Hollowgram SiSL Chainline or... Why I machined my spindle

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seahuston
Posts: 161
Joined: Mon Mar 31, 2008 8:49 pm
Location: San Francisco

by seahuston

I'm running a Hollowgram SiSL crankset on my System6 with SRAM Red compact chain rings. The chain line has been giving me a lot of issue, I can't make it into the lowest 3 gears in the middle ring without the chain rubbing on the outer ring. In the lowest gear the ramps pretty much auto shift into the big ring.
Measuring the chain line, it was a little less than 1mm inboard.

There is no way to adjust chain line on these cranks but this thread indicated that I could machine off the shoulder and move the wave washer to the NDS to fix this. viewtopic.php?f=3&t=114357
I didn't see anyone who actually did this machining so I thought I'd share my setup.
It's really simple, if you don't have a lathe you should be able to take one to a local machine shop and have them do it on the cheap.

Here is the spindle in the chuck:
Image
It's simple, just machine the shoulder off so that there is no material proud of the bearing surface. Try not to take off any more than is needed.

For the installation, just follow the SiSL2 instructions using SRAM 2.5mm BB30 (cheaper than the Cannondale kit) washers. You can adjust the chain line by adding or subtracting the 0.5mm washers from the drive side spindle. Because the SiSL spindle is 106mm and the SiSL2 is 109mm you'll need to use a smaller NDS spacer than the instructions say.
Image

by Weenie


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Calnago
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by Calnago

Yeah, I had a heck of a time with the SiSl spindle and chainline issues. Very difficult to get Shimano 9000 working as it should (with all 4 positions working as intended). Plus the front derailleur tab on pre 2013 Evos is not designed at all well for the 9000 derailleur and support screw.
As for the spindle, it's actually 104mm and I managed to get one made for SRM that had "some" of the shoulder machined off, but not all. Still, would have been nice to have more to play with as it didn't really solve the issue but made it a little better. The next generation spindle has no shoulder and is 109mm. In hindsight I wished I had just gone with the 109mm spindle. So good for you for taking on the task of machining it yourself, I'd just wonder if after adjusting your chainline outwards there's enough NDS spindle left to secure the left crank arm properly.
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seahuston
Posts: 161
Joined: Mon Mar 31, 2008 8:49 pm
Location: San Francisco

by seahuston

Regarding the ability to securely attach the NDS crank, it's pretty simple to test:
Just need to attach the crank without any spacers and verify it doesn't bottom out before reaching the torque spec.
In this case it didn't bottom out so just add spacers to the NDS to get the wave washer compression correct.

Buying the 109mm spindle is of course the easier option but it's always fun to see how you can do it on your own.

TheDarkInstall
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Joined: Sun Jan 26, 2014 3:44 am

by TheDarkInstall

This gave me a headache...

So, to summarise, you basically just machined your SiSL spindle to be like an SiSL2 spindle (which has no shoulder), then played around with the spacers... ?

Not putting the hat spacer on the NDS would surely mess up the NDS crank arm lateral positioning... ?

seahuston
Posts: 161
Joined: Mon Mar 31, 2008 8:49 pm
Location: San Francisco

by seahuston

Yeah pretty much just machined it to match the SiSL2 spindle but this spindle is a little shorter so you need to play with the spacers a bit to get the wave washer compression.

Regarding NDS arm position, it's about 1mm inboard of where it was before but this is mostly controlled by adjusting the chainline. The top hat is used by cannondale so that they can share the same spindle on 73 and 68mmbottom brackets. A lot of crank systems have the downside of moving the NDS to adjust chainline but for the magnitude of adjustments needed, it's pretty inconsequential.

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shoemakerpom2010
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by shoemakerpom2010

What's your clearance from the inside of the arm to the frame....... :unbelievable:

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