they have the ability to make the thing already. They make the wicked light lefty stems with the machine as it is. From a production standpoint they are able to use them (the current SISLs) on their mountain and road bikes with different spiders and spindles. The 2 piece setup would be great for road. They'd likely have to make a purpose built mountain frame that would have a narrower BB than anything currently out and the frame would be limited to that crankset. The new Flash bikes are BB30 only and are selling well so it wouldn't surprise me if they made did it that way.
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Also, Sastre's cranks were solid before they were drilled out. The SiSl are hollow because they are formed with two pieces (clam shell). The walls are so thin that drilling them would not be healthy.
I've poured through the Cannondale site, and all I can find is a pdf instruction sheet for the sisl, which mentions that the si version uses 8mm crankarm bolts to the 10mm sl. But that says nothing about the ext. diameter of the threading and the profile of the fit.... Or any other differences. But the document is titled SISL, so it is probably not intended to cover the si version completely.
So, I'm hoping some of you wonderful cannondale experts can welcome me to the family with a little schooling on the cross-compatibility between these two version!
To mix and match you need to buy the tools; KT012 and KT013 are the cannondale part numbers. Those are the crank arm removal tools and the spider lockring removal tool.
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