Can a Norton engine run without vibration?

Status
Not open for further replies.
Yeah, They are no fun when they don't vibrate- it probably means it's out of gas. Jim
 
DogT said:
comnoz said:
Actually I think the original question was can a Norton be without vibration- are you still there Dog. :p
Click to expand...
Actually Norton 'engine'. Yes, I think I've gotten my fill. Thanks to all, it's been informative, but I don't understand most of it, just a smattering, but it's been entertaining and I appreciate all the input, not that I'm going to try to make my engine vibration free.

Dave
69S
Click to expand...
10-4 to that, Dave. Who would want to ride a Singer anyhow?
 
pvisseriii said:
10-4 to that, Dave. Who would want to ride a Singer anyhow?
Click to expand...
Or a Gold Wing. Good grief, what is a M/C about anyhow?

Dave
69S
 
You got that MF'er. Us Rockers er gonna kick yer mod ass all the way to Liverpool. You Keith Stone wannabees keep off our forum or else..........
 
Haven't read all 6 pages, since there seem to have been some flamers. However, no parallel twin can run without vibration. Don't matter what the cranshaft angle is, don't matter how the valve timing is arranged, two pistons going up and down together cause inertial vibration. Two pistons going opposite (like the Honda small twins) are better for inertial vibration, but the uneven firing impulses cause almost as much vibration as the out of balance of a Norton-style arrangement.

Norton chose to isolate the engine vibration from the frame and the rider as much as possible using "elastic" engine mount technology. This "isolation by elastic mounts" is the origin of the term "Isolastic". We weren't 100% succesful, but on the prototypes, there was no vibration transmitted to the frame above about 1000 rpm.

I rode a 650SS to and from work and I was overjoyed whe I got to take a Commando porotype home instead. Although the 650SS was a lot less of a vibrator than the Atlas, the Commando was a revelation. it's unfortunate that later develpments and the attention of after-market "tweakers" has diluted the crispness of the original. Even given the mods to strengthen the frame, to eliminate the bell-mouth distortion of the cross tubes and to make the Isolastics adjustable, it should be possible to set the thing up so that there is no vibration felt by the rider from 1000 rpm up. If you feel ANY vibration in the bars, the seat or anyplace else, something isn't right.

I was only at N-V for 18 months or so and only on the Commando for the last 6 months of its development but I'm very disappointed that so many people experience vibration after they have done post-delivery mods. I repeat, there should be NO VIBRATION felt by the rider at any engine speed above 1000 rpm. If you have it, something's wrong, so go fix it.
 
Right . I can visualise consultations by the rubber supliers consultants at that time . The Bristol Centaurus was rubber mntd.
2.000 + hp on Iso Biscuits . :p :wink: . Disapointing to see further advancements not taken recently .
Bent frames dont enhace the opperation , not a bit unusual .Personally , opinion is the Mk 3 Adj. are a ' conveniance '
more than a improvement in the isolateing function ? .

Like the Nolathane suspension bushes of differand grades of resilance , Id presume the isolation is ' Tuneable '.
Alledgedly rubber is ' self dampening ' , but I think it can get into phase at the ' chuntering ' common at 1800 rpm .
Though , again , the Harmonics bit , combined with temperature related hardness variyations may play a part .
 
I like my bike just fine too. I went for a ride today on my VFR and I noticed that a lot of what comes across as vibration on the Norton are actually power pulses, feels kinda nice at low rpm's and then it's unnoticeable at higher rev's. It would be good though to get rid of some of the reciprocating weight for vibration, but also to free up some power and not feel guilty about flogging it.
Click to expand...

Bob you keep bringing up same things I notice but don't hear about from others. I think there is some magic in the isolastics being part of and in line with the drive train thrust, especially flogging it leaned. My C'do definitely hook up better on loose hill climbs than my fat sticky non DOT shod SV650 which is also a twin that has similar power pulse band rpm range as C'do. Sure its got almost 9K red line but its useless to rev that high as torque drops by 8K. Its starts to just spin and lag where the C'do are still eagerly accelerating upward. SV is 365 lb the C'do over 430 so not mass that accounts for this. C'do's hook/climb better than my semi hot rod 4 wd short bed with mudder ice studded tires kept in best spin grind. Something magic lurking - so could engine orbits be tuned to tire even more? We are taking like 2 mm for/aft iso motion on road loads back into tire patch.

BTW do you feel the valve train buzz in the VFR?
 
frankdamp said:
it should be possible to set the thing up so that there is no vibration felt by the rider from 1000 rpm up. If you feel ANY vibration in the bars, the seat or anyplace else, something isn't right.
Click to expand...
C'mon Frank, the engine is vibrating like crazy. There is no way that anything is going to isolate that vibration so someone can't feel it. My 69 in around 75 to 80 was loose as a goose because the isos were worn out and the shims were powder and it did about as good as anything per vibration, but with new rubbers and tight clearances, there is going to be some vibration, the shields on the S exhausts don't last 4K miles. Just look at a Norton idling, the rear fender shakes, the front fork shakes. It's always been like that. I'm not trying to start an argument here, but the engine and the handle bars shake, even if they're set up right. Now when you get on the road and up to 4K, it's smooth as a baby's butt.

Dave
69S
 
Dave I think something else must be going on then. They really should smooth out before 4,000 rpm, are you sure she is running spot on? My bike really does run smooth, I'd check the clearance again. Maybe the iso's are too hard????
 
I pay all kinds of music in my head while on a Commando, mostly hard acid rock but have no talent otherwise. I'm a survivor of the Timothy Leary daze so the didergy doo does me in nicely but a bit much to lug on a cycle. I've got some harmonicas this brings back to mind to try all alone.
http://www.youtube.com/watch?v=JHUuqsSCn5g

Get back to why sole Survivor has a gas tank with Norris D over the Norton logo.
 
frankdamp said:
Two pistons going opposite (like the Honda small twins) are better for inertial vibration,
Click to expand...

Sorry, but that is simply wrong. Without the addition of balance systems all you can do is change the direction in which the P-twin is shaking. The 180deg crankshaft has the highest rocking couple and it depends on the installation whether this is an advantage or not. The biggest advantage of the 270deg crank e.g. is that you only need to add one balance shaft and you're done for first order mass forces. The 0° and 180°e.g. need two balance shafts for the same purpose.


Tim
 
hobot said:
I pay all kinds of music in my head while on a Commando, mostly hard acid rock but have no talent otherwise. I'm a survivor of the Timothy Leary daze so the didergy doo does me in nicely but a bit much to lug on a cycle. I've got some harmonicas this brings back to mind to try all alone.
http://www.youtube.com/watch?v=JHUuqsSCn5g

Get back to why sole Survivor has a gas tank with Norris D over the Norton logo.
Click to expand...


From your posts on here I would hesitate to suggest you have survived your experiences with acid..............lol
 
Tintin said:
frankdamp said:
Two pistons going opposite (like the Honda small twins) are better for inertial vibration,
Click to expand...

Sorry, but that is simply wrong. Without the addition of balance systems all you can do is change the direction in which the P-twin is shaking. The 180deg crankshaft has the highest rocking couple and it depends on the installation whether this is an advantage or not. The biggest advantage of the 270deg crank e.g. is that you only need to add one balance shaft and you're done for first order mass forces. The 0° and 180°e.g. need two balance shafts for the same purpose.


Tim
Click to expand...

Tim,
How would it be possible to use one balance shaft with a 270 degree crank in a parrallel twin? Would'nt you still have a rocking couple or were you referring to a v-twin. Jim
 
Rocking Couples are Nice . :mrgreen:Look at it not as a 360 deg. twin , but a 180 deg. twin , with a Cylinder 90 Deg Out . 8)

A 270 Deg. Crank , IS a V Twin , With the Cylinders PARRALLEL . :p :roll: Hence , " A Parrallel V- Twin " . :lol: :shock: :D
 
I think our Frankdamp is not responding to the original question...but stating the rider should'nt feel any vibes above 1000. Down to fine tuning of the iso's, which by the way are made softer [by some well known supplier] by using a differant Shore hardness rubber...basicly the Whole bike "feels" smoother...but the engine shakes more.
Dogt asked a question "can the engine run vibration free"? Not "can the bike run vibe free"..completly differant.
 
DogT said:
comnoz said:
Actually I think the original question was can a Norton be without vibration- are you still there Dog. :p
Click to expand...
Actually Norton 'engine'. Yes, I think I've gotten my fill. Thanks to all, it's been informative, but I don't understand most of it, just a smattering, but it's been entertaining and I appreciate all the input, not that I'm going to try to make my engine vibration free.

Dave
69S
Click to expand...
If you can? ...i for one will be very interested.
 
Lets face it , All British bikes shook themselves to bits . :( And all the Japers couldnt go round a corner , even on the end
of a rope . :(

The Olde 60 Bonneville sorted it out though , just Jap parts feel off , footrests , tail lights and things . :D 8)

Pommy bikes have ' PRIMARY ' ( Good ) Vibration . hopefully .
Jap ones have ' Secondary ' Vibration .Yuk . Buzz , wobble , have incredably optimistic speedos and are undergeared for acceleration . How can you tell its a Yam. , not a Triumph . LISTEN , That sound , the Triumph'd be doing twice the speed .
The Norton , you probly wouldnt hear it, Till its past you . :wink:

:p :shock: :lol: :| :mrgreen:
 
Hortons Norton said:
Dave I think something else must be going on then. They really should smooth out before 4,000 rpm, are you sure she is running spot on? My bike really does run smooth, I'd check the clearance again. Maybe the iso's are too hard????
Click to expand...
The iso's are probably set up a bit tight. I plan on getting the Hemmings adjusters this winter to see if I can improve things without resorting to major surgery.

Dave
69S
 
john robert bould said:
Dogt asked a question "can the engine run vibration free"? Not "can the bike run vibe free"..completly differant.
Click to expand...
Right.

Dave
 
Matt Spencer said:
Rocking Couples are Nice . :mrgreen:Look at it not as a 360 deg. twin , but a 180 deg. twin , with a Cylinder 90 Deg Out . 8)

A 270 Deg. Crank , IS a V Twin , With the Cylinders PARRALLEL . :p :roll: Hence , " A Parrallel V- Twin " . :lol: :shock: :D
Click to expand...


It is a parrallel v-twin only in the exhaust note and power pulses. Not the balance. Jim
 
Status
Not open for further replies.
Back
Top