Bigger (wider) rear tyre

[Kiwi Graham]

The standard tyre width is 150 and I find I'm right on the edge of the tyre on occasion (front is fine) has anyone experimented with a wider tyre? Beliving it will provide more surface area further around the profile on the rim.

I'm considering the new Michelin PR4 trail and they do a 170 section option and thought Mmm.

I do 90% of my riding on tar seal with the odd bit of metal thrown in on the tours I do, I commute on it every day and enjoy a little spirited riding now and again.

Thoughts!?

 

[EricV]

Thoughts? The wider tyre will slow turn in a bit. Perhaps a FZ-09 would be of interest to you?

I've seen it done on other bikes like the FJR. It doesn't really change what you're hoping it will, the bike is still rolling over to the edge of the tire and the difference in contact patch is virtually nil.

What pressures are you running, and what tyres?

 

[Kiwi Graham]

Hi Eric,

Standard OEM tyres on recommended pressures..

In my Supermotad days we used to oversize the rear tyres to give more side grip (an over size tyre pulled onto the rim drags the profile of the tyre down the sides more.and am aware of the slower turn in but with such wide bars it is going to be very neglidgible. I could increase the contact patch by dropping pressures I suppose but dont want to stress the carcass and over heat the tyre.
I run an R1 Superbike at club and National level and run a 200 section tyre for similar reasons (Pirellie's at 24 psi rear) but its only good for 25 laps ha ha

I'm guessing but looking at clearences I think there wont be an issue between tyre and swinging arm/shaft drive, just wondered if anyone else had tried it.

 

[EricV]

I would agree about the clearance. I suppose I'm just thinking the S10 is not really the tool for the job if you're using it all and concerned enough to consider the wider tyre. No harm, no foul. I just don't choose to ride the S10 quite that hard on the street.

 

[Rasher]

I found may dual sport tyres have a flatter profile, I get much closer to the edge of tyres like Tourances than I do with things like the Roadsmart 2's I now run, maybe a 160 would be a better bet if you must change size.

 

[Firefight911]

Adjust the rider. Tire change will not help.

Change your lines and adjust your body positioning to maximize the available contact patch. Moving your upper body forward and toward the inside of the turn and get your weight off the bars. Adjsut your footbpeg weighting.

Get the right tool for the job.

 

[Kiwi Graham]

I would agree about the clearance. I suppose I'm just thinking the S10 is not really the tool for the job if you're using it all and concerned enough to consider the wider tyre. No harm, no foul. I just don't choose to ride the S10 quite that hard on the street.

Hi eric,
I hear what your saying and take no offence
The S10 is the least sporty bike I have ever run on the road but it is still an extreamily capable bike and one that ticks the vast majority of my boxs so to speak;
A good every day commuter bike
A comfortable one up day ride scoot
Despite its weight and my limited experience good on the dirt/metal too
A Phenomenal tourer two up with luggage
And yes a very capable bike to have a play on too.

I chose the S10 after a day riding one with my wife on a recent tour we did, We were on a Tiger 1050 and swapped rides for about 300k's. We both loved the comfort and mile munching ability of this bike and I was very prepared to loose some of the sporty aspect of my road riding in order to gain on these aspects. However I was supprised to find (as I have got more used to it) that it is no slouch either and was just asking if what I perseve as a potential limiting facter being the tyre geometry had been experimented with.

 

[Kiwi Graham]

Adjust the rider. Tire change will not help.

Change your lines and adjust your body positioning to maximize the available contact patch. Moving your upper body forward and toward the inside of the turn and get your weight off the bars. Adjsut your footbpeg weighting.

Get the right tool for the job.

Hi phil,
Fully aware of what ride inputs are required to go round corners and there is nothing wrong with the tool, just considering trying to improve it for my purpose.........a bit like the off road guys changing there tyes to suit there purpose
You say a tyre change wont help, how do you know/ have you tried it/

 

[Firefight911]

Hi phil,
Fully aware of what ride inputs are required to go round corners and there is nothing wrong with the tool, just considering trying to improve it for my purpose.........a bit like the off road guys changing there tyes to suit there purpose
You say a tyre change wont help, how do you know/ have you tried it/

My engineering prowess, just a guess, isn't on the same level as Yamaha's. That and many years racing pro level (ARRA, WSMC, WERA ('90 Grand National Finals)) for Vance and Hines revealed a nugget or two along the way. But, you are correct, I have not done it on the Super Tenere.

 

[Firefight911]

I would challenge your logic of a larger tire giving a bigger contact patch......as would some tire manufacturers......

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=1&cad=rja&ved=0CCYQFjAA&url=http%3A%2F%2Fwww.avonmoto.com%2Fdownload%2FTires101forConsumers.pdf&ei=HLvhUuy1G4aFogSgpoHgAg&usg=AFQjCNEXwcYD5b9Ph9C6DSY1hp0k1U8hKg&bvm=bv.59930103,d.cGU

I'm not dealing in absolutes but I would challenge your gaining any worthwhile gains in changing any tire size. There are so many other variables that need to be taken in to consdieration. Even BMW offered as an option a new rim for those who wanted a larger tire on the K1200RS line. The net result ended up being a slower turn in.

Are you sliding the tire now? Just because your wear is to the edge does not indicate necessarily that you are at a reduced contact patch. Again, there are so many other variables to be asked and considered. As you indicate one, tire pressures.

So, what have you done to your suspension? Is it up to snuff for your weight? I guarantee it is not up to snuff for "sport" riding. That has been tirelessly (pun intended) and repeatedly posted by me and several others.

 

[Kiwi Graham]

Hi Phil thanks for the feedback and kudos for the experience you have.
As you clearly know reducing pressure in a tyre will increase the contact patch at a cost to longevity but I'm sure there is an option (for a road rider) to change the profie of a tyre to gain a small gain in that contact patch.

The profile of a 150 section PR4 (being a totaly diferent type of tyre) may provide that in this case in which case no worries (see pic) with my question being fitting the next size up in width would it not pinch in the side walls increasing the available 'treaded'area on the side of the aspect ratio.

yes I've had a couple of slides but nothing that threatened to get out of control just the indication that there was no more grip left hence pondering the option

 

[Firefight911]

If you want to explore a possibility try going with a lower aspect ratio. Say a 60 series versus the stock 70 series.

 

[autoteach]

If you are working the edge of the tires and dont have updated suspension, you should consider that first. Setting up your suspension and sag and ride heights is going to help utilize the tires' contact patch, and putting some money into the suspension valving is going to utilize the grip provided to a greater degree. Changing the tire to alter handling prior to doing suspension is a waste of time.

 

[Kiwi Graham]

If you are working the edge of the tires and dont have updated suspension, you should consider that first. Setting up your suspension and sag and ride heights is going to help utilize the tires' contact patch, and putting some money into the suspension valving is going to utilize the grip provided to a greater degree. Changing the tire to alter handling prior to doing suspension is a waste of time.

Hi Autotech,
Thanks for the reply.

I have set the sag/ride hights according to my weight but your right in saying the stock suspension is a limiting factor and I too am an advocate for spending money on suspension upgrades over anything else to improve performance.
Here in NZ we have an excelent Ohlins tech who looks after my race bike suspenders and would be more than willing to help on the S10 but I haven't over run the current stock (all be it set up) suspension yet and dont think (I will).
The peg isn't touching down indicating that the suspension is running close to this (although I do admit the springing is on the soft side) but the tyre is running out of grip. its not upseting the bikes handling as such and gives you plenty of feedback it was just a thought I had putting out there if anybody else had experinced this and tried a wider profile tyre.