[MegaMatt]

I just installed a Trubine LP cranksed and a RF Cromo spindle on my xc race bike. (ti-hardatail) I had move the drive side cup all the way in to get proper chainline. Since the ISIS bb was only availabe in 113mm length, this is probably to be expected from a 107mm BB that was in my bike previously. I have also found these cranks do not stay tight for very long. They must be retightened after every ride, even during the middle of a long ride (more than two hours). The system does run creak free. All in all I give it 5 stars.

Share your thoughts about ISIS here.

 

[RideMonkey]

My experience with spline drive has been bad. Heres a couple of threads with pertinent info:

Creaky Isis Bottom Bracket

Creaky Shimano XT Crank/BB

 

[Merwin5_10]

FYI- ALL splined systems require repetative tightening of the crankbolts. There's no friction created by the slpine like there is on press fit models. Here's a tip for you though. Use blue locktight on your crankbolts. That will hold 'em in tight until you're ready to remove them again. Also, I'm not exactly sure what your concern is with the fit you've established on your bb. Does it work? Are you wondering if it will work? Or is this just info on how you got it to work?

 

[oldfart]

Mine don't require repeated tightening? XT. Put them on in Feb and took them off to replace rings once and another time just to see. There is the same mechanism in force too and its not just friction. The crank bolts and all bolts for that matter stretch when tightened properly. That stretch is what holds things on. Go too far and the stretch becomes permanent or way too far and something fails. Over tighten repeatedly and the part will fail from fatigue meaning eventually the threads strip or the bolt breaks or something. This is why you have to be super cautious with Aluminum bolts. Often whith stuff like aluminum stems the steel bolts thread into a deep hole just cause with soft aluminum you need more material to get it it work without failing or a steel insert. The old XTR cantilever brakes have steel threads and bolt for the cable clamp for example. There is a amount of taper on the new splined ISIS and Shimano systems is there not???? I think I read there was some on ISIS. There has to be some way for the crank to press on tight. Any slight movement at an aluminum/steel interface will lead to more movement and ultimate failure.

 

[Merwin5_10]

There is a amount of taper on the new splined ISIS and Shimano systems is there not????

Not really, the only taper offered on Shimano's splined systems that I am aware of is that which eats up play. We're talking about very little taper to help reduce the squeeking.

I don't mean to scare anyone away from splined sytems. I love mine. I feel it is important to acknowledge what WILL happen if you neglect your cranks.

Splined systems were created to help reduce the risk of wallowing out your cranks. The idea is this. On a square axel, you have four sides which absorb the load of pedalling. As the crank loosens, its easy to start the crankarm stripping. On a splined system there is more surface area to divide these forces. This should help to reduce this. The disadvantage is if the crank is allowed to back far enough off you can completely ruin your cranks in ONE RIDE. This is entirely a preventative maitenance issue. If you are regularly checking the tension on your bolts you have nothing to worry about. If you don't, the bolts can allow the crank to push far enough away from the bb to allow the splines to strip. Since the splines are so small, it doesn't take a ton of pressure to damage them. (Say, one hard, mashing climb on a loose crank to create visible damage.)

 

[oldfart]

I think splined systems were designed to provide a stronger, stiffer and lighter bb. As you point out, loose interface with either system will lead to disaster.