Rotor BSA30 and Hollowgram

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

Will it work? Anyone tried it? Looking to run with a Hollowgram SRM.
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ty-ro
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by ty-ro

I spoke to Rotor and they only guarantee that it will work with their 3D+ crank.

by Weenie


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STARNUT
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by STARNUT

no

starnut
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Q-FACTOR IS A RED HERRING

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scott_racer
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Location: Melbourne, Australia

by scott_racer

STARNUT wrote:no


Hang on, what if he used a 122mm spindle for the hollowgrams? More spacers and wider Q-factor, but surely you could space it to work?
Start flat out ... then pick the pace up halfway

bricky21
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by bricky21

scott_racer wrote:
STARNUT wrote:no


Hang on, what if he used a 122mm spindle for the hollowgrams? More spacers and wider Q-factor, but surely you could space it to work?


This has been re litigated over and over and over and over and over and over and over and over and over and over again .

HOLLOGRAM CRANKS WILL NOT FIT A BSA FRAME WITHOUT SERIOUS MODIFICATIONS, AND THEY STILL WON'T BE IDEAL

gabbott
Posts: 29
Joined: Mon Jul 12, 2010 8:39 pm
Location: Houston, TX

by gabbott

So please excuse my ignorance but if I were to use my Vuma Quad BB in my non/pre BBright Cervelo, still no dice w Hollowgram?

Thanks
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mlchang
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by mlchang

The spindle lengths won't be right. It's not just about spindle diameter and bearing ID. Lightning cranks probably would work with the Rotor BSA30 and Zipp bottom bracket cups, but even then I don't know for sure because Lightning cups are pretty thin.

skinnyrider
Posts: 26
Joined: Thu Aug 23, 2012 1:12 pm

by skinnyrider

Bump on this.
I run a hollowgram SRM but my team bike is BSA, and i don't get a power meter. So i want to fit mine.

Now I know it needs some modification, is anyone out there doing it currently?

I've seen the Rotor BSA30 bb and longer spindle idea.
Or the zipp package?
http://www.cannondale-parts.de/epages/6 ... ucts/KP094" onclick="window.open(this.href);return false;

Does anyone have any first hand experience.


I've seen this;
http://forum.slowtwitch.com/forum/Slowt ... _P4459895/

eric
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by eric

The extra wide axle might work. But what will the resulting Q factor be?

WileEcoyote
Posts: 39
Joined: Mon Jul 30, 2012 10:33 pm

by WileEcoyote

I was just going to post about the wider spindle. Curious also if this would work with the Rotor BSA30 cups and a 68mm frame. I have a friend that is interested in trying this.

http://www.ebay.com/itm/Cannondale-SI-B ... 564a04a405

eric
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by eric

The standard BB30 spindle is 27mm shorter. If the Q factor with that is 144mm, with the 131mm spindle it will be 171mm. Bleah.

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ms6073
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Location: Houston, Texas

by ms6073

Even with a longer spindle, an SRM Hollowgram is not going to work well on a BSA frameset. The Hollowgram spider has next to no overlap so using BSA30 or Zipp Vuma Quad bearing cups with a longer spindle, will simply push the spider and chainrings further out moving the chain further out from the correct chainline. I am of the opinion that there are two ways to get a Hollowgram crank to work on a BSA frameset: first would be to have the bottom bracket shell faced to remove material from each side (~5mm to 7mm per side) then use the BSA30 cups. Alternately, if we are talking about a carbon frame with a large enough diameter alloy insert, it seems like it you could have the bottom bracket shell milled/machined to accept Enduro's BB86/92 to BB386 EVO or Rotor's BB4130 bearings.
Last edited by ms6073 on Fri Mar 15, 2013 4:09 pm, edited 1 time in total.
Michael - The Anaerobic Threshold is neither...

skinnyrider
Posts: 26
Joined: Thu Aug 23, 2012 1:12 pm

by skinnyrider

Right but talking about Q factor, wouldn't that be the same as the BSA cranks that are on the frame originally?

And I'm sure this will work.
http://www.cannondale-parts.de/epages/6 ... ucts/KP094

Or if you can find a 128 axel and remove the shoulder it'd only need a few small spacers extra.

skinnyrider
Posts: 26
Joined: Thu Aug 23, 2012 1:12 pm

by skinnyrider

If you say that it'll be well off on the chainline.
But wouldn't it put it int he same place, as bsa cups will be outside of the shell anyway, so they're in the same place when using rotor bsa30 cups. Longer spindle to accomodate this, and it'll put the chainring in near enough the same place.

I need to try it and see.
Unless anyone's done it.

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ms6073
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by ms6073

skinnyrider wrote:And I'm sure this will work.
http://www.cannondale-parts.de/epages/6 ... ucts/KP094" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;
Or if you can find a 128 axel and remove the shoulder it'd only need a few small spacers extra.


If you look at Cannondale's install diagram for Hollowgram cranks on a mountain bike with the SiSL spindle w/shoulder, note that a drive side spacer is required so for the BSA cups and the spindle without the shoulders, the cups replace the drive-side spacer and non-drive side offset produced by the shoulder on the spindle while maintaning close to the same chainline/q-factor.

skinnyrider wrote:I need to try it and see. Unless anyone's done it.
I have SRM Hollowgram's on a BB30 and PF30 cross bikes and have become very familiar with the intricacies of the bottom bracket. I wanted to put one of these SRMs on my time trial bike which has a BSA 24 bottom bracket and I already have both the new 109mm SISL2 as well as an SiSL 104mm road spindle with the shoulder machined off, I purchased a Zipp Vuma Quad bottom bracket to give this a try. There is currently an SRM FSA K-Force Standard installed on the bike and even though I have not installed the Zipp bottom bracket, I can tell based on observation and static measurements, it would be a waste of time unless I at least first reduce the width of the bottom bracket shell on the drive side!
Michael - The Anaerobic Threshold is neither...

by Weenie


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