Yamaha R3 Forums banner
1 - 15 of 15 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter · #1 · (Edited)
Bought the bike in June 2018, finally got around to replacing the stock tires with and OH MY GOSH is there a difference. I've ridden on and off with different bikes in the past, but never tried for any replacement tires other than what originally came on the bike. I put on Pirelli Angel GT II's and after riding for the last couple days, I am loving it.

I haven't noticed a huge a difference in the torque yet, but it is slightly less flickable than it was before. With that being said, leaning in feels a lot less squirrelly in the back that it did before. I also adjusted the preload from 3 to 5 so that may have made a difference as well.

Overall, very satisfied in the short term with the tire-size increase. Once I break them in more, I'll really put them to the test in a couple mountain runs?

***edit : It has been brought to my attention that I failed to ever mention what tire sizes I swapped the stock setup for :rolleyes:.
120/70/17 int front.
160/60/17 in back.

Thank you @adamedunn for pointing that out.
 

Attachments

·
Registered
Joined
·
11 Posts
Discussion Starter · #3 ·
I'm not understanding. Did you increase width? If so, what width did you go with? You don't list a tire size.
Not sure how I got through that whole write-up and never mentioned the size facepalm.
I went up to a 120/70/17 in the front and a 160/60/17 in the back. It's been a couple weeks now and has been by far the best decision I've made since getting the bike imo.
 

·
Super Moderator
Joined
·
1,270 Posts
Maybe not with these sizes.
120/70/17 is 0.4" wider... than the OEM 110/70/17.
160/60/17 is 0.8" wider... than the OEM 140/70/17.
 

·
Registered
Joined
·
43 Posts
The same here, 160/60/17 in the rear but I keep 110/70/17 in the front, I have been using cheap tires like Continental Contimotion in different riding condition, like rain, I mean in florida, no ice, lol. and now I am riding Dunlop Sportmax GPR-300, I felt better on the contimotion, better lean, but I just ride street, not really aggressive. I keep the stock rims because is an ABS model, if you wanna swap rear rim for a 5" or a 5.5" is a few choices but you would have to adapt the ABS ring on the rim. Have been riding with this tires for over year and a half, I went with tis as soon I replace the stock Michelin pilots. I have to say that I like the handling and everything, I don't know everyone is different. I am staying with this tires sizes, because I couldn't find a bigger rim compatible for ABS model, but maybe a bigger size could be too much, as right now with a 160/60/17 on stock rim feels good
 

·
Registered
Joined
·
43 Posts
An update, I got a 5.5” rim and now I just install the pirelli angel gt 180/55/17, I came from a 160/60/17 on the old stock rim, as you see on the pic
 

·
Registered
Joined
·
415 Posts
Why do people try to put "big" tires on a small(er) bike??? All it does is detract from the handling, and add to the un-sprung/rotating mass. You might look "cool" with wider tires, but you are doing NOTHING to help help with the performance of the bike. You are actually making your bike slower, and handle poorly- If you think I'm "wrong", look at ANY MotoAmerica starting grid within the Junior Cup (R3 class).... Not a single racer at the pro level, is running anything wider than a 150 series rear, and a 110 series front... If there was any advantage of doing so, those folks would be doing it- they are NOT.....
 

·
Registered
Joined
·
41 Posts
Not a big fan of cramming big tires under sport bikes. There is a balance between handling, efficiency and stability that is met with the narrowest profile that will provide the proper amount of grip. Just stuffing bigger rubber under a bike is often a poor choice. The rolling resistance is greater (more effort to keep moving), the diameter is greater (150/70 = 105mm, and 160/70 = 112mm, which changes gearing over the stock 140/70 = 98mm), the inertial resistance is greater (slower acceleration under the same power), the weight is higher (more mass to move), and the location of the contact patch when cornering is raised (increasing resistance to changing direction - however, this feels more stable). When you get onto the shoulder of the tires, the radius of the tread has more impact on grip when cornering, which is not dramatically increased by a wider tire. A tire too wide for its rim actually may have a smaller shoulder radius, and may even have an inconsistent edge radius profile, thus less or inconsistent cornering grip. So, when you are cornering (where grip is most important), unless there are associated rim changes, the amount of grip from narrow to wide will likely be unchanged - if not reduced in some cases.

I suggest that most of the improvement in the bikes feel when a wider tire is fitted has to do with the better tire itself (quality and construction), and the extra stability (great for touring bikes and crap chopper geometries, but antithetic to the goal of a sport bike). In fact, some level of instability is built into sport bike geometries (rake.trail, tire size), that makes them more ready to change direction. Adding tire width works against that dynamic design. Further, what works great for 300HP GP bike isn't going to work on a 600cc 100HP street machine. What works for that 600cc street machine is not work at all for a 320cc 40HP lightweight, as they all use their tires differently, and have different geometries elsewhere.

Another often ignored aspect of tire application is slip angle. What many fail to realize is that the best grip is when the tire is actually slipping a little. Add more traction that reduces that slip and the bike will handle poorly. Too much slip is not good when it happens, but no slip is bad all the time. That subtle feeling of "lightness", wiggle or squirliness in the rear under cornering that so many whine about, is actually part of what makes the bike corner so well. Take that out, and the bike will feel numb, or will understeer, or may take a lot more lean to get the same corner response.

It certainly makes sense to seek tires that optimize performance, and nothing feels better than brand new rubber.

I find comparing the tire size of a YZFR6 (120/70-ZR17 on the front, and 180/55-ZR17 rear), and applying the 120/70 front with a 150 or 160/70 rear on an R3 with far less power, and far less cornering force a dubious mod. The R3 has a lower CG, greater rake (25 for R3 vs 24 for R6) and greater trail (3.74 for R3 vs 3.4 for R6), with less weight (366 vs 401). It appears to me that Yamaha utilized the narrower tire to optimize efficiency (less power loss through the tires), and compensated for stability by increasing rake and trail, to produce balance without the heavier rubber. This produces a stable straight-line ride, with great turn-in response and edge grip, while maintaining a very responsive mid-corner character - which fat tires would only improve in increased straight line stability.

I also find it amusing when digging into tire selection. I have seen many instances of forum commentary deriding stock rubber selection from one bike - that, on another forum for a different model bike is touting what a great tire that is to upgrade to from their "bad" OEM rubber.
 
1 - 15 of 15 Posts
Top