Building a DRM 400

[Jens]

Hello folks!

Needing some advice on my latest project. Found me self a cheap -82 DR 400 this summer and since I already have a -80 125 RM chassis I thought what the heck, why not combine these two to make me the perfect thumper! Maybe this is the wrong way to go? Seen a couple of DRM conversions (only on paper though) before and they have all been based on RM 250/500 chassis (same chassis I belive) so my question is, is it possible at all, any big differences between a 125 chassis and a 250/500? The same wheelbase, ridehight etc etc or? If someone is sitting a 125 and a 250/500 I'll be glad to get some messurements and ofc DRM builders please point me in the right direction.

Full throttle folks!

[oldfart]

Jens the DR 400 motor is too tall to fit into a RM frame .

Dr 400 frames are as close as they get to Rm frames , 
type Dr 400 into search colum ....RH corner (  above )
Option 1  ..... Do as I have done cut and shut a Dr 400 frame and add Rm parts.
Option 2  ..... Rm or PE 250 -400 frame ( 1980 )  by removing and adding the DR engine craddle.   

Bazza            DRM 400      Read VMX mag  # 24   page  45
Oldfart           DRM 400

 

[David Lahey]

Mine worked out well too:
SP370 engine loop of frame, SP370/DR400 motor and airbox
RM250C (1978) front end, swingarm, tank, wheels, seat, sidecovers and rear subframe

[Jens]

Thanks for the tips mates!

Oldfart, I did give it a try searching old posts for DRM´s but the only project i did find was a DR 400 engine into a PE 400 frame, looking smooth. So my question is, could you either point me to pics of your bike in older posts or even, if I may be so bold asking, fit a couple of pics into this post as well?

Jens

[GMC]

Option 3
Wait till CD6 where I should have a replica Hallman-Suzuki frame on show.

[cyclegod]

That looks GOOD!! It will certainly be easier to get a new tank than those YZc HL replica's 

[LWC82PE]

are going to make it just by going by that photo or do you have a frame to copy?

[mx250]

Option 3
Wait till CD6 where I should have a replica Hallman-Suzuki frame on show.

Now you tell me, just after I gave away all my SP 'junk' .

[Graeme M]

That is very nice. I only found out very recently that they made those kits. I remember when I had an SP370, I was always reading about trick SP/DRs. Dirt Bike had a few good articles on RM/PE/DRs, and ADB had a nice looking one in it at some stage. My SP was used for trailriding and enduros and I recall it being a fun bike.

It had a plastic tank, Boge shocks, Protec cam, S+W valve springs, Hi-Comp piston, 36mm carb, lightly ported head and a nice pipe. Set up like that it was about as fast as a stock TT500, handled better, was easier to start and good fun. Of course, it was also slower than my mate's IT400, far heavier than my other mates PE250, and to say it handled better than a TT500 is perhaps not much of a recommendation. But it was neat to ride, and to have slung that engine in a Hallman chassis would have been way cool.

Look forward to seeing it!

[Tony T]

I did a little research in this area some time ago. Apparently Dick Mann made 25 frames to suit the DR370 engine in the late 70's, but I have never seen one or even had anyone confirm their existance despite a LOT of emails/phone calls. Rick Sieman had never seen one and Dick Mann never returned any of my emails. Makes me want one even more........... 
If you want to be put off by the idea of building a DRM, talk to Rick Sieman about his evil project..........  He eventually sold that to the head of Maico at the time................
Graeme Boyd does have a C&J frame to suit that he won't sell. He had mentioned making a copy of it once............ 
I've also got the Motocross action Test of the Hallman DR370. PM me if anyone wants a copy.

[oldfart]

GMC  is that the frame you had at CD5 and some chap from     Suzuki of New Castle  was comparing to my set up .
The posted pic looks nice 

Go to suzuki pages   #  2   half way down   DRM 400

[Tony T]

"Some guy from Suzuki of Newcastle" is Graeme Boyd....... 

[firko]

Hagon also made a monocoque frame for the DR/SP engine that I assume is similar to the Yamaha Hagon that Jonesy has.
We'll all die of old age before Graeme Boyd either sells any of his hoarded collection or makes a copy of his C&J. He's got some tasty stuff but none of us mere peasants will ever see them...
Below: Jonesys Hagon Yamaha. Martin Hagon has a DR400 powered version that he races in the UK.

Mike Jollys DR400 in NZ

[Jens]

Your proposal is certainly interesting GMC since the Hallman frames essentially is rebuild -74 Husqvarna CR frames. Shouldn't be too hard finding one of those since I live in sweden... But still I wonder if I couldnt squeze the DR 400 lump into the RM frame, ofc there would have to be made some serious mods to the cradle and further more. Well, have to give that one a good thinkover.

Oldfart, if you got some good explanatory pics of your DRM I would be very glad if you could priv them to me or just paste theme here 

So long folks and remember:

[Jens]

Forgot this:

http://www.thumperpilot.com/pages/DSCF0010.htm (edit: sorry, looked at the bike again and saw it was a yamaha and not zusuki :-( , colors tricked me)
 
If you all haven´t been to www.thumperpilot.com go there. Some pretty sweet rides, you could also upload pics of your own rides, atleast the good lot of you riding thumpers...

Jens