Front axle sequence

spimx
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spimx
Edited Date/Time 11/22/2019 1:58pm
Ive had a few people tell me different.

What is the right order?

Tighten the axle, pinch bolts then axle again.

Tighten pinch bolts then axle.

Tighten axle, left side pinch bolts, axle again then right side pinch bolts.
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Falcon
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Falcon 11/21/2019 1:55pm
11/21/2019 1:55pm
Here's my process:

Tighten rider's right side pinch bolts, so the axle doesn't turn.
Tighten the axle nut to torque.
Remove bike from stand and compress the forks a few times.
Tighten rider's left side pinch bolts.
Check torque on the axle nut.
1
seth505
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seth505 11/21/2019 2:59pm
11/21/2019 2:59pm
Falcon wrote:
Here's my process: Tighten rider's right side pinch bolts, so the axle doesn't turn. Tighten the axle nut to torque. Remove bike from stand and compress...
Here's my process:

Tighten rider's right side pinch bolts, so the axle doesn't turn.
Tighten the axle nut to torque.
Remove bike from stand and compress the forks a few times.
Tighten rider's left side pinch bolts.
Check torque on the axle nut.
I do this but after your step 2 I have an additional step to loosen the riders right side pinch bolts to ensure the right leg isn't binding.Then I tighten both side pinch bolts to torque spec.
2
Falcon
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Falcon 11/21/2019 4:43pm
11/21/2019 4:43pm
Falcon wrote:
Here's my process: Tighten rider's right side pinch bolts, so the axle doesn't turn. Tighten the axle nut to torque. Remove bike from stand and compress...
Here's my process:

Tighten rider's right side pinch bolts, so the axle doesn't turn.
Tighten the axle nut to torque.
Remove bike from stand and compress the forks a few times.
Tighten rider's left side pinch bolts.
Check torque on the axle nut.
seth505 wrote:
I do this but after your step 2 I have an additional step to loosen the riders right side pinch bolts to ensure the right leg...
I do this but after your step 2 I have an additional step to loosen the riders right side pinch bolts to ensure the right leg isn't binding.Then I tighten both side pinch bolts to torque spec.
A word to the wise: unless your axle bottoms out on something inside the rider's right fork lug, you could technically introduce a loose axle that way. With both pinch clamps free, there is nothing keeping the axle tight on the right side. The axle could slide left when compressing the forks (at least on Yamahas; there is nothing in the right-side fork lug to hold the axle on my YZ250.) Be sure to re-torque the axle nut, like I have in step 5.

Also, remember that binding of the suspension action is caused by the axle and its relationship between the two forks. We want a completely stress-free, even geometry between the two fork legs. Imagine an arbitrary line drawn across the bottom of the axle - this line should line up perfectly with two identical points at the bottom of the fork legs. There would be no "twisting" forces applied through the axle and acting on the forks in this condition.
If one side (right) of this equation is rigid initially, it doesn't really matter - as long as the other side (left) is given a chance to conform to the same alignment. And thus, we cycle the suspension as in step 3 before tightening the pinch clamps on the left.
FWYT
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FWYT 11/21/2019 11:22pm
11/21/2019 11:22pm Edited Date/Time 11/21/2019 11:28pm
Here's my method-
Keeps things loose.
Collapse the forks.
Tighten axle while holding axle with an allen.
Tighten pinch bolts.

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nate1001
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nate1001 11/22/2019 4:23am
11/22/2019 4:23am
Falcon wrote:
Here's my process: Tighten rider's right side pinch bolts, so the axle doesn't turn. Tighten the axle nut to torque. Remove bike from stand and compress...
Here's my process:

Tighten rider's right side pinch bolts, so the axle doesn't turn.
Tighten the axle nut to torque.
Remove bike from stand and compress the forks a few times.
Tighten rider's left side pinch bolts.
Check torque on the axle nut.
seth505 wrote:
I do this but after your step 2 I have an additional step to loosen the riders right side pinch bolts to ensure the right leg...
I do this but after your step 2 I have an additional step to loosen the riders right side pinch bolts to ensure the right leg isn't binding.Then I tighten both side pinch bolts to torque spec.
Falcon wrote:
A word to the wise: unless your axle bottoms out on something inside the rider's right fork lug, you could technically introduce a loose axle that...
A word to the wise: unless your axle bottoms out on something inside the rider's right fork lug, you could technically introduce a loose axle that way. With both pinch clamps free, there is nothing keeping the axle tight on the right side. The axle could slide left when compressing the forks (at least on Yamahas; there is nothing in the right-side fork lug to hold the axle on my YZ250.) Be sure to re-torque the axle nut, like I have in step 5.

Also, remember that binding of the suspension action is caused by the axle and its relationship between the two forks. We want a completely stress-free, even geometry between the two fork legs. Imagine an arbitrary line drawn across the bottom of the axle - this line should line up perfectly with two identical points at the bottom of the fork legs. There would be no "twisting" forces applied through the axle and acting on the forks in this condition.
If one side (right) of this equation is rigid initially, it doesn't really matter - as long as the other side (left) is given a chance to conform to the same alignment. And thus, we cycle the suspension as in step 3 before tightening the pinch clamps on the left.
You should tighten the right side last as the left side can't conform. The axle clamps against the left lug so when you tighten the nut, there is no play. The right side has a smooth bore and the axle is smooth there also. When you compress the suspension it will slide to the forks neutral/center and then the pinch bolts hold it.
4
seth505
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seth505 11/22/2019 6:48am
11/22/2019 6:48am Edited Date/Time 11/22/2019 6:50am
Falcon wrote:
Here's my process: Tighten rider's right side pinch bolts, so the axle doesn't turn. Tighten the axle nut to torque. Remove bike from stand and compress...
Here's my process:

Tighten rider's right side pinch bolts, so the axle doesn't turn.
Tighten the axle nut to torque.
Remove bike from stand and compress the forks a few times.
Tighten rider's left side pinch bolts.
Check torque on the axle nut.
seth505 wrote:
I do this but after your step 2 I have an additional step to loosen the riders right side pinch bolts to ensure the right leg...
I do this but after your step 2 I have an additional step to loosen the riders right side pinch bolts to ensure the right leg isn't binding.Then I tighten both side pinch bolts to torque spec.
Falcon wrote:
A word to the wise: unless your axle bottoms out on something inside the rider's right fork lug, you could technically introduce a loose axle that...
A word to the wise: unless your axle bottoms out on something inside the rider's right fork lug, you could technically introduce a loose axle that way. With both pinch clamps free, there is nothing keeping the axle tight on the right side. The axle could slide left when compressing the forks (at least on Yamahas; there is nothing in the right-side fork lug to hold the axle on my YZ250.) Be sure to re-torque the axle nut, like I have in step 5.

Also, remember that binding of the suspension action is caused by the axle and its relationship between the two forks. We want a completely stress-free, even geometry between the two fork legs. Imagine an arbitrary line drawn across the bottom of the axle - this line should line up perfectly with two identical points at the bottom of the fork legs. There would be no "twisting" forces applied through the axle and acting on the forks in this condition.
If one side (right) of this equation is rigid initially, it doesn't really matter - as long as the other side (left) is given a chance to conform to the same alignment. And thus, we cycle the suspension as in step 3 before tightening the pinch clamps on the left.
I forgot how my YZ axles were but the ones on my KTMs have a step in them that sits flush against wheel spacer, it can't introduce a loose axle. The first step is to tighten the axle nut but I have that pre-first step of temporarily tightening the right side pinch bolts only so the axle doesn't spin and I can get it to torque spec'd.
walent215
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walent215 11/22/2019 8:26am
11/22/2019 8:26am
seth505 wrote:
I do this but after your step 2 I have an additional step to loosen the riders right side pinch bolts to ensure the right leg...
I do this but after your step 2 I have an additional step to loosen the riders right side pinch bolts to ensure the right leg isn't binding.Then I tighten both side pinch bolts to torque spec.
Falcon wrote:
A word to the wise: unless your axle bottoms out on something inside the rider's right fork lug, you could technically introduce a loose axle that...
A word to the wise: unless your axle bottoms out on something inside the rider's right fork lug, you could technically introduce a loose axle that way. With both pinch clamps free, there is nothing keeping the axle tight on the right side. The axle could slide left when compressing the forks (at least on Yamahas; there is nothing in the right-side fork lug to hold the axle on my YZ250.) Be sure to re-torque the axle nut, like I have in step 5.

Also, remember that binding of the suspension action is caused by the axle and its relationship between the two forks. We want a completely stress-free, even geometry between the two fork legs. Imagine an arbitrary line drawn across the bottom of the axle - this line should line up perfectly with two identical points at the bottom of the fork legs. There would be no "twisting" forces applied through the axle and acting on the forks in this condition.
If one side (right) of this equation is rigid initially, it doesn't really matter - as long as the other side (left) is given a chance to conform to the same alignment. And thus, we cycle the suspension as in step 3 before tightening the pinch clamps on the left.
nate1001 wrote:
You should tighten the right side last as the left side can't conform. The axle clamps against the left lug so when you tighten the nut...
You should tighten the right side last as the left side can't conform. The axle clamps against the left lug so when you tighten the nut, there is no play. The right side has a smooth bore and the axle is smooth there also. When you compress the suspension it will slide to the forks neutral/center and then the pinch bolts hold it.
Money^^
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Luxon MX
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Luxon MX 11/22/2019 9:13am
11/22/2019 9:13am
The point of tightening the axle nut is to preload the bearings. Tighten rider's right side bolts to keep the axle from spinning and torque the nut to spec (should be on rider's left). Tighten rider's left side pinch bolts to spec. Loosen rider's right side bolts and then do whatever you do to get things aligned. Once aligned, tighten rider's right side bolts.

Regarding alignment, there are multiple techniques. If you have a good set of triple clamps and the forks aren't bent or anything weird, you can usually just let the axle self align in the lug and torque the bolts (bike on a stand, wheel in the air). That assumes the fit between the lug and axle is loose enough for it to float around some. If not, you'll have to spread it with a screwdriver or something. In general, the fork lug outer surface should be flush with the axle surface. If it's way off, then something is probably wrong.

You can open up the fork caps and compress everything fully then tighten the axle as shown earlier, but if you know everything is straight (forks/clamps), then that's a bit overkill. Or you could do it once, note the relationship between the axle surface and lug, then match that the next time you do it without all the work of compressing everything.
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Falcon
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Falcon 11/22/2019 11:33am
11/22/2019 11:33am
Falcon wrote:
A word to the wise: unless your axle bottoms out on something inside the rider's right fork lug, you could technically introduce a loose axle that...
A word to the wise: unless your axle bottoms out on something inside the rider's right fork lug, you could technically introduce a loose axle that way. With both pinch clamps free, there is nothing keeping the axle tight on the right side. The axle could slide left when compressing the forks (at least on Yamahas; there is nothing in the right-side fork lug to hold the axle on my YZ250.) Be sure to re-torque the axle nut, like I have in step 5.

Also, remember that binding of the suspension action is caused by the axle and its relationship between the two forks. We want a completely stress-free, even geometry between the two fork legs. Imagine an arbitrary line drawn across the bottom of the axle - this line should line up perfectly with two identical points at the bottom of the fork legs. There would be no "twisting" forces applied through the axle and acting on the forks in this condition.
If one side (right) of this equation is rigid initially, it doesn't really matter - as long as the other side (left) is given a chance to conform to the same alignment. And thus, we cycle the suspension as in step 3 before tightening the pinch clamps on the left.
nate1001 wrote:
You should tighten the right side last as the left side can't conform. The axle clamps against the left lug so when you tighten the nut...
You should tighten the right side last as the left side can't conform. The axle clamps against the left lug so when you tighten the nut, there is no play. The right side has a smooth bore and the axle is smooth there also. When you compress the suspension it will slide to the forks neutral/center and then the pinch bolts hold it.
walent215 wrote:
Money^^
All good, except on my YZs there is nothing to keep the inner part of the fork lug against the wheel spacer if you do this. The axle can pass right through the right-side fork lug, and it relies on the right-side clamps to achieve and keep the tension that the axle nut supplies over on the other side. The axle will bottom out on the right-side wheel spacer but not in the fork lug.
Conceivably, I could fasten the front wheel to the bike without the right-side fork at all.

Even with the axle nut torqued to spec., the left-side fork leg can rotate on the axle with force. This is why we compress the forks several times and then use the pinch bolts. Nate's method would definitely work better for bikes featuring a right-side fork lug interface with the axle, though.
nate1001
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nate1001 11/22/2019 1:02pm
11/22/2019 1:02pm
Nope. YZ Crf, probably all of them are that way. Right side lug is smooth inside and the axle will slip right through. The axle pulls against the wheel spacer, then bearing race, then another spacer to the other bearing race, then the other wheel spacer and holds it all tight to the left lug with the axle nut. Like you said, it all gets held and torqued to the left fork lug. There is a hex inside most axles so you can hold it and don't even have to tighten the right pinch bolts to torque the nut down.

You leave the right side loose when you compress the suspension so right lug centers itself on the axle. Then the pinch bolts keep it from moving or sliding on the axle.
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