Featured Thruxton ‘r’. Beware! Front Wheel Fitment

If you leave the pinch bolts until last that clamp the spindle,they all come into alignment

 

Refit wheel with spindle hand tight, refit calipers and torque up, tourque wheel spindle, torque pinchbolts. Good to go

 

Hi Ken glad I have found someone with the same issue
as me, likewise I carried out same procedure as you and after a weekend away got home to discover the disc scoring the inner of caliper. Luckily I it has not damaged disc or caliper. I think this is a shitty design as normally you would expect the spacer to be hard up against fork leg ,not with a gap of approx 4mm .
What are your thoughts on this
Allan

 

exactly Ken I was concerned about the fork seals as well but good to hear that it is not a concern.
cheers Allan

 

I have exactly the same issue and my local dealer did as you and moved the bottom of the right hand fork leg out before reclamping to the spindle (wheel axle) This did not completely centralise the caliper in relation to the disc but created enough clearance to prevent metal to metal contact. As an engineer I am not impressed by this poor tolerencing but my big concern is that we now have a 3 mm gap between spacer and fork so the wheel is no longer "fixed" relative to the axle! ONLY the brake pads are preventing the wheel moving from side to side. I would be very pleased if someone can provide the error in my logic?

 

I was taught years ago to finger tighten the axle pinch bolts and apply the front brake and bounce the suspension 3 or 4 times to align everything then torque up (even more vigorously if the triple trees/yokes had been fiddled with and also needed aligning.)

 

Sound practice .so imagine you have done just that and you find your left brake disc is running in the centre of the corresponding caliper whilst the right is scraping on its disc, that is the caliper itself not just the pads, because the brake disc is not in the middle of the casting. No scope to move the caliper on its mounting screws and the disc is "floating" correctly. Lever the fork leg out?

 

Sound practice .so imagine you have done just that and you find your left brake disc is running in the centre of the corresponding caliper whilst the right is scraping on its disc, that is the caliper itself not just the pads, because the brake disc is not in the middle of the casting. No scope to move the caliper on its mounting screws and the disc is "floating" correctly. Lever the fork leg out?

 

In that event I would first check that the fork legs were parallel. Tightening the pinch bolts before the axle bolt will ensure they won’t be!

 

Can you provide two pictures for better further advice,
Picture 1 showing the 3mm gap
Picture 2 showing the spindle on its own.

Depending on the design, if a stepped spindle is employed then there will not be a gap. Im pretty certain that lateral wheel position will not be dictated by the brake pads as you suggest.

 

Firstly thanks to Ken for the original post & thread and also to all who replied to me. So this morning I satisfied myself that the stepped diameter wheel spindle means the right hand wheel spacer is held tight to the hub whilst the left hand spacer is clamped between the left fork and the wheel hub. The wheel cannot move out of position with the spindle tightened up, irrespective of the clamping of the RH fork leg to the wheel spindle. At this stage, on my bike, the left hand caliper is correctly positioned (central) to its brake disk. In order to position the right hand caliper satisfactorily, relative to its disc, the right hand fork must be moved along the wheel spindle which, for this bike, meant a 2mm gap between the wheel spacer and fork to gain 0.3mm clearance between the caliper lugs and disc.(min clearance quoted in the Haynes manual) As Ken showed this corresponded to the head of the spindle aligning with the chamfer in the fork (see pics). The following is not a recommendation that anyone should implement unless they are satisfied it is safe & advantageous - your decision. Not liking the appearance of the gap between the RH fork and the wheel spacer, to avoid use of any lever and to fix the dimensions to simplify future assembly, I used some suitable aluminium washers from my shed stock as shims (see pics). I needed two of these to get the correct dimension but I will replace these with a single 2mm thick version when I've made it. Note the hex head clamping screws were yet to be re-fitted when I took the photos. Your call as to who is the worst bodger, me or Mr Triumph.

 

Hey Ken,

Could it be that the axle wasn't quite free to rotate in the RHS fork and so as the axle went in it dragged the fork in with it?

I read your post before I did mine and so was super-cautious. As new, from the factory, my axle was inset 3.8mm inside the outer edge of the fork before I released the clamp bolts.

I followed the procedure in the Haynes manual - ensured the clamp was not restricting movement of the axle AT ALL (i.e. not even finger tight), torqued up the axle, pumped the forks up and down and torqued up the clamp bolts. I measured the the inset and again, it had naturally settled back to 3.8mm.

I don't believe the factory would have been levering the fork leg around to get it to fit when they assembled the bike.

If your fork is deflected inboard then I would guess that either the fork has a defect... and I would get that checked. Or something's dragging it inboard as you tighten the axle up.

If I recall correctly, someone said on here that it can't be right that there's a 'gap' between the RHS fork and the RHS spacer. It is OK - the axle itself compresses the [RHS spacer, bearings, wheel and LHS spacer] assembly against the LHS fork - so there's no way the wheel can wander around laterally. The RHS fork then clamps on the end of the axle head but that only provides a 'vertical' mounting - it doesn't need to play any part in compressing the wheel assembly.

Good luck - hope you can get your fork leg to sit where it wants to... as that is (or should be) where it is straight.

Dave

 

So what would happen if an undersized [on the width] front mudguard was removed from the equation prior to the commencement of the axle tightening sequence

 

Is this video any use gents ?



Regards

 

I would be seriously concerned if I had to lever a fork leg out to get the brake caliper to sit centrally .For one thing the forks will not be parallel anymore and will cause excessive friction /stiction , which could compromise the way the suspension acts . Something amiss somewhere I reckon