slimline featherbed center stand/ proper tire size?

Atlas came with  19  or 18 inch rear  wheels . Must have been 2 sizes of stand?.  Our Atlas has 19 inch and its still almost a 2 man job to get it on the stand .  Its a bad design , usually made worse with wear to the stops under the frame that allow the action to go too far over center. Get a decent prop stand. Helps too with climbing on and off.

I once bought an Atlas which the previous owner had fitted with Manx stanchions on the front end. Losing around 1.5" comapred to those normally fitted on Short Roadholders made using the mainstand an interesting challenge. 

I once put 2  19" wheels alongside each other. One had an Avon SM with its very deep sidewalls, the other a modern  low profile  tyre.  There appeared to be a couple of inches difference in overall height.  Not very scientific but  food for thought. At the time I was more interested in the effect on rolling radius and overall  gearing and was prompted by this   to fit a bigger engine sprocket . This also had the unexpected result in lowering the kickstart  ratio  a  little and helping me to kick  the beast over compression.

Hi Steve.........check out the recently released Heavy Twins Compendium Version 2.2. Link above left in the News column. There is an excellent article about Wheels & Tyres starting on page 180. This comprises of a blend of contributions from various NOC members with years of riding experience on various Norton models. 

The Compendium is a really good resource . With regard to tyres , a  shedule  of actual fitted tyre widths would be most  usefull ,  Pointless saying a 90 90 is the equivalent to a 3.00 x19  etc  if when you buy it its  far too wide to fit the bike.

Hi All,

Avon tyres have a useful area on their website that gives key dimensions for their tyres, including fitted widths and diameters (when on their recommended rim sizes for the tyre width).

See: https://www.avontyres.com/en-gb/tyres/roadrider-mkii as an example for their Roadrider2 range. Similar data is available on their site for all the tyres that they do.

Obviously this is for Avon tyres, so won't apply to other makes.

Of interest to me was the matter of tread depth. I have an 18" WM3 rims front and rear on my 650 and if I were to buy a rear specific tyre, I get 7.5mm tread depth, whereas if I were to buy one suitable for front or rear, I would only get 5.6mm tread. 

Putting on the stand, I have 100/90x18 on the front, 110/90x18 on the rear, and putting onto the stand is reasonable for me. Having 7 3/8" yokes opens up your tyre choice immensely.

If you wish to retain the 19" rims for a UK spec,650 or Atlas, Avon also sell a modern construction 'GP' tyre in 3.50x19 size that would have been original factory fitment on the rear wheel.

Best regards to all,

George.

I have just ordered a new Speedmaster for the front £68 delivered , and happily  due to this thread I got a 3.25x19   (the correct size)    instead of the 3.00 x19  I was planning . After 7 years  the old one was too hard. I have been buying the wrong size for years .

It might be worth checking that you have the correct length shock absorbers fitted.

I took the trouble to check and Uk  Atlas spec was 19" rear wheel ,  It would seem logical that a shorter stand would be made for US spec bikes with 18" wheels   but  perhaps they just "winged" it. For sure building up the frame stop plates  has reduced the effort needed to get the bike off the stand.

Atlas had 4x18 tyre, not 3.50x19. So half inch bigger tyre balanced half inch smaller radius as far as stand ( and speedo) was concerned.

I bought a new wm3  rim for the Atlas  rear  as a wm2 just looked wrong . Thats why I checked  the Spec. Perhaps they supplied some  of either size, or changed the spec at Woolwich.

I have learnt to cast a critical eye on ground levels when parking as pulling off the stand uphill  is a thankless task.  The prop stand is your friend  and getting your leg over  from the nearside is much easier . I have even considered  fitting a 2nd prop stand  to the offside .