Yamaha RD400 ('76-'78)

(updated September 99)

Rim Stock Size Possible Alternate Original Tyre
Front 1.85 x 18 3.25S-18 3.00-18 or 90/90-18
Rear 1.85 x 18 3.50S-18 4.10-18 or 110/80-18

Manufacturers' Recommendations

Manufacturer Front size Rear size
Avon
(no data)
Bridgestone (RD400DX) BT35 90/90H-18 BT35 110/80-18
BT45 90/90H-18 BT45 110/80H-18
Dunlop
(no data)
Metzeler (U.S.A.)
(no data)
Metzeler (Germany) (RD400, 76-) ME-11 3.60H-18 ME-77 4.10S-18
ME-11 3.60H-18 ME-22 4.10S-18
ME-22 3.00S-18 ME-77 3.50S-18
ME-22 3.00S-18 ME-22 3.50S-18
RILLE 12 3.00S-18 ME-77 3.50S-18
RILLE 12 3.00S-18 ME-22 3.50S-18
ME-11 3.25S-18 ME-99A 110/80H-18
ME-11 3.25S-18 ME-77 3.50S-18
ME-11 3.25S-18 ME-22 3.50S-18
ME-77 3.00S-18 ME-77 3.50S-18
ME-77 3.00S-18 ME-22 3.50S-18
Michelin
(no data)
Pirelli (U.S.A.)
(no data)
Pirelli (Germany) (RD400, 76-) MT65 3.00S-18 MT65 3.50S-18
MT65 3.25S-18 MT75 110/80H-18

Martyn's Opinion

General Comments

What are the correct rim sizes?  What are suitable tyre sizes?  Until I've really sorted this out, this page has to be taken as unreliable.  I've only included it here because I'm about to add one of these bikes to my stable.

One of the basic problems is finding a rear.  1.85" is a narrow rim for the rear, and there's very little available in the stock 3.50-18 and the alternate 100/90-18.  Can a 110/80 substitute on the rear?  That's not clear; that size is rather wide for a 1.85", the normal minimum being 2.15" for a 110/80.  I have included rears of that size for reference, pending further information -- they may not fit well.

The Safe Bet

Brand Model Size MAW
Front
Rear

Hmmm.

A Tight Budget

Brand Model Size MAW
Front
Rear

Hmm.

General Purpose

Brand Model Size MAW
Front
Rear

Hmmm....

Touring

Brand Model Size MAW
Front
Rear

Hmmm....

Sport-Touring

Brand Model Size MAW
Front
Rear

Hmmm....

Sport-Riding

Brand Model Size MAW
Front
Rear

Hmmm....

Martyn's Choice

Brand Model Size MAW
Front Avon Roadrunner AM20 90/90H-18 $96
Rear Avon Roadrunner AM21 100/90H-18 $98

This choice is pending investigation of the 110/80 situation...

The Full List

(from MAW and manufacturer web pages)

Well-sized matched pairs

Brand Front size MAW match Rear size MAW match
Avon Roadrunner AM20 90/90H-18
100/90H-18		 $96
$97		 excel
good		 Roadrunner AM21 100/90H-18 $98 good
Super Venom AM20 100/90V-18 $102 good Roadrunner AM21 100/90H-18 $98 good
Kenda K657 Sport Challenger 100/90H-18 $45 good K657 Sport Challenger 100/90H-18 $45 good
Metzeler ME-77 100/90H-18 $72 GOOD ME-77 3.50-P-18T
3.50-S-18T		  - 
 - 		 exact
exact

Over-sized matched pairs

This table lists pairs with a 110/80-18 (possibly too wide) rear

Brand Front size MAW match Rear size MAW
Avon Roadrunner AM20 90/90H-18
100/90H-18		 $96
$97		 excel
good		 Roadrunner AM21 110/80H-18
Super Venom AM20 100/90V-18 $102 good
Bridgestone BT35 Sports Mileage 90/90H-18
100/90H-18		  - 
$93		 excel
good		 BT35 Sports Mileage 110/80H-18 $98
BT45 Sports Mileage 90/90H-18
100/90H-18
100/90V-18		 $70
$72
$68		 excel
good
good		 BT45 Sports Mileage 110/80H-18 $73
IRC Durotour RS-310 90/90H-18
100/90H-18		 $49
$48		 excel
good		 Durotour RS-310 110/80H-18 $52
Metzeler ME-33 Laser 90/90H-18
100/90H-18
100/90V-18		 $75
 - 
$83		 excel
good
GOOD		 ME-99A Perfect 110/80H-18
Pirelli MT75 90/90H-18 excel MT75 110/80H-18
Strada MT69E 90/90H-18
100/90H-18		 $76
$74		 excel
good		 Strada MT68E 110/80H-18 $78

Listing by Manufacturer

Avon

Front size MAW match Rear size MAW match
Roadrunner AM20 90/90H-18 $96 excel Roadrunner AM21 100/90H-18 $98 good
Roadrunner AM20 100/90H-18 $97 good Roadrunner AM21 110/80H-18 GOOD
Super Venom AM20 100/90V-18 $102 good

Bridgestone

Front size MAW match Rear size MAW match
BT17 Sports Mileage 100/90V-18 $90 good
BT35 Sports Mileage 90/90H-18 excel
BT35 Sports Mileage 100/90H-18 $93 good BT35 Sports Mileage 110/80H-18 $98 GOOD
BT45 Sports Mileage 90/90H-18 $70 excel
BT45 Sports Mileage 100/90H-18 $72 good BT45 Sports Mileage 110/80H-18 $73 GOOD
BT45 Sports Mileage 100/90V-18 $68 good
BT53 Sports Touring 100/90VR18 good
SE11 100/90H-18 $74 good

Dunlop

Front size MAW match Rear size MAW match
F11 100/90H-18 $71 good
K491 Elite II Touring 100/90H-18 $62 good
K591 Sport Touring 100/90V-18 $65 good

IRC

Front size MAW match Rear size MAW match
Durotour RS-310 90/90H-18 $49 excel
Durotour RS-310 100/90H-18 $48 good Durotour RS-310 110/80H-18 $52 GOOD
Road Winner RW-010 90/90HX18 $61 excel
Road Winner RW-010 100/90HX18 $64 good

Kenda

Front size MAW match Rear size MAW match
K657 Sport Challenger 100/90H-18 $45 good K657 Sport Challenger 100/90H-18 $45 good

Metzeler

Front size MAW match Rear size MAW match
ME-33 Laser 90/90H-18 $75 excel
ME-33 Laser 100/90H-18 good ME-99A Perfect 110/80H-18 GOOD
ME-33 Laser 100/90V-18 $83 GOOD
ME-77 100/90H-18 $72 GOOD ME-77 3.50-P-18T exact
ME-77 3.50-S-18T exact
ME-88 Marathon 100/90H-18 $78 GOOD

Michelin

Front size MAW match Rear size MAW match
Macadam 50 90/90H-18 $92 excel
Macadam 50 100/90H-18 $94 good
Macadam 50 100/90V-18 $101 good
Tarmac 100/90H-18 good
Tarmac (old) 100/90H-18 $96 good

Pirelli

Front size MAW match Rear size MAW match
MT75 90/90H-18 excel MT75 110/80H-18 GOOD
Match MT09 100/90V-18 $94 good
Phantom MT29 100/90V-18 good
Strada MT69E 90/90H-18 $76 excel
Strada MT69E 100/90H-18 $74 good Strada MT68E 110/80H-18 $78 GOOD

Key:

Exact Precisely matches original spec
Excellent Precisely matches a recommended alternate
Good An exact or alternate in a different sizing system
Short Exact or excellent width, lower profile.  Consider these both ends to lower the bike
Soft Similar diameter by using a taller profile and narrower width; used on the rear only
Tall Taller profile, stock width; similar in effect to "soft", but for the front only
Wide Same profile, wider tyre.  This MAY NOT FIT your rim.  BE CAREFUL!!!