Bike pulling to the left...

Bonzo

Bonzo

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..when I let go of the bars.

Throttle off, going down a hill, try going no-handed and it wants to fall over to the left.

I'm sure this is related to the vibration I'm experiencing through the bars when I'm not on the throttle. Particularly on the RH side of the bar (the mirror blurs through vibration).

I'd love to cure this. Any guidance?
 
Supposedly why the factory moved the disc to the left side on the Mk3.
 
Common. Go by the doctor's advice on Hee Haw:

"Doc, the bike pulls left when I take my hands off the bar!

"Well, don't take your hands off the bar!" ;)

As LAB pointed out, supposedly the left side disc mount corrected that but since I've never ridden a Mark III I have no idea if that really eliminated that tendency. Every pre Mark III disc-braked Commando I have ridden pulled left with hands off.
 
Ahh, OK. So I'm not paranoid and imagining that my yokes are bent & my frame is off at an angle.

I wish it didn't do that, but I'm kind of glad it's not just mine :rolleyes:
 
Bonzo said:
Ahh, OK. So I'm not paranoid and imagining that my yokes are bent & my frame is off at an angle.

I wish it didn't do that, but I'm kind of glad it's not just mine :rolleyes:
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Lean right when you take your hands off :D

Of course, there's always the possibility of the rear wheel not straight or the forks not parallel. If it's pulling hard then look more. If just trying to drift left, then it's normal.
 
Just had a talk with the new owner of a mk3 in my locale and mentioned the bike seemed to have a mk2 front end...forward mudguard stays and right side disc. I mentioned Norton had the left side disc on mk3 but was uncertain of reasons why . Speculated it might be due to having rear on right so having two rotating lumps off centerline to rightside might induce some weird torque steer/gyroscopic effects at speed.

But we do see modern bikes with disc's same side front and back.

He was glad it was right side at front after I explained the factory just flipped the mk2 fork slider to place disc on left side with the caliper sitting in front of slider....in the name of saving not to make a new left mount slider casting. Also hence the reason for no forward mudguard stay on mk3. Since my mk2 has a mk3 front mudguard, I told him we oughta swap mudgaurds to be period correct....
 
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Tornado said:
Just had a talk with the new owner of a mk3 in my locale and mentioned the bike seemed to have a mk2 front end...forward mudguard stays and right side disc. I mentioned Norton had the left side disc on mk3 but was uncertain of reasons why speculated it might be due to have rear on right so having two rotating lumps off centerline to rightside might induce some weird torque effects at speed.

But we do see modern bikes with disc's same side front and back.

He was glad it was right side at front after I explained the factory just flipped the mk2 fork slider to place disc on left side with the caliper sitting in front of slider....in the name of saving not to make a new left mount slider casting. Also hence the reason for no forward mudguard stay on mk3. Since my mk2 has a mk3 front mudguard, I td we oughta swap mudgaurds be period correct....
Click to expand...

Simply flipping the sliders for the Mk3 aint great for draining the oil either I would've thought.
 
Bonzo said:
Simply flipping the sliders for the Mk3 aint great for draining the oil either I would've thought.
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I'd think it should work, as it's more forced out by pumping action than just left to drip out.
 
My '74 Shovelhead did that. Couldn't zip my jacket while underway.
It had a custom girder front end.
Custom mural on the tank.


Many years later, I realized it had been crashed hard💡
Bent frame I expect.

What's the history of your bike?
 
concours said:
Many years later, I realized it had been crashed hard💡
Bent frame I expect.

What's the history of your bike?
Click to expand...

Well, there's no obvious evidence to suggest it's been biffed up a wall. It all seems to be in line and in good order.
 
Bonzo said:
Well, there's no obvious evidence to suggest it's been biffed up a wall. It all seems to be in line and in good order.
Click to expand...
MexicoMike said:
Common. Go by the doctor's advice on Hee Haw:

"Doc, the bike pulls left when I take my hands off the bar!

"Well, don't take your hands off the bar!" ;)

As LAB pointed out, supposedly the left side disc mount corrected that but since I've never ridden a Mark III I have no idea if that really eliminated that tendency. Every pre Mark III disc-braked Commando I have ridden pulled left with hands off.
Click to expand...
My '74 goes straight.
 
Common practice is to loop a string line around the front and rear wheel and line them up. If you space out the string line at the rear of the rear wheel, you can turn the steering to get the front wheel centralised and in line with the rear wheel. If it does not line-up, move the rear wheel to get the front of it equi-distant from the string.
When adjusting the rear chain, If there is a draw adjuster, I usually count the number of turns and adjust each side equally. But you need the wheels in line first.
Is is possible, but not likely that you have a twisted swing arm or frame.
 
My 1974 Mk11 Roadster pulled hard to the left for years. Was also a headshaker above 80 mph.

Finally fixed it by stripping to bare frame and going through the World's Straightest Commando article.

One quick check which may work is checking your wheel rims are central to the front forks and rear frame. For vibration through the bars make sure the front wheel is properly balanced. And isolastics are not set too tight.
 
That's interesting. There is a long hill down to my house and I often take my hands off the bars going down the hill. Since I've changed to disc brake on the Atlas it has wanted to slowly track to the left. I counter it with sitting just slightly to the right side. I was wondering why the change. Please explain why the disc does this.
 
Why the caliper was moved to the left on the MkIII?

I quote Robert (Bob) Rowley ex Norton development engineer / tester…

“We moved the Caliper over to the left to help reduce the road grit and dirt that ran down the fork leg directly into the caliper, next time you ride in torrential rain look down if a right-hand Calliper you'll see that the water runs off the mudguard directly onto the one pad, this also accelerated the pad wear bias. Keyboard warriors need not respond”

The last sentence are his words not mine;)
 
cliffa said:
Why the caliper was moved to the left on the MkIII?

I quote Robert (Bob) Rowley ex Norton development engineer / tester…

“We moved the Caliper over to the left to help reduce the road grit and dirt that ran down the fork leg directly into the caliper, next time you ride in torrential rain look down if a right-hand Calliper you'll see that the water runs off the mudguard directly onto the one pad, this also accelerated the pad wear bias. Keyboard warriors need not respond”

The last sentence are his words not mine;)
Click to expand...
Alot of good info here, the caliper is addressed at the 55.00 mark.

50 Years of Norton Design: Interview with Brian Slark and Mick Ofield

www.accessnorton.com www.accessnorton.com
 
...back when these bikes were regularly ridden in all weathers...
 
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