Wider Tires & Wheels?

[guzz46]

And because the 140 has a lack of chicken strips it is obviously better?

That depends on ones opinion, the main reason why I went with the 140/70 apart from the whole chicken strip thing, is because it gives you more ground clearance.

 

[jokerio]

What do you base this on?

I would think KTM did some R&D on these things before going into production. Why would they put a incorrect size tire on them?

Because a 150 looks more impressive, KTM even mention in their marketing that it has the biggest rear tyre in the class, the150 has chicken strips, the 140 doesn't.

And because the 140 has a lack of chicken strips it is obviously better?

Well I mean 140 is smaller/less weight/less drag if the traction is still there and you're not using all of the 150, but it's kind of silly to change tire size if you're not racing and there don't seem to be any race tire options in 140.

That depends on ones opinion, the main reason why I went with the 140/70 apart from the whole chicken strip thing, is because it gives you more ground clearance.

To answer Oldvet, the sizing charts I have seen from one or two tire manufacture specifies a 4:00 inch rim requires a 140 section tire. You need a 4.5 inch wide wheel for a 150 to fit correctly. The reason the stock 150 leaves chicken strips is proof its too big for the rim width. The problem I see with that is the more you lean it over the steeper the edge of the tire becomes…. No thanks !

And yes Guzz46, I believe it is all marketing (bigger is better mentality)

Bigsur, I run the pirelli Diablo Super Corsa in a 140/70/17 and are a race compound only available at the track by the race tire vendors (not over the counter)

Guzz46 is correct, it does give you more ground clearance because its taller than the 150, Also, it effects your gearing slightly. It will make your gearing taller…. Probably similar to running a 44 tooth sprocket.

 

[RC390 Fan]

I am on board the 140 train. I can see the 150 is too steep but what about the front? Any options for as better fit?

 

[guzz46]

The problem I see with that is the more you lean it over the steeper the edge of the tire becomes

You're right, I forgot to mention that it also alters the profile of the tyre, here's a brief article on the subject.

Does Size Matter | Sport Rider

Also the promo video where they say "the rear tyre is the widest tyre for this class of bike"

https://www.youtube.com/watch?v=ew9ETVqIJvU

but what about the front? Any options for as better fit?

There's no chicken strips on the front tyre so I believe that's the correct size for the 3.0" rim, a 120 would might fit, but it may have chicken strips as I believe they're generally made for 3.5" rims.

 

[ArkansasDave]

I've seen a 150 rear without chicken strips, maybe you're not going fast enough?

 

[guzz46]

I've seen a 150 rear without chicken strips, maybe you're not going fast enough?

On the RC 390? where about's? I might not be going fast enough (it all depends on who I'm being compared to) but then if that were the case my front tyre would have chicken strips too, which it doesn't.

 

[OldVet]

That depends on ones opinion, the main reason why I went with the 140/70 apart from the whole chicken strip thing, is because it gives you more ground clearance.

Okay this brings me to another question. So a 140 gives you more ground clearance by razing the bike effectively changing the geometry I assume? So do you need to compensate for that by adjusting ride height on the shock?

This thread is getting very informative thanks all

 

[Willasan]

My front is worn all the way to the edge, my rear is only worn to the Pirelli logos. Every other bike I've owned the rear will usually have less of a chicken strip than the front... I think I might try out the 140 this next go around, especially if it's going to give me more ground clearance. Then again, Bridgestone says via their website both the 150 and 140 S20 Evo are recommended for a 4 inch rim...

 

[ArkansasDave]

On the RC 390? where about's? I might not be going fast enough (it all depends on who I'm being compared to) but then if that were the case my front tyre would have chicken strips too, which it doesn't.

At CMRA race weekend, not a super fast rider but faster than me. Next weekend if they show up I'll look at the cup racers tires.

also the not going fast enough was a joke.

 

[guzz46]

Okay this brings me to another question. So a 140 gives you more ground clearance by razing the bike effectively changing the geometry I assume? So do you need to compensate for that by adjusting ride height on the shock?

This thread is getting very informative thanks all

Yes that's correct, from memory the 140/70 gave me 6mm more clearance under the pegs compared to the stock 150, I'm no expert on suspension, but I wouldn't think you would need to change the ride height of the shock (that's assuming you have a shock with ride height adjustment) unless you don't like the way it handles with the extra ride height.
It should also put slightly more weight over the front end, so you may have to back off the rear preload by a notch to retain the same sag numbers, or the weight transfer could so minimal that there's no real noticeable difference in the rear sag, I never measured to see if there was any difference in the rear sag between the 140 and 150.

At CMRA race weekend, not a super fast rider but faster than me. Next weekend if they show up I'll look at the cup racers tires.

also the not going fast enough was a joke.

That would be interesting, pics of their front and rear would be handy too, if people here have chicken strips on their rear and none on their front, then I find it odd how a racer could go to the edge of the 150 without riding off the edge of the front and crashing.

 

[OldVet]

Yes that's correct, from memory the 140/70 gave me 6mm more clearance under the pegs compared to the stock 150, I'm no expert on suspension, but I wouldn't think you would need to change the ride height of the shock (that's assuming you have a shock with ride height adjustment) unless you don't like the way it handles with the extra ride height.
It should also put slightly more weight over the front end, so you may have to back off the rear preload by a notch to retain the same sag numbers, or the weight transfer could so minimal that there's no real noticeable difference in the rear sag, I never measured to see if there was any difference in the rear sag between the 140 and 150..

I don't now, but will have soon as I got in on the JRi group buy.

Thanks for the info...

 

[nino209]

Yes that's correct, from memory the 140/70 gave me 6mm more clearance under the pegs compared to the stock 150, I'm no expert on suspension, but I wouldn't think you would need to change the ride height of the shock (that's assuming you have a shock with ride height adjustment) unless you don't like the way it handles with the extra ride height.
It should also put slightly more weight over the front end, so you may have to back off the rear preload by a notch to retain the same sag numbers, or the weight transfer could so minimal that there's no real noticeable difference in the rear sag, I never measured to see if there was any difference in the rear sag between the 140 and 150.





That would be interesting, pics of their front and rear would be handy too, if people here have chicken strips on their rear and none on their front, then I find it odd how a racer could go to the edge of the 150 without riding off the edge of the front and crashing.

Grey Pham, one of the kids racing in the moto america cup was at my last event at sow, and the alpha 13 he had on the rear was burned all the way to the edge, i think is going to depend on the tire compound,race tire=more grip we all know that, i was running the stock pirelli, and i was not comfortable at all leaning the bike so much, i could tell it got really loose once i got that far.
i will find out in about a week I'll be racing my cup bike in the CVMA series on the alpha 13s, ill post an update.

 

[guzz46]

Grey Pham, one of the kids racing in the moto america cup was at my last event at sow, and the alpha 13 he had on the rear was burned all the way to the edge, i think is going to depend on the tire compound,race tire=more grip we all know that, i was running the stock pirelli, and i was not comfortable at all leaning the bike so much, i could tell it got really loose once i got that far.
i will find out in about a week I'll be racing my cup bike in the CVMA series on the alpha 13s, ill post an update.

I assume he was on the 150? Sure a grippier tyre will allow more lean angle, but that lean angle should be the same front and rear, people have been to the edge of their front, yet they have chicken strips on the rear, so if they some how manage to go to the edge of their rear, then surely they would be running off the edge of their front?

 

[reenmachine]

We had a similar discussion and some examples a while back in this chicken strip thread.

 

[nino209]

I assume he was on the 150? Sure a grippier tyre will allow more lean angle, but that lean angle should be the same front and rear, people have been to the edge of their front, yet they have chicken strips on the rear, so if they some how manage to go to the edge of their rear, then surely they would be running off the edge of their front?

yeah he was on the 150, and yeah for sure the race compound makes a difference, i did not feel comfortable on the Pirelli, i gets really sketchy after a certain point during the lean.
even tho they had really good grip, but once you got to the side it would get scary.

 

[guzz46]

yeah he was on the 150, and yeah for sure the race compound makes a difference, i did not feel comfortable on the Pirelli, i gets really sketchy after a certain point during the lean.
even tho they had really good grip, but once you got to the side it would get scary.

I've got the alpha 13's on mine too, but my point was the lean angle should be the same front and rear regardless of how sticky the tyres are, so if your already using all of the front but still have an unused 10mm strip on the edge of the rear, then if you managed to lean it over further to the edge of the rear then surely you would be rolling off the edge of the front?

 

[nino209]

I've got the alpha 13's on mine too, but my point was the lean angle should be the same front and rear regardless of how sticky the tyres are, so if your already using all of the front but still have an unused 10mm strip on the edge of the rear, then if you managed to lean it over further to the edge of the rear then surely you would be rolling off the edge of the front?

that makes sense, he will be at chuckwalla racing on the 19 also, i will take a look at his front

 

[HermannNW]

are the metzelers m5 the best option? what do you think about the metzelers m7 rr?

 

[HermannNW]

wich trade mark did you buy?

 

[Biker]

Rding in hyderabad, India I always get people especially teenagers wanting to take selfies with this bike when I park!!