Rd400 damper diffrences

[BCRD]

I read an old article on rd suspension recently that stated the early 76 rd400 came with a 13mm damper rod and the later ones had the improved 17mm ones. Is this accurate? Where am I measuring mine to find out what I have? The center shank I assume. Thanks

[teazer]

Last models of RD350/400 had different forks with different damper rods.  They changed to steel 17mm damper rods at least for Australian market.  Early models are similar to RD350 with smaller diameter aluminum damper rods.

The improvement from my perspective was the change to using a piston ring at the top which according to my very incomplete notes changed from 24mm to 27mm.  The top of later damper rods were also open with a bi-hex arrangement which is easier to hold in place than earlier rod which had two flats to try to lock on to.

[BCRD]

Here's the damper. It's steel and it's 17mm around the tube. Reason I ask is because previous owner bought the bike crashed. He replaced the forks so I just want to confirm what year they are from.

[teazer]

Most likely an F or G model ie Daytona. I'm not familiar enough with what was supplied to your market but I think they were the same as we got in Australia. The US always had a cost reduced model to suit the market dynamics.

[SoCal250]

FYI - the CAN 3J7 RD400F and RD400G use the same part as the US 2V0 RD400F & AUS 3M4 RD400F (and AUS 3M3 RD250F)

[teazer]

Thanks SoCal.  That's useful info.

[SoCal250]

and there are probably others globally that use the same part. I just included the models that were pertinent to the conversation.