Sexy Bike thread continuation - TM or RN ???

[Doc]

A continuation of the discussion regarding the bike pictured below.

It's a TM made to look like an RH..

Are you sure John? it looks like the real deal to me. RN370/400 with long stroke top end. Notice the spacer under the barrel and the narrow tube used in the rear subframe.   

Doc the cylinder head is totally different to an RN, it looks like TM and the bottom of the fork legs are different, they look like machined down TM forks and what's with the barrel spacer? The lower fork legs are also longer than RN fork legs. The flat seam around the edge of the tank is different to RH/RN also.
 It looks to me like a very good copy of an RN possibly using RM370 wheels, triples etc and a hand made tank, not sure if it's an RN frame or a copy.
Have a look at the pics of Dave Tanners RN400 on vintageworksbikes.com for comparison.

John,  here is another picture of the same bike but this time with a different head



Dave's is also a '74 model which will have variations from the '73. DeCoster's RN's were always under constant development and in many instances what appeared the same machine was changed numerous times during a season. I was also told once there were numerous options he had available in regards to engine capacity, these capacities were 400/420/440 and 500 with some short stroke and some long stroke and some which required the cylinder spacer. I can't recall who, where, how I came by that information but it stuck in my mind over the years. I've emailed MX Classic racing website it is featured on to ask for some clarity. For the life of me I can't tell if it's a damn good replica or the real deal. Also if it were made from a TM wouldn't it have been so simple to use a later TS/TM head that did look more like the regular RN/RM shape? If you look at the clutch cover it too has an extra gusset under the clutch pinion and the said pinion is set at less of an angle to the TM. It has a totally different case shape around the kickstart area, looks more like an RM without a reed valve as the TM engines were quite long in comparision. I really don't know but I am still inclined to think RN

[211kawasaki]

its RN no question about it - also the frame is RH/RN as ID by the roller bearings on the swing arm. Tank dosnt look right but would be if alloy - it sure has the right bits to be one. Either way nice bike but dosnt look like it gets used or was partially complete resto. Hate the pipe they just didnt look like that. Love to know the engine frame #

[VMX247]

Where can we get those kicks starts ...nice idea for the TM..
Yep sorry-that pipe is the most ------ .!   
So RN never ran the Milkine carb like the RH ?
cheers A

[Doc]

211, my sentiments also, looks too much like it not to be.

Alison, the RN did run Mikuni carb but normally made from magnesium. The carb shown is a Mikuni but the colour and finish appear it maybe an alloy replacement.

I agree the pipe would look much nicer painted black but the actual shape isn't so bad. Was thinking it maybe a 'Precious Factory' pipe from Japan but like genuine theirs don't have so many sections and for most parts are water formed in the lower picture of just the engine you can see the pipe is/was black.

[JohnnyO]

Dave the bike in the top pic has a different cylinder head and different lower fork legs to your RN (they are longer) and the tank is slightly different, that's why i thought it maybe not the real deal.
Doc production RH and RN's only came out in '74/'75, they are not as trick as the exotic factory bikes of DeCoster/Robert from the same years with titanium and billet alloy parts all over them and different suspension. That bike in the pics is not a full works bike, it doesn't have the billet triple clamps, magnesium carby, titanium bolts etc..

[TM BILL]

I thought the prody RN was a 74 release only  the Prody RH was 74 and 75 ?

[Rossvickicampbell]

and here I was thinking the exhuast pipe was great!!

[Doc]

John I wasn't thinking production RN, I was thinking it maybe a practice bike of RD's.

[JohnnyO]

John I wasn't thinking production RN, I was thinking it maybe a practice bike of RD's.

Could be right Doc, would be nice to know the history of this bike..

[Doc]

yeah I'd like to know some more also John, hoping the inquisitive email will throw some light on the subject. On the website that nobby posted it seems to have had some changes including the original pipe and head. Nice site btw nobby..lots of sexy bikes

Alison, if you want the alloy kickstart it appears it would be available over the counter as it's a current RM-Z450 item. Only thing is it doesn't have a pinch clamp like the TM and uses a retaining bolt like the RN or RM N/T models so it'd require some work to fit. Not impossible but not a straight bolt up item sorry.

[Toolboy]

What type of shocks are fitted???

I need a set for my TM400 as they still have the standards!!

Tim

[Davey Crocket]

I keep looking at it and although I'm no expert I reckon it's a bitzer, theres definately later model RM parts on the bike, I think it has a Yamaha throtle cable, forks are just farked....you nearly need a ladder to get up there, the gold handlebars and kickstarter just look so wrong, when I first saw it I thought it maybe was one of Mike Feltons jobbies......theres definately some RH/RN parts there....maybe oldmate just scored a frame and swingarm and has made the rest up as he goes....it's so close to a very cool bike though...RM125/250/370 A/B guards and wheels, 80's model carby........

[bazza]

carb not magnesium cast,forks turned down,kickstart off my rmz ,pipe just wrong,looks like RMS engineering brake lever= interesting

[JohnnyO]

Here's a pic of Dave Tanner's bike for comparison..
Forks are different as is back of seat at mounts, tank slightly different, lower shock mount is further up the swingarm. I still think like Davey that it's a bitza..

[Davey Crocket]

The Kiwi's are keeping quiet, I reckon it's another "Fine Cotton afair"....I just looked at Terry Goods site and theres too many iregularities (shit thats a big word).....I think maRc may be able to shed some light on this.