Why did Norton switch front rotor sides?

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Hobot

Hobot

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Every cycle I've ridden in N America drifts more or less hands off up the road crown to the left. There is some difference between bias vs radial tires whether it seeks more to climb a crown or tends to run down off it. Related to principle of flat belt drives and crowned pulley rim. Meaningless mystery for snowed in day off. Most known they had to reverse thread the rotor side's bearing retainer ring or circlip it but why bother after Combat bombs almost sunk Norton by that time?
 
To stop it pulling to the left, that's what Norton said. But who (not including you Steve) would let go of the bars because that's when it'll shake wobble and weave. :wink:

Cash
 
UGH i've had plenty of anal reactions to even hands on weave wobble and hinging but got both Combats eventually sorted to ride smooth hands off almost to a stop. Yet all my bikes and others I've tricked into letting me ride all drifted up crown to the left in level-ish straights. I would have to lean off to RH some to balance straight tracking and even that took some seconds before effective. IIRC 850's tend to drift L up road crown too, but don't have one to know myself.

I do know bikes on level drift to side of most weight, so RH disc is opposite expected but still so close to mid line don't think its much a factor so mystery remains.

Most straight tracking bike so far is tri linked Ms Peel. i have a bit of a beef with Keith Code philosophy of front tire controlling real turning, so last time out on Peel was 110 mph winter wind shield body slams to get a bit more tip each slam in time to easy around a curve hands off before slowing under the ton. Most wonderful thing on Peel was she'd just stay in a lean hands off no effort once there. Her rotor is on Combat LH. Hands off front wheel will naturally follow the road surface and that means straight steering not counter.
Hmm.
 
It's been discussed here before, but basically with the rear disk on the right side they felt it necessary to move the front disk to the left to balance things out. Don't ask me to explain it, but I'm sure ludwig or comnoz could discuss it in detail...
 
Yes balancing out L/R brake forces is the common lore but I don't believe its a factor - just lore. Hope some 850 riders chime in on their hands off drift on not.
 
Damn it.... Right at the time when I was thinking of being fluent in the Hobot language!!!! I see now that I can only read the words I am completely lost with the whole .... Cannot understand anything on the disc position ..... Have to study more for the final exams!! :?

Philippe
 
I passed my exams, so have time to ponder the imponderable.
hobot is a handle not my name so its don't deserve a capitol even if
at beginning of sentence. Yet I'm still alive so never write my name in all CAPITOLS like a head stone or artificial Corporation or boat name.

I don't *think* flipping rotor mass to either side makes much difference as they have so little rotating compared to whole wheel and is so close to center line.
Back to the study grind Phillpe so its pays back later.
 
I read once that people often move the the right as they mature. Maybe it was just time.

Actually I never noticed a difference in which way the bike drifted but I do prefer having the caliper behind the fork tube to put it closer to the centerline of the steering stem. So right is right on a Norton. Jim
 
Greetings All,
I own an 850 and I swapped sides with the forks and cured the pull to the left. In fact I posted about it here in this forum, the thread is titled "Pull to the left cured". While it is true the pull is very slight and no I don't ride with my hands off the bars, I found myself always sitting off center of the bike and it was a constant reminder that something just was not correct. Anyhow, the swap was quick and easy (OK I had to loose the front front fender stay and no I did not worry about the wheel bearing) and did the trick. Try it you'll like it !!!!

GB
 
interesting report Geo, will keep it in mind while pondering the principles that made such nice improvement. My Combats in Dixieland don't annoy me with a drift I have to consciously compensate on bars or seat position but they do tend to begin a drift to L hands off no throttle. Will have to ride in opposite lane to see if road crown is a factor or just the innate spinning dynamics. Bb220, I ride with the big twin dogs at times and they sure like to ride in oncoming lane as much as they can, usually over the ton too. Maybe its easier on them too?
 
I posed the question, right vs. left front brake, some time ago to a Cycle World column. Essentially the answer was that it made no difference. My thoughts are that since all front brake master cylinders are on the right, would it not be cheaper for the manufacture to hang the disc and caliper on the right, eliminating the expense and hassle of crossing over to the left with the brake line? It's been pointed out that there are more than Nortons with a disc on the right, but most discs are on the left side.
 
Ugh JimC, good points on the continuing mystery of Norton switch. One noticed switch to R side nullified drift yet my meager understanding and your Cycle World report and the review of number of cycles on either side leave me wondering why.
Only thing I can think of is mass of caliper behind or in front of the fork/axle.
I'll have to just take my disc off on both my Combats and see if that drifts em more or less, when wind not an issue. I'll interweb search and see if other breeds complain to drift one way or the other. Can't remember a magazine comment unless crooked frame or tire wear issue.
 
JimC said:
I posed the question, right vs. left front brake, some time ago to a Cycle World column. Essentially the answer was that it made no difference.
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Moto Guzzi some years back went with calipers in front of the fork legs - they said it gave better braking. Something about the trailing calipers...

It may be this rather than sides that Nortons were addressing - but having only a single disk up front made it seem like an issue of which side. ??
 
If the Guzzi theory were being pursued, why would Norton not just rotate the fork slider 180 degrees? This left side, right side brake thing may be more black art than science.
 
More to ponder on front brake.

http://www.braketech.com/index.php?opti ... &Itemid=69
Caliper Mount Location; here's where and how the caliper is mounted on the forks becomes a factor, and this is strictly focused on the occurrence of TORSIONAL caliper flex. Bear in mind and heretofore, all conventional calipers are mounted at the trailing edge of the line of force, combined with the fact the energy transfer (to the forks) of the braking forces are focused on just one side of the spinning rotor. Then factor in the normal production tolerances between the mounting faces of the rotor/wheel, fork/caliper, plus perpendicular axle alignment within the wheel to these faces, and more. Of course we can stir the pot with greater possibilities for misalignment with (even just slightly) out of true axles and fork tubes. The end result is there’s always some degree of mating issues that ultimately effect performance potential yet are still within factory tolerance. But it is predominantly the torsional twisting effect of the caliper that is the main culprit for setting the gremlins loose during hard braking. The relatively new radial mount caliper design virtually eliminates this torsion flex problem since it more efficiently spreads the load equally both fore and aft to the line of force. It also offers the additional advantage of better (quicker) release at the end of the braking sequence as an additional design benefit.
Click to expand...
 
JimC said:
If the Guzzi theory were being pursued, why would Norton not just rotate the fork slider 180 degrees? This left side, right side brake thing may be more black art than science.
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Nortons forklegs are not symmetrical, so just cannot be rotated 180 degrees - would recquire a new casting.

The way Nortons did it with the Mk3, all existing parts were used, except for the bearing retainer in the front hub (?).

I'd agree about the black art, it would be interesting to hear or read whatever who was behind this change had to say ?
 
Nortons forklegs are not symmetrical, so just cannot be rotated 180 degrees - would require a new casting.
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I was guessing the lugs were cast symmetrically and could be machined from the either side. I haven't looked, the bike's been under the tarp for some time, my K75RT seems to have become my favorite. No doubt, Rohan, you are correct.
 
hobot said:
Yes balancing out L/R brake forces is the common lore but I don't believe its a factor - just lore. Hope some 850 riders chime in on their hands off drift on not.
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My 850 MKII didn't lean left or wobble with hands off the day I rode it from the dealer's lot. Over the years however, it developed both behaviors. Three years ago I redid the front forks and wheel - new down tubes, bushes etc and respoked the rim and renewed wheel bearings and a new front tire - and the low speed wobble went away. Last year a buddy showed me how to "propperly" align the rear wheel and the left lean went away too. I confess to occaisionally removing my hands from the bars while coasting nowadays just to verify that all is well - after 20 years of funkiness it's a wonderful thing to experience.
 
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