Why do my tires wear like this every year???

[Paul]

For as much as I love my Trophy, it is by far the WORST bike I've ever had when it comes to keeping tires on it. Why do they were like this every year? Last year I thought the Battlax T31 GT's would last longer than others I've tried, and I was somewhat correct in that they lasted about a year and a half. But the front has become so unevenly worn that yesterday it felt like it was going to slide out from underneath me. The rear isn't much better, and of course too low of a downshift resulting in a compression skid didn't help matters! (I'm just glad I saw that shiny bit of steel cords before heading out for another ride). I didn't check how many miles I've put on these, but I think it's close to 8500. Was I wrong to expect longer life? Since it's somewhat late in the season now, I ordered a set of Sportmax GPR-300's to get me to by for the rest of the year. Any suggestions on keeping tires on this thing for more than a year or so would really be appreciated!

[Coconut]

One of the best ways to extend the life of your tires is to regularly check their pressures.

While doing so, check the tread depth and check for any damage
or foreign objects ( nails, screws, glass etc etc ) embedded in the rubber.

Most Countries have a legal minimum tread depth, and if the cords have been exposed
it is likely that not only has the bike been ridden in an illegal condition,
but more imporatantly in a dangerous condition !

Running with the pressures "too low" will result in the tires wearing more quickly.

Some Members run the front tire a little higher than the recommended pressure of 36 PSI,
and have reported good results for handling and reduced "scalloping" type wear.

How long a tire should last would not normally be measured in years, but in the miles ridden,
and will depend to a large extent on the riding style, and the composition of the tire being used,
which is a trade off between soft rubber compounds that provides better grip but wear quickly,
and harder compounds that give longer life at the expense of reduced grip.



 

[Paul]

Originally Posted by Coconut

One of the best ways to extend the life of your tires is to regularly check their pressures.

and if the cords have been exposed
it is likely that not only has the bike been ridden in an illegal condition,
but more imporatantly in a dangerous condition !

Some Members run the front tire a little higher than the recommended pressure of 36 PSI,

Thanks for the feedback.
I regularly check the pressures using the TPMS data on the display. I ran the front at 38, rear at 42; maybe I'll need to knock the front down to 37 and see what happens. And as I noted, the cords were exposed only because I downshifted too low yesterday and let the clutch out too soon, which resulted in a momentary lockup of the rear tire (compression skid).

[Coconut]

I regularly check the pressures using the TPMS data on the display.

That may be your problem, and could lead to you inadvertently riding with the Pressures too low.

Page 50 of the Owners Handbook has this Warning :

WARNING
The daily check of tyre pressures must not be excluded because of
the fitment of the TPMS. Check the tyre pressure when the tyres
are cold and using an accurate tyre pressure gauge (see page 140).

Use of the TPMS system to set inflation pressures may lead to incorrect
tyre pressures leading to loss of motorcycle control and an accident.

Page 52 of the Owners Handbook advises :

WARNING
The tyre pressure monitoring system is not to be used as a tyre pressure gauge when
adjusting the tyre pressures. For correct tyre pressures, always check the tyre pressures
when the tyres are cold, using an accurate tyre pressure gauge (see page 140).

Use of the TPMS system to set inflation pressures may lead to incorrect tyre
pressures leading to loss of motorcycle control and an accident.

Page 140 of the Owners Handbook :

Tyre Inflation Pressures
Correct tyre inflation pressures will provide maximum stability, rider comfort and tyre life.
Always check tyre pressures before riding when the tyres are cold. Check tyre pressures
daily and adjust if necessary (see Specification section for correct inflation pressures).
Alternatively, ask your authorised Triumph dealer to inspect your wheels and tyres.

Tyre Pressure Monitoring System (if fitted)
The tyre pressures shown on your instruments indicate the actual tyre pressure
at the time of selecting the display. This may differ from the inflation pressure set
when the tyres are cold because tyres become warmer during riding, causing the air
in the tyre to expand and increase the inflation pressure.
The cold inflation pressures specified by Triumph take account of this.
Owners must only adjust tyre pressures when the tyres are cold using an accurate
pressure gauge, and must not use the tyre pressure display on the instruments.

The images of your rear tire would appear to suggest that it was
quite worn even before the compression skid you described, but I'm not
a tire expert and am only expressing my opinion based on what I see.

To try and stress the importance of checking your tires daily ( i.e. before the first ride of the day ),
how else are you gomg to know that there are no screws etc. stuck in it, or other damage that could
let you down, or that the tread depth is within safe and legal limits ?

Cheers 

[Kiloecho]

At 18,000 miles my 2004 R1150R wore the front tire like yours. The tire installer noticed the front wheel wheel bearing was worn. Replaced the bearing, rode it another 17,000 miles . Gave the bike to my brother and he then to my nephew. 37,000 total miles and no more front tire scrub off. Check and see how your front bearings are.

[Paul]

Originally Posted by Kiloecho

Check and see how your front bearings are.

That's a good idea and something I hadn't thought about. I'll check tomorrow before I pull the front wheel off. Thanks!

[Paul]

As a former ASE Certified Technician and someone who's worked in the automotive industry for over 35 years, it's really embarrassing for me to admit that the rear tire was a LOT worse than I thought. After removing it tonight and cleaning the contact patch, I could clearly see it was down to secondary rubber. I am second guessing whether my low downshift did in fact cause a compression skid based on how far down the tire is actually worn. I will say that the TPMS data on the display has always matched the air pressure readings on my digital gauge, and that of the gauge used at Firestone when I didn't fell like turning on my compressor for a pound or two of air. With that in mind though, and given the fairly small width of wear on the rear tire, I can't help but think 42 PSI is too much, especially for how much the pressures go up riding on hot days. I'd also like to note that I'm not an overly aggressive rider, I don't do burnouts, wheelies, or anything of the sort.

My replacement tires will be here tomorrow, so they'll get dropped off at a local shop to have them installed. I think I'll try the recommended 36 in the front and 40 in the rear. Oh, and front bearings spin freely, there was no play, coarseness or binding felt, so I'm on the fence about replacing those.

[GarminDave]

Amazing a tyre thread that piqued my interest.

I'd go with new front wheel bearings, it's a very small investment for peace of mind and service-free riding.  I actually carry a spare set of bearings, dust covers and circlip because if they fail during a trip it is likely I could find a garage to do the fix, but unlikely they would have spare bearings; even Triumph Dealers sometimes do not have bearings in stock.

Enjoy your ride, and just to add I use either Dunlop RoadSmart III's or Michelin Road Pilot 4GT's and change both at about 8,000 to 9,000 miles.