The Honda PCX / Forza / ADV150 / SH Forums

Those tires are anywhere between 3-5lbs heavier each per tire. The feeling of stability you're encountering is from increased gyroscopic effect from the heavier tires, which is a negative effect. The increased gyro effect with the heavier weight tires will also help keep the bike slightly more upright in heavy winds, but I can assure you, no matter what, you're not going to get blown over. Performance junkies that race all value lightweight components, especially when it comes to rolling weight. You have few options regarding performance rubber, but really, this is not the bike to be attacking the corners with. Regarding swerving and emergency maneuvers, the lighter weight rubber is going to help to some degree...but with a bike this light, it's not going to be a deal breaker.

@Whitenoise
Your maturity is encouraging, I shall respond in kind.

First, sadly I missed Mgalutia88's original application - old eyes and brain - and offer apologies. But I stand by the stated consequences had that been the case. Even so, experience has taught me that varying more than 10mm from OEM specs almost always has more negative than positive resutls.
My paltry knowledge of motorcycle tires derives from 40 years of changing my own - and fellow rider's - tires and wheels, learning more every day. Despite changing, oh, surely several hundred sets of tires, and enjoying discussions with friends of the BMW forum - some of whom are engineers, I like to think of myself as a trainee.
Tire choice is always a compromise, as I am sure you know. And manufacturers spend vast resources matching wheels and tires to a machine. We have no hope of bettering them at this, but I have seen people try repeatedly. Usually claiming that they succeeded.
When a friend wants to change the OEM profile, I always ask two questions: "What is defective with the current profile?", and, "how will the new profile correct the problem?"
In only the most adverse riding conditions - not intended by the manufacturer - are profile changes generally fruitful. Doing so is usually a solution in search of a problem.

beos59 wrote:120/70 front and 140/70 back seems to be pushing the limits. Is there some alternatives in between this extreme and the standard 90/90 and 100/90?

I think Michelin makes a 110/80 "rear"... other than that most 120's are "front only"(I think the Avon Stryke are the same tread pattern front and rear... they come in a 120...).

The US is very limited with 14 inch "PCX" size tires... But since Burgmans etc. have a 120 front and 140 rear those sizes are more plentiful.

As a follow on to my above post:

Regarding fitting 140 and 120mm width rubber, and benefit you gain from a grippier rubber compound will be negated in confidence lost in an inferior tire profile as a result of squeezing too much rubber on a narrower rim.

Those who do fit the wider rubber, feel free to post up your impressions and how much it's affected your acceleration, or speed going up hills, especially up grades on the highways.

Nice post Tribpreper. I agree. I'm a certified motorcycle technician, MMI grad from 1996 and worked in every position in the dealership(sales, parts mgr, service writer, technician), as well as doing tech support for a major aftermarket motorcycle parts supplier to the country's largest distributor...Parts Unlimited. I also worked at several automotive tire shops and managed one of those. I've seen a lot of dumb things. Heck, I like to experiment myself to some degree with tires. I even put a 160mm tire on a sportbike that came with a 180mm tire because I wanted to 2-3lb weight savings because I was using it for stunts (wheelies). It stretched the tire in such a way that if I tried to lean the bike over all the way, it would have no tread left and slid out. Some called me stupid, but I could clutch up my zx-6R in 3rd gear with OEM gearing by using weight reduction and removing one of the two front brake rotors and calipers. I had my 636cc sportbike lighter than a 250 ninja. And yet people called me stupid, and said it was dangerous, even sticking to that argument when I showed them the new 900cc Kawi and yamaha cruisers that weigh nearly 700lbs and come with only a single disc front brake, the same size as my disc at 300mm.

You can really NEVER benefit from a wider tire unless a wider rim is used.

A 140mm width rear tire really needs to be run on a 4.0" rim at a minimum btw. In rare circumstances, a tire is specifically designed for a narrow rim. Dunlop did it for the VFR 700 back in the day by creating a 160mm tire for a 3.5" rim. The sidewall was designed in such a way so as no to distort the tire profile. But that is the only exception that comes to mind.

All that said. THose who are running a 140, if you like it and are willing to deal with the pros and cons...to each their own. =)

There are several alternatives in the michelin city grip, however, not in the pirelli diablos. In the Pirelli's this is the next size up.

Hey scooterman so we agree on weight reduction... but not tires

see my original post on wider tires http://www.hondapcx.org/viewtopic.php?f=9&t=680

I love my wider/bigger tires and will never go back to a stock size, they just plain work better than stock.
Performance losses are minimal if any... its still just a scooter not a sportbike.
Sure I would like a wider rim(3 inch maybe), but those don't seem to be available.

Yeah to each their own... so don't tell some one "you'll have that 140 off in a week"...

My rear is mounted and ready to go on. I'll have it done this afternoon.

Hey Dasshredder, what did you do to make the rear clear easy again?

Mgalutia remember I don't have a stock fender... ask Kramnala, I think he just lifted the stock inner fender with a ziptie.

Just so we're clear, I'm not a hater of guys who put wide tires on narrow rims, just wanted to make you aware of the consequences of doing it...that's all. I wouldn't do it myself, and DemonK1d has already said that he lost "power" with the wide rubber as it adds 3-4lbs per tire.

There is a company that widens OEM wheels, called Kosman. Not sure if they still do it. They were popular with racers back in the 80's when motorcycles all came with skinny wheels. They are extremely pricey though and doing a set cost around $1000 at least. Not worth it in our case.

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saw a gold wing with a car tire yesterday.
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Wondering what size car tire might fit the PCX ??
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Mgalutia88 wrote:... what did you do to make the rear clear easy again?

Yup, I'm the guilty one who raised my rear fender for a bit of clearance. I had replaced the stock breather with a canister one which meant that there was a bolt hole on the fender where the stock breather had previously attached to it. I put a zip-tie through the bolt hole and fastened it to the frame above. It gave me an additional 1/4" to 3/8" clearance.

I really don't understand. Is it ok to put on bigger tires or not? To much confusion going on and I'm not that technically savy regarding my scoot.

Steph, lots of opinions here. Some members are considering sizing up, some willing to size up and some have already sized up their tires. Me, I worry first about safety. IF ALL was good, I'd go with wider tires. I think I've read that going up 1 size might be okay (safe). But....
I don't think we'll have a meeting of the minds here. They'll be no set answer. Our Ages, experience, level of risk taking, & personalities all factor in.
It's Simply This: To each his own (boring over used statement) but true.
One does as one wants. Stay @ stock tire sizes or go big(ger). Bigger Sound scary? Don't doit

I'll be here, I'm still curious and the heats picking up!

@ GeeGusKahn, the cookie part? So funny!

This topic reminds me of a staged photo I took not long ago.
"Before and After"

So the rear is on and it rides nicely. I'll post pics next but first...
I removed my inner rear fender as I was already cracked from a previous oil catch tank that was mounted above it and was hitting on it on bumps. A new inner fender is $5 from honda. So currently I have no inner fender on the bike, just the rubber curtain that hangs from the seat bucket.
I did have an issue with the airbox clearing the tire. I addressed this by purchasing 6mm x 35mm bolts (10 mm longer than stock) to mount the airbox and spaced it with 4 m8 lock washers on each bolt between the airbox and the mounting holes as spacers. Perfect

The tire tits barely rub the engine case so they'll be worn off in a jiffy anyway.
On to pics

So here you all are. Is there a way to aim the headlight without shimming the mounting holes?

Steph wrote:I really don't understand. Is it ok to put on bigger tires or not? To much confusion going on and I'm not that technically savy regarding my scoot.

Put a set of standard size city grips on it. Job done.

I'm not going to lie, after all that talk I did about distorting the tire profile, it really looks as if this tire was made for the PCX's narrow rim. In this case, the only tradeoff would be to added weight of the tires, which is significant enough to slow down accel noticably, as well as top speed on flats and especially up hills. But if you were one who lived somewhere where there were lots of corners that you liked to attack, then maybe this is the mod for you.

Anyway, thx for the pix and for clearing up the debate a bit. That last pic is the money pic. =)

WhiteNoise wrote:Me, I worry first about safety. IF ALL was good, I'd go with wider tires. I think I've read that going up 1 size might be okay (safe). But....
It's Simply This: To each his own (boring over used statement) but true.

Not boring at all, such is the pillar of freedom. Say, dress, be as we wish. And if another chooses not to accept us for being so, we must respect that choice also.

Consider this: altering a vehicle's safety equipment invites insurance companies to refuse coverage in the event of an accident. Furthermore, even were that not the case, there are millions of "victims" on the road looking for an excuse to file suit. If the vehicle inspection turns up equipment drastically out of manufacturers spec, that is the door they are looking for. Even if they don't win the case, defending oneself could be devastating financially.