If you want a top-of-the-range replacement bottom bracket for your ISIS splined cranks, you ought to consider the Stronglight Twister Titanium bottom bracket.
The initial poor lifespan from early ISIS bottom brackets severely affected consumer conﬁdence in the standard, but Stronglight kept faith with the oversized splined axle design, believing it could do better – a challenge we reckon it has met.
We’ve spent a year on the lightweight Twister and given it a hard time, including full submersion, jet washing, dousing with degreaser and running a set of cranks a tiny bit loose. There’s not been even the hint of a hiccup from the unit. Just as well, since it is not user-serviceable.
At the heart of the Twister unit is a hollow titanium axle which has a slippery blue nitride coating applied to help the axle and the crank work better together and to ward off bi-metallic corrosion if used with alloy cranks. The axle itself is encased inside a full CNC-machined alloy housing.
The axle stubs have pre-ﬁtted bumpers inboard of the splines. These act as a guide when you’re tightening the cranks onto the splines – when the splines hit the bumpers, you know they’re on properly. Stronglight’s zero-exposed axle design also means there is no unsupported axle – so, unlike some other titanium BB axles, this doesn’t feel like it’s ﬂexing when you’re giving it full welly up a hill. It will also help increase the lifespan of the bearings.
The hollow design helps keep the weight down to an impressive 180g and also aids the overall level of stiffness. This low weight may prove tempting enough to encourage XC and marathon racers to opt for an ISIS crank, and thereby drop weight from the current crop of integrated crank/external BB models which ﬁll the bike shop shelves.
Our 113mm Twister bottom bracket mated perfectly to our Stronglight Magma, Bontrager XXX and Middleburn Duo ISIS pattern cranks. Once the cranks are installed, whichever set you go for, you can feel how smooth Stronglight’s bearings are. Just unmount the chain and give the arms a ﬂick to see them spin.