- Joined
- Mar 18, 2006
- Messages
- 2,841
- Age
- 70
- Location
- Ilkley, W Yorkshire, UK
- Bike
- 2013 ST1300 A9
- 2024 Miles
- 000679
- STOC #
- 2570
When the bearings are replaced in the front wheel, the order of installation is important. Get it wrong and the front wheel will not be on the centre line, and this may affect steering and the performance of the braking system.
The issue is to do with the fact that the distance collar (that fits between the two bearings inside the hub) is longer than the distance between the two shoulders inside the hub of the wheel.
If the left bearing is driven in first it will end up being slightly too far to the right of the bike and this will displace the right hand bearing when that is driven in. As a result, the front wheel will be positioned too far to the right.
The diagrams show the cross section of the hub, bearings and axle, viewed from the front of the bike.
In the top diagram, the right hand side bearing shown looking from the front of the bike on the left of the diagram has been installed first and is seated correctly against the (green) shoulder in the hub. This is the correct way of installing the bearing. The left hand bearing is then driven in with the (blue) spacer in between. This does not sit on the shoulder in the hub. It seats with its inner race on the distance spacer (blue), a little way from the shoulder (green). To help distinguish when the wheel is off the bike, the side with the pulsar ring is the right hand side.
The red dotted line is the centre line between the forks. The black arrows indicate where the centre line of the hub, wheel and tyre sits.
Please note that the diagram is shown when viewed from the front of the bike - as per the manual.
The bottom diagram shows what might happen if the left hand bearing is wrongly installed first. The left bearing is now seated on the (green) shoulder in the hub, and the right hand bearing is held away from the right hand shoulder by the (blue) distance spacer. The arrows on the green hub are in the same position, but the entire hub, wheel and tyre have been moved towards the left fork leg.
This may present issues with the clearance of the calipers on the brake disk rotors - but the front wheel is now marginally out of line.
I haven't taken any measurements to produce these drawings, and the distance involved may be only a mm or two. I don't know. But I do know that the workshop manual makes the point in text and on diagrams about installing the right hand bearing for the front wheel first, until it is seated.
There must be a reason for that, and I don't know what effect on ridability this has. Maybe some. It will certainly affect the relations hip of the caliper brackets to the brake disc/rotor.
I am merely pointing out how the wheel ends up off centre if the bearings are installed in the wrong order.
(nb The rear wheel has similar issues, but for the rear wheel, the manual says to install the left hand bearing first).
The issue is to do with the fact that the distance collar (that fits between the two bearings inside the hub) is longer than the distance between the two shoulders inside the hub of the wheel.
If the left bearing is driven in first it will end up being slightly too far to the right of the bike and this will displace the right hand bearing when that is driven in. As a result, the front wheel will be positioned too far to the right.
The diagrams show the cross section of the hub, bearings and axle, viewed from the front of the bike.
In the top diagram, the right hand side bearing shown looking from the front of the bike on the left of the diagram has been installed first and is seated correctly against the (green) shoulder in the hub. This is the correct way of installing the bearing. The left hand bearing is then driven in with the (blue) spacer in between. This does not sit on the shoulder in the hub. It seats with its inner race on the distance spacer (blue), a little way from the shoulder (green). To help distinguish when the wheel is off the bike, the side with the pulsar ring is the right hand side.
The red dotted line is the centre line between the forks. The black arrows indicate where the centre line of the hub, wheel and tyre sits.
Please note that the diagram is shown when viewed from the front of the bike - as per the manual.
The bottom diagram shows what might happen if the left hand bearing is wrongly installed first. The left bearing is now seated on the (green) shoulder in the hub, and the right hand bearing is held away from the right hand shoulder by the (blue) distance spacer. The arrows on the green hub are in the same position, but the entire hub, wheel and tyre have been moved towards the left fork leg.
This may present issues with the clearance of the calipers on the brake disk rotors - but the front wheel is now marginally out of line.
I haven't taken any measurements to produce these drawings, and the distance involved may be only a mm or two. I don't know. But I do know that the workshop manual makes the point in text and on diagrams about installing the right hand bearing for the front wheel first, until it is seated.
There must be a reason for that, and I don't know what effect on ridability this has. Maybe some. It will certainly affect the relations hip of the caliper brackets to the brake disc/rotor.
I am merely pointing out how the wheel ends up off centre if the bearings are installed in the wrong order.
(nb The rear wheel has similar issues, but for the rear wheel, the manual says to install the left hand bearing first).
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