BritBike Forum logo
BritBike Sponsor BritBike Sponsor BritBike Sponsor
BritBike Sponsor

BritBike Sponsor

BritBike Sponsor
BritBike Sponsor BritBike Sponsor BritBike Sponsor
  JWood Auction  
Home | Sponsors, Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons, "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Photo posting tutorial

Member Spotlight
Roger Gulledge
Roger Gulledge
Oahu Hawaii USA
Posts: 255
Joined: January 2012
Show All Member Profiles 
Shout Box
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
Who's Online Now
221 registered members (57nortonmodel77), 1,770 guests, and 551 spiders.
Key: Admin, Global Mod, Mod
Newest Members
XTINCT, Bruce Roberts, Brian Ellery, Jon Andrews, Berni Ernst
9957 Registered Users
Top Posters(30 Days)
btour 190
koan58 100
Stuart 86
NickL 71
Popular Topics(Views)
437,702 mail-order LSR
Forum Statistics
Forums33
Topics65,282
Posts632,294
Members9,957
Most Online3,995
Feb 13th, 2017
Like BritBike.com on Facebook

Previous Thread
Next Thread
Print Thread
Rate This Thread
Page 1 of 2 1 2
#120482 - 07/29/07 2:39 am Tyres/Tires  
Joined: Aug 2006
Posts: 706
BrianFromOz Offline
BritBike Forum member
BrianFromOz  Offline
BritBike Forum member

Joined: Aug 2006
Posts: 706
NSW Australia
why is there 2 different recommended sizes ?
(T140V Workshop manual)



help laugh


"What are you rebelling against?
What have you got?"

77 T140V

Is Your Bike Here?
MembersBikesBritBikeForum
http://s165.photobucket.com/albums/u51/MembersBikesBritBikeForum/
Support Your #1 BritBike Forum!
Membership Type! Free
Member
Premium
Member
Premium Life
Member
Vendor
Member
Site
Sponsor
Recognition No Premium Member Premium Life member (5 years) Vendor Member Site Sponsor Membership
Post commercial threads No No No Yes Yes
Custom title No Yes Yes Yes Yes
Upload avatar & photos No Yes Yes Yes Yes
Link avatar & photos Yes Yes Yes Yes Yes
Private Message Storage: 10 100 100 100 100
Length of signatures 255 600 600 600 600
Removes this very advert island between post 1&2 No Yes Yes Yes Yes
Price Free $12.90/year $105.00 No End
$55.00/5 years
$210.00/year
($17.50/month)
Email
Click on button >>
  Premium Member Premium Life member Vendor Member Site Sponsor Membership
#120483 - 07/29/07 12:20 pm Re: Tyres/Tires  
Joined: Nov 2005
Posts: 7,220
JubeePrince Online content
Life member
JubeePrince  Online Content

Life member

Joined: Nov 2005
Posts: 7,220
Back on the mainland!
Brian -

This is strictly conjecture on my part, but the workshop manual covers the 73-78 years, allowing for different tire sizes....i believe 3.25 was a common size for the drum brake front wheels.....

I have the original owners handbook for my bike. In the book the original tire specs were for a 3.25 front and a 4.10 rear. The factory actually pasted a new spec over the original (or the dealer put it there as supplied by the factory) the new spec reads 4.10 front and 4.10 rear....I can still see the original specs underneath the pasted piece of paper 3.25 front and 4.10 rear

The tire pressures were also changed from 24 front and 25 rear to 28 front and 32 rear.......

Having said all that, I run K81 Dunlop Roadmasters on my bike.....4.10X19 on the front and 4.25X18 on the rear......

Cheers,

Steve


'77 T140J
"Vintage Bike". What's in your garage?

"The paying customer is always right."

Fitting round pegs into square holes since 1961...
#120484 - 07/29/07 12:37 pm Re: Tyres/Tires  
Joined: Jun 2002
Posts: 9,297
Stuart Online content
BritBike Forum member
Stuart  Online Content
BritBike Forum member

Joined: Jun 2002
Posts: 9,297
Scotland
Hi,

Someone has misunderstood tyre sizing (it's slightly less confusing if you ignore the bracketed metric measurements). :rolleyes: Ime, the giveaway is the different pressures - the more-modern the tyres, the higher the pressures required for a given bike, irrespective of the tyres' sizes.

3.25x19 front and 4.00x18 rear are known as '100% aspect ratio' tyres, because the nominal section height is the same as the nominal section width (3.25 and 4.00). These sizes are what Triumph and BSA certainly fitted to US-market twins and singles in the late 1960's and early 1970's.

4.10x19 front and 4.10x18 rear are known as '90% aspect ratio' tyres, because the nominal section height is 90% of the the nominal section width (4.10) (their metric designation would be '100/90x19' (or '18'), the figure after the '/' indicating the percentage ratio).

When (by then just) Triumph started fitting 90%-aspect-ratio tyres, the equivalent of the old 3.25 is 4.10 and the equivalent of the old 4.00 is 4.25/85. However, there were numerous complaints of speed wobbles and, if an owner went so far as to go to the Meriden Service Department, apparently a 4.10x18 rear would be quietly fitted while the owner was plied with tea elsewhere, the owner would be asked to try his bike again and, if he/she was happy, sent on his/her way with nothing more said. wink

Hth.

Regards,

#120485 - 07/29/07 2:03 pm Re: Tyres/Tires  
Joined: Nov 2005
Posts: 7,220
JubeePrince Online content
Life member
JubeePrince  Online Content

Life member

Joined: Nov 2005
Posts: 7,220
Back on the mainland!
Quote:
Originally posted by Stuart:
apparently a 4.10x18 rear would be quietly fitted while the owner was plied with tea elsewhere, the owner would be asked to try his bike again and, if he/she was happy, sent on his/her way with nothing more said. wink
Now that's what I call customer service..... bigt

Steve


'77 T140J
"Vintage Bike". What's in your garage?

"The paying customer is always right."

Fitting round pegs into square holes since 1961...
#120486 - 07/29/07 2:28 pm Re: Tyres/Tires  
Joined: Mar 2006
Posts: 3,647
raf940 Offline
BritBike Forum member
raf940  Offline
BritBike Forum member

Joined: Mar 2006
Posts: 3,647
gastonia nc
so...i see in some ads the k81 size as 4.25/4.60x18.is this the same as the 4.25x18 which is 'really' 4.00x18 in the k70????


1972 Triumph T120
1968 BSA A65
1968 MGB Roadster
1979 Chevrolet Camaro Berlinetta
1969 Honda Mini Trail
1939 farmall f30 tractor
2004 Honda Shadow Aero
1972 BSA Thunderbolt
1975 yamaha xs650b
1972 Norton commando project
#120487 - 07/29/07 2:57 pm Re: Tyres/Tires  
Joined: Apr 2006
Posts: 190
retired-fireman Offline
BritBike Forum member
retired-fireman  Offline
BritBike Forum member

Joined: Apr 2006
Posts: 190
Sydney Australia
Hi Brian, I run 3.25/19 Bridgestone BT45 on the front and 120/19/18 BT45 on the rear of my 1976 TR7. Handles great with no wobbles or problems with chainguard clearence! bigt

#120488 - 07/29/07 7:06 pm Re: Tyres/Tires  
Joined: Jun 2002
Posts: 9,297
Stuart Online content
BritBike Forum member
Stuart  Online Content
BritBike Forum member

Joined: Jun 2002
Posts: 9,297
Scotland
Hi,

Quote:
Originally posted by raf940:
so...i see in some ads the k81 size as 4.25/4.60x18.is this the same as the 4.25x18 which is 'really' 4.00x18 in the k70????
There is no such thing as 'same' when comparing tyres in different aspect-ratio categories. wink What I forgot to put in my last post, but have said before, is one thing you can/must *not* do is compare by nominal size - the *only* way is to compare *actual* dimensions (I use 'overall width' and 'turns per mile'); that's the *only* way you know bolts do/don't gouge it and it does/doesn't keep the front/back the same height off the road.

Thus, you'll find, say, an Avon AM26 Roadrider 110/90x18 (metric 4.25/85x18) is fractions of an inch (aka a few millimetres) both shorter and narrower than a 4.00x18 AM26 which, in turn, is slightly shorter and narrower than a 120/90x18 AM26; however, say, the superseded AM21 Roadrunner 4.00x18, while very similar in tpm (thus height) to the AM26, was some 9/16" wider, which could cause fitting problems in old Brit. bikes. :rolleyes:

Confused? Good, I have a consultancy where you pay me lots of money to explain this in more detail. laugh

Hth.

Regards,

#120489 - 07/29/07 9:08 pm Re: Tyres/Tires  
Joined: Aug 2006
Posts: 706
BrianFromOz Offline
BritBike Forum member
BrianFromOz  Offline
BritBike Forum member

Joined: Aug 2006
Posts: 706
NSW Australia
Confused?...i was confused before, now i have a headache bigt ...further confusing comments welcome laugh
....i think ill go have a lie down....


"What are you rebelling against?
What have you got?"

77 T140V

Is Your Bike Here?
MembersBikesBritBikeForum
http://s165.photobucket.com/albums/u51/MembersBikesBritBikeForum/
#120490 - 07/29/07 9:59 pm Re: Tyres/Tires  
Joined: Mar 2006
Posts: 3,647
raf940 Offline
BritBike Forum member
raf940  Offline
BritBike Forum member

Joined: Mar 2006
Posts: 3,647
gastonia nc
let me rephrase my question.how wide in INCHES is a 4.25/4.60x18 k81


1972 Triumph T120
1968 BSA A65
1968 MGB Roadster
1979 Chevrolet Camaro Berlinetta
1969 Honda Mini Trail
1939 farmall f30 tractor
2004 Honda Shadow Aero
1972 BSA Thunderbolt
1975 yamaha xs650b
1972 Norton commando project
#120491 - 07/29/07 10:00 pm Re: Tyres/Tires  
Joined: Mar 2006
Posts: 3,647
raf940 Offline
BritBike Forum member
raf940  Offline
BritBike Forum member

Joined: Mar 2006
Posts: 3,647
gastonia nc
let me rephrase my question.how wide in INCHES is a 4.25/4.60x18 k81


1972 Triumph T120
1968 BSA A65
1968 MGB Roadster
1979 Chevrolet Camaro Berlinetta
1969 Honda Mini Trail
1939 farmall f30 tractor
2004 Honda Shadow Aero
1972 BSA Thunderbolt
1975 yamaha xs650b
1972 Norton commando project
#120492 - 07/30/07 3:20 am Re: Tyres/Tires  
Joined: Jun 2002
Posts: 9,297
Stuart Online content
BritBike Forum member
Stuart  Online Content
BritBike Forum member

Joined: Jun 2002
Posts: 9,297
Scotland
Hi,

Quote:
Originally posted by BrianFromOz:
im leaning towards the Avons
Good choice, ime and imho.

Quote:
Originally posted by BrianFromOz:
whats the equivalent of 4.10/18 and 4.10/19 in this list?
100/90x18 = '4.10/18' and 100/90x19 = '4.10/19'

Quote:
Originally posted by raf940:
let me rephrase my question.how wide in INCHES is a 4.25/4.60x18 k81
In a word, dunno; there isn't any such thing as a '4.25/4.60x18 k81'. frown

From memory (which isn't any great shakes, I'll admit), this reads like one of those stupid Cheng-Shin-type designations, typed up by some muppet who neither knows nor cares. mad I *think* the '4.25' here refers to a 100%-aspect-ratio size while the '4.60' refers to the *equivalent* 90%-aspect-ratio size.

100%-aspect-ratio Imperial nominal widths are divisible exactly by 0.25 (e.g. 3.00, 3.25, 3.50, 4.00) while 90%-aspect-ratio Imperial nominal widths (e.g. 3.60, 4.10, 4.60) aren't. The one that screws up this cosy rule is 4.25, being used for both 90%- and 100%-aspect-ratio tyres. :rolleyes: K81's (and Roadrunners) were *only* ever 90%-aspect-ratio tyres so, to show their 4.25x18 wasn't a 100%-aspect-ratio, both Dunlop and Avon designated their tyres '4.25/85x18' (as was to become common in metric designations) (Yes, I know '85' isn't '90' but let's not go there, at least not without some paracetamol).

Thus, a '4.25x18' 100%-aspect-ratio tyre is wider again than than 4.00x18 K70/AM21/AM26 (backed up by the '4.60' 90%-aspect-ratio equivalent) and sounds like it might be a dirt-bike rear?

Hth? That'll be UKú50, sir.

Regards,

#120493 - 07/30/07 3:54 am Re: Tyres/Tires  
Joined: Aug 2006
Posts: 706
BrianFromOz Offline
BritBike Forum member
BrianFromOz  Offline
BritBike Forum member

Joined: Aug 2006
Posts: 706
NSW Australia


"What are you rebelling against?
What have you got?"

77 T140V

Is Your Bike Here?
MembersBikesBritBikeForum
http://s165.photobucket.com/albums/u51/MembersBikesBritBikeForum/
#120494 - 07/30/07 4:09 am Re: Tyres/Tires  
Joined: Aug 2006
Posts: 706
BrianFromOz Offline
BritBike Forum member
BrianFromOz  Offline
BritBike Forum member

Joined: Aug 2006
Posts: 706
NSW Australia
....so the front is settled... 100/90x19....

now should the rear be...the same width?,wider?,extra wider?
triumph says 4.10
avon says 4.00
fireman uses 120 (4.7?)
jubee uses 4.25
...am i on the right track or will this cost me another 50 quid? laugh


"What are you rebelling against?
What have you got?"

77 T140V

Is Your Bike Here?
MembersBikesBritBikeForum
http://s165.photobucket.com/albums/u51/MembersBikesBritBikeForum/
#120495 - 07/30/07 4:40 am Re: Tyres/Tires  
Joined: Jan 2007
Posts: 178
Phrog Offline
BritBike Forum
Phrog  Offline
BritBike Forum

Joined: Jan 2007
Posts: 178
Sydney, Australia. I might be ...
Quote:
Originally posted by BrianFromOz:
Confused?...i was confused before, now i have a headache....i think ill go have a lie down....
Your confused confused after reading all this I'm now happy if my tyres are holding air & there is no canvas showing laugh

P.S. I like your Avatar, vegemite on toast, makes me hungry just looking at it bigt


Glenn.
1969 T120
"SUCH IS LIFE"
#120496 - 07/30/07 4:55 am Re: Tyres/Tires  
Joined: Aug 2006
Posts: 706
BrianFromOz Offline
BritBike Forum member
BrianFromOz  Offline
BritBike Forum member

Joined: Aug 2006
Posts: 706
NSW Australia
...spoken like a true aussie laughing laughing

and actually my present tyres look hardly worn but they could be 20+ years old.... eek
laugh


"What are you rebelling against?
What have you got?"

77 T140V

Is Your Bike Here?
MembersBikesBritBikeForum
http://s165.photobucket.com/albums/u51/MembersBikesBritBikeForum/
#120497 - 07/30/07 5:51 am Re: Tyres/Tires  
Joined: Jun 2002
Posts: 9,297
Stuart Online content
BritBike Forum member
Stuart  Online Content
BritBike Forum member

Joined: Jun 2002
Posts: 9,297
Scotland
Hi Brian,

Quote:
Originally posted by BrianFromOz:
The corresponding e-mail from Paypal has obviously been delayed ...

Quote:
Originally posted by BrianFromOz:
now should the rear be...
Being objective about the subjective is a variation of the original consultancy contract (so it'll cost more) ...

Can't speak for the big twins, apart from pointing out that Triumph always fitted a slightly fatter rear than front, until the 4.10x19 front/4.10x18 rear that started this thread, although I knew people who fitted a 3.60x19 (90/90x19) front with the 4.10x18 (100/90x18) rear.

Otoh, the triples started out with 3.25x19 front and 4.10x*19* rear, albeit quickly replacing the front with another 4.10x19. When the K81 and original Roadrunner were superseded, plenty of owners (me included) switched to a 4.25/85x18 (110/90x18) rear. This does lose noticeable cornering clearance on a triple, because the standard footrests are further out than they are on a twin; however, even with rearsets, you still touch down the centrestand relatively easily, which is likely to be similar on a twin.

To get the cornering clearance back, many triple owners moved on to 120/90x18 or 120/80x18 (and at least one masochist has fitted a 130/90x17 eek ) but then encountered problems clearing chains, chainguards, swinging arm, etc. unless all the alignments and spacings were spot-on.

Fwiw, my preferred solution, on a triple, is the 4.00x18, which is slightly narrower overall than a 120-width but still has a similar height to the original 4.10x19.

Quote:
Originally posted by BrianFromOz:
....so the front is settled...
I'm intrigued as to why Avon recommend a 100/90x19 on the front, when they make 3.25x19 AM26 too. confused

Hth.

Regards,

#120498 - 07/31/07 2:13 am Re: Tyres/Tires  
Joined: Aug 2006
Posts: 706
BrianFromOz Offline
BritBike Forum member
BrianFromOz  Offline
BritBike Forum member

Joined: Aug 2006
Posts: 706
NSW Australia
thanx for all responses ....especially thanx stuart for taking the time to explain things....i think im at least armed with enough knowledge to tackle the tyre purchase....
a 110 (which is wats on it now) or 120 on the rear sounds the go.........

..ps...if i ever get to the UK the pints are on me beerchug


"What are you rebelling against?
What have you got?"

77 T140V

Is Your Bike Here?
MembersBikesBritBikeForum
http://s165.photobucket.com/albums/u51/MembersBikesBritBikeForum/
#120499 - 07/31/07 4:49 am Re: Tyres/Tires  
Joined: Aug 2006
Posts: 706
BrianFromOz Offline
BritBike Forum member
BrianFromOz  Offline
BritBike Forum member

Joined: Aug 2006
Posts: 706
NSW Australia
...and also....do u forsee any problems with a "modern" bike shop fitting tyres to an old bike?...no one in this town would know an old brit bike from a dead mullet....are they fitted and balanced with the sprocket and discs still attached? smile


"What are you rebelling against?
What have you got?"

77 T140V

Is Your Bike Here?
MembersBikesBritBikeForum
http://s165.photobucket.com/albums/u51/MembersBikesBritBikeForum/
#120500 - 07/31/07 7:50 am Re: Tyres/Tires  
Joined: Jul 2007
Posts: 594
649 Offline
BritBike Forum member
649  Offline
BritBike Forum member

Joined: Jul 2007
Posts: 594
australia
I just put K81s on my 650...australian price 3.60x19 front $95, rear 4.00(or 4.10) x 18 $103,...just a bike shop price with no chasing around...was going to do BT 45s but they were around $300 a pair, same with metzelers


1970 tr6r dryframe
#120501 - 07/31/07 10:52 am Re: Tyres/Tires  
Joined: Jul 2002
Posts: 604
Tom_dup1 Offline
BritBike Forum member
Tom_dup1  Offline
BritBike Forum member

Joined: Jul 2002
Posts: 604
England
Brian,

Clearance can be a problem for wider than stock tyres. I have a 110 Avon rear and Koni shocks. The wider than standard shocks push the chainguard inwards towards the tyre leaving very little clearance and requiring the chainguard bracket to be bent a little. If you still have Hagons on your bike (looked at your bike pic) you should be OK with a 110 at least.

#120502 - 07/31/07 5:18 pm Re: Tyres/Tires  
Joined: Jun 2002
Posts: 9,297
Stuart Online content
BritBike Forum member
Stuart  Online Content
BritBike Forum member

Joined: Jun 2002
Posts: 9,297
Scotland
Hi Brian & Tom,

Quote:
Originally posted by Tom:
Clearance can be a problem for wider than stock tyres.
A good point. According to Avon's own data, the 120/90x18 AM26 is 11mm wider overall than the 4.00x18 AM26, although the overall diameters are within 2mm of each other.

Fwiw, ...

... with the previous AM20/AM21 Roadrunner and AM20/AM18 Super Venom ranges, for given nominal sizes like 3.25x19 and 4.00x18, Avon significantly increased *overall* widths from the the same nominal sizes in the SM range or equivalent Dunlop K70's (this was the same for all tyre makers - NGO's like the European Tyre & Rim Technical Organisation had changed their standards). As a search of old Board posts would reveal, this led to Brit. bike owners finding it difficult or impossible to fit, say, an AM20 or AM21 Roadrunner in place of a SM or K70, even though both old and new tyres had '3.25x19' or '4.00x18' on the side.

... on the AM26 range, Avon have *reduced* the overall widths of all tyres again, and particularly the 3.25x19 and 4.00x18 have similar widths to the same nominal sizes in SM's (or K70's), so AM26's should fit as easily as SM's or K70's between old Brit. bike forks and swinging arms.

Fwiw, unless the recommended AM26 sizes aren't available (e.g. the old 3.25x19 AM20 and 4.00x18 AM21 Roadrunners weren't imported into some countries), I'd be inclined to go with the Avon recommendations. I get the impression that Avon specifically want AM26's in old Brit. bikes, so something like a T140 will almost certainly have been tested. Only thing I might do before ordering is fire off an e-mail to Avon tech. help asking why they recommend a 100/90x19 front instead of the 3.25x19 they make.

Quote:
Originally posted by BrianFromOz:
do u forsee any problems with a "modern" bike shop fitting tyres to an old bike?
No modern Jap bike owner is going to want his bike's rims chipped, bashed or scratched, so I can't see why any of the local tyre fitters should do it to your T140's chromed steel rims. One thing I would insist on is, when the shop orders your tyres, they should also order a good make (e.g. Continental) tubes - no Chinese name no-one's ever heard of.

Quote:
Originally posted by BrianFromOz:
are they fitted and balanced with the sprocket and discs still attached?
Yes - it's all rotating mass.

Hth.

Regards,

#120503 - 07/31/07 9:16 pm Re: Tyres/Tires  
Joined: Nov 2005
Posts: 7,220
JubeePrince Online content
Life member
JubeePrince  Online Content

Life member

Joined: Nov 2005
Posts: 7,220
Back on the mainland!
Quote:
Originally posted by Stuart:


Quote:
Originally posted by BrianFromOz:
are they fitted and balanced with the sprocket and discs still attached?
Yes - it's all rotating mass.

Hth.

Regards,
Guys,

AIUI, dynamically balancing a rear wheel with rim locks (or any wheel with rim locks for that matter) is not possible, difficult at best.....perhaps it could be statically balanced...

My local Triumph shop guy refused to try and balance my rear wheel unless he/I removed the rim locks.....I passed on it, being as that I had/have no issues with my rear wheel being out of balance/true......he claimed that you would never get the same balance reading twice.......not sure if this is factual or not.....anyone know for sure?

I've read here where the rim locks can be removed and the holes plugged with some silicone to prevent moisture and pebbles from penetrating the rim and tube......

If you do remove them to clean/repair the wheel and plan on putting them back on, be sure to note from what holes they came from....

Cheers,

Steve


'77 T140J
"Vintage Bike". What's in your garage?

"The paying customer is always right."

Fitting round pegs into square holes since 1961...
#120504 - 07/31/07 9:18 pm Re: Tyres/Tires  
Joined: Aug 2006
Posts: 706
BrianFromOz Offline
BritBike Forum member
BrianFromOz  Offline
BritBike Forum member

Joined: Aug 2006
Posts: 706
NSW Australia
" quote:Originally posted by BrianFromOz:
are they fitted and balanced with the sprocket and discs still attached?

Yes - it's all rotating mass."

...i thought as much for that reason but id prefer to look silly amongst u guys then amongst the wallys at the bike shop..... laugh


stuart...i fired off an email to Avon (Cooper Tires) with a few questions about how they came to their recommendations and the 100/90,3.25 thing..
thanx again one and all bigt


"What are you rebelling against?
What have you got?"

77 T140V

Is Your Bike Here?
MembersBikesBritBikeForum
http://s165.photobucket.com/albums/u51/MembersBikesBritBikeForum/
#120505 - 07/31/07 9:45 pm Re: Tyres/Tires  
Joined: Aug 2006
Posts: 706
BrianFromOz Offline
BritBike Forum member
BrianFromOz  Offline
BritBike Forum member

Joined: Aug 2006
Posts: 706
NSW Australia
missing in action!



"What are you rebelling against?
What have you got?"

77 T140V

Is Your Bike Here?
MembersBikesBritBikeForum
http://s165.photobucket.com/albums/u51/MembersBikesBritBikeForum/
#120506 - 07/31/07 10:50 pm Re: Tyres/Tires  
Joined: Sep 2001
Posts: 69
MikeTRP Offline
BritBike Forum member
MikeTRP  Offline
BritBike Forum member

Joined: Sep 2001
Posts: 69
Melbourne, Australia
We used to refer to 3.60/4.10/4.25 K81's as wide profile 3.25/3.50/4.00 respectively. All with a lower aspect ratio than the round ones, to roughly match the original diameter.
All K81's come from Japan now, so do K70's and have good grip, reasonable life.
I have been using K81 GP compounds for some time, with less life but even better grip, even from cold. These are listed in metric 90/100/110mm x 90%.
In Aus, Dunlop published their 06/07 tyre brochure listing K81's and K81GP's, hence any local tyre shop shouldn't be flustered when asked about these sizes.
I am investigating a Euro brand called heideniou or something, which lists a 110/90x19 in a certain tread pattern, with no accompanying picture. Trying to find out if it's front or rear and if any good. Maybe a godsend for T160/Norton owners if its a good rear. let you know.

Page 1 of 2 1 2

Moderated by  John Healy 


Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.542s Queries: 15 (0.069s) Memory: 1.0071 MB (Peak: 1.3590 MB) Zlib disabled. Server Time: 2017-11-22 05:40:51 UTC