Best year for the 390?

[cntymnty]

"The 78 Cr 390 had 10" travel on both front and rear" That's three and a half in front and six more in rear than I have now!! Just have to find a clean one.

 

[Chayzed Pilot]

78's were my favorite.

 

[cntymnty]

There is a 78 390 OR available in my area. What's the diff now between the CR and OR?

 

[suprize]

gear ratios...Close Ratio (CR) and Optimum Ratio (OR) which has a spread of WR and CR ratios

 

[cntymnty]

Everything else the same? Motor, frame, suspension, head angle?

 

[ct cr430]

I think the 78 or had a slightly larger gas tank , different rear shocks , ignition lighting capable even though didn't come with lights and as others have said different transmission . Please correct me if I'm wrong on any of these , just going by memory . I had a 78 Cr 390 but also looked at the or 390 . Don't remember if or gas tank was aluminum or not , want to say steel .

 

[87husky500xc]

Maybe rear wheel size? I know my 79 or has a 17 but I think the 78 had an 18. Correct me if I'm wrong. Not sure if wheel size changed between models or not but I know it did in those years.

 

[jimspac]

I think the 78 or had a slightly larger gas tank , different rear shocks , ignition lighting capable even though didn't come with lights and as others have said different transmission . Please correct me if I'm wrong on any of these , just going by memory . I had a 78 Cr 390 but also looked at the or 390 . Don't remember if or gas tank was aluminum or not , want to say steel .

I am not sure but it likely had the steel 3 gallon WR tank

 

[ruwfo]

Yes OR got the WR size black gas tank

Here's a better description from Craig's site, referring to the 78 250 OR

In 1978 Husqvarna introduced the OR (Optimal Ratio) model to fit the needs of high speed desert racers. The desert guys had been using CR's (Close Ratio), but when top end speed was increased on CR's with sprocket changes, the lo gears were too tall. To "optimize" the gearing, WR (Wide Ratio) gears were used for first second third, and the CR's gears were used for 4th, 5th, 6th. Desert racer"Curnutt" rear shocks were used and they are easily distinquished by their long orange/red springs . The 78 250 OR used an 18" rear wheel and both rims were polished Akronts, making this 250 model different from all the other 78's which had switched to17" rears and gold Nordisk rims. Altho still part of the ML frame series, all 78's had an additional curved tube added under the motor for protection and the sheet metal skid plates no longer used. The 250 OR used the large steel tank like the WR in Husky Red of course. WR Motoplat ignition was used on the OR models and if lights were needed, you just bolted them on and wired them up. The carburetors on all 78 models are Mikuni 38mm (except the 125 which retained a Bing). There is a Husky logo on the seat tail, a new round style ignition cover, and the 250's now have the intake manifold built into the cylinder. Engine number is a riveted tag just above the sprocket on the engine "shark fin".

 

[suprize]

there you have it

 

[Bigbill]

I think using a '82 Husqvarna frame with a newer 40mm (mid 80's) front disc brake and add a 390 CR or OR would be a fun ride.

 

[jimspac]

I would rather have it in a true 1984 WR frame with the tucked in rake. And yes I have thought about it after dropping the 390WR engine shell into the 1983 CR frame I have. With ITC Ohlins that would be the best 390WR ever.

 

[Bigbill]

I have a orginal barn fresh 84/250wr the last air cooled bike with the cr cylinder. I'm building an orginal 83/430 WR with drum brakes all stock. I'm planning a 77/250cr right now, The 430cr, & 390or I'm thinking front disc brakes. Just some fun rides with lots of power. I have new rear shocks for a few bikes.

 

[jimspac]

Everything else the same? Motor, frame, suspension, head angle?

The head angle on the 1978 OR was the first of the 30.5° rake angle. All other 1978 models had the 29° rake. I know because I have a 1978 OR frame and it also has a more rectangular shaped cradle while the standard ML frame cradled have an oval shape where it meets the front downtube.

 

[Bigbill]

With the Swedish bikes I could switch to any late 70's to '86 bikes and ride them the same. They all felt similar in handling. I didn't care I just road.

 

[Kartwheel68]

I have a orginal barn fresh 84/250wr the last air cooled bike with the cr cylinder. I'm building an orginal 83/430 WR with drum brakes all stock. I'm planning a 77/250cr right now, The 430cr, & 390or I'm thinking front disc brakes. Just some fun rides with lots of power. I have new rear shocks for a few bikes.

The air cooled '84 250WR was not really an '84, it was a leftover '83 that they put '84 tank and side panels on, the real '84 250WR with the steeper rake was water cooled.

 

[Bigbill]

It surely runs better than my two '83 250wrs did. Maybe the cr porting.

 

[Kartwheel68]

Yes, they used leftover '83 CR cylinders on leftover '83 chassis.

 

[jimspac]

If I keep my 84 250WR it will get a cleaned and matched WR cylinder and get the rake pulled in to 28°. Low end and mid range much more important for the Northeast and any place else the trees are tight together.

 

[Kartwheel68]

Personally, I dont think the sharper rake works with 40mm forks, I think the steeper rake causes more lateral flex and causes less precise steering than the 30.5 rake, the opposite of what you would expect.