The Sportster and Buell Motorcycle Forum - The XLFORUM®
 

Go Back   The Sportster and Buell Motorcycle Forum - The XLFORUM® > SPORTSTER MOTORCYCLE FORUM > Sportster Motorcycle Era Specific and Model Specific > Ironhead Sportster Motorcycle Talk (1957-1985)
XLF Blogs XLF Arcade XLF Disclaimer/Privacy Statement/Terms Of Use

Notices

Ironhead Sportster Motorcycle Talk (1957-1985) For all those that wanna talk about Ironhead Sportster Motorcycles

Active Threads
0 Automotive Motor Oil In Sportster
Last Post: Hippysmack
Posted On: 31 Minutes Ago
Replies: 15
Views: 263
0 Snippets
Last Post: Crusty
Posted On: 35 Minutes Ago
Replies: 493
Views: 67,676
0 KT - 2021 - You're In It Now
Last Post: IXL2Relax
Posted On: 37 Minutes Ago
Replies: 66
Views: 11,727
0 Hammer 1275 clang noise, slow oil feed, kinked crankcase vent.
Last Post: Turbo Sporty 48
Posted On: 38 Minutes Ago
Replies: 1,405
Views: 93,337
0 Keep & Kill
Last Post: Graywolf
Posted On: 53 Minutes Ago
Replies: 24,616
Views: 1,451,364
0 First start question
Last Post: doodah man
Posted On: 1 Hour Ago
Replies: 54
Views: 1,341
0 Should I buy a Sportster??
Last Post: riceburner
Posted On: 1 Hour Ago
Replies: 528
Views: 214,138
0 Not funny... I Crashed it....
Last Post: sportsterpaul
Posted On: 2 Hours Ago
Replies: 28
Views: 2,006
0 Q cams in 73 xlh ??
Last Post: Ferrous Head
Posted On: 2 Hours Ago
Replies: 36
Views: 1,701
0 Official XL Forum Random Image Thread (NO NUDITY!)
Last Post: Graywolf
Posted On: 2 Hours Ago
Replies: 51,985
Views: 8,747,828
0 Front deflection
Last Post: denguy
Posted On: 2 Hours Ago
Replies: 1
Views: 29
0 what are acceptable oils for primary ?
Last Post: brucstoudt
Posted On: 3 Hours Ago
Replies: 24
Views: 2,280
0 What song do you have stuck in your head?
Last Post: iNSaNeSHaNe
Posted On: 3 Hours Ago
Replies: 2,413
Views: 257,297
0 This week on Craig's list
Last Post: Fivecats
Posted On: 3 Hours Ago
Replies: 5,366
Views: 874,957
0 Do Loud Pipes in fact save lives?
Last Post: Steve9
Posted On: 3 Hours Ago
Replies: 2,605
Views: 313,832
0 Stroker pistons
Last Post: Ferrous Head
Posted On: 3 Hours Ago
Replies: 77
Views: 4,066
0 Ran out of gas.
Last Post: Hellbent_4
Posted On: 4 Hours Ago
Replies: 167
Views: 26,729
0 Food porn
Last Post: Stairman
Posted On: 4 Hours Ago
Replies: 2,495
Views: 576,116
0 This is gonna hurt.
Last Post: Stairman
Posted On: 5 Hours Ago
Replies: 8,901
Views: 2,072,342
0 Best seat for long rides
Last Post: Diogenes415
Posted On: 5 Hours Ago
Replies: 145
Views: 41,450
0 need help with 68 XLH
Last Post: sportsterpaul
Posted On: 6 Hours Ago
Replies: 10
Views: 318
0 Finally some nice weather in the northeast!
Last Post: sportsterpaul
Posted On: 6 Hours Ago
Replies: 53
Views: 6,098
0 2021 Iron Butt Rally
Last Post: sportsterpaul
Posted On: 6 Hours Ago
Replies: 132
Views: 13,737
0 Hottie of the day, no nudity.
Last Post: Stairman
Posted On: 6 Hours Ago
Replies: 32,089
Views: 3,727,241
0 Was your 1st bike a Sportster?
Last Post: riceburner
Posted On: 6 Hours Ago
Replies: 1,052
Views: 293,745
0 Valve Stem Seal ID
Last Post: BruceM
Posted On: 9 Hours Ago
Replies: 5
Views: 156
0 78 Ironhead switchgear parts
Last Post: bustert
Posted On: 11 Hours Ago
Replies: 3
Views: 119
0 video & pics
Last Post: cal43
Posted On: 12 Hours Ago
Replies: 425
Views: 42,594
0 Hot Chicks on Hot Bikes
Last Post: cal43
Posted On: 16 Hours Ago
Replies: 12,519
Views: 2,908,520
0 Hot Rods, Rat Rods, and Customs.
Last Post: cal43
Posted On: 16 Hours Ago
Replies: 4,724
Views: 911,819
More...
Members Birthdays
black pearl (77), SDREDD (60), pig (58), BonRu (56), wandawells42 (52), cbass (48), HawkeyeTX, SxysCowboy (38)
Reply
 
Share Thread Tools Display Modes
  #1  
Old 1 Week Ago
ZTatZAU ZTatZAU is offline
Biker
 
Join Date: Aug 2021
Posts: 52
Sportster/Buell Model: XLH1000
Sportster/Buell Year: 1973
Other Motorcycle Model: GL1500 Goldwing
Other Motorcycle Year: 1989
Reputation: 15
ZTatZAU is an unknown quantity at this point
Default Dunlop K81 Roadmasters? Anyone?

I'm wondering if anyone here is running Dunlop Roadmaster (K81-TT100) tires on their Ironhead? And, in particular, a 4.10H-19 on the front of a 1973 XLH.

I bought my 1973 XLH in 2003 from a dear friend who bought it used from a Harley Dealer in 75. As far as I know the bike has always had the same set of Dunlop Roadmaster tires... (K81-TT100)... 4.25/85H-18 on the rear and a 4.10H-19 on the front. (The FSM specifies a 3.75H-19 for the front.) I've always liked the look and feel of these tires on my Sportster; especially the slightly beefier tire up front. I'm now in the process of getting the bike back in shape and roadworthy again and have purchased a new set of the same Dunlop Roadmasters.

I've mounted the rear tire but not yet the front tire which I can still return for a refund if that's the best path. The bike has about 21K miles with me adding the last 1000 or so and I was never concerned or aware of a possible tire clearance issue. Other than... tire spins good, stops good and pressure good, I never paid much attention to clearance! Until now, with freshly painted tank and fenders and dealing with replacing my drilled out strut rivets, that I'm paying any attention to tire clearance.

And while I'm pretty sure I can deal with the clearance behind the four rivets (or replacement screws) at the ends of the struts, it's really the clearance between the tire sidewall and the two vertical fork supports on each side (1/8" at most) that has me second guessing the 4.10-19 on the front. Thoughts? Comments?

My FSM shows a MM90-19T (3.75-19T) for the front but something seems wrong there! After researching equivalent standard, metric and alpha tire sizing, I find MM90 crosses to a 3.25/3.50" (100/90) tire rather than a 3.75" wide tire. The 3.75 tire should cross to a MN90 (110/90). Then I go on Dennis Kirk and search front Dunlop tires for a 73 XLH and they show 100/90-19 is correct. OK I say, but then I look at four Dunlop Tires that "Fit My Ride" on DK, all 100/90-19, and look at their "inflated width"s and only two of the four "correct tires" are narrower than the 4.10-19 that I'm worried about...
D404, 100/90-19, 3.9" W
D401, 100/90-19, 3.94" W
K591, 100/90-19, 4.10" W
F24, 100/90S-19, 4.2" W

Does anyone here run any of these Dunlop tires on the front of your 1973 or other year Ironhead? And, if so, do you have a stock front fender?

I read one old post where, IIRC, I think it was IronMick who bent his fork supports and struts to fit a wider than stock tire but I don't think it was a 73. Since the supports attach to the inside of a 73 fork (inboard of the horizontal struts) and attach to and go up and over the inside of the fender, those two points are fixed. Any outward bending between those two points (the fender and the fork attachment) could increase tire sidewall clearance but would also lower the fender slightly too.

Has anyone here bent or considered bending the fork supports outward to increase tire clearance on a 73 Ironhead. Other years may be similar but I'm not sure?

And BTW, what front tire are you running on what?

Again, any thoughts or comments appreciated! ZT
Reply With Quote
  #2  
Old 6 Days Ago
sportsterpaul's Avatar
sportsterpaul sportsterpaul is offline
XL FORUM LIFE MEMBER
 
Join Date: Jan 2009
Location: In a swamp/Michigan
Posts: 15,744
Sportster/Buell Model: XL1460C
Sportster/Buell Year: 2000
Sportster/Buell Model #2: XL1200R
Sportster/Buell Year #2: 2006
Other Motorcycle Model: XL1200R
Other Motorcycle Year: 2004
Reputation: 14859389
sportsterpaul has a reputation beyond reputesportsterpaul has a reputation beyond reputesportsterpaul has a reputation beyond reputesportsterpaul has a reputation beyond reputesportsterpaul has a reputation beyond reputesportsterpaul has a reputation beyond reputesportsterpaul has a reputation beyond reputesportsterpaul has a reputation beyond reputesportsterpaul has a reputation beyond reputesportsterpaul has a reputation beyond reputesportsterpaul has a reputation beyond repute
Default

Clearance is clearance, that 1/8” off the sliders is plenty. DON’T bend the legs for additional clearance.
__________________
I.B.A.#26543,

Dads words of wisdom:”behave and if you can’t behave don’t get caught!”

The XL Forum Sportsterpedia:
http://sportsterpedia.com/doku.php/start
Reply With Quote
  #3  
Old 6 Days Ago
rg500 rg500 is offline
Biker
 
Join Date: Oct 2014
Location: Uppsala, Sweden
Posts: 57
Sportster/Buell Model: XLH
Sportster/Buell Year: 1971
Sportster/Buell Model #2: XLH
Sportster/Buell Year #2: 1978
Other Motorcycle Model: XLCH
Other Motorcycle Year: 1971
Reputation: 27438
rg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to all
Default K81/tt100

Have you seen that the dimension K81/TT100 F/R 3.60-19 52H TT exists.
Reply With Quote
  #4  
Old 6 Days Ago
The Doctor71 The Doctor71 is online now
Senior Chief Master Mechanic
 
Join Date: Mar 2010
Location: Toronto, Ontario
Posts: 931
Sportster/Buell Model: xlch
Sportster/Buell Year: 1971
Sportster/Buell Model #2: xlh
Sportster/Buell Year #2: 1974
Other Motorcycle Model: xl1200cp
Other Motorcycle Year: 2011
The Doctor71 has disabled reputation
Default

I don't run Dunlop tires, so can't share any experience with Dunlop's.

Quote:
Originally Posted by ZTatZAU View Post
And BTW, what front tire are you running on what?
Avon Roadriders 90/90-19 F and 100/90-18 R on both my '71 xlch and '74 xlh.

FWIW, I found out the hard way about 10 years ago, Avon Roadriders 100/90-19 F and 110/90-18 R were both too wide and rubbed on my bikes. I wasn't into grinding or bending stuff so this lead me to drop down one size. And yes I run the stock OEM rims & fenders.
Reply With Quote
  #5  
Old 6 Days Ago
ZTatZAU ZTatZAU is offline
Biker
 
Join Date: Aug 2021
Posts: 52
Sportster/Buell Model: XLH1000
Sportster/Buell Year: 1973
Other Motorcycle Model: GL1500 Goldwing
Other Motorcycle Year: 1989
Reputation: 15
ZTatZAU is an unknown quantity at this point
Default

Thanks for the replies!
Quote:
Originally Posted by sportsterpaul View Post
Clearance is clearance, that 1/8” off the sliders is plenty. DON’T bend the legs for additional clearance.
I like your thinking Paul though it turns out my 1/8" guestimate was a tad generous. Would you feel the same about 3/32" where shown at the sidewall?



Notice that the outside flanged edges of my fork supports taper down to almost nothing at the fender attach point. Is this tapered flange stock to provide additional side clearance at the tread? Or did a PO taper it down with a grinder or a file to fit the 4.10-19 tire up front?

Quote:
Originally Posted by rg500 View Post
Have you seen that the dimension K81/TT100 F/R 3.60-19 52H TT exists.
No. I hadn't seen that but I was looking for a 3.75 K81. I'd prefer not going narrower than the original 3.75. I did a quick search for a 3.60 k81 and only saw one on ebay for almost $300!!! Did you find them readily available at normal prices elsewhere?

Quote:
Originally Posted by The Doctor71 View Post
I don't run Dunlop tires, so can't share any experience with Dunlop's.
Avon Roadriders 90/90-19 F and 100/90-18 R on both my '71 xlch and '74 xlh.
FWIW, I found out the hard way about 10 years ago, Avon Roadriders 100/90-19 F and 110/90-18 R were both too wide and rubbed on my bikes. I wasn't into grinding or bending stuff so this lead me to drop down one size. And yes I run the stock OEM rims & fenders.
Thanks Doctor! I appreciate you sharing the Avon info and your experience with the wider tires. Do you normally ride two up? Are you a big guy?

Thanks everyone! ZT
Reply With Quote
  #6  
Old 6 Days Ago
rg500 rg500 is offline
Biker
 
Join Date: Oct 2014
Location: Uppsala, Sweden
Posts: 57
Sportster/Buell Model: XLH
Sportster/Buell Year: 1971
Sportster/Buell Model #2: XLH
Sportster/Buell Year #2: 1978
Other Motorcycle Model: XLCH
Other Motorcycle Year: 1971
Reputation: 27438
rg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to all
Default

Quote:
Originally Posted by ZTatZAU View Post

No. I hadn't seen that but I was looking for a 3.75 K81. I'd prefer not going narrower than the original 3.75. I did a quick search for a 3.60 k81 and only saw one on ebay for almost $300!!! Did you find them readily available at normal prices elsewhere?
I just find it interesting that it exists in Europe: see link, unfortunately in Swedish.

https://www.dunlop.eu/sv_se/motorcyc...00--tt100.html
Reply With Quote
  #7  
Old 6 Days Ago
rg500 rg500 is offline
Biker
 
Join Date: Oct 2014
Location: Uppsala, Sweden
Posts: 57
Sportster/Buell Model: XLH
Sportster/Buell Year: 1971
Sportster/Buell Model #2: XLH
Sportster/Buell Year #2: 1978
Other Motorcycle Model: XLCH
Other Motorcycle Year: 1971
Reputation: 27438
rg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to allrg500 is a name known to all
Default

In English:

https://www.dunlop.eu/en_gb/motorcyc...00--tt100.html
Reply With Quote
  #8  
Old 6 Days Ago
ZTatZAU ZTatZAU is offline
Biker
 
Join Date: Aug 2021
Posts: 52
Sportster/Buell Model: XLH1000
Sportster/Buell Year: 1973
Other Motorcycle Model: GL1500 Goldwing
Other Motorcycle Year: 1989
Reputation: 15
ZTatZAU is an unknown quantity at this point
Default

Quote:
Originally Posted by rg500 View Post
I just find it interesting that it exists in Europe: see link, unfortunately in Swedish.
https://www.dunlop.eu/sv_se/motorcyc...00--tt100.html
I think the K81 was quite popular on Nortons. The 3.60 tire was likely stock width for the front.
Quote:
Originally Posted by rg500 View Post
Thanks for that! I went to the same K81 page for Dunlop USA, and they only show the one 4.10 for 19" rims. The USA chart has more info than yours though; namely, overall width in inches to two decimal places which is my main concern. The 4.10-19 shows overall width at 4.17" which makes me curious about the overall width of the 3.60-19. Perhaps it is 3.75"? The 4.25-18 shows 4.37" wide! So the inch spec is not always accurate.

Likewise, Im finding not all 100 tires are 3.94" wide and not all 90s are 3.54" wide.

ZT
Reply With Quote
  #9  
Old 6 Days Ago
mikethebike61's Avatar
mikethebike61 mikethebike61 is offline
Senior Custom Bike Builder
 
Join Date: Jan 2011
Location: Paradise
Posts: 2,981
Sportster/Buell Model: xlch
Sportster/Buell Year: 1977
Other Motorcycle Model: BMW K-1200/GT
Other Motorcycle Year: 2004
Reputation: 292763
mikethebike61 has a reputation beyond reputemikethebike61 has a reputation beyond reputemikethebike61 has a reputation beyond reputemikethebike61 has a reputation beyond reputemikethebike61 has a reputation beyond reputemikethebike61 has a reputation beyond reputemikethebike61 has a reputation beyond reputemikethebike61 has a reputation beyond reputemikethebike61 has a reputation beyond reputemikethebike61 has a reputation beyond reputemikethebike61 has a reputation beyond repute
Default

I ran K291's for years.....good tires.....
__________________
I could be wrong....I'll ask the wife....she ALWAYS knows when I'm wrong......
Reply With Quote
  #10  
Old 6 Days Ago
ZTatZAU ZTatZAU is offline
Biker
 
Join Date: Aug 2021
Posts: 52
Sportster/Buell Model: XLH1000
Sportster/Buell Year: 1973
Other Motorcycle Model: GL1500 Goldwing
Other Motorcycle Year: 1989
Reputation: 15
ZTatZAU is an unknown quantity at this point
Default

Quote:
Originally Posted by mikethebike61 View Post
I ran K291's for years.....good tires.....
I looked at the Elites but thought they looked too modern for a vintage Ironhead. They're a lot like what I run on my Goldwing.

ZT
Reply With Quote
Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT +1. The time now is 02:20.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
XL Forum® - Linson Media LLC