Through-Axle Thread Wear/Cross-Threading: A Question
04-17-17, 12:50 PM
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Through-Axle Thread Wear/Cross-Threading: A Question
[Yes, I searched]
My TREK SuperFly 9.7 has through-axles front and rear and I transport it in a pickup rack with the front wheel removed and the axle screwed through the rack mount.This incurs lots of screw/unscrew cycles into a damned expensive front suspension.
If I bugger the threads by wear or by cross-threading, is my only remedy a replacement front suspension?
Mind, I haven’t done it yet, but it’s a concern.
[Related, does buggering the thread on the rear axle require trashing the whole frame?]
My TREK SuperFly 9.7 has through-axles front and rear and I transport it in a pickup rack with the front wheel removed and the axle screwed through the rack mount.This incurs lots of screw/unscrew cycles into a damned expensive front suspension.
If I bugger the threads by wear or by cross-threading, is my only remedy a replacement front suspension?
Mind, I haven’t done it yet, but it’s a concern.
[Related, does buggering the thread on the rear axle require trashing the whole frame?]
04-17-17, 01:37 PM
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Best preventive thing you can do is to keep the threads clean and greased to minimize wear, and engage the threads carefully. I am fairly certain that if threads get damaged they can be renewed by insertion of threaded inserts (e.g. Helicoils) . But I would not put it past manufacturers to use a non-standard thread or proprietary locking system which might make this difficult.
04-17-17, 01:48 PM
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Systems vary (what doesn't these days), but through axles are kinda sorta like traditional QRs except that the skewer is not the axle itself. But it's still the same, a shaft separate from the fork or hub that joins them together.
So, if you damage the thru- axle, that's generally all you'll need to replace. (except that they do cost much more than the old QRs did.
All this grief because BITD when disc brakes first came out, nobody thought about the reaction torque, and didn't have the sense to put the caliper forward of the fork.
So, if you damage the thru- axle, that's generally all you'll need to replace. (except that they do cost much more than the old QRs did.
All this grief because BITD when disc brakes first came out, nobody thought about the reaction torque, and didn't have the sense to put the caliper forward of the fork.
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04-17-17, 02:26 PM
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It depends a little on the through axle system. On my Fox 36 fork, the axle is also held by two QR clamps, so even if the threads were totally wrecked you'd be fine.
Theoretically, you are right that buggering the threads could damage the fork. Although the axle is usually soft aluminum, so the most likely thing to damage is just the axle part.
As for the frame, on most carbon frames, the rear TA is part of the rear derailleur hanger and is replaceable. There's an exploded diagram on Trek's page of the rear frame mount, it's easily replacable.
Theoretically, you are right that buggering the threads could damage the fork. Although the axle is usually soft aluminum, so the most likely thing to damage is just the axle part.
As for the frame, on most carbon frames, the rear TA is part of the rear derailleur hanger and is replaceable. There's an exploded diagram on Trek's page of the rear frame mount, it's easily replacable.
04-17-17, 04:06 PM
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Simple solution: Be careful to start the threads properly each time and the problem will never occur. There is no rule that says you have to cross thread them.
04-17-17, 04:18 PM
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Best preventive thing you can do is to keep the threads clean and greased to minimize wear, and engage the threads carefully. I am fairly certain that if threads get damaged they can be renewed by insertion of threaded inserts (e.g. Helicoils) . But I would not put it past manufacturers to use a non-standard thread or proprietary locking system which might make this difficult.
Shimano's E-Thru axle system allows that....although being Shimano and under licensing probably no one uses it on production frames. Paragon Machineworks makes slider plates with it at least.
