Asymmetrical front tire wear

[atomsplitter]

Well, after removing the front wheel, here are the results:
- The guy who tightened the front wheel axle didn't apply the correct torque (65 Nm). It took me 10 minutes to loosen it...
- The two spacers are identical (25 mm each)
- The original wheel is probably the cause because, on the ABS side, there's an excess thickness which, as a result, shifts the wheel to the right by about 5 mm.

So, beyond the problem related to the engine architecture, it seems that Triumph has chosen to consider a wheel offset of a few mm not a problem... I'm really disappointed

in the brand's engineers!!!

The pinch bolts were likely over torqued too in that case. Putting it back together with the proper torque may not solve your problem, but it sure will help with future maintenance chores. Also I would think your wheel bearings may need to be looked at since the internal spacer (#6 in the above diagram) applies pressure to the inner race. If they turn smoothly it's good to go.

 

[Journeyman]

As you said, it's by design- all of our front wheels are offset on the 2.5s.

As far as wearing on the right, and this may contradict what someone said earlier about driving on the right side of the road, I was told by a mechanic years ago with my '98 Thunderbird Sport that this is normal due to our right turns being sharper than turning left.

What I suspect on the 2.5s is that the way it always wants to drift left (evident if you take your hands off handlebars) forces you to constantly apply just a slight amount of right turn pressure to compensate. This constant steering pressure to the right wears the right side of the tire more than the left. That's my theory and I'm sticking to it

Static balance on front and dynabeads in the rear

 

[Tripps]

My Touring has also always wanted to drift left if you take your hands off the bars. When I asked my dealer, he said that's an easy fix, don't take your hands off the bars.

 

[Jagster]

Back tracking a little on this discussion, can someone confirm (once more if they believe they have already) what exactly is being measured as being offset.

What is the reference to this so called offset?

 

[RUN666]

The offset I measured is between the bottom of the fork and the disc collar. Take a good look at your bike and you'll see, without measuring, that the left side is larger than the right side. You can also see this offset by looking at the front mudguard.

 

[Jagster]

The offset I measured is between the bottom of the fork and the disc collar. Take a good look at your bike and you'll see, without measuring, that the left side is larger than the right side. You can also see this offset by looking at the front mudguard.

Ok. But it's not clear to me how you are able to conclude that those particular differences result in the steering geometry being out of alignment.
Surely you would need to take a line from the centre of the front and rear tyre (or rim) and reference from there to the centre of the axis of rotation of the headstock.
If the headstock axis is offset (in plan view) to the centre of the wheel rims when they are aligned with each other, then you could state that the bike has an offset, but it's a very difficult thing to measure, so i'm somewhat doubting your conclusion.
You might be right, but then again.......
I'm not suggesting that you just noticed the front mudguard being out of alignment with the tyre and declared the chassis as being out of alignment, but I think there's is more to this than what we have been discussing earlier in the thread.
I have to confess that I had noticed the mudguard offset etc.. before, on my bike about a year or so ago, when I was making my front fender extender, but I kinda just accepted it and then forgot about it.

Every shaft drive bike i've ever owned looked like it had some offset at the rear wheel, but i've never investigated it to any extent because it's difficult to do with any accuracy. Perhaps this kind of thing is more common than we are aware???

 

[Journeyman]

The wheel does not sit centered between the forks. Not that way on the 2.3s

 

[Jagster]

The wheel does not sit centered between the forks. Not that way on the 2.3s

Ok...So?...That might be a fact, but beyond that, does it mean anything significant or matter in the wider context?

Do the fork stanchions sit equally on either side of the headstock? for example...

I'm just asking the question, as i'm not (yet) convinced that anyone has an accurate or relevant conclusion on any of this.

 

[Journeyman]

I have no idea, but figure Triumph did it for good reason and therefore probably not, in my opinion, the cause of uneven tire wear. You were asking about the offset and I guess we thought you hadn't noticed the wheel is not centered between the forks.

As far as the uneven tire wear I believe it is... "....the way the bike always wants to drift left (evident if you take your hands off handlebars) forces you to constantly apply just a slight amount of right turn pressure to compensate. This constant steering pressure to the right wears the right side of the tire more than the left."

We all just throwing ideas out there

 

[Jagster]

I have no idea, but figure Triumph did it for good reason and therefore probably not, in my opinion, the cause of uneven tire wear. You were asking about the offset and I guess we thought you hadn't noticed the wheel is not centered between the forks.

As far as the uneven tire wear I believe it is... "....the way the bike always wants to drift left (evident if you take your hands off handlebars) forces you to constantly apply just a slight amount of right turn pressure to compensate. This constant steering pressure to the right wears the right side of the tire more than the left."

We all just throwing ideas out there

Yes.
I'm thinking...Who knows for sure.
If there is a deliberate small offset (after all, it's highly unlikely to be an error) perhaps it's to combat a harmonic resonance in the bike ?????

The C of G of the bike could easily be one side of the centreline through the tyres contact patches, so I guess my point is, that nothing is absolutely balanced symmetrically on these bikes.......or probably any other bike for that matter...........or perhaps i'm looking at everything wrong.