JIS BB Length for Grand Mightys
05-09-16, 07:08 PM
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JIS BB Length for Grand Mightys
Yeah, I know you're probably thinking, why the F*CK is he trying to use a JIS taper bb with ISO cranks? Well my friend picked up a set of Sugino Grand Mightys which he found out were messed up and unusable on any ISO taper spindle since the previous owner used a JIS taper bb with them. I'm taking them off his hands but I gotta know the length spindle I'd need for the JIS taper. Anybody know?
05-09-16, 07:12 PM
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Calamari Marionette Ph.D
05-09-16, 07:26 PM
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05-09-16, 08:55 PM
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Clark W. Griswold
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You can't really go wrong with Sheldon's advice. If there was something he didn't know it probably wasn't worth knowing.
05-10-16, 08:58 AM
#5
Your cog is slipping.
^ Truth.
For the record, the crank arms will sit about 4.5mm further in total, not per side. Sheldon isn't 100% clear on that.
Also, you may be okay using a 109mm ISO bottom bracket as long as the crank arms weren't overtightened and the interface isn't damaged.
For the record, the crank arms will sit about 4.5mm further in total, not per side. Sheldon isn't 100% clear on that.
Also, you may be okay using a 109mm ISO bottom bracket as long as the crank arms weren't overtightened and the interface isn't damaged.
05-10-16, 10:57 AM
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Sooo my 113mm JIS would be a tad too short then, yeah? My friend tried mounting them on his SG75 bb, taper is totally ****ed for ISO use.
05-10-16, 11:13 AM
#7
Your cog is slipping.
No...it will be too long. As Sheldon states, using ISO crank arms on a JIS spindle causes the arms to site further out. A 113mm JIS spindle will essentially be like using a 118mm ISO.
You'll probably need to experiment a little depending on how deformed the interface is. Your best bet is starting with a 107mm JIS spindle and seeing where the chainline ends up.
You'll probably need to experiment a little depending on how deformed the interface is. Your best bet is starting with a 107mm JIS spindle and seeing where the chainline ends up.
Last edited by Scrodzilla; 05-10-16 at 11:50 AM.
05-11-16, 11:03 AM
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No...it will be too long. As Sheldon states, using ISO crank arms on a JIS spindle causes the arms to site further out. A 113mm JIS spindle will essentially be like using a 118mm ISO.
You'll probably need to experiment a little depending on how deformed the interface is. Your best bet is starting with a 107mm JIS spindle and seeing where the chainline ends up.
You'll probably need to experiment a little depending on how deformed the interface is. Your best bet is starting with a 107mm JIS spindle and seeing where the chainline ends up.
