hairpins/low speed turning with 55 rear profile

[martin_14]

Not sure if this one goes to Accessories and Modifications, but I'm sure Jim will fix it if needed.

Anyway, I did a training on Monday in a proving ground, with a selection of tracks, surfaces and maneuvers. Truly interesting what the differences are between what is, in essence, an engine between 2 tandem wheels and a handlebar in different flavors. I got to drive about 12 different bikes, from a 65 HP scooter to a 200 HP sports bike.

In the evening I returned home on my C14 and noticed, as usual, the heavy steering, in particular the extra force you have put in a curve to keep the steering from turning in. I mean the force you need to push the grip on the inside of the curve. Also, the steering feels pretty heavy, "massive" would be a better word. This makes low speed maneuvers a challenge, together with the snatchy load transfer when getting on the gas (trick: keep a slight pressure on the rear brake, but only valid for '08/'09 models).

My question to those with the 55 rear profile, instead of the original 50: do you notice any improvement in low speed? The rear of the bike should be slightly raised so the rake angle slightly more vertical...

[VirginiaJim]

I've heard that the 55 improves handling.  Unlike many people here, I haven't noticed any improvement.  I'm just an unfeeling sod, I guess.  YMMV.  If your tires have some age on them, like your battery, that could be a cause of poor handling as well.  It could also be you riding those other bikes.  Lighter bikes will handle 'better' for the most part.  In my situation, I went from a C10 to a C14.  The C14 handled better than anything I've ever rode (GL500 SilverWing, C10, Voyager XII....I've led a sheltered life), but I still kept the C10 and rode it occasionally until I sold it.  After one day on the C14, the C10 felt like  and there wasn't anything wrong with it.  It could be perception and there really isn't anything wrong with your bike at all.

[Rembrant]

I've heard that the 55 improves handling.  Unlike many people here, I haven't noticed any improvement.

I've tried the 55 series rear tires a couple times, and I don't like the feel of them at all. I'm much happier with a 190/50 rear tire on my C14, and I find it handles just fine as it is. Most guys do love them though, so I guess I'm an odd man out;).

Cheers,
Rem

[Conrad]

I thought that Jim was the odd man? I guess we have at least one more.   

[B.D.F.]

I find the -55 tires to be more nimble at all speeds; the bike is far more willing to tip in, will do it faster and it takes less effort to initiate. As far as holding the bike in a turn, I don't think I have really noticed a difference with tire profile alone. The only difference I notice is when the rear tire is worn, it takes more and more effort to hold the bike down in a turn. Funny thing but the best acting tires and definitely the most neutral (will stay at any attitude with little or no effort) have been Pirelli Angel STs; the worst tire for holding the bike down in a turn and the one that takes the most effort is a Pirelli Angel ST.... when they are about 1/3 worn. They lose their good manners and act much worse long before they are worn out.

I like the -55 profile in PR3 and have used a few of them. I am currently trying an Angel Pirelli GT in -55 and it too started out acting very well. I do not yet have enough miles on it to know but it does seem to be flatting a bit faster than a Michelin Pilot Road at this point (maybe 20% into the life of the tread).

Brian

Brian

Not sure if this one goes to Accessories and Modifications, but I'm sure Jim will fix it if needed.

Anyway, I did a training on Monday in a proving ground, with a selection of tracks, surfaces and maneuvers. Truly interesting what the differences are between what is, in essence, an engine between 2 tandem wheels and a handlebar in different flavors. I got to drive about 12 different bikes, from a 65 HP scooter to a 200 HP sports bike.

In the evening I returned home on my C14 and noticed, as usual, the heavy steering, in particular the extra force you have put in a curve to keep the steering from turning in. I mean the force you need to push the grip on the inside of the curve. Also, the steering feels pretty heavy, "massive" would be a better word. This makes low speed maneuvers a challenge, together with the snatchy load transfer when getting on the gas (trick: keep a slight pressure on the rear brake, but only valid for '08/'09 models).

My question to those with the 55 rear profile, instead of the original 50: do you notice any improvement in low speed? The rear of the bike should be slightly raised so the rake angle slightly more vertical...

[clogan]

I'm dubious that our senses are keen enough to actually notice any real difference between a 50 series vs. a 55. At least, I doubt my senses are keen enough. The difference we are talking about is only 9.5 mm, or roughly a quarter inch?  That would only be an eighth-inch difference in height. (please check my math!)

There is no doubt that many have reported feeling differences. Even I have said that I "think" the 55 handles better. But is it simply the result of mounting a new tire? Would we get the opposite impression if we replaced a worn out 55 tire with a new 50 series?

I just don't think my butt-o-meter is that accurate. In any event, I will confess this: at replacement time, I'm going with a 55 series again, if for no other reason than to have a more accurate speedometer.

[3redzxs]

I don't feel any difference, but I do remember hearing racers talk about how poorly the 190/50 does at the track. I stick with the 55 because I can use any help I can get.

[C14lvr]

When I went from the stock 'stones 50 rear to the PR2 55 rear, and a PR2 front, I noticed a HUGE difference in handling. It also corrected 2 of 3 mph error on my speedo.

For a while, I wondered if the 'stones being worn flat down the middle was the cause...
After 7000 miles on the PR2's, the rear is beginning to show some flatness in the middle, the front still looks new.

So far, handling is still much better.
For me, I'll never go back to a 50 on the rear... Ever.
I dig it!
Also, I have recommended this swap to others, who tried it, and they say the same thing.

Everybody's different, I know. But for me, this is what Kawasaki should have always used on the C14.
And why they've never once addressed their incorrect speedo readings baffles me.
6 models of the same mistake...repeated. (8 if you count since late '07 models.)
Especially when tire size correction is an easy 2fer...

I now see speedo readings actual/ registered listed in all Motorcycle specs in the reviews.
Heavy handling has always been a point of contention with the C14, and has always gotten negative reviews from the press in the mags. Better tire choice would've helped it a lot.

I also see other bike manufacturers are now installing 55 series rear tires stock on their new bikes.

[Daytona_Mike]

How come no one is talking suspension settings? That is really the issue here. When your sag is wrong or too much and you go from a worn out 50  tire to a new 55 tire of course your going to notice a big change . Your probably talking about more than a 15mm difference.
Fix your suspension and you fix the handling.

[Stephen.G.Fiddes]

First off, I have adjusted my sag accordingly. 

I must say, that in order to fix the heavy steering with the 50 rear tire, I dropped my front end 2.5-3 mm and holy cow what a difference.  Lock to lock I can throw that bike around like a toy now in hairpin turns. 55 is going on this weekend, haven't decided if I'm going to leave the front end slightly dropped, or bring it back up to counter the extra rise in the rear going from a worn out 50, to a brand new 55

[maxtog]

How come no one is talking suspension settings?

Exactly.

You should be able to simulate the exact same thing as a 55 rear by just lowering the front (raising the fork tubes) by the same amount the 50 to 55 rear would raise the rear.

I won't even be able to add anything helpful, since I need the bike as low as possible due to short legs.... so I would NEVER put a 55 on the rear, and I already have the front dropped and use a lowering link for the rear.  I am sure it is not helping the handling much, but it is necessary AND with new/decent tires now, I am very happy.

[gPink]

You are not taking into account the rounder profile of the 55 series. I don't know the source so I cannot attest to the accuracy but this will give you the idea.

[gPink]

Now compare to a 60 series....

[maxtog]

You are not taking into account the rounder profile of the 55 series. I don't the source so I cannot attest to the accuracy but this will give you the idea.

Ah, that is very good info.  I imagine that would also affect the handling.

[Stephen.G.Fiddes]

Leaves for a much bigger footprint in corners. 

[connie14boy]

When I went from the stock 'stones 50 rear to the PR2 55 rear, and a PR2 front, I noticed a HUGE difference in handling. It also corrected 2 of 3 mph error on my speedo.

For a while, I wondered if the 'stones being worn flat down the middle was the cause...
After 7000 miles on the PR2's, the rear is beginning to show some flatness in the middle, the front still looks new.

So far, handling is still much better.
For me, I'll never go back to a 50 on the rear... Ever.
I dig it!
Also, I have recommended this swap to others, who tried it, and they say the same thing.

Everybody's different, I know. But for me, this is what Kawasaki should have always used on the C14.
And why they've never once addressed their incorrect speedo readings baffles me.
6 models of the same mistake...repeated. (8 if you count since late '07 models.)
Especially when tire size correction is an easy 2fer...

I now see speedo readings actual/ registered listed in all Motorcycle specs in the reviews.
Heavy handling has always been a point of contention with the C14, and has always gotten negative reviews from the press in the mags. Better tire choice would've helped it a lot.

I also see other bike manufacturers are now installing 55 series rear tires stock on their new bikes.

I agree 100%-  the PR 55 series profile is awesome and I'll never go back to a 50 series tire.

[C14lvr]

I keep seeing 180 /55's a lot, but harder to find the 190 / 55's.

They're also cheaper. Has anybody tried one?

I'm thinking that would be a step backwards...

I noticed that's now the size Yamaha has chosen for the 2014 FJR. BT-023's, no less.
Can't imagine why they chose that tire brand...
Guess they must get a great deal on them.
Seems like a better tire choice would be the smarter move, to me.
Any additional cost they'd incur would be like a wise investment, especially when they'd get better mag reviews....

[Racer Boy]

The difference in handling is the rounder profile of the 55 series, not the slightly higher rear ride height. My other bike is a Yamaha FZ1, and the second generation FZ1's come stock with a 50 series rear tire (and just like the C14, they look really cool!). A lot of owners put 55 series tires on them to improve the handling, and the results are the same as on our C14's; easier turn-in, and less effort at the handlebars to turn.

[JS_racer]

...........I noticed that's now the size Yamaha has chosen for the 2014 FJR. BT-023's, no less.
Can't imagine why they chose that tire brand...
Guess they must get a great deal on them.
Seems like a better tire choice would be the smarter move, to me.
Any additional cost they'd incur would be like a wise investment, especially when they'd get better mag reviews....

the 023 is a very good tire, have run many sets on my c14,

[clogan]

The difference in handling is the rounder profile of the 55 series, not the slightly higher rear ride height. My other bike is a Yamaha FZ1, and the second generation FZ1's come stock with a 50 series rear tire (and just like the C14, they look really cool!). A lot of owners put 55 series tires on them to improve the handling, and the results are the same as on our C14's; easier turn-in, and less effort at the handlebars to turn.

I had not thought of that. It does make sense that a tighter radius, from a "rounder" profile, would make turning easier. But then again, for my 63-year-old butt-o-meter, I just do not have enough sensitivity to focus in on the effect of a rounder profile when there are so many other variables present: tire air pressure, road surface, suspension setting, air temperature, road temperature, carrying load, etc.

But I will stipulate to the opinion of others that the 55 does indeed handle better.