Just wondering what the general consensus is about running a 120 rather than the spec 110 tyre on the front rim?
Safe to do so? Does it depend on the quality of the tyre?
Mine came with a 120 on it but it looks like it's pushing it...

 

My 1989 f-j came with a 120/70/17 on the front and I think a 150 or 160/70/17 in the rear, (Metzlers), it felt like it was flopping into corners and was white-lining, I went back to a pair of Conti's standard sizes 110/80/17 in the front and 140/80/17 in the back, miles better, tracks through corners better and no white lining.

I've always stayed with standard sizes over the last 40 years with bikes and for me the manufacturers set tyre sizes for a reason, although I have experimented with different makes, unfortunately I've only found these standard sizes in Conti's, Avon's and Bridgestones.

Hope this helps, just my 'umble opinion.

Cheers, Steve

 

I'm running standard size Avons on my Gen 1 and have no problems at all as far as handling / cornering goes... my tyre guy flatly refuses to fit anything over-sized (I've asked in the past)

If you're thinking about a wider range of tyres, it might be a good idea to convert to Gen 2/3 wheels ....

 

very bad idea , you will change the profile of the tire and it will not perform as intended, as Shakey said, make the bigger wheel conversion, it is not that expensive and way safer.

 

I'm running a dunlop q2 120 70 17 on my stock 87 rim and while it handles/feels fine I would not run it again. The profile just seems a bit off. i actually had to take a 160 off of the back because the profile was scary.

 

Well I just took my 87 out to scrub a set of Conti Motions with 120 up front - 150
down back - no f'n chicken strips left

I'd say no farking problems matey's

This bike (Gen one) is one nimble m'fer and goes like a hot snot off UV a sheet of wax paper

BTW PCMG thanks for the fuel line - worked out to be the *****

But I should mention - these Conti Motions have a great rounded profile - compatible with
squeezing onto a narrower rim imo.

After 50 miles I was able to lean the BeJayus out of her - down right to the point of getting
a knee down - I love the ease of turn, lightness & nimbleness of the Gen 1 + this one hauls
*** big time

 

Sounds like I need to man up

 

U - never

Funny tho

Different brands of tires do different things depending on profile
imo if you are going wider than spec on a rim - then up the profile
as much as possible to get the tread pattern/shape to round out properly.

Telling ya after you said stick to 150 at most PCMG - glad I did

The bike is a pure hoot & joy to go bombing around the back roads
here - doing twisties at 75 - 80 no sweat & the stiffer fork springs
Mega 's no dive or wallowing - totally planted and precise steering
with the rear totally holding the line - complete control Karma

 

Sprock do you really notice the weight difference? You should send me a pic of your line maybe I'll have to switch mine.

 

No prob I'll send a pic in the am - yeah forsure big diff in weight - felt like I was whizzin'
around on a new 600 - took her out on 95 - had to roll off at 125 .....lol

Running like greased lightening - but have to figure out a low rpm stumble at 1700
rpm to 2100 rpm - think the pilots are dirty ! - hopefully seafoam will eventually
shine them up tho' probably needs sync and balancer adjust and I notice the valve
cover has never been off - soon valves need checking first.

Think I'll throw a set of stick coils in this too !

Anyhow I'm Thread Jacking here - so suffice as to say - IMO - 120 .......no sweat
depending on tire Brand that is and I'd recommend these Conti Motions on a Gen 1