issis cranks

On a post by Nurse Ben he makes the observation that issis hubs/cranks in the biking world are becoming rare.
as I’m currently acquiring the parts for my new fattie I can’t help but wonder what is replacing them and if I should reconsider an issis for my project?

The bike industry is going toward two piece crank/spindle systems where one crank is permanently mounted to the spindle. One less interface to worry about and the component manufacturers get to sell more expensive “systems” when/if something breaks.

Fat bikes will probably stick to a 3 piece systems since long spindles are a niche market item. Unicycles will definitely stick to a 3 piece system.

What Eric says is true, but also ISIS was losing favor before the current through spindle cranks due to a bad Bottom bracket design. Riders were blowing through BB’s very quickly. Other similar, but vastly better designs, were deceloped to remedy the ISIS BB problems like the Truvativ GXP (very similar to ISIS, but not compatible).

The interface itself is sound. I think the manufacturers bailed on it due to the bad rep from the bottom brackets. If they would have thought of external bearings as a part of ISIS it would probably be the predominant system.

Of course this is for bikes. Uni’s only use the interface, and no BB, so there is no problem at all with ISIS on a uni. Maybe someday it will be known as USIS :wink:

You could do something like the Q-axle cranks, which are a non-tapered type spline, but that isn’t likely to catch on quickly if at all. ISIS gives you the most options right now, and works really well. Plus if you stock up on moment cranks, you’ll never need to buy anything later because good luck breaking them : ) (I’m sure it’s been done… but it’s hard)

actually… I take that back, the inside mounted disc (on the only hub available) probably means the flanges would be too small to build up one with a fat rim (65+mm)

The only problem with ISIS is that you should use spacers with it on uni and you can’t use them with Schlumpf, so Q-axle style would help here. But I don’t think Schlumpf unis are big enough market to change that soon.

The new version of the Schlumpf hubs, which will probably enter the market within the next few weeks, is fully compatible with spacers.
Q-axle would not be compatible with external disc brake.

Eric could you explain why? Is it just lack of cranks of something more?

I believe, that you may have to loosen the rotor bolts when you want to tighten the two clamping bolts of the crank. The slot in the crank will get tighter by tightening the bolts and thus, the thread holes for the rotor will move. Also on the side, where the slot and the two clamping bolts are, there would not be enough space to put in a thread hole for a rotor bolt. So in the end, you could mount your rotor only with 4 or 5 bolts.

Just compare the Q-axle crank to a Spirit crank

Somebody posted a similar comment on FB, and as I wrote there, nothing other than ISIS is coming to a Schlumpf any time soon. For unis ISIS is an excellent crank connection standard - there’s really nothing at all wrong with it when done properly with spacers, and the new version of the Schlumpf which allows the use of those gets rid of any final objections. There is no advantage to changing to anything else.

As for it being an obsolete standard on bikes, that’s pretty much irrelevant. The only cranks or hubs I have on a uni which aren’t uni specific are a set of square tapers on my first generation Schlumpf. There’s no particular reason why ISIS no longer being used on bikes makes any difference to the companies making uni parts.

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