brakes 79 750 and bigger rear tire

[yamahafella03]

ok so i wanted to get a bigger tire cause on my 79 750 there is only a 110 and you can only lean so much on such a thin tire, so i was planning on getting a bigger one but i cant. the biggest tire i can get is 120 or maybe a 130 but it'd be a tight fit. the retaining bar that holds the caliper on is in the way cause its a massive bar, does anyone no how to get a thinner bar or something so that i may have a 130 tire?? thanx

[tkent02]

You can lean as far as you need with a skinny tire, these bikes could certainly drag everything thirty years ago, tires are much stickier now. To go wider requires a bigger wheel, probably a different swingarm, and you have two wheels to think about...

[JHawkins]

ok so i wanted to get a bigger tire cause on my 79 750 there is only a 110 and you can only lean so much on such a thin tire, so i was planning on getting a bigger one but i cant. the biggest tire i can get is 120 or maybe a 130 but it'd be a tight fit. the retaining bar that holds the caliper on is in the way cause its a massive bar, does anyone no how to get a thinner bar or something so that i may have a 130 tire?? thanx

I have been running a 130 rear for the past few years, no rubbing, no problems at all on a 79 750L. I was under the impression that most folks run a 130 on the rear.

[tkent02]

I have been running a 130 rear for the past few years, no rubbing, no problems at all on a 79 750L. I was under the impression that most folks run a 130 on the rear.

"L"s came with fatter wheels and tires because they were thought to look cool by the geeks in Marketing.
Although the Engineering Department said it would make the bike handle like crap, Marketing prevailed.

[JHawkins]

"L"s came with fatter wheels and tires because they looked cool.

Ahhh, that explains it then! Yes, I must admit the L's do look much cooler, finally someone admits it! hehehe


/me ducks and hides from all the "L" haters!

[yamahafella03]

i understand you can lean as far as you want but if you hit the edge of the tire then you probably wont be riding for long. and a 130 would fit minus the brake caliper retainer bar but yeah idk

[tkent02]

i understand you can lean as far as you want but if you hit the edge of the tire then you probably wont be riding for long.

True on a fat tire as well, and at the same angle.
A fat tire on a skinny wheel will not stick as well as the proper size tire for the wheel.
With the beads pinched together, the whole thing isn't shaped right.
A stock GS can't get to the edge of a decent modern tire, too much of the bike scrapes the ground first.
I've been riding quite a while, thank you.

[yamahafella03]

if i got a bigger wheel and a tire to fit then wouldnt it make it better or no?? or would sticking with a 110-120 be best bet

[GSBuilder]

You can lean as far as you need with a skinny tire, these bikes could certainly drag everything thirty years ago, tires are much stickier now. To go wider requires a bigger wheel, probably a different swingarm, and you have two wheels to think about...

Yes, you can lean on a skinny, but a fat tire with larger contact patch means more grip... Or do those silly MotoGP, Superbike and other racers just want more unsprung mass by going wider.

[Skievryday]

Missing the point

Tkent's point is- where is your exhaust?

Look at a pic of a GSXR or R1 or any of that. The bike is shaped like a V so that the underbody is extremely narrow and until you get to the cases it remains narrow. This allows the bike to close to the width of a thigh away from the ground. GP bikes. Knees touching ground, blah blah.

Now look at a GS. Your foot pegs will certainly touch down before you get that far out. Exhaust, magneto cover, etc. So the skinny wheel works because you probably will still be chicken stripping it.

Face it... if your tire has any more than 1" on each side that is not worn down then you probably don't need a fatter tire.

[tkent02]

One more thing, the modern bike has what, three times the torque to spin up a rear wheel?
That modern bike needs a fatter tire to help control all that power.
And yet, both in the seventies and today a tiny little sport bike with skinnier tires will still outcorner a big powerful one.
The bigger models then as now had wider rear tires than the smaller ones, with today's tires being so much more sticky than what these bikes were designed for going wider just isn't necessary.

Back when these were made, the chopper shows on TV with the grotesquely wide rear tires were not around to influence the public perception of what a tire should look like.

[GSBuilder]

Tkent's point is- where is your exhaust?

Look at a pic of a GSXR or R1 or any of that. The bike is shaped like a V so that the underbody is extremely narrow and until you get to the cases it remains narrow. This allows the bike to close to the width of a thigh away from the ground. GP bikes. Knees touching ground, blah blah.

Now look at a GS. Your foot pegs will certainly touch down before you get that far out. Exhaust, magneto cover, etc. So the skinny wheel works because you probably will still be chicken stripping it.

Face it... if your tire has any more than 1" on each side that is not worn down then you probably don't need a fatter tire.

I'll agree with that, if your bike has all stock hardware in all stock locations forget a fatter tire.

[Steve]

if i got a bigger wheel and a tire to fit then wouldnt it make it better or no?? or would sticking with a 110-120 be best bet

There have been reports of success in fitting a wider wheel, but be aware that you will have to also juggle spacers, sprocket offset and caliper location with the new wheel.

Yes, you can lean on a skinny, but a fat tire with larger contact patch means more grip... Or do those silly MotoGP, Superbike and other racers just want more unsprung mass by going wider.

Yes, they have much wider tires, but I'll bet anything they have wheels that are wider, too. Most of our GS wheels are no more than 2.5" wide.

One more thing, the modern bike has what, three times the torque to spin up a rear wheel?
That modern bike needs a fatter tire to help control all that power.
And yet, both in the seventies and today a tiny little sport bike with skinnier tires will still outcorner a big powerful one.
The bigger models then as now had wider rear tires than the smaller ones, with today's tires being so much more sticky than what these bikes were designed for going wider just isn't necessary.

Any good tire on the proper-size rim is going to work relatively well. The tires of yesteryear were good enough to let these bikes drag hardware easily and comfortably. With today's tires, it's even easier, so hardware is your limitation, not your tires.
Then, as now, a good 600cc bike will likely outrun a 1000cc bike around a tight road course. Yes, they have smaller tires, but they are not asked to do as much, either. Less power, less weight, smaller tires are OK.

Although you might be able to fit a larger tire in the swingarm, you have to consider that squeezing it onto the relatively narrow rim will tighten the curve of the tire's profile and likely decrease the size of the contact patch. If you plan on going gonzo in the corners on a regular basis, it is a simple matter today of choosing performance-oriented tires with optimal grip. Your hardware (footpegs, exhaust, etc.) will still be your limiting factors.

.

[80GS1000]

Meh, I have no chicken strips on my GS which has a 120/180 combo of modern sportbike radials on it. Wide radials make for a smoother, more stable ride at deep lean angles. More contact patch = more grip. A GS on even good bias rubber like the Pirelli Sport Demons is squirrelly at full lean compared to a Pilot Power radial shod GS. You feel like you have lots more real estate to lean over on.

If you have the time, skill, and inclination to put wider wheels, brakes, and tires on your bike, go for it. You'll need to change your steering geometry to take advantage of it.

[Mark M]

Yes, you can lean on a skinny, but a fat tire with larger contact patch means more grip... Or do those silly MotoGP, Superbike and other racers just want more unsprung mass by going wider.

Correct, but they also run 6" rims. You cannot force a big tire onto a skinny rim without compromising it's profile. That limits your lean angle as effectively as anything else. If you take the same model of tire (same brand, construction and compound) in two different sizes, the correct size for the rim will perform better.

And you did know that the superbike and supersport racers have put 180's on the rear for years in place of the stock 190's because they handle better and result in lower lap times? Wider is not always better.


Mark