Tyre age.

Quite a good explanation here: https://www.oponeo.co.uk/tyre-article/tyre-s-date-of-manufacture

Given how dependent we are on our tyres I would replace anything more than 6 years old or so - although I have seen cracking on tyres (not bike) as new as 3 years!

I am the lucky recipient of a 1998 Enfield Bullet that was lying for 17 years. The Avon tyres on it are in perfect condition (the bike has only 1,000 miles on the clock) and I am happily riding around on them. No sign of cracking, plenty of tread and plenty of grip.

I usually run the securing nut up to the valve cap. I believe that was something described by Sammy Miller so that you'd see the valve tilt before it was ripped out of the tube. More valid with 4 psi than 28 of course!

If you look at the Michelin Airstop packet front top corner you will see an illustration of a valve showing the dished washer against the tube with a nut against it and the other nut further up which suggests to me that it can fit on the outside of the rim.

Whether this is what Michelin intended I can't say but that is how I do it and with no problems.After all we have not needed a lock nut in the past and for some time they were supplied with round nuts with milled edges that could be done up tight by finger and thumb.

Look closely at the pics of this Avon front tyre that I purchased for my 650 about 10 years ago. It was ordered from a well-known tyre supplier whose base is/was in the New Forest. The tyre was delivered by courier.

I was not too happy with crazing marks on the sidewall and top tread. Unbelieveably........those brown blobs on the tyre are rust. I physically took the tyre back to the supplier who claimed that the crazing is the 'natural finish' and the brown blobs rust stains from the manufacturing mould. However, the latter was disproved when the biggest blob was picked out and was large enough to have easily been the head of a nail. All of the other blobs were clearly pieces of rusty metal embedded in the tyre wall.

The replacement tyre was completely normal in appearance and has now covered 5,500 miles with no problems.

The compounds in tyres deteriorate in the presence of oxygen and sunlight. Your well known supplier should never have tried to palm you off with that specimen. Clearly badly stored. By contrast, the Avon tyres on the Enfield mentioned above look factory fresh. The result of being kept in a cold dark shed perhaps.

Yep - that tyre is definitely "cream-crackered" as we used to say in the trade! Look at that sidewall cracking too!

Previously philip_hannam wrote:

Look closely at the pics of this Avon front tyre that I purchased for my 650 about 10 years ago. It was ordered from a well-known tyre supplier whose base is/was in the New Forest. The tyre was delivered by courier.

I was not too happy with crazing marks on the sidewall and top tread. Unbelieveably........those brown blobs on the tyre are rust. I physically took the tyre back to the supplier who claimed that the crazing is the 'natural finish' and the brown blobs rust stains from the manufacturing mould. However, the latter was disproved when the biggest blob was picked out and was large enough to have easily been the head of a nail. All of the other blobs were clearly pieces of rusty metal embedded in the tyre wall.

The replacement tyre was completely normal in appearance and has now covered 5,500 miles with no problems.

hello now looking at my Norton Manxman's rear tyre is now some 30 years old a dunlop gold seal k70 64S rated So now just bought two new type Dunlop Arrowmax 4.00-18 rear and 3.25-19 front all weather tyre and long lasting lets hope It lasts as long as the Gold seal K70 did, and if anyone near me would like to help fit the rear tyre my strength is not what it use to beI just made two nice tyre irons as there not easy to find even on ebay you should all know my photo number by now its 01430430831 thanks you for reading yours anna j

hello Now Got my Dunlop Arrowmax street smarts400.-18 rear fitted by my self its been a four hour struggle but with time and patience I got there in the end, I have been to most garages around here and no one can fit them as there wire wheels and has a tube inside in other words they have not the know how, to fit classic motorcycle tyres , its a good job my father taught me and I have this skill set in fitting classic motorcycle tyres but need some more tooling witch I have not seen any more for a long time Now as for front wheel its need a new chrome rim as Devon rim that i bought in 2009 the chrome as come off in places and its not been chromed right it look like they throw in the chrome bath and hoped for best and not removed the rust first, and you pay out top money for crap DEVON RIMS Well lets hope this Jones rim NEW fairs better and stands the test of time , as for stainless rim get them the magnet test if it falls of there stainless if sticks like glue there dummies there is loads of fake parts out there yours Anna J Dixon

Better to fit Devon Stainless rims, they are excellent. Don't know if this has been mentioned on the forum but be aware that there have been issues with Avon tubless tyres fitted with tubes. There was a spell when they had a small plastic label inside the tyre which can fret the tube leading to deflation. This label is no longer being fitted to tyres.

Tubless tyres are a tighter fit but still possible with the old 6" tyre levers and patience.

I have learned that the 'appliance or science' helps with the fitting of new tyres. So I try and leave each new tyre in a nice warm environment, for a good few hours, before tying to fit it. Generally the greenhouse, conservatory or when desperate, the airing cupboard .......... as long as my wife has not noticed. You will be very suprised at what a difference this can make and can help to save skinned knuckles, broken finger nails and an awful lot of bad language.

Phil - do you mean you get the skinned knuckles, broken finger nails and bad language if your wife does notice?!

Previously robert_tuck wrote:

If Patience is a big strong lass ======.

Hello well I do not know about Strong lass I am now 64 going on 65 with two dodgyknees, it's more like loads of skill and know-how and my big leatherhammer and my homemade long tyre irons these new type tyres are harder to fit on your own, were it really need two of you, But it seems there are, No Norton owners around here willing to help, well that'sthe East Yorkshirebranch for you, AS I have No contact details of members any more after this privacy policy, had to destroyall contact details of members even clean my computer, as well NO data files Anymore yours Anna J -

Previously robert_tuck wrote:

Hi Anna, I recently fitted some new tubeless tyres AVONS to my Atlas, using new tubes. They were very difficult to fit ,both in not wanting to stretch over the rim and not wanting to sit evenly at the bead. I did all the usual things,warming the tyre,lubrication ,pushing the bead into the opposite well etc, I concluded that the tubeless tyres are a tighter fit to ensure a good seal when used tubeless.

Hello Robert Well I did look and read up on new type tyres for Classic and vintage Mortorcycles to see what the so Called Experts say And Avons roadriders Am64, did not get a very good report the top brands were Perelli and Bridgstone along with Dunlop next to top in British brands the Dunlop Gt601 Arrowmax Streetsmart have a good rating and there speed rating is a H rating witch is 130mph were as the Dunlop K81 TT100s are speed rated as a S rating of 112 mph and P Speed rating is 90 mph so beware of your speed ratings , before bying new tyres anyway the new Dunlop Arrowmax Streetsmart have a good tread depth and give very good roadholding in all weathers and are long lasting rubber componds anyway now fitted and inflated and fitted back on my Norton they do not look out of place with this bike, and the Rear tyre is a bit narrower to the OLD Dunlop K70 Gold Seal in the same size of 4.00-18 rear, witch is 12 pounds cheapper to the metic size of 110/90-18 , witch is the same size as the imperal one, Why I do not know, the Front tyre was 23 pound Cheaper to the Metric size od 100/90-19 witch is the same has 3-25-19 witch I bourht in the end witch is a Arrowmax Streetsmart , so two matching tryers long with a new Jones Chome Rim , fort the Front wheel the spoke are original in very good condition And as For Tyre lubircation Fairy Washing up Licquid work's wonders and at the end with some water around the rim edge you can see if you niped the tube or Not, becaue you see Bubles as the air comes out, Its best to get as far round the tyre as you can and then ease back and forth untill yuo have treched the rim cords a bit and keep the other end of the tyre in the mid way of the rim and banging the tyre round with a heavy leather or rubber hammer ,to settel the tyer into the rim but Do not use a steel hammer you risk damaging the tyre and tube in side the rim , the motorcylist skills of tyer fitting are now deminishing by the year, has us lot get older , PS no knuckles knocked up or fingernails broken just lot of hard work and sweat witch is good for you, like a cheap work out in the gym , yours Anna J

Anna J! Been reading your comment regarding tyre fitting from 2018.

Interesting. I'm stuck with a new Roadrider Mk II 4.00-18 that binds between the swing-tubes unless I move it right to the back. I'm not afraid of shaving the ridge at the side of the tread, but shaving off 1/4" on each side to get a decent fit with some clearance is going too far.   

Everybody with an Atlas with an 18" WM3 rim at the rear has this problem with new tyres, but nobody seems to have a convincing answer.  

I was interested to see your post referring to the narrow width of the Arrowmax Streetsmart. I've tried to do a complete survey of all tyre makes, and as far as I can see, Dunlop are the only makers that do an 18" tyre that is actually 4.00" wide. These are the TT100 (4.10-18) and the Arrowmax (4.00-18). All other makes and types are wider.  

Next problem is the outer diameter of the cover. The Atlas is a big lump to heave up onto the stand, so I'm looking to avoid a tyre with a small diameter, meaning I have to lift even more. The "original" Avon SM MkII has a cover diameter of 26,7"/677 mm, so that's the kind of size I'm aiming for.

Problem now is that I can't find complete data for the Arrowmax! Does anybody have a measurement for the outer diameter so that I can do a comparison?

No, not joking. With sharp blades, a very fine cut (and a lifetime's experience of using wood planes) it worked well. And with the dust extractor attached there's no rubber-mess that you get with any other shaving/filing method. I'm still hoping to get data on the Arrowmax that Anna mentioned.

Christophers comments have got me thinking. Is there more than one type of 'Slimline' swinging arm I wonder, as this subject has come up before. What was the size and fitted width of the Avon GP as originally specified for the 650SS?

For info, I have a WM3x18" rear wheel in my 1967 650, fitted with a Metzeler Roadtec 01 110/90x18 tyre, and this comes out at 4.12" wide fitted. With the chain adjusters 1/3rd out I have a clearance to the swinging arm of approx 1/4" both sides. The chainguard is closest - clearance to that is just over 1/16" and as there are no contact witness marks from the tyre on it, it must be enough.

I will agree with others - many modern tyres seem to be harder to seat on the rims than in the old days. With the white tyre lube not working, I ended up with some 'truck tyre lube' from my tame tyre shop - it looks a bit like vaseline - and at 90PSI it finally went out with an arse puckering 'pop'. On the good side, the tyres no longer creep on the rims these days, so security bolts aren't needed.

Regards,George

"Anna J! Been reading your comment regarding tyre fitting from 2018."

Pretty sure she no longer comes here.

More Atlas tyre fitting issues. The bracket for the fully enclosed chaincase is a problem with today's wider tyres: I've read on Access Norton of owners cutting off the forward bracket to get more clearance.

 I'm not aware that there were any other differences over the years - unless there was a bodge-up during the welding and brazing of the swinging arm. Mine's a Plumstead Atlas, and the quality of of the rest of the frame welding is poor, not to mention the engine castings. So who knows, maybe the jig slipped! I don't have another swinging arm to compare.

In the event, after a comprehensive survey of virtually all available 4.00x18, 4.10x18 and 110/90x18 classic touring tyres I've plumped for the good old Dunlop K70. It's one of the most narrow, and has an inflated diameter as good as the original Avon SM. It's a bias tyre with modern rubber composition, so fingers crossed. I'll keep George Farendens tip about the Metzeler Roadtec 01 in mind for the future. The two tyres, the K70 and the Roadtec are in the same price class. i.e. far too expensive. But what do you do?

Regards, /Chris

I have managed to run all my Atlas bikes with 4.00 x 18" rear tyres. A Roadrunner would just about fit if the chain was half worn and the tyre towards the back of the swinging arm. With a new chain I used a 'half-link' to get a similar result.

Many rears ago I looked into a Dominator replacement swinging arm, from Dresda Autos, which was 'Box' section and designed for a range of wider tyres. The drawback being the cost. Dave D  showed me a swinging arm modification which was very easy to do, cost very little and worked for  me.

It consisted of marking the swinging arm where the tyre was going to rub. The arm was then removed from the bike and measured with a line along 1" each side of that mark. The area was then heated up to cherry red and the line punched in around 1/4" with a cold chisel. This folded the inner S/A metal into the arm and gave at least 1/8" extra clearance each side. Dave suggested welding the fold to add strength but this was apparently not necessary on road bikes.

The modifcation allowed me to use a range of 4.00 or 110 tyres on the back apart from TT100s which needed the side block shaving. This worked on two of my Atlas bikes for 20 years and gave no problems.

Think I've read that Mick Hemmings also did a swinging arm that was wider.  Something to look out for. It's easy enough to fit.

Not too keen on the "blacksmith's method" even though I'm sure it's effective. Pin my hopes on the K70 that's on it's way from Däckonline. /Chris

Hi Robert,

My sentiments exactly, I’ve been up the ladder today repairing gutters.

When you think of the condition of tyres and vehicles in general before the 10 year test (M.O.T.)

was invented I’m surprised I’m still here.

You could have a heart attack on your ladder and fall into the fish pond with your electric drill in your hand to make a good job of it.

Regards

Dick

Road bike tubing is essentially weldable mild steel, not '531', so 'blacksmith' work should not harm it.

Even on my 88SS, with 19" wheels, there is just the thickness of a credit card between the front left tyre edge and the tube.

Incidentally my steering was horrendous after I replaced the 'brinelled'  rollers, because in my ignorance I fitted them with small preload. They felt free, but they weren't free enough.  The actual issue was a feeling of the back of the bike feeling unstable.  It proved to me something I read once...if the back of the bike feels unsafe, the problem is most likely to be at the front.

My first Norton was a 1955 88, which I bought in 1963.  I crashed it and damaged the timing side crankcase (A Thames van turned across my path as I was wearing my Cloak of Invisibility!) but I didn't have the patience to restore it as a 1959 99 came on the horizon, so I broke the 88 and sold the frame to a Manx racer (no idea who it was).  He said he was fed up with the Reynolds 531 frame breaking at one of the top loops!  The saving in weight was offset by the possibility of death I guess!