Is Octalink a tapered spline???

[wilmar13]

I am thinking of buying a SRM crank, but I need to be able to switch the crank from my road race bike to my TT bike (can't afford two cranks)... I do this now with my dura-ace crank, but I would not want to with tapered cranks because of wear, chance of stripping something, etc...

Is the Octalink spline interface a psuedo-press fit similar to ISIS or the traditional square taper or does it rely on only the spline and crank bolt, i.e. it is easy to take the crank on and off???

 

[531Aussie]

9sp Simano Octalink is splined and uses an 8mm alen bolt

 

[wilmar13]

9sp Simano Octalink is splined and uses an 8mm alen bolt

I know it is splined .. I am wondering if it is a tapered spline or straight... if straight it should be a piece of cake to remove, just like the newer integrated crank/BB styles, if tapered it will be a ***** to do it with any frequency.

 

[531Aussie]

oh, sorry, do you want me to trust my eye? Because I've got some sitting here

 

[531Aussie]

the splines are straight, but the rest of the axle has a very slight taper

I do mine up pretty tight, and they're a minor pain to get off; nowhere near as easy as 10sp. I definitely wouldn't want to do it regurlarly.

 

[531Aussie]

I'm not sure it's obvious in this picture, but there is a subtle taper below the splines




......................................................this one

 

[wilmar13]

the splines are straight, but the rest of the axle has a very slight taper

I do mine up pretty tight, and they're a minor pain to get off; nowhere near as easy as 10sp. I definitely wouldn't want to do it regurlarly.

yeah I guess in hindsight a simpler way of phrasing my question would have been: Do you need a crank puller (or self extracting bolts) to remove a crank arm with an octalink spindle?... it looks like you are saying yes.

 

[531Aussie]

yep, it uses an 'auto puller' washer thingy on the bolt, and it takes a bit of 'oomphf' to get it moving.

 

[artemidorus]

yeah I guess in hindsight a simpler way of phrasing my question would have been: Do you need a crank puller (or self extracting bolts) to remove a crank arm with an octalink spindle?... it looks like you are saying yes.

Yes, you definitely need a puller if you haven't a self-extracting bolt.

 

[hd reynolds]

Is the Octalink spline interface a psuedo-press fit similar to ISIS or the traditional square taper or does it rely on only the spline and crank bolt, i.e. it is easy to take the crank on and off???

The later. Coz of the close tolerances there will be some resistance, hence a puller would be needed, or, self extracting bolts are sufficient since resistance is not that great compared to, say, a square taper.

http://cycle.shimano-eu.com/publish/content/cycle/seh/nl/en/technical_service/faq_s/general_faq_s/what_is_octalink_.MainContent.0002.Image.gif