Cervelo Bbright with Cannondale Hollowgram SiSl ?

Discuss light weight issues concerning road bikes & parts.
bjavern
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by bjavern

Thanks for the reply eric.

Can I swap out the spindle for say one from Rotor or Quark or wont that fit Cannondale cranks? I've never swapped/taken apart a BB before (in case I just said something stupid).

Cheers

JensW
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by JensW

even if it would be possible the chainline and q-faktor will nog be that good, considering that the crankset is made for 68 bottombracket shell

bjavern
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by bjavern

ok, thanks for the reply jensw - thats a very valid point. i guess im gonna have to take another look at rotor 3d. i guess theyre good, i just hate the graphics on them :-)

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pritchet74
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by pritchet74

Image

It's been done, but it required a custom fabricated bottom bracket that you can't get anymore. I had 2 and sold both. I really wish that I had kept both of them....
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styrrell
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by styrrell

I'm not so sure that it cant work. Keep in mind that the sisl2 is wider than the sisl and doesn't have the step on the sisl axle. You'd have to leave off all spacers from the none drive side. Just use the the crank and bearing cover, then see if their is enought clearance for the crank to fit without bottoming out on the frame on the drive side.

It may be possible to buy a tiny bit more space by sanding down the lip on the Pressfit cups also.

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rmerka
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by rmerka

eric wrote:A true BB30 crank will not fit in a BBright frame. The spindle is too short. They only fit in 68mm wide frames. Rotor and Quark 30mm spindle cranks have longer spindles and will fit.

Just a point of clarification. Your RS is NOT BBRight. It's a standard English threaded BB. Have a look at the Rotor BSA 30 BB. Might do the trick.

http://www.rotorbikeusa.com/products/bsa_bottom_bracket.html

eric
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by eric

BBright is 11mm wider on the NDS. Does the SISL2 spindle have that much room? The ones I have seen on bikes do not look like they are even close... there are little to no spacers on the NDS, not 11mm worth.

If you could find a longer SISL spindle, or use an MTB one, you'd end up with a very wide Q factor.

30mm ID BSA external bearings won't work for a true BB30 crank. They add about 10mm to the 68mm BB width on each side. Cranks with long 30mm spindles like Rotor and Sram Quarks will work.

I understand about the Rotor graphics. But they'll go on a bike with a giant CERVELO on the down tube and a bunch of logos elsewhere so it is not going to stand out. And when you are riding you won't be looking at it.

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ms6073
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by ms6073

rmerka wrote:Just a point of clarification. Your RS is NOT BBRight. It's a standard English threaded BB. Have a look at the Rotor BSA 30 BB. Might do the trick.

With a mix of BB30 and BB86 frames and 3 Hollowgram & 2 FSA SRM powermeters, nobody wishes this would work more than me but sorry, the Rotor's BSA 30 BB is not going to make that work either. The Rotor 3D+ crank spindle incorporates the BB386 standard which has a 86.5mm long spindle and enough offset on the backside of the spider to allow it to work with either Rotor's BSA 30, BB30/PF30, or BB386 bottom bracket standards. As already mentioned, because of the offset of the spindle, a true BB30 crank like the Hollowgram SiSL will only work with BB30/PF30 framesets and because the hollowgram spider has next to no offset, an adapter or longer spindle is only going to push your chainrings further out from the bottom bracket shell. Take the image below of a cross chained engagement and then ask how well would that setup work if the chainrings were 5-10-15mm further out?

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styrrell
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by styrrell

Good drawing. Have you tried a sisl2 spindle with BBright and hollowgram crank arms? I'm just curious how much more spindle width is needed , if any , not worried about chainline.

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mythical
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by mythical

The idea behind BBright is having BB30/PF30 on the drive side and a width similar to Shimano on the non-drive side. It could be an idea to make a FrankenCrank, using the SiSL2 drive side and a BBright non-drive side arm/axle, but that requires the same spline interface with the correct placement width. Just a thought...
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bjavern
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by bjavern

yes it's become clear that it's a 68mm english threaded bb and nothing else. someone over on the cervelo forum (was it perhaps you rmerka?) also wrote about the bsa bb allowing for a 3d+ crank. it's not the hollowgram and not superlight, but as far as consolation prices go, I'll take it.

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mythical
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by mythical

For the price of an SiSL2 crankset you might be able to get an THM M3 cranks instead. It'll work with BSA and is lighter than Rotor. Take our host's offer, for example:http://www.starbike.com/en/thm-carbones-clavicula-m3/
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ms6073
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by ms6073

styrrell wrote:Have you tried a sisl2 spindle with BBright and hollowgram crank arms? I'm just curious how much more spindle width is needed , if any , not worried about chainline.
Our bikes are BSA, BB30/PF30, and BB86 but I have no experience with BBright. Based on the outline in BikeRadar's article 'Complete guide to bottom brackets', on the drive side BBright and possibly BB386, is a true BB30 interface with no drive side offset and an 11mm longer spindle length. So at least in theory, it sounds to me like a longer Hollowgram spindle, one that has had the bearing ridge machined off - say the new 109mm hollowgram II spindle - might work with no ill effects but we will not know for certain until such time as someone gives it a shot.

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eric
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by eric

If you could get that to work the NDS crank arm would be 11mm farther out from the centerline of the bike than the DS arm.

I think that would mess up ergonomics quite a bit.

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ms6073
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by ms6073

eric wrote:I think that would mess up ergonomics quite a bit.
Based on what I read about BBright, that seems a forgone conclusion regardless of the crank.
Michael - The Anaerobic Threshold is neither...

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