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Posted: Tue Sep 18, 2012 8:56 am
by BrynP
[quote="robh1f"] Bryn $64000 question , do you know of a dealer stocking k87s over here?? quote]

Sorry, I don't.
At Cambrian Tyres we only distribute the official UK ranges of the various manufacturers.
The only way you could find out is to contact the likely candidates.

Posted: Tue Sep 18, 2012 11:31 am
by quivals189
I just spoke to Phil at Z- Power and he said they had just got a shipment of F11 and K87 in stock.

Posted: Tue Sep 18, 2012 7:21 pm
by Neil the Don
I have fitted some of those K87 etc things on H1-C rims.

They may be period , but they just look crap !!!

Either put some sensible modern tyres on that work, like Avon roadriders , or Metzeler ME77/ME11`s. Which look old-ish but still WORK !!!

I know some folk are using TT100`s. Modern versions are not as triangular as originals. But I`m sure they`ll still wobble or at least make the front steer like its running on low pressure .

Pointless me saying all this I know. But I am always right....actually....don`t you know. !!!

Posted: Tue Sep 18, 2012 7:45 pm
by Tartan Triple
road riders for those that ride :smt023

Posted: Tue Sep 18, 2012 8:27 pm
by robh1f
Where did you get the K87s Neil...............front AND rear ???? 8)

Posted: Tue Sep 18, 2012 8:29 pm
by bbb
All my triples have TT100's, love em, I get them from BMTR in Birmingham, Perry Bar, 0121 331 1122. as I know the boss, they supplied all my racing tyres back in the day.
they have them in stock as far as I know but usually at their depot, I think, in coleshill?
Sure if you talk to them they'll know.

Posted: Tue Sep 18, 2012 8:58 pm
by Tartan Triple
why?? if your going to do 100 miles a year and trundle it in and out a van fine,otherwise,get real ones to ride on :smt023

Posted: Tue Sep 18, 2012 9:01 pm
by Peter Mac
Tt100's me thinks... K87 is not available in the front size & f11 is not correct for the 500.... So tt's for me :smt023

Posted: Tue Sep 18, 2012 10:05 pm
by Eric
Did 400 miles on the TT100`s two up in at the Manx this year, no problem.
Glad most of you guys were not about back in the day as you would never have ridden them especially with the ribbed front tyre.

Posted: Wed Sep 19, 2012 12:45 am
by bbb
Tartan Triple wrote:why?? if your going to do 100 miles a year and trundle it in and out a van fine,otherwise,get real ones to ride on :smt023
I do 2/3 thousand miles a year on the 750 and 500, a bit less on the 400/350's (virtually nothing on the 250) The TT100's/K82's (which look identical) are fine!

Posted: Wed Sep 19, 2012 7:09 am
by johnnymoped
I put the Dunlops on from Z power - even with the 600 miles I've done running in - it's nice and easy to get the stand ground away :lol:

Posted: Wed Sep 19, 2012 10:37 am
by BrynP
I have to admit to being in Neil and Tartan's camp on this subject. If it's a little-ridden resto then going the TT100 (or similar) route is fine and I completely understand why many make this choice. And while anyone who rode in the '70s can tell you how good the TT100 was against most of its opposition that was 30+ years ago and tyre technology has moved on considerably and it can't possibly hope to compete against a more modern design.

Improvements in tyre design and materials have led to better side grip, increased braking and acceleration traction performance, improved high-speed stability, better handling progression and much more feedback. In short, a safer product to ride on and because of more uniform profiles, tyres such as Avon's Roadrider are just so much nicer to use.

And it's not just Avon that makes good tyres in the 3.25-19 and 4.00-18 sizes for the H1/H2. Sure, for the moment the Avon is the performance king but Bridgestone's evergreen BT45, Continental's ContiGo, Dunlop's GT501 and Metzeler's Lasertec are all very close behind and in our experience also last longer than the Avon - durability is not the Roadrider's strongest point.

And as Neil points out, Metzeler's ME11/ME77 pairing is still available for someone wanting a more classic-looking tyre (althought these days the ME11 front is only available in S speed rating, for speeds up to 112mph). And even though it's not quite as "period" as the TT100 it does have a more uniform profile that gives better handling progression.

There's also Continental's RB2/K112 pairing. These designs pre-date the ME11/ME77 so could be considered slightly more "period". The tread pattern (to my eye) certainly looks more like an early '70s designs. But crucially, like the Metzelers they have a more uniform profile for nicer handling progression.

However, all of these tyres are cross-ply (aka bias-ply) design and there's no hiding the fact that even though the newer designs are far better than older tyres, cross-ply design has not advanced as much as radial tyre design. This should come as no surprise as the vast majority of sport, sport-touring and naked bikes over 500cc have used radials for years so that's where the tyre manufacturers have poured the majority of their road tyre development budgets.

But there is some news on the horizon. Some of you may have noticed a small report in MCN a few months ago. Continental has developed radial tyres in sizes to suit H1s and H2s and in the 23 years that I've been in this game this is potentially the biggest news I've heard of for the classic bike tyre scene.

For those that don't know, radial tyres use fewer components and therfore run cooler, which means compounds that are less stiff can be used for increased grip. But outright grip isn't the only advantage the radial. The casing design doesn't suffer from the same levels of dynamic growth as cross-ply tyres. Dynamic growth is the increase in the tyre's overall diameter the faster you go. This is virtually eliminated by the radial's design and means that the contact patch isn't constantly changing shape and size and this leads to far better stability at speed. You'll also find that braking traction should be on a different level to cross-plys. But one of the things where radials really score over cross-plys is in shock absorption. The results will be a smoother ride and the potential for increased corner grip. This is because when a bike is leaned over the suspension cannot work as efficiently as it does when the bike is upright. Greater demands are then placed on the tyre to absorb the bumps and keep the tyre in contact with the road. A more compliant casing, but still with good lateral control will enable this.

The great thing for classic bike riders is that from the late '80s, when they were launched, radial motorcycle tyre development has been gradual. But if you rode a modern radial back-to-back with a 20 year old radial you'd certainly notice the huge difference in overall performance. With all of this radial development already done, and after many years of incremental gains in cross-ply performance, it looks like tyres for classic bike could take a big step forward in the not too distant future.

Posted: Wed Sep 19, 2012 1:07 pm
by Bizkarts
Bloody hell :shock: Bryn Phillips, ex Cambrian tyres. Martin Dellow from BIZ karts here, small world.

Nice to see you on here and with some very useful info as I would expect. Are you tripled up at the moment, or considering taking the plunge?

Posted: Wed Sep 19, 2012 2:44 pm
by BrynP
And back at Cambrian Tyres after a few years away, Martin. Good to hear from you again. :smt039

I bought a H1E from RB earlier this year but a few things got in the way of me starting work on it. But it's now fully stripped and waiting for the parts to be farmed out for powder coating, etc.

Period tyres / Rims

Posted: Sun Oct 07, 2012 6:32 pm
by Klawsuc
Anyone interested i have a few Dunlop gold seal F6 3.50 x 18 NOS as fitted to the Z1R Z1R Turbo and some Z650's.
I also have a few NOS original Yokohama 3.35 x 19 as fitted to the very first 1972 H2's.
Both are front fitment , not cracked or hardened but because of age i recommend that they are fitted for show purposes only.
Phil

Re: Dunlop tyres

Posted: Sun Oct 07, 2012 10:29 pm
by scouse
BrynP wrote:Dunlop Europe, and therefore Dunlop UK doesn't import the OE-spec F11 and K87 in classic sizes. Any you see for sale in the UK are as a result of dealers importing them independently.
When I was at Dunlop I made enquiries about several sizes that dealers had requested, only to be told by Dunlop Japan that they were not E-marked so not available to us. (Tyres have to be E-marked to be legal for sale for road use over here). I'm not saying this is the case with these two sizes but it would always be worth asking the supplying dealer.
Dunlop would also argue that the demand for these sizes is limited and they already have the K81 TT100 and K70 in their range for the classic market.
By the way, the K70 range carries different speed ratings dependent on size. The 3.25-19 and 3.50-19 are P speed rated, i.e. up to 93mph. The 4.00-18 rear is S rated, which is 112mph.
Sorry to drone on but it's also worth pointing out that the 19 inch K70s are actually intended for rear wheel use only (common Brit bike sizes) but many people also fit them on front wheels and even Dunlop supplied them to Triumph in the 1970s for front wheel fitment on T120s and T140s.
K81 TT100s are H speed rated for speeds up to 130mph so are a better bet for the 500 and 750. They also qualify as being "period" because they were launched in 1969.
The only thing that confuses people with the K81 TT100 are the sizes. This is because they are 90% aspect ratio imperial-sized tyres; a form of sizing that was fairly short-lived. The equivalents of 3.25-19 and 4.00-18 are 3.60-19 and 4.25/85-18 respectively.
I won't go into how this came about because I'm sure you all have better things to do with your lives! :D

Also worth noting if you fit the wrong speed rated tyre to your bike and are unlucky enough to crash, don't expect a pay out as your insurance will be invalid :smt023

Happy Sunday everyone :twisted:

Gary T