Hollowgram chain line

Discuss light weight issues concerning road bikes & parts.
User avatar
Gearjunkie
Posts: 746
Joined: Tue Feb 19, 2008 5:17 am
Location: NZ

by Gearjunkie

Hi Nic

My problem is the opposite of yours. My chain rings (DS obviously) are too close to the frame causing the same issue as the OP.

My set up is SISL2 (but with TA chain rings, not the Spidering) on a Cannondale Evo Black Inc. Installed as per instructions, 2.5mm spacer on DS, larger spacer on NDS.

I'm thinking of adding more spacers to the DS but concerned that will mess with the overall length of the spindle and put the Q factor slightly out.

How can it be that we have the opposite problem?

Cheers

GJ

nicrump
Posts: 742
Joined: Thu Oct 23, 2003 5:18 pm
Location: Austin
Contact:

by nicrump

I think your problem is the result of the spider and ring. Can you measure the Q both right and left from frame centerline? I assume you are using the 109 spindle since you mention the spacers.

mine is 76mm DS and 71mm NDS to the outside face where the pedal meets the arm

Gearjunkie wrote:Hi Nic

My problem is the opposite of yours. My chain rings (DS obviously) are too close to the frame causing the same issue as the OP.

My set up is SISL2 (but with TA chain rings, not the Spidering) on a Cannondale Evo Black Inc. Installed as per instructions, 2.5mm spacer on DS, larger spacer on NDS.

I'm thinking of adding more spacers to the DS but concerned that will mess with the overall length of the spindle and put the Q factor slightly out.

How can it be that we have the opposite problem?

Cheers

GJ

by Weenie


Svetty
Posts: 447
Joined: Thu Mar 26, 2009 11:06 pm
Location: Yorkshire - God's Own Country

by Svetty

It's a 'design feature' of the frame ;). If you move the spacer to the NDS you'll likely get the chain rubbing on the inside of the outer ring when using the inner ring and the outer sprockets of the cassette. The best solution I found was to try and optimise the set-up by trial and error, firstly to identify how many of the thin spacers are needed overall to get the correct wavy washer compression, and then to determine exactly how many of these spacers are needed on each side to get the best compromise with respect to chain-line vs ring rub.

User avatar
ms6073
Posts: 2295
Joined: Fri Jul 23, 2004 8:24 pm
Location: Houston, Texas

by ms6073

Alternately (but more expensive) get a set of the SISL2 crank arms which I think are slightly asymmetric to address such issues.
Michael - The Anaerobic Threshold is neither...

nicrump
Posts: 742
Joined: Thu Oct 23, 2003 5:18 pm
Location: Austin
Contact:

by nicrump

Svetty wrote:It's a 'design feature' of the frame ;). If you move the spacer to the NDS you'll likely get the chain rubbing on the inside of the outer ring when using the inner ring and the outer sprockets of the cassette. The best solution I found was to try and optimise the set-up by trial and error, firstly to identify how many of the thin spacers are needed overall to get the correct wavy washer compression, and then to determine exactly how many of these spacers are needed on each side to get the best compromise with respect to chain-line vs ring rub.


yes, already know this as a solution. just wanted to know if that really is what they intended. apparently so. the chainline sucks out of the box.

nicrump
Posts: 742
Joined: Thu Oct 23, 2003 5:18 pm
Location: Austin
Contact:

by nicrump

thats is exactly what we are talking about.

ms6073 wrote:Alternately (but more expensive) get a set of the SISL2 crank arms which I think are slightly asymmetric to address such issues.

Svetty
Posts: 447
Joined: Thu Mar 26, 2009 11:06 pm
Location: Yorkshire - God's Own Country

by Svetty

yes, already know this as a solution. just wanted to know if that really is what they intended. apparently so. the chainline sucks out of the box.


Seemingly so. The change in spindle design does move the chainline relative to the older one. This [speculation mode] might be associated with Shimano reverting to a narrower space between rings after the wider spacing with 7900 and 6700 [/speculation mode] and the consequential effect on ring rub referred to above.

User avatar
Gearjunkie
Posts: 746
Joined: Tue Feb 19, 2008 5:17 am
Location: NZ

by Gearjunkie

nicrump wrote:I think your problem is the result of the spider and ring. Can you measure the Q both right and left from frame centerline? I assume you are using the 109 spindle since you mention the spacers.

mine is 76mm DS and 71mm NDS to the outside face where the pedal meets the arm

Gearjunkie wrote:Hi Nic

My problem is the opposite of yours. My chain rings (DS obviously) are too close to the frame causing the same issue as the OP.

My set up is SISL2 (but with TA chain rings, not the Spidering) on a Cannondale Evo Black Inc. Installed as per instructions, 2.5mm spacer on DS, larger spacer on NDS.

I'm thinking of adding more spacers to the DS but concerned that will mess with the overall length of the spindle and put the Q factor slightly out.

How can it be that we have the opposite problem?

Cheers

GJ



Hi

I get 75.2mm DS and 73.6mm NDS but (even though those numbers are to the tenth of a mm) my measuring might not be too accurate, I found it hard to be sure I was measuring accurately to the centre line and the crank arm face.

Cheers
GJ

thisisatest
Shop Owner
Posts: 1980
Joined: Sat Jun 13, 2009 4:02 am
Location: NoVA/DC

by thisisatest

Hollowgram cranks used to have a chainline that was too far to the left compared to everyone else. It was way out of spec. That is why you had to do so much fiddling to get SRMs to clear frames. Never had to fiddle with other SRM cranks. Then PF30 came out, the lip on the cups takes yet more room away, someone at Cannondale woke up and decided go even everything out. At the same time they got rid of the pointless sloulder on the spindle, all it did was complicate matters (mainly when you're trying to do things beyond what was intended). So 109 puts the chainline at 43.5mm, just like everyone else. With that, no PF30 specific lockring, no PF30 specific spider, nop SRM specific anything is ever needed. It is how it should have been all along.
@Svetty,
I'm not aware of Shimano reverting back to closer chainring placement with 11sp. Sure seems like there's a wide sloping shelf on the left side of the big ring. I haven't measured though. Can you confirm?

CrossRob
Posts: 63
Joined: Tue Dec 14, 2010 9:18 pm

by CrossRob

Can anyone tell me the width of the NDS spacer please for BB30 on the 109mm spindle?

I've got a (non-Cannondale) 68mm shell and am switching to the 109mm spindle to fix a chainline problem.

The SISL2 instructions show a massive NDS spacer for 68mm shells - much wider than the 2.5mm one on the drive side.

http://media.cannondale.com/media/uploa ... r_1012.pdf

Someone above's said that you can use standard SRAM 2.5mm spacers, but how many would I need for the NDS? Instinct suggests just one (as it's a 5mm wider axle and we're adding a 2.5mm spacer to the DS) but am I missing something?

Thanks

User avatar
shoemakerpom2010
Posts: 250
Joined: Mon Apr 11, 2011 6:28 pm
Location: Palm Coast, Fl.

by shoemakerpom2010

you will have to use 3 2.5mm spacers. You can also have a Cannondale shop order that special spacer or buy the spacer kit from Cannondale Experts.com. Either way do not deviate from the directions in the pdf and it will install correctly. Any deviation leaves you short of threads to have the crank arm bolts on correctly. :thumbup:

CrossRob
Posts: 63
Joined: Tue Dec 14, 2010 9:18 pm

by CrossRob

shoemakerpom2010 wrote:you will have to use 3 2.5mm spacers. You can also have a Cannondale shop order that special spacer or buy the spacer kit from Cannondale Experts.com. Either way do not deviate from the directions in the pdf and it will install correctly. Any deviation leaves you short of threads to have the crank arm bolts on correctly. :thumbup:


Excellent - thanks.

Post Reply
  • Similar Topics
    Replies
    Views
    Last post