Needle Bearing Mains .oh my!

jimbo · Oct 29, 2025

34-Years-Owned 1971 Norton Commando 750 Roadster

Bid for the chance to own a 34-Years-Owned 1971 Norton Commando 750 Roadster at auction with Bring a Trailer, the home of the best vintage and classic cars online. Lot #218,125.

bringatrailer.com

........the prior owner rebuilt the engine about 6,000 miles ago. He installed BMW needle bearings for the main bearings and also rebuilt the carbs. My mechanic did not rebuild the engine, but can if the next owner wants it done. He uses titanium rods and lightened pistons to make the engine run smoother w/ less vibration.

grandpaul · Oct 29, 2025

Either clueless or that thing is a ticking time bomb.

acotrel · Oct 31, 2025

Speculation and supposition - school teachers do it. Changing the balance factor by adding weight to the crankshaft is not easy. And the way I have done it presents a risk. Fixing the vibration problem in the way Norton have done it, works. But it is bullshit. They have detuned a sports bike. How could they have sold a motorcycle which rocks backwards and forwards when it idles ? I would buy it, but I never rode motor scooters.
Old British motorcycles are a joke, however I absolutely love them. They are like sitting in an armchair instead of on a plastic stool. I was impressed by the VFR400 Honda - it did everything right - took no brains to ride it. One of my friends has a 750cc Norton Atlas - that would be fun at full blast. He used to ride it in A-grade road races in the 1970s.

baz · Oct 31, 2025

acotrel said:
Speculation and supposition - school teachers do it. Changing the balance factor by adding weight to the crankshaft is not easy. And the way I have done it presents a risk. Fixing the vibration problem in the way Norton have done it, works. But it is bullshit. They have detuned a sports bike. How could they have sold a motorcycle which rocks backwards and forwards when it idles ? I would buy it, but I never rode motor scooters.
Old British motorcycles are a joke, however I absolutely love them. They are like sitting in an armchair instead of on a plastic stool. I was impressed by the VFR400 Honda - it did everything right - took no brains to ride it. One of my friends has a 750cc Norton Atlas - that would be fun at full blast. He used to ride it in A-grade road races in the 1970s.

"Detuned a sports bike"
Same old bulshit over and over
How many times has this been answered!!!
There must be something wrong with you Al ?

concours · Nov 1, 2025

Like so many other things, the seller simply repeating what he thinks is the truth.
Where the story got watered down, we don't know.
I'd bet a six-pack he is referring to ROLLER bearings.

But, reminds me of a funny conversation 40 years ago, bunch of motorheads standin around at lunch break in the parkin lot. Talking chevy engines.
The topic of torque was at hand, in pickup trucks.
The one camaro guy, insisted that HIS small block had more torque, because "his crankshaft had 1/4" journals"

My co-worker & I exchanged glances & smirks and let him go on & on.

We never did call him out, but mocked him for years...

Jonez69 · Nov 1, 2025

B

Thread 'Needle main bearings?'

Oct 26, 2016

From the text of a beautiful 1971 Commando on Edmonds, Washington Craigslist ad:

Engine/Clutch Package: 750 cc. Commando engine with approximately 100 miles on full rebuild by prior owner, Rick McEldrey, featuring case milled to accept BMW needle bearing main bearings.

I have never heard of this conversion?

Looks like this has been discussed before many years ago, same bike I bet....

jimbo · Nov 4, 2025

needle bearing bike showing some love.....

Needle Bearing Mains .oh my!

Similar threads