I really like how it looks. Not sure if I would like riding it though. Might be kind of cramped with the low seat on the Breakout.

 

Being new to riding and having recently purchased the E3 250 rear and 120 front combo for my future tire change, your thoughts caught my interest. With my stock tires, I counter-steer and the bike leans into a turn as easily and predictably as one might expect, or so I thought. This turn resistance that I'm currently experiencing without realizing it; how does it manifest itself ? Do I understand correctly, that you're suggesting this will change for the worse (??) once I replace a 130 bias belted front tire with a 120 radial one ?

I can grasp the idea that bikes with longer wheel bases (Breakouts) should demand a somewhat larger turning radius but I'm missing the point with the wide tire issue I'm afraid. What am I missing ?

Thanx

 

It is generally acknowledged that the use of a very wide rear tire geometrically causes a bike to be more reluctant to initiate a turn. This effect is magnified by the relative difference between the width of the rear tire and the front tire. In addition, it is generally acknowledged that since MOST wide rear ties are also heavy (like the Dunlop 240 at 21.75 lb), there is also the negative effect of significantly higher moment of inertia, particularly since the extra weight is right at the outer circumference of the wheel and tire combination. In the case of the Dunlop versus the Pirelli Diablo 240 (pn 1682600), the difference is particularly huge since the weight difference is about 6 1/4 lb. This moment of inertia effect not only negatively affects dynamic turn-in, it very negatively affects the nimbleness of the bike. For analogy, reasonably sensitive riders describe it as "like the bike is wearing cement overshoes".

A change to a 120mm wide front tire will accentuate the geometric differential. How much you will feel this depends upon your riding sensitivity. To use extremes, an amateur or pro racer would feel it right away, while a casual cruiser focused on other things might not notice or might not care.

There are other issues though too.

Unfortunately, the 120mm tires I have looked at have a proportionately higher sidewall (120x70 versus 120x60) so their rolling diameter is higher than the stock tire, by in at least one case, a little over 1/2 inch. This raises the front end of the bike. This helps a bit to keep the foot pegs from grounding on corners, but is aesthetically negative. It will "fill" the fender better, but maybe TOO much better. It also increases the rake slightly which in theory will add to a bike's resistance to turning. It also appears that the available 21" tires are radial, while the stock tire is bias belted. The impact of this change I cannot predict. Fiinally, since they are narrower than stock, they will likely require a different tire pressure to achieve the correct working hot tire temperature.

There are also 140mm wide front tires. They are also radial is appears. They may or may not fit with the fender (I would think it is likely they would, but you'd have to check). They will change the aesthetics significantly, which you may regard as a positive or a negative. They will improve the ride in terms of resistance to pavement grooving and other road effects. They MAY add weight because of their obviously larger size, but if you find a "performance" tire versus a touring or cruising tire, that might not be the case (I haven't looked hard enough yet). They will lessen the differential between front and rear tire width, and so should help mitigate the turn in issue. They will have a larger diameter, because even if you find a 140mm 21" tire that has a .60 section like the stock tire, it will still be larger in diameter because 0.60 x 140mm is larger than 0.60 x 130mm, so again the front of the bike gets higher. It will "fill" the fender better, but maybe TOO much better. The combination of PROBABLE weight increase coupled with larger diameter will negatively affect moment of inertia, and thus both handling and nimbleness, but your sensitivity to the bike will determine if that is or is not an issue for YOU. And just like with the 120mm tire, the correct cold psi will likely need to change, since the tire footprint is going to be different and probably larger, and since the tire design is obviously different.

I do NOT claim to be any sort of tire expert, but the above would appear to be applicable.

Jim G

 

You are close, but a little off on the 120 and 140 sizes.
Stock tire is 130/60/21
Other sizes available are ...
120/70/21
140/70/21

The 130/60 is 130mm wide, and 27.14" tall
The 120/70 is 120mm wide and 27.62" tall
The 140/70 is 140mm wide and 28.71" tall

The 120 will fit and depending on brand does not really look that much different from the stock tire. the 140 will not fit with the stock fender unless you space it up.

I have seen a Metzeler 120/70/21 side by side with my Dunlop 130/60/21 and the difference was almost unnoticeable to the naked eye.

Everyone keep in mind the numbers on the tire are not exact. The sizes will still vary between brands, and even between models of the same brand.

 

I agree. The actual width versus theoretical is really there, as evidence by the difference in width of tires that are nominally 250mm - some will apparently fit and some won't.

Here's something worth knowing: I test rode a Victory Jackpot "Ness" (the tricked out 2007 model) with 240 rear tire and 120 front tire, and did so a total of 3 times on different days (I was considering buying it at one point). The resistance to turn in and tight turns was quite pronounced - much more than on the Breakout. It was enough to be, for me, a distraction. Naturally, there could be other factors at work beyond differential between front and rear tires, but all the road test reports on the Victory commented on the harder turn-in, and did all blame it on the wide rear tire. The should have commented on the differential, but did not, so I cannot know fir sure that that was the cause. But the circumstantial evidence is there . . .

Jim G

 

I do not know of any 250 rear tire that will not fit, as well as 260.
As for the differential, I doubt any of us here will notice. I would think tread pattern, and inflation would be felt more than the 1/4 = 3/8" difference in width from stock to a 120.

 

Here's something else to be aware of:

The stock front tire on the Breakout is unique. Not only to Dunlop, but apparently to the Breakout, period.

Here are the specs, which it took me several tries to find, but I finally found them on an obscure tire website:

Dunlop Model D408
Size: 130/60B21 63 H Front TL
Season: Summer
Load index: 63 = max 272 kg (598 lb)
Speed rating: H = max 130 mph
Vehicle type: Motorcycle cruiser / chopper
Weight = 5.94kg = 13.07 lb

You will NOT find this tire anywhere in the Dunlop tire website catalog.

I have no way of knowing for sure, but my GUESS is that HD wanted a stylishly "large" 21 inch front tire for the CVO breakout when they designed it, and basically asked Dunlop to provide one. The only tire design that could be provided was this BIAS (versus radial) tire, and I'm sure that Dunlop was not thrilled with Harley's intention to mate it with a radial rear and a very, very wide rear at that. That's probably why neither Dunlop nor HD advertise this tire for general sale, and why I have never been able to find it anywhere except at a Harley dealership (where you also pay list price for the darn tire, versus the 30 to 45% discounts readily available on other tires).

Note also that the maximum speed rating is only 130 mph, which is not a match for the rear ("V" rating on the rear versus "H" rating on the front). This was apparently unavoidable given the tire design used as the basis for the Breakout front tire. It is obviously not desirable, even though I doubt any of us are dumb enough to try to ride a cruiser like the Breakout at even 130 mph let alone 168 mph. It probably does mean the tire will overheat faster than the rear one if overloaded or run at low psi.

The wear characteristics are also inferior. The front tire on the Breakout is way less loaded than the rear tire because of the bike's rearward weight distribution with rider aboard (that's why the 63H or 600 lb weight limit is so much lower than the 967 lb weight limit of the rear 240). In addition, there is of course no wear due to driving force on the front tire. Nevertheless, at just 4500 miles, my front tire is down to roughly 1/2 its usable tread depth. For ME, that's very rapid tread wear as I am a pretty gentle rider (I average 43 to 45 mpg on the Breakout).

Finally, HD's recommended psi for the FRONT tire is 36 psi, but actual testing, at least for me on my bike, shows that the ideal 10% psi rise from cold to hot tire is achieved with 38 psi, not 36. This is just speculation, but, running it at 36 per the manual MAY have contributed to more rapid tread wear due to slight under inflation.

All in all, I cannot be impressed with HD's choice of stock Breakout tires, front or rear.

Jim G

 

You should write books. I have over 11k miles on my front tire so far and suspect it will be good for at least another 2 or 3k.

 

I wonder if the difference between your tire wear and mine is the Texas heat. We have had our usual hot summer, with daily highs hitting 95 to 105 degrees, and even nightly lows staying at 75 and above.

I can't imagine how else I can explain the difference.

Following up on my last post, I noticed that the new Victory "Magnum" bagger uses a 180/60R16 rear tire with a 120/70R21 tire, and that both are a dunlop "Elite 3". I checked the Dunlop site, and in the Elite 3 section where it shows ONLY rear tires, it says:
"To complement the rear tire, custom-style 21-inch front tires are also available in 120/70R21 and 90/90-21 sizes for custom applications."

Note the "custom" in that sentence.

By the way, the Magnum is considerably heavier than the Breakout (the Magnum weighs 760 lb DRY before oil, brake fluid, gas) and runs the smaller 120/70R21 whose load capacity is, IF typical for this size of tire, is about 100 lb LESS than that of the Breakout's front tire. This SUGGESTS that HD chose the 130mm front tire NOT for weight capacity reasons, but rather for less differential between the front and rear tires.

Finally, I DID write a book. My 320 page e-book, "The SSR Experience", has sold like hot cakes to owners of the Chevrolet SSR retro pickup truck for over 8 years now. It's considered "the bible" for owners, or prospective owners, of an SSR.

My own SSR, which tested and proved many of the ideas in the book, eventually got to 575 crank horsepower (Magnuson supercharger, Z06 cam, tune by the best tuner, etc), had a specially built bulletproof GM tranny from Phoenix Transmissions that shifted in 300 milliseconds (chirped the tires at 80 mph with a 4900 lb truck weight), 4.54 gearing (29.25" diameter tires on 20 inch wheels), a 3800 rpm stall converter, headers, crossover, "resonators only" dual exhaust, and ran without any problems for 40,000 mile before I sold it to an SSR website member. I did have to do a "few things" to it just like I am doing to my Breakout to "get it right."

Jim G

 

Something different than tires...

Got some powder-coating done by the guys at Powder Pro. The customer service was simply excellent and Joe couldn't do enough to help me out getting this job done quickly while I am in the US.




Now off to LA to collect my new front fender from Bithcin Seats and then Miami to pick up 12 boxes of other bits and pieces. Travel to the US is an expensive trip!