Tyres

Fortunately there is now a wide range of tyres available with the correct sizes and appearance and supply of these is pretty good. Should you wish to fit something more modern, size can be a problem as can supply, with manufacturers constantly vying with each other to produce new tyres. We can supply any currently available tyre to order in a few days and at competitive prices.

The profile of the front tyre should be the same as, or more rounded than the rear but never less rounded. The usual choice is a ribbed front and universal or block tread rear. Ribbed front tyres were around at least by the early 1930’s and were usually fitted to the more sporting bikes, whilst the de-Luxe and touring models usually had the universal or block tread tyres fitted to the front as well as the rear, as they last longer.

There have been 5 schemes of listing tyre sizes over the years starting with referring to tyres by the overall diameter of the tyre rather than rim diameter and height, for example a standard 3.50” x 19” was listed as 3.50” x 26”; rim diameter equals the diameter less twice the height, however this method causes problems when the tyre is 3 1/4” wide! This was replaced in the early 1930’s by width x rim size. In the late 1960’s the low profile tyre was born that required a new method of marking so the width marking was increased by .6 in most cases, in our example the 3.50” x 19” became 4.10 x 19. A low profile tyre is one that is wider than it is tall; our 3.50” tyre was still 3.50” tall but 4.1” wide. At some point tyre sizes went metric and as other profile ratios were coming in that was included in the size as well. Some of these will fit the older bikes but are to be avoided as they will upset the handling geometry and centre stands will be too close to the ground. The 4.10 x 19 became 110/90×19, i.e. the tyre is 110 mm wide and the height is 90% of 110 mm, rims are still made and listed in imperial sizes. The latest scheme is to replace the width by a 2 letter code, the first letter is always ‘M’ and our 4.10×19 has now become MN90x19, bureaucracy gone mad!

Tyre Size Conversion, some popular sizes

Rim Size

Really old

Old

Modern

Metric

Silly

WM 3 x 18 (3”)

400 x 26 4.00 x 18 4.25/85 110 MN

WM 1 x 19 (2 1/4”)

300 x 25 3.00 x 19 3.60 90 MJ

WM 2 x 19 (2 1/2”)

3.25 x 26 3.25 x 19 3.60 90 MJ

WM 2 x 19 (2 1/2”)

3.50 x 26 3.50 x 19 4.10 100 MM

WM 3 x 19 (3”)

3.50 x 26 3.50 x 19 4.10 100 MM

WM 3 x 19 (3”)

4.00 x 27 4.00 x 19 4.25/85 110 MN

WM 1 x 20 (2 1/4”)

3.00 x 26 3.00 x 20 3.60 90 MJ

All models were fitted with a WM2 x 19” front rim as standard except for the Red Hunters, which had WM1 x 20” until 1955, although pre-war Colts were fitted with a 20” rear tyre and the OG had a 20” front as well. Rear rims were also WM2 x 19” except for the 1937-58 Square Fours, which used WM3 x 18”. As with any other aspect of Ariel it was possible to order whatever could be fitted and was available.

Original Style Tyres Ariels fitted many makes over the years, no doubt dependant on where the best deal could be obtained but most commonly Avon’s were used. The Dunlop TT100 tyre was not available when our bikes were new as it came out in the late 1960’s but was a popular fitment among the ‘boy racers’ of the day and does not really belong in the ‘Modern Section’. The K81 version is rated to 130 mph; the K82 version is rated to 112 mph.

Size

Fitment

Make

Model/Style

Part Number

3.25 x 16 Universal Dunlop TT100, sports, K82

TY16-325DK82

3.25 x 17 Front Avon Speedmaster, ribbed

TY17-325ASMF

3.25 x 17 Universal Avon SM, block

TY17-325ASMR

3.00 x 18 Universal Dunlop TT100, sports, K82

TY18-300DK82

4.10 x 18 Universal Dunlop TT100, sports, K81

TY18-410DK81

3.25 x 18 Universal Dunlop TT100, sports, K82

TY18-325DK82

3.50 x 18 Universal Dunlop TT100, sports, K82

TY18-350DK82

4.00 x 18 Universal Avon SM, block

TY18-400ASMR

4.00 x 18 Universal Dunlop K70, block

TY18-400DK70

4.25 x 18 Universal Dunlop TT100, sports, K81

TY18-425DK81

3.00 x 19 Front Avon Speedmaster, ribbed

TY19-300ASMF

3.60 x 19 Universal Dunlop TT100, sports, K81

TY19-360DK81

3.25 x 19 Front Avon Speedmaster, ribbed

TY19-325ASMF

3.25 x 19 Universal Ensign Block

3.25 x 19 Universal Dunlop K70, block

TY19-325DK70

3.25 x 19 Universal VTS Block

TY19-325VUNI

3.50 x 19 Universal Ensign

TY19-350ENSUNI

3.50 x 19 Front Avon Speedmaster, ribbed

TY19-350ASMF

3.50 x 19 Universal Dunlop K70, block

TY19-350DK70

3.25 x 19 Universal Ensign Block

TY19-350VUNI

3.50 x 19 Sidecar Avon Sidecar

TY19-350ASCAR

3.50 x 19 Universal Avon SM, block

TY19-350ASMR

4.10 x 19 Universal Dunlop TT100, sports, K81

TY19-410DK81

4.00 x 19 Universal Avon SM, block

TY19-400ASMR

4.00 x 19 Universal Ensign Trials

TY19-400ETU

3.00 x 20 Front Avon Speedmaster, ribbed

TY20-300ASMF

3.00 x 20 Universal VTS

TY20-300VUNI

3.00 x 20 Universal Avon 50s TT

TY20-300TTUNI

3.00 x 21 Front Avon Speedmaster, ribbed

TY21-300ASMF

Budget Alternatives – These are generally very good tyres, much better than the budget tyres of 30 years ago made from re-cycled non-stick frying pans. They look pretty good, have adequate grip and wear for the older bike and are a lot cheaper.

Size

Fitment

Make

Model/Style

Part Number

2.75 x 19 Universal Mitas H-02 Block

TY19-275MCU

3.25 x 19 Front Dunlop, India Ribbed

TY19-425DRIB

3.50 x 19 Mitas H-02 Block

TY19-350MCU

3.50 x 19 Universal Dunlop, India Block

TY19-350DUNIV

4.00 x 19 Universal Mitas H-02 Block

TY19-400MCU

4.00 x 19 Universal Dunlop, India Trials

TY19-400DTU

Modern Tyres Suitable for the Older Bike – There are only a few modern tyres available in the right sizes.

Size

Fitment

Make

Model/Style

Part Number

3.00 x 18 Universal Metzler ME22

TY18-300ZME22

3.25 x 18 Front Metzeler ME11

TY18-325ZME11

4.00 x 18 Rear Avon Roadrider

TY18-400ARRR

4.00 x 18 Universal Michelin M45

TY18-400MM45

3.00 x 19 Universal Metzeler Block C

TY19-300ZC

3.25 x 19 Front Metzeler ME11

TY19-325ZME11

3.25 x 19 Front Avon Roadrider

TY19-325ARRF

3.50 x 19 Universal Avon Roadrider

TY19-100/90ARRU

4.10 x 19 Universal Avon Roadrunner

TY19-410ARR

Trail etc.

Size

Fitment

Make

Model/Style

Part Number

4.00 x 18

Rear

Vee Rubber

Trail

TY18-400RTRAIL

4.00 x 19

Universal

Dunlop

Trials Universal

TY19-400DTU

90/90 x 19

Front

Pirelli

MT60, Trail

TY19-90/90P-MT9

90/90 x 21

Pirelli

MT90, Trail

TY21-90/90PMT90

90/90 x 21

Continental

54S

TY21-90/90TY21-90/90

2.75 x 21

Universal

Vee Rubber

Trail

TY21-275RTRAIL

Inner Tubes and Other Bits ‘n’ Bobs

Regrettably ‘detachable inner tubes’ are no longer available, whether butt ended or Riches patented type.

Part No

Description

Size

MB16

Inner tube 275/300/325 x 16

MA17

Inner tube 275/375 x 17

MA18

Inner tube 250/325 x 18

MB18

Inner tube 350/410 x 18

MC18

Inner tube 400/450 x 18

MA19

Inner tube 275/300 x 19

MB19

Inner tube 325/350 x 19

MA21

Inner tube 250/300 x 20 & 21

TY-WM2

Security bolt WM2

TY-WM3

Security bolt WM3

TY-18TAPE

Rim tape 18″

TY-19TAPE

Rim tape 19″

TY-20TAPE

Rim tape 20 & 21″

TY-CAP

Metal tyre valve dust cap with valve key

TOOL-27

16” tyre lever, get those tyres off

6636-05

Use 21st century technology to inflate tyres with this compact CO2 gas canister and adapter, slip one in the tool kit for those awkward sinking moments
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