Dreer 880 article

The 880s did not hold together for long if the extra power was used. This is why Kenny Dreer decided to make an all new design with the 952.
One owner got less than 100 miles on his 880 before the engine grenaded. Some got a bit further, but it soon became clear that the hotrod 880 idea wasn't going to work.

It would be nice to know what the most common failure point was.

Glen
 
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Whilst stressing out the stock crank, cases, gearbox, etc will always cause discussions about what will fail when, I also believe we have to look a the times and circumstances.

Kenny put his bike out there as a modernised bike. He put it in the hands of modern journalists who wanted to test the performance. Those guys have no idea about old bike foibles and would have ridden it like a new Japanese sports bike. They talk about shooting for 11 sec quarters and have pictures of them wheeling everywhere etc. I would venture that stock Commandos wouldn’t have lasted all that much longer in their hands either !
 
Self grenading is a Norton feature that should not be used. The factory Combat configured bikes probably got a lot of the same kind of abuse.

I rode my last 750 build like it was something it wasn't. Tore it down after less than 2500 miles. Next build I'm going to restrain myself as much as possible. Probably won't be able to, because my exhaust sound is intoxicating, and well, come on you know if you've been riding for a half century or more. Resistance is futile.

I was not aware of the 880 when it came out. I never saw one in the Alice's Restaurant parking lot on Skyline in 1999. Pretty bike. I might have bought one if it had come out 4 years earlier before I bought the Ducati 996S. Heavy on the "might have". I have a feeling I would have been disappointed though. I was deep into the 170mph stuff British bike owners refer to as boring. lol
 
There's no doubt that they were a step too far on the performance vs longevity equation as built.
I've chatted with two owners who blew their 880s up just doing the same things I regularly do with my 850, albeit they were likely doing them a little quicker until failure!
Kenny said of the 880s " We were building expensive time bombs"
The article states that 80% of the bike had been replaced with non Norton parts.
Did some of these replacement parts fail or was the problem in the 20% Norton that remained?

Glen
 
worntorn said:
There's no doubt that they were a step too far on the performance vs longevity equation as built.
I've chatted with two owners who blew their 880s up just doing the same things I regularly do with my 850, albeit they were likely doing them a little quicker until failure!
Kenny said of the 880s " We were building expensive time bombs"
The article states that 80% of the bike had been replaced with non Norton parts.
Did some of these replacement parts fail or was the problem in the 20% Norton that remained?

Glen
Click to expand...
Stock crank, cases, rods, gearbox, all mentioned in the article.

Steve Maney reckons the rods are good for 90bhp IIRC.

So my money’s on wanna the other 3 !
 
"Decidedly unstock is the left-side crankcase, usually the Achilles heel of any high-performance Norton-Ron Wood’s flat-track Commandos used to go into battle at Ascot with braids of external weld reinforcing the case. Dreer’s solution is more sanitary; cracks are kept at bay with a new, recast left-hand case up to an inch thick at the critical bearing wall."

The crank was lightened as well. That shouldn't necessarily spell doom, depending on how it is done, but then the Norton crank is not a super strong item to start with.

90 bhp on the stock rods? That is good to know.

Glen
 
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Missed that about the case. That’s how Maney started to doing cases, the left side only.

Regarding the crank, obviously, lightening doesn’t strengthen it any, so the weak points of the PTO shaft and potentially really exploding flywheel remain.

And the gearbox.

So they’d be my guess, but as you say, it would be interesting to know what the actual failure modes were.
 
Crankcase failures on Commandos are probably due to balance factor. My 850 feels as though it will rev easily to 8000 RPM. But I never do that. A 650SS or Atlas revs higher than a Commando without trouble.
 
acotrel said:
Crankcase failures on Commandos are probably due to balance factor. My 850 feels as though it will rev easily to 8000 RPM. But I never do that. A 650SS or Atlas revs higher than a Commando without trouble.
Click to expand...
But for how long and how many times?
I had a great chat with Herb Becker the other day. He mentioned that Andy's Bonneville bike has only been called upon to run 30 minutes or less at power to date.
It changes things when you start using full power on a great distance over and over with an expectation of maybe a 100,000 mile lifespan. Even there, we expect to have a worn out but still rebuildable engine.
As Herb said though " If it breaks I'll start again"
The hotrodder's perspective!
I mainly worry about things coming unzippered when I'm in the passing lane with a Kenworth grill coming at me!

Glen
 
UhOh... Doomsday awaits my arrival

Only strengthening my old antique left side case has is the 1/4" thick spacer with the 3 bolts for the inner primary case. :) The case is smooth on the inside with zero webbing and only a 1" wide 3/4" thick band of cast in material around the pocket for the main bearing.

I'm sure my motor would rev freely to 8000 RPM, but it might only do it for a few second before I'd have to pullover and call a tow truck. ;)

Dreer 880 article
 
Schwany said:
UhOh... Doomsday awaits my arrival

Only strengthening my old antique left side case has is the 1/4" thick spacer with the 3 bolts for the inner primary case. :) The case is smooth on the inside with zero webbing and only a 1" wide 3/4" thick band of cast in material around the pocket for the main bearing.

I'm sure my motor would rev freely to 8000 RPM, but it might only do it for a few second before I'd have to pullover and call a tow truck. ;)

Dreer 880 article
Click to expand...
The extra strong crank is a good piece of insurance.
 

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