BB30 Cranksets for 135mm OLD Disc Brake Chainline

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Valbrona
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by Valbrona

FSA have their two 'DB' cranksets, but both are BB386EVO and I don't want those things in my BB30 shell anymore than I want a ....

Any BB30 110BCD cranksets with disc brake chainline out there yet?

Thanks.

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Calnago
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by Calnago

Ha! Pretty soon we may reach a point where it's easier to modify a mountain bike for road racing than jump through all the hoops necessary to make road bikes fully perfectly functional with all the new requirements that disc brakes seem to demand... Beefed up forks and chainstays, beefed up wheels, no radial spoke lacing, different offset cranks with potentially wider q-factors in order to accommodate the increased chain line requirements, longer chainstays to accommodate the chainline differential (really hate this one because longer chainstays affect the tight handling we've come to appreciate on a finely balance road bike). The list is just so far reaching for something that is just so unnecessary on a top end road bike. Rant over.
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deek
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by deek


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bikerjulio
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by bikerjulio

Chill.

This starts from an assumption that a 130 mm rear spacing results in an ideal chain line.

Well yes, for one one cog maybe. But what about the rest?

And now if we move the cassette 2.5 mm to the right, what will happen?

Guess?

Nothing? Or a different cog becomes more ideal?

Check on a metric ruler and contemplate what 2.5 mm looks like.
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

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Calnago
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by Calnago

It looks like 2.5mm. Absolutely that's a significant difference when it comes to functioning perfectly across the entire cassette range. Especially with the narrow front dérailleur cages out now and how finely they have to be adjusted.
Check out the daylight between a campy chain and the inner face of a 2015 outer Campy chainring when it's in the small/small combo. It's much less than 2.5mm.
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dwaharvey
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by dwaharvey

My Wilier Cento1SR disc has 40.6cm chainstays and 135mm OLD rear wheel. I'm using a normal FSA 52/36 BB386 crankset with Sram Red22 hydro shifters. I haven't experienced any shifting issues at all. To be fair, I am never in the 36-11 combo... just not a gear I have much use for. I tend to use the big ring on the front unless I'm doing real climbing, and as bikerjulio points out, while the 36-11 combo _might_ not work as well as it should, the 53-23 or 53-26 becomes somewhat better. I'm 100% happy with my setup.

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Valbrona
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by Valbrona

Calnago wrote:It looks like 2.5mm. Absolutely that's a significant difference when it comes to functioning perfectly across the entire cassette range. Especially with the narrow front dérailleur cages out now and how finely they have to be adjusted.


I'm going with 2.5mm as well. And of course with today's kit, 2.5mm is easily the difference between gears working correctly/incorrectly.

Would have been sweet if you could just put a 2.5mm spacer on the DS side of your average crankset, but it ain't that easy.

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