Can I use a 128 mm hoollowgram spindle to fit my 86mm bb
Moderator: robbosmans
Dear cannondale experts, I have an 86 mm wide bb designed to use clavicula cranks (spindle measure 128 mm end to end on the clavicula). I want to put an sisl crank now. Can I use cannondale hoollowgram 128 mm spindle? Will I have to grind down the lip on the cannondale spindle?
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- Posts: 235
- Joined: Tue Feb 28, 2012 9:13 pm
This has been discussed on here sooo many times.
Please use the search.
In short, no. There is nothing you can do to use hollowgrams on a bb86
Please use the search.
In short, no. There is nothing you can do to use hollowgrams on a bb86
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- Posts: 235
- Joined: Tue Feb 28, 2012 9:13 pm
Doesn't matter, chain line would be way off
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- Posts: 235
- Joined: Tue Feb 28, 2012 9:13 pm
mike wrote:If the clavicula is128mm long why wouldn't 128 mm hoolowgram with machined off lip work? How could it be off center if it is same length?
Not all cranks are made equal.
Because the hollowgrams are made specifically for bb30/pf30 frames. If you take a closer look at the variety of bottom brackets THM provides, you will notice that the bb30/pf30 ones have outboard bearings, as do the bsa, bbright and so on. The bb86 ones press into the frame. They are all different because their purpose is to place the chainrings a certain distance from the midpoint of the bb shell in order to meet the chain line tolerances of each group set.
Installing the mountain spindle on your frame with the hollowgram cranks will push the spider out too far. I want to say it is like an extra 13-15mm or something, too lazy to look it up right now, but hopefully you get my point.
If you really really feel inclined to do it, try it out and let us know how it goes. Take pictures and all. It will be a good reference for people who will inevitably ask the same question in the near future.
Thanks I will try. When I said 86 mm bb she'll width, this already includes bearings already press fitted into frame like the cannondale frames. So there is no outboard bearing.
A regular cannondale frame is 68 mm bb shell width (bearings included) and uses a 104mm hologram spindle. 104 mm minus 68 mm = 36 mm extra length needed to clear the bb shell.
I then applied the same math to my 86 mm shell width (30 mm ID bearings included). 86 mm + 36 mm needed to clear bb = 122 mm.
I am thinking if I can source the 122 mm spindle or a 128 mm spindle (same length as clavicula spindle) and remove the lip if needed, it should work perfectly without any problems.
Thoughts from you would be appreciated.
A regular cannondale frame is 68 mm bb shell width (bearings included) and uses a 104mm hologram spindle. 104 mm minus 68 mm = 36 mm extra length needed to clear the bb shell.
I then applied the same math to my 86 mm shell width (30 mm ID bearings included). 86 mm + 36 mm needed to clear bb = 122 mm.
I am thinking if I can source the 122 mm spindle or a 128 mm spindle (same length as clavicula spindle) and remove the lip if needed, it should work perfectly without any problems.
Thoughts from you would be appreciated.
Mike it sounds like what you have is an 386Evo bb. Basically a 30mm version of bb86.
The SISL with a longer spindle will not work. As was mentioned it's not about fitting the crank to the frame, this is certainly something that can be done, but it's about the offset in the spider. The Cannondale has a spider that is designed to have proper chainline with a 104 spindle, adding 24mm to the spindle moves the drive side crank arm (but more importantly chainrings) away from the bb center point by more than a cm. This means your chainrings are no longer in line with the cassette. You'll find a couple of problems with this. First you'll have front derailleur issues because your double front derailleur is not designed to swing out so far away from the frame. Second you're rings will be far enough to the right that the front rings will only line up properly with a couple of cogs in the rear.
The Thm cranks is designed to be used with the longer spindle so the spider has more offset to it which keeps the rings where they are suppose to be.
The SISL with a longer spindle will not work. As was mentioned it's not about fitting the crank to the frame, this is certainly something that can be done, but it's about the offset in the spider. The Cannondale has a spider that is designed to have proper chainline with a 104 spindle, adding 24mm to the spindle moves the drive side crank arm (but more importantly chainrings) away from the bb center point by more than a cm. This means your chainrings are no longer in line with the cassette. You'll find a couple of problems with this. First you'll have front derailleur issues because your double front derailleur is not designed to swing out so far away from the frame. Second you're rings will be far enough to the right that the front rings will only line up properly with a couple of cogs in the rear.
The Thm cranks is designed to be used with the longer spindle so the spider has more offset to it which keeps the rings where they are suppose to be.
mike wrote:So if I source the 122 mm spindle (even if I have to grind down the lip so I could center the spindle)' this would not work?
Take a look at the image below and imagine those chainrings moved out an additional 12mm - while that would certainly improve the chainline for the little chainring and the smallest rear cog, using the big chainring on anything but the smallest rear cog is not going to work. So unless you want to 'machine' off ~10mm of carbon from each face of the bottom bracket shell, then no, you absolutely cannot make a hollowgram crank work on a non-BB30/PF30 frameset!
- Michael
"People should stop expecting normal from me... seriously, we all know it's never going to happen"
"People should stop expecting normal from me... seriously, we all know it's never going to happen"
If someone was to manufacture a Hologram spider with a different offset, could the cranks be made to work then?
Ti or dye!
The Weenie formally known as CAADHEAD
The Weenie formally known as CAADHEAD
I assume so, but your Q factor would still be massive (like a mountain bike).
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