# Hollowgram SL and chain rub



## Aschster (Nov 11, 2012)

Hi all,
I'm hoping some of the other Cannondale owners can help with a problem I have with my System six.

I just recently changed over my old square taper sleeved crankset to make use of the BB30.
I picked up a second hand Hollowgram SL crankset and installed them with no issues aside from the fact that now I have chain rub on the large chainring when using the smaller ring at the front.
This happens on the 3 smallest gears on the rear cassette.

I did experience chain rub with the old crankset by only lightly and when only using the last gear.

I know I can always shift up and run a similar ratio but I tend to use the small chainring with the third gear up quite a lot it's just a comfortable gear to use when cruising with the pack.
Plus on a Cannondale bike with BB30 and Cannondale cranks I think it should work a bit better.

Just wondering if any other Cannondale/ system six riders experience the same problem?
Is it normal when using the hollowgram?
Any fixes?

This is the run down of the Bike

Cannondale system six 56cm
104mm standard BB30 spindle with Hollowgram SL crankset
No shims installed, just the wavy washer (seems compressed enough)
130 BCD spider with stronglight CT2 chainrings 53/39

There's approx 4mm clearance from the crank arms to the chainstays on both sides.
The rear cassette is campagnolo 10 Speed
front dérailleur is campag veloce'
Chain is campagnolo

The drive line runs super smooth with no shifting issues at the front or rear aside from the chain rubbing on the large chainring.

Your help would be greatly appreciated,

Regards,
Ash


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## RCMTB (Apr 20, 2012)

Is the chain rubbing the front derailleur? Maybe it's just a matter of a adjusting the front derailleur.


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## Dan Gerous (Mar 28, 2005)

I can use all gear combos on mine... But I have a SRAM Red setup. The Hollowgrams have a narrower chainline than many other cranksets though so it can produce what you notice... but it's done on purpose.

It's much more important to have a better chainline so that when you're on the big ring, you can use the whole cassette without stressing the chain too much. Doing the same in the small ring is not really important to 99% of riders. These cranksets are optimized for the highest performance and for going fast, not for cruisers...

I still don't understand why some people absolutely want to use these silly gear combos though. Using a similar ratio on the big ring is more efficient anyway (chain pivots pivot less, rear derailleur keeps a better tension on the chain...), and you'd look more 'pro'!


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## metoou2 (Mar 18, 2009)

You can install a (38) tooth small ring up front.
The (38) will allow you to achieve similar gears ratios as before without having to dump the chain all the way to the first cog in the back.

But as Dan said............why do it? Get used to using the big ring for everything except steep / long climbs. You can cruise all day in the BIG with the correct selection in the back. And the BIG feels so much better.
The drive train will be quiet, efficient, and well...............faster.


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## eekase (Nov 10, 2009)

Dan Gerous said:


> Using a similar ratio on the big ring is more efficient anyway (chain pivots pivot less, rear derailleur keeps a better tension on the chain...), and you'd look more 'pro'!


Like Dano said. I don't cross chain a lot...but when I do, its big ring up front & the larger gogs in the back.
Also like previously asked, is the chain rubbing on the inside of the big ring or the FD, when you are in small ring up front and smaller rear sprockets?


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## skleins (May 19, 2010)

I had exactly the same issue with the smallest 3 sprockets on the cassette and small chainring, obviously the smallest 2 - I'd run the big ring instead but the third was a combo i'd use a lot and never rubbed when used with my chorus ultra torque cranks.

I concluded the hollowgram cranks run the chainrings closer together.

It was immaterial, as I ended up going back to my campag cranks, as my next bike was non BB30.


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## Aschster (Nov 11, 2012)

The front dérailleur is clear of the chain, With the Campag shifters I have plenty of trim options, 
The chain Rubs the Large chain ring at the front when using the last three at the rear - the last 2 on the cassette I never used to use anyway with the old Campag cranks, But I did use the 3rd.


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## Dan Gerous (Mar 28, 2005)

The rings are not closer together, the two chainrings are just closer to the frame (by a few mm compared to a SRAM Red for exemple). So when you cross chain from the small ring, the chain is twisted more severly toward the small cogs. It's not a defect, it's normal. You could try to adjust the chainline with a wider spindle if for a mysterious reason you really need to be riding those gear combos... but then you would have a bigger q-factor. Or put little spacers to have the rings further apart... but then risk having the chain not shift well between both, even dropping between them. Lots of trouble for nothing though. It's like not using the front brake and complaining that the bike doesn't stop quick enough or that the rear wheel locks up when braking hard...


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## RCMTB (Apr 20, 2012)

So I installed my hollowgrams that came with MKV (34/50) rings a few months ago and they are great on the CAAD10. Only problem is, when I'm in the big ring up front and using the last three big cogs on the rear the drive train is very noisy. The chain appears to not like the angle and sounds as if it wants to come off the big ring. I installed the cranks with two plastic washers and a wavy washer on the drive side. I plan to take the FSA rings from my Gossamer pro cranks and try them. I'm hoping this will help with the noise. Any ideas\tips other than swapping the rings?


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## metoou2 (Mar 18, 2009)

You shouldn't have any issues with that set-up. A pic or three would be helpful.

A new chain will be noisy for a week or two. Did you recently install one?


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## NWS Alpine (Mar 16, 2012)

It's noisy because the chain and derailleur is at it's max. Cross chaining like that will wear your drivetrain down. 

What type of chain lube do you use? If you use something like chain-l then it will help but in the end the chain will make noise as it's being pushed in ways that isn't optimal.


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## RCMTB (Apr 20, 2012)

NWS Alpine said:


> It's noisy because the chain and derailleur is at it's max. Cross chaining like that will wear your drivetrain down.
> 
> What type of chain lube do you use? If you use something like chain-l then it will help but in the end the chain will make noise as it's being pushed in ways that isn't optimal.


I've been using Pedro's Go! for chain lube which is a thin lube. I don't ride in wet conditions much. Maybe a heavier lube like Chain-L might be better?

I understand the cross chaining is making the noise. It's just that when I had the Gossamer's on the bike the cross chaining noise was less and the chain seemed to work well with the FSA rings where none of the hopping occurred.


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## NWS Alpine (Mar 16, 2012)

The stronglight rings are most likely stiffer than the FSA rings from the Gossamer. I didn't notice any noise difference going from FSA to hollowgram with praxis rings. Might need some time to wear the chainrings a little to stop the jumping.


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## metoou2 (Mar 18, 2009)

NWS Alpine is correct. Your noise is due to cross chaining. Drop down to the small ring up front when you need the biggest cogs in the back.

I read your post incorrectly. I thought you were getting noise while in the big up front and the (11,12,13) teeth in the back.


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