The wife had a 170/60-17 Conti Attach on the bike when we purchased it and now has a Conti TKC 150/70-17 on. We had to adjust the chain out to fit the TKC to compensate for the knobbies.


And I agree Tony, here in LV it hardly rains, so when it does it's slick as snot. Last week there where about 50 wrecks before 9am.

 

So I have a new 160/60 tire I want to put on. What do you think a bike shop would charge to put that on for me?

 

The KTM 390's feature a 4.5" rear rim, the same size as the competitive bikes from Yamaha, Honda and Kawasaki. All of those bikes come with an OEM 140/70 rear tire. The KTM's come with a 150/60 rear tire. Why? Because it "Looks Better" (ie more macho). Marketing, not performance. What happens when you put an oversize tire on a rim optimized for a smaller size? The bigger tire must be pinched in order to fit, resulting in a distortion of the tire's designed profile. Consequence: At high lean angles the bigger tire is unable to put down its full, designed contact patch because of this distortion. The tire makes contact with the road in a shape the designer never intended. The illusion of an "extra contact patch" associated with a bigger tire is simply nonsense. The much-discussed "chicken strips" apparent on the rear tires of most 390's with the OEM rear tire are clear evidence of the smaller contact patch the oversize tire is able to put on the road.

The correct tire size for the 390's rim size, as the Japanese engineers unanimously demonstrate, is 140/70. This size requires no pinching, no distortion to fit on the rim, and therefore its profile is able to run as designed. It should be no surprise that the 140/70 is therefore able to lay down a larger contact patch than the stock 150/60. No chicken strips. The majority of the RC racers have already switched to a 140 rear. They are seeking ultimate performance.

Perhaps oversize tires may have some benefits if most of your riding is done offroad. But if pavement is your venue (The Duke is Cycle World's "Best Lightweight Street Bike" of 2016), then your optimum tires sizes for performance are 110/70 front, 140/70 rear. Bigger tires are simply "style over function" fluff and will degrade performance.

 

I guess I should have asked... How much did your local shop charge to change out the tire?

 

My shop charges $30/wheel if I buy the tires from them. They do it for $20/wheel if I just take them the wheels.

 

I do tire changes myself, at home. It takes only about 3 tire changes to amortize the cost of the necessary equipment.

Most shops will charge something in the neighborhood of $50 to change a tire.

 

Do you think that's me removing the wheel from the bike or me just taking the whole bike up there?

 

Obviously, if you just bring the bike to the shop and ask them to change the tire, the shop will have to dismount the wheel. If you do this part of the job yourself and just bring them the wheel, the job will take fewer man-hours and they should charge you less.

 

So I did fit a wider 160 Michelin Pilot road 3 tyre the other week : mainly because I wanted to try it and looks better . My initial findings . I ran 200 Km with them of which a day when it was raining pretty heavily . Ok , the turning in is somewhat compromised compared to the 150 size but I feel you can apply earlier the power coming out of the bends . I certainly has it's pro's and con's . We'll see what it sums up to in long run .

 

Trimapa. Let us posted about your impression since It can be valuable at the next replacement.
Luis

 

Not sure about you guys in america but here in oz 90% of bikers would get passed by car drivers in the corners so fitting a 340 rear tyre would make zero difference to getting the power to the ground.

If it looks tough and thats what you like then fit that bad boy

 

Ok, so 140 is about ideal and 160 is too much.
What about going one size down?
Is 130/70/17 feasible?
Circumference-wise, it's almost identical to 150/60 (unlike 140/70).

 

Okay to sum everything up! You could fit with stock rim and swing arm a 170, stock the bike comes with 150, some have selected the 140 so it could look like a bicycle with a lawnmower engine. To each there own
Sense the original post was asking what the largest tire you could fit, the answering being 170. To continue with that topic. Is there a different bike swing arm ..... maybe 690, or 1290 ..... that could be transferable to the Duke 390. So that we could fit a bigger rim and tire?

 

i read through the thread and found it very interesting. I'm ready to replace the stock Rosso II on my duke 390. This will be my third track day, and most likely 3-4 more this year. I also squirt around the local twisties on the weekend and take the bike to work which is also through hill country. Point is, I don't commute, or do long rides.

i found the concept of going down in width convincing as far as increased performance. I still have 1/2" chicken strips on the 150/60 in rear while scraping pegs. I also get a non-confidence inspiring wiggle in the rear during aggressively turn in. Putting the suspension in the stiffest setting helps with bite, but i can feel it.

so i'm shopping tires for track use and occasional street. No one has really mentioned anything about availability. I was going to get the rosso corsa but the smallest rear is 160/60 and its not cheap if ends up too fat and doesn't handle well. Not many sport rear tires in the 140/70 either, but I did find a 'race' tire Michelin Power RS in the 120/70 and 140/70. The new Rosso III which is getting rave reviews comes in 150/60 rear and reasonably priced, but no 140/70.

so go with cheaper race option at risk of short life span but better handling, or go with the safe Rosso III that should handle as well, if not better than the IIs, and live with the chicken strips? Going with the fatter sticky Corsa seems like a waste of good money.

 

Installed Michelin Pilot Street 140/70 today. I don't do track days just aggressive commuting to work. My main priority is longevity since I am cheap. I will post an update in about a month to share my thoughts.

 

Michelin Pilot S5

Very interested in your experience on this tire.

 

The pilot street 140/70 is stock tyre in Thaikand.
I got DUKE 390 year 2017-8 since 3rd Dec'18.

My front and rear tyres are Michellin Pilot Street Radia. They were made in 47th week of December 2017. Therefore, they are not as soft as newer tyres.
! I am considering tyres change soon and have Timsun tyres in mind as I use TIMSUN ??????????????????????????? Timsun ?????? on my Ducati Scrambler ICON and TIMSUN OAsis ??????????????????????????? Timsun ?????? Honda PCX 150. They are very grippy and soft.

I am not going to use bigger tyre size.

 

The pilot street 140/70 is stock tyre in Thaikand.
I got DUKE 390 year 2017-8 since 3rd Dec'18.

My front and rear tyres are Michellin Pilot Street Radia. They were made in 47th week of December 2017. Therefore, they are not as soft as newer tyres.
! I am considering tyres change soon and have Timsun tyres in mind as I use TIMSUN ??????????????????????????? Timsun ?????? on my Ducati Scrambler ICON and TIMSUN OAsis ??????????????????????????? Timsun ?????? Honda PCX 150. They are very grippy and soft.

I am not going to use bigger tyre size.

What difference do you expect with other tires? Better breaking? Lower and faster in corners? ...?
I have the original tires and I am happy with them. But I know I am not going with the bike anywhere near it's limits.

 

on duke I hope for grips and traction.

on scrambler it was simply for faster cornering as PIRLELlI MT60 is vert flat at centre of tyre and therefore slow cornering.

 

It really comes down to whats comfortable for the rider. Everyone prefers different things, but just as long as they feel comfortable riding I think that trumps having big chicken strips. A confident driver/rider is a safer one in my experience, and comfort plays a huge roll in that.

I just went from Michelin Pilot Street 110/70 & 150/60 to Dunlop Sportmax D222 120/70 & 160/60. It feels a lot more stable and I dont have to turn my front wheel left and right at creeping speeds just to keep balance. I probably wont see the track with this bike but if I do I'm sure I'll be able to run faster times with these Dunlop dual compound rubber.

Plus, I think the bigger tires look better. But to the untrained eye it probably looks the same cause no one gives a sh*t.. really.

 

Nope too big of a rear will end up pushing your front end when exiting corners... don’t go over a 165 on a 390. Your just a looks boy if you go bigger. Go get a corvette to sit in and look good.

 

KTM is known for their off road dirt bikes, and the 390 certainly has some dirt bike character, I think more so than a crotch rocket. It would look better with knobbies than a fatty IMO.

 

The bigger tire issue has been discussed on here to exertion with the conclusion (from people that know, not think of feel) the rear rim is best fitted with 140 max.
The reason is that the whole of the tire profile is used as meant.
Even the 150 as delivered as stock is too wide but for show reasons been put on.
If not mistaken most of the RC racers use 140 on the track.
Love the "creeping speed" remark ha ha ha

 

That's good to know. Suggest going one size down up front as well?

 

Have to say that the bike does look better with the wider tyres

 

Managed to order a set 140 - 110 of the Pirelli Scorpion STR's to replace my MT60's in January/February 2021.
These seem to perform even better with less road noise and vibrations on tarmac so happy the Thai import was willing to order me a set in this 17" size in their new batch.
@mikey 100% true, then again if someone asks for pro's- and cons they have been given.
If your preference is looks over riding so be it.

 

Ya'll put 110 and 150, me on the other hand 90/90 front and rear 130/80.

 

Can't find the thread where someone asked to put a pic on my front fender modification in order to accommodate the Pirelli MT60 tyres so will post them here.

 

Anyone else here who thinks the duke would look better on bigger rear tires?

I think the rear tires look really slim looking at the bike from behind.

The stock rear tire size is 150/60 but it looks like the swing arm has enough space to add 5mm on each side. Maybe this would be enough space to fit a tire size 160/60.

Any thoughts? Would this be possible?

Shinko big block 👍🏻

 

Hi, Could you illustrate how I modified the fender?

 

With regards to tire size greater might be a new pattern, however that doesn't mean it's ideal for each driver or vehicle. Most new vehicles are outfitted with 16-to 18-inch tires. In any case, secondary selling hefty estimating builds wheel measurements from 1 to 8 crawls past the first tire size.