# new forged SI crank vs SI SL (not SISL2)



## are (Feb 5, 2005)

I'm thinking of getting a bike that has the new forged SI crank on it. I have the SI SL crank on my current bike. I assume the SI SL is slightly lighter and stiffer than the new forged SI crank. Does anyone know if this is true? Due to the re-use of model names it's hard to find good info online.

Also, assuming the SI SL is better, should I be able to just swap the arms from my current setup to the new bike?

The SI SL crank is from 2009, so probably has 15k+ miles on it, fwiw.

In either case the crank would have normal spider & rings, not the new SpiderRings.

Thanks


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## Dan Gerous (Mar 28, 2005)

Yes, your SI SL are lighter. The 3D forged SI is about the weight of the older, original silver SI cranks... As for stiffness, I'm not sure how it compares but I think you wont gain much if at all over the SI SL.

As for a swap, everything is cross compatible between every generations and versions so yes, you could keep the new bike's BB, spider and only use your SI SL arms. Compact 110bcd spider, Standard 130bcd spider, Campy 135bcd spider, SpideRing, they can all be used on whatever crankarms you'll use.

Only thing, if your new bike has a PF30 and not a BB30 bottom bracket, use the newer spider lock ring. It tapers a bit at the tabs where the tool engages the ring while older lock rings are flat. The old flat ones don't have enough clearance for the PressFit cups. And use the spacers that go with the spindle (not sure about the forged SI but SISL2 use a longer spindle without a lip on the non-drive side so the spacer setup is different). But if you only swap the arms, you can leave the BB and spindle with it's spacers on the bike.


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