[dgrif]

i see **** on ebay that have both in description.. is the howitzer bb isis? i wouldnt think so, else they would just call it isis.. i wouldnt mind havin a set of holzfeller cranks, but i believe they're only "howitzer" compatible.. can anybody clear this up for me?

thanks

 

[dgrif]

nobody?

 

[tomacdaddy]

Dude, I'm not exactly sure b/c I have only run some of the older Holzfellers, but my interpretation is that the slines are ISIS, but that the B.B. system is only compatible with Howitzer cranks. May be because of the spindle/crank interface....may just be a marketing ploy.
Either way, they have a setup for 100mm shell and I understand that they are decent.

 

[dgrif]

weird..

 

[davep]

Correct. The spline 'shape' is common to the isis standard, but that is where it ends. The ISIS standard also lays out a standard for a 'stop' or bottom out ring on the spindle at a specific destance from the bicycle centerline. This is so that a 113mm bb from one mfg puts your cranks at the same distance 'out' as a 113mm bb from another company. Same for using different crank mfg.

The Howitzer bbs have an outboard bearing. Because of this, the spindle and thus the splines need to be further 'out' to give space for the bearing. The crank arm is made differently, to compensate for the howitzer splines being further out. So it is NOT fully ISIS compliant.

Howitzer cranks + ISIS bb equals cranks WAY too far in.
ISIS cranks and + howitzer bb equals cranks WAY too far out.

 

[dgrif]

gotcha.. thanks guys.