Bent swingarm

[RanchoFM]

Sadly, this winds up being my first post. I searched all over and oddly didn't find any precedent for this.

So, after 15k wonderful miles I dropped my 08 C14 in a bonehead 0mph maneuver. Bike touched down on the left side on the mirror, lower front fairing, saddlebag, and the pivot between the swingarm and final drive unit. Oh yeah, and my foot.

I checked the bike over and rode it home. It tracked straight and handled normally. Last week, I took a 1200 mile trip and about 3/4 of the way through, the back tire started showing some noticeably uneven wear, wearing on the left side much more than the right. When I put a level up to the sidewalls (not very scientific, I know) it shows that the bottom of the wheel is kicked out to the right a bit. I would think the swingarm component of the Tetralever would be stout enough to take this, but I don't know. Any experience with or thoughts on this? Thanks!

Eric

[VirginiaJim]

I've had my bike fall in a 0mph fall and the only thing damaged was a scuff on the mirror and the lowers.  Granted it did fall on me and I broke it's fall.   With 0mph falls, I don't think we've heard of a swingarm component being bent.   There's ways to check if the tracking is on.  Hopefully someone will chime in with that.

[jimmymac]

It sounds like something got knocked loose, but a bent swingarm? Pretty tough pill to swallow. Did a car back over it?

[RanchoFM]

It sounds like something got knocked loose, but a bent swingarm? Pretty tough pill to swallow. Did a car back over it?

That's what I thought, but with all the linkages I don't know. It was a simple drop. Also, I had 4k miles on these tires before the "incident", and they were wearing evenly.

[jwh20]

wearing on the left side much more than the right.

I'm going to suggest that this is typical, at least in places where we drive on the RH-side of the road.  The left side of your tires will always wear more quickly.  Why?  Think about turns, it's reasonable to assume that left turns and right turns are roughly equal but a left turn will take you much farther around a larger circle than a right turn.  So you are leaning to the left and wearing the left side of your tires out much more.

The swing arm is very stout material on the C14.  I think the chances of you bending it with a simple drop are pretty remote.  But if bent, I think you're going to be experiencing some really odd handling which would be a lot more noticeable than some uneven tire wear.  But you will probably want to inspect it anyway.  I don't agree that your "level" test is valid though.

[tweeter55]

I'm going to suggest that this is typical, at least in places where we drive on the RH-side of the road.  The left side of your tires will always wear more quickly.  Why?  Think about turns, it's reasonable to assume that left turns and right turns are roughly equal but a left turn will take you much farther around a larger circle than a right turn.  So you are leaning to the left and wearing the left side of your tires out much more.

Also typically there is a crown in the road, slight as it might be, to promote drainage to the shoulder.

[RanchoFM]

Also typically there is a crown in the road, slight as it might be, to promote drainage to the shoulder.

I've considered the crown, but this wear is more uneven than any tires I've had, including the ones in question (for the first 4k miles). I'll try to put up a pic tonight.

I don't put much stock in the level test; just a quick assessment.

[B.D.F.]

I basically agree with every single post so far in this thread, and think others have about covered the whole subject.

The only other thing I can think of to add is that it is possible that one of the pivots / joints on the rear linkage is worn, corroded, loose or similar. And having had a few of them apart on C-14's, I really do not believe any of that is likely at all, whatsoever. The rear suspension, specifically the 4-bar link system is truly built like a brick outhouse; actually, I believe it is really very overbuilt, especially the joints and in this particular case, that is the way to go 'cause it really does not cost a lot of weight and just about eliminates failures.

As to your level measurement, how are you establishing vertical? In other words, if a level shows the rear wheel (you should not do any measurements from any tire, the wheels are more accurate), how do you know the mid- line of the bike is not canted by that amount, effectively making the rear wheel in- line with the chassis?

Brian

[jwh20]

By the way, what kind of tires and how many miles on them?

[maxtog]

Everyone posted before I could, so I was just going to add another voice to the "I don't see how it is possible to bend any part of the suspension on a C14 with a simple zero/low-speed drop, it is just too strong/reliable/robust".  And also the wear possibly being normal for RHD.  Anything else to me would be a mystery.  It is sad that has to be your first post instead of "just installed tip-over protection!!"

[RanchoFM]

It is sad that has to be your first post instead of "just installed tip-over protection!!"

Indeed. When I was looking into the C14 as my next bike (after a seriously ill-fated Ducati experience) the search function here and on cog-online pretty much eliminated the need to ask any questions. The fuel filter fix was a bike-saver when I first bought my Conc and it started bucking uncontrollably. Great sources of info.

All of your comments got me thinking that the trip I just took was through northern PA, the Catskills, Vermont, Adirondacks and out to the Finger Lakes. And we ride back roads as much as possible. Some narrow country lanes, rough surfaces and quite crowned in some places. Thinking maybe it's just my typical paranoia when it comes to machines. I took it out this evening and I can't find anything unusual about the way it rides. These are PR3's btw. ~5500 miles. The PR2 I had on the rear before this didn't wear like this in the 10k I had it, but then again it wasn't ridden quite as hard.

On a more superior note, we spent one day swapping bikes, and I switched with an R1200RT, R1150GS, 1st Gen V-Strom 1000 and an 1190 Super Adventure (so tall. so very very tall.) Every time I got back on the Conc after one of the big twins (which I do love), I was laughing in my helmet at how ridiculously suave and sophisticated the C14 is. Seriously refined machine.

Thanks for the replies now, people.

[gPink]

Some folks get phenomenal mileage out of their tires....I'm not one of them. Five to seven K is about it. I'd call the tire toast and move on.

[Hooligan]

Some folks get phenomenal mileage out of their tires....I'm not one of them. Five to seven K is about it. I'd call the tire toast and move on.

I have to agree with"G"......

Oh, and welcome to the forum.....

[jimmymac]

10,000 miles out of a tire?



Peace Brah, I'm out.

[mikeyw64]

Some folks get phenomenal mileage out of their tires....I'm not one of them. Five to seven K is about it. I'd call the tire toast and move on.

Based on pictures on FB most of those (claiming extreme high mileage) are probably the sort of people that think running down through to the wire & canvas is a cool thing to do.

Haven't run a full tyre down on the GTR yet but on the Bird (CBR1100XX)  with an Avon 3D XM fitted I could regularly get between 7 & 8k miles out of a rear (thats down to the TWI) and around 11- 12k from a front

[maxtog]

I just got 18,000 miles on a set of PR4GT and no cords showing.  There are lots and lots of factors that affect how long tires will last.  A lot of it has to do with the condition of the pavement.... in that regard we must be lucky around here (because we certainly aren't when it comes to traffic, weather, debris, etc).

[jimmymac]

I'll bet you're so super smooth with that throttle, you've never got a ticket!
 

[chap]

I get about 12,000km from my PR3's. The front still has wear left but I change in pairs.

Remember the tires wear fast at the end of life, so this may be part of what you are seeing.

Give the bike a quick lookover and put on a new set of tires and see how it drives. If there is something wrong you will likely notice it when you are pulling the wheels.

[mikeyw64]

12,000 km is around 7500 miles and that sounds/feels about right for a rear on a large sports tourer.

On the other hand 18,000 miles (or just shy of 29,000 km) sounds (no offence intended) like a  pile of <insert epithet of choice>

[B.D.F.]

I get excellent mileage out of tires, at least the Pilot Road series, on a C-14. I got just over 16K out of three sets of PR2's, and a similar although maybe a little less, out of a set of PR3's. Not nearly so many miles out of Pirelli Angels (tried both ST and GT) although when brand new, I LOVE Angel STs on this bike. I got 9,3XX miles out of the original Brickstones. And while I use the whole tire, down to about the wear bars, I never, ever get past the rubber; I have never had a streak of tire carcass or belt show on any vehicle since I was a teenager and did not know better / care much / sometimes did not have the dough for tires when I really did need them.

Now I generally ride like Mary Jane Tinklepants and always accelerate, decelerate and brake smoothly. Not a fan of slapping the throttle / gear shifts / brakes ON / OFF and so even when riding fairly hard (Boys!) I try to be smooth. And a lot of my miles are on the highway (motorway) rather than in the twisties; I am the other guy on the planet who does not hate riding a motorcycle on the slab and actually enjoy it.

After having a lot of discussions with others around the country, and the world I guess, and thinking about it for a bit, I think tire wear depends on a few things, some controllable, some not. I live in the northeast US, and do not ride at really high outside temps. if I can help it (80 or maybe 85F is tops for me unless going to an event). And as I ride all year, a lot of miles add up with the temps. under, say, 60F, and a sizeable number below freezing as well. I think this makes a tremendous difference in tire life compared with those riding in the southern US, where temps. swing between hot and extremely hot. Higher temps. are really hard on tires I think. The other thing is that the paving in the south seems to be done with different asphalt than the north  and west of the US. Tennessee is notorious for tearing up tires in very few miles and their road material is usually blamed for this.

I have no idea how things are in the UK other than I do not believe it gets extremely hot or extremely cold there. Otherwise, I have no idea of normal riding types nor any idea of what your roads are made out of. ?? But here in the US, there are people who cannot get 3K miles out of a set of tires and others who can get close to 20K. It does not have to make sense, it just "is". 

Brian

12,000 km is around 7500 miles and that sounds/feels about right for a rear on a large sports tourer.

On the other hand 18,000 miles (or just shy of 29,000 km) sounds (no offence intended) like a  pile of <insert epithet of choice>