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Q about SPLINED DURA ACE crankset INSTALLATION(6 posts)

Sep 4, 2001 4:22 PM
Hello everyone. This is my first time trying to installed these new splined crankset. Well, I have a important question. When matching the crankset and the BB, do their groves fit and interlock??? That is do the serrations or groves on the crankset clearly fit and interlock with the bottom bracket? My do not seem to fit. I have the right BB (Both new DA). It appears that I can only put the groves of the crankset on the surface of the holes of the BB, as if they should continue to go "in" and fully interlock, but this is not the case. They do not seem to fully "fit". Is this normal? Am I supposed to just leave it there and just put the bolt and lock it? That is what I did and it looks fine but I am worry that since it did not fully interlock then It will not stand the torque of pedaling. Thanks....NL
re: Q about SPLINED DURA ACE crankset INSTALLATIONnuke
Sep 5, 2001 9:28 AM
Be very very careful!!!

Your equipment is behaving as it should. They do not "fit together"...placing the cranks onto the BB by hand will only allow you to put the grooves of the crankset just above the holes/slots of the BB. You cannot push them into the grooves by hand. You must tighten the crankarm down with the allen wrench in order to get them to slide into the grooves.

Now THIS is the part you have to be careful about. IF you have badly misaligned the groove & slot, when you use the allen wrench it will mar the splines! So make sure they are lined up correctly! I've seen even bike shop mechanics put them on and just keep on cranking get them tight only to find the splines marred and jammed onto the surface of the grooves.

You said that you "...left it there and put the bolt on and locked it..." Hopefully you haven't ridden it. If you're not you said you were not...I'd take it apart again, check it and reseat it correctly to pull the splines into the grooves.

It's not that difficult to do this procedure...but you just need to make sure you understand how it goes together to prevent newbie mistakes.

If you mar the splines, you'll most likely have to replace the crankset as it'll never go together as tight as a DA set should.
Sep 5, 2001 9:48 AM
Thanks. they are fine. i got them out to put more grease and make sure that they were ok and tey look perfect. I will put them back together being very careful. WOW, Shimano's instructions SUCK. I wonder if they mean them to suck so that people go to their LBS instead. I always complain about their instructions. Cheers. nestor
Doom and gloomEric
Sep 5, 2001 5:03 PM
I know there have been people ruin D/A cranks from poor installation, but it's really not that difficult to do properly. Rotate the BB so that one of the splines on the BB is pointing straight up (12 o'clock). Then slide the crank on with either the arm pointing straight up or straight down (the grooves in the arm are machined such that two align parallel to the arm's length). Then start the bolt in the threads, and if everything is aligned the bolt should turn easily and the crank should visibly slide its way onto the spindle. If things are aligned then the short end of an allen wrench can be used to turn the bolt as the crank slides on - ie. requires little torque. The length it travels from first engagement is pretty far (1 cm) or so. If it isn't aligned, the bolt will tighten up after only a couple of turns and the crank will not slide up the spindle appreciably. Once the cranks are on straight, torque the bolts to Shimano recommended specs and check them after a ride.
re: Q about SPLINED DURA ACE crankset INSTALLATIONVictorChan
Sep 6, 2001 8:39 AM
Yup, they should interlock all the way in. The crankarms should be almost touching the sidewall of the BB. You can't do this by hands or a typical 8mm allen key. You would need a torque wrench. About 45ft/lb torque.
re: torque wrenchbattaglin bob
Sep 6, 2001 2:27 PM
crank installation is a case where a torque wrench is the best way to go. As victorchan mentioned this is the best way to take the guesswork out of installation. Sears has a good one for about $20.00.