HarleyTechTalk

Technical Forums => General => Topic started by: fleetmechanic on February 08, 2020, 03:02:33 PM

Title: Dunlop rear tires
Post by: fleetmechanic on February 08, 2020, 03:02:33 PM
Yesterday we had 5 sidecar rigs marooned in the snow and ice because the 180 back tires have no bite in the snow like the 130s did.
The dealer was showing me a Dunlop D427 in a 180/70-16 size that is OEM now on the Fatbobs so I looked at Dunlop's website and it said this tire will not fit on 2009-later touring models.  The original touring tire is 180\65-16 but the D427 has a lot more grooves in the tread.  Any idea why these wouldn't work?
Title: Re: Dunlop rear tires
Post by: Hossamania on February 08, 2020, 03:31:51 PM
Load rating?
Title: Re: Dunlop rear tires
Post by: PoorUB on February 08, 2020, 03:33:52 PM
908 pounds.
I have no clue why they would not fit.
Title: Re: Dunlop rear tires
Post by: kd on February 08, 2020, 04:05:12 PM
Maybe a softer sidewall for the lighter models for ride quality?

added

I just had a quick look on a couple of tire test sites and one rated it 5/5 for tire heat up speed.  I expect that means quickly but didn't see an explanation.  If that is true it will probably support the thought that the sidewall may be softer for the lighter bike.
Title: Re: Dunlop rear tires
Post by: fleetmechanic on February 08, 2020, 05:05:42 PM
The load ratings for the D407 and AE rears are both 81H.  The rating for the D427 is 77H.  Chart on Web Bike World says 908 lb. for 77H and 1,019 lb. for 81H.
There is also a Dunlop D251 tire in the 180/70-16 size that is made for the Honda 1800s.  Anyone tried one of these?  They are available in the aftermarket whereas the D427 is an HD dealer only model.

We did try a car tire on the rear of one rig but after two seasons the tire stared losing air around both sides of the beads.  The soft sidewalls on the car tire may be a little too flexible when fit on an HD wheel.
Title: Re: Dunlop rear tires
Post by: Roadflyer on February 08, 2020, 06:18:04 PM
Tons of people run car tires without them leaking air.
I had a 205-55-16 Yokohama on my bike, and while I didn't care for the handling on a 2 wheel bike, I'd think it work awesome on a sidecar.
Give it another try.
Title: Re: Dunlop rear tires
Post by: hogpipes1 on February 09, 2020, 10:01:35 AM
I would figure a way to sand bag the axle for traction before i would buy new tires.
Title: Re: Dunlop rear tires
Post by: PoorUB on February 09, 2020, 12:40:48 PM
How about buying a tire groove knife and cut in your own groves?
Title: Re: Dunlop rear tires
Post by: fleetmechanic on February 09, 2020, 12:41:00 PM
One of the bikes had so much snow packed into the rear sprocket that it forced the inside retaining ring off and threw the belt. The tire on that one is close to done so I'll put on a Yokohama tire while I'm screwing the ring back onto the sprocket.  The other car tire that we tried that leaked was a Bridgestone 195/60-16.  So we'll give it another shot with a 205/55-16 instead.
Title: Re: Dunlop rear tires
Post by: Leed on February 09, 2020, 02:00:24 PM
I ran a car tire on my Gold Wing and never had leaking problems. If you think the side walls are too soft try a run flat tire.  They should be much stiffer.
Title: Re: Dunlop rear tires
Post by: Hossamania on February 09, 2020, 02:11:18 PM
Part of the problem is the wider 180 tire verses the thinner 130. Thinner is better in the snow.
Title: Re: Dunlop rear tires
Post by: fleetmechanic on February 09, 2020, 04:21:11 PM
Quote from: Hossamania on February 09, 2020, 02:11:18 PM
Part of the problem is the wider 180 tire verses the thinner 130. Thinner is better in the snow.
It's most of the problem.  The 180 combined with the rounded profile makes these rear tires just float on the snow.  We never had anybody totally stuck when all the bikes had 130s.  Some of the winter storms also seem more intense than they were in the 88 cu.in. 130 tire years.  Or maybe it is just the tires.
Title: Re: Dunlop rear tires
Post by: smoserx1 on February 10, 2020, 05:11:37 AM
QuotePart of the problem is the wider 180 tire verses the thinner 130. Thinner is better in the snow.

How could it be any other way.  Pressure is force divided by area.  Same force (from bike's weight), bigger tire = bigger area = less pressure and is worse in the snow.
Title: Re: Dunlop rear tires
Post by: PoorUB on February 10, 2020, 05:27:40 AM
I was just thinking, is there a narrow rim that would bolt up the the later touring pulley and brake disc? Then you could run the narrow tires.
Title: Re: Dunlop rear tires
Post by: Buglet on February 10, 2020, 06:41:43 AM
    A 08 wheel Assembly with the right spacing will work.
Title: Re: Dunlop rear tires
Post by: fleetmechanic on February 10, 2020, 08:21:15 AM
When we first saw this problem on the 2009 models I did consider a wheel swap but didn't do it hoping we could just get used to it.
Next year I may reactivate some of our older ones with sidecars that are just sitting around.
Title: Re: Dunlop rear tires
Post by: a_disalvo on February 10, 2020, 09:08:27 AM
When it comes to wider rear tires, I remember what my father in law use to say," I never saw a model T stuck in the snow" !!!
Title: Re: Dunlop rear tires
Post by: kd on February 10, 2020, 09:32:43 AM
When we first saw this problem on the 2009 models I did consider a wheel swap but didn't do it hoping we could just get used to it.
Next year I may reactivate some of our older ones with sidecars that are just sitting around.

Just a thought here.  Overcoming the traction problem won't resolve the snow build-up in the belt issue.  You can do a chain conversion on a couple of your older ones while they are apart and "Bob's yur uncle".
Title: Re: Dunlop rear tires
Post by: SixShooter14 on February 10, 2020, 09:36:11 AM
Quote from: a_disalvo on February 10, 2020, 09:08:27 AM
When it comes to wider rear tires, I remember what my father in law use to say," I never saw a model T stuck in the snow" !!!
:potstir: I have! I have!!! about 3" of snow on 2" of ice. An old man that used to live about a mile from me. He was mid-90s and would drive his restored model T down to my store for a coke or some hardware parts or just to BS. He showed up one day driving his tractor because his T was stuck in the snow. Yup, this 90 year old man drove his old tractor without a cab down the road in the snow and ice for a coke and sammich. They don't make them like that anymore.
Title: Re: Dunlop rear tires
Post by: Hossamania on February 10, 2020, 10:26:13 AM
Quote from: SixShooter14 on February 10, 2020, 09:36:11 AM
Quote from: a_disalvo on February 10, 2020, 09:08:27 AM
When it comes to wider rear tires, I remember what my father in law use to say," I never saw a model T stuck in the snow" !!!
:potstir: I have! I have!!! about 3" of snow on 2" of ice. An old man that used to live about a mile from me. He was mid-90s and would drive his restored model T down to my store for a coke or some hardware parts or just to BS. He showed up one day driving his tractor because his T was stuck in the snow. Yup, this 90 year old man drove his old tractor without a cab down the road in the snow and ice for a coke and sammich. They don't make them like that anymore.

It's not like the model T was much warmer...