Frame swap compatible?

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I just got back an old Norton 850 I owned 30 years ago. Unfortunately it's been wrecked. For starters I need a frame, then who knows. Can anyone tell me if a 72 750 frame will swap into my 74 850? My guess is yes, but...
Next, Forks are shot too. Anyone put on any modern forks and triples? And if so, what fits?
Pete
 
peshleman said:
I just got back an old Norton 850 I owned 30 years ago. Unfortunately it's been wrecked. For starters I need a frame, then who knows. Can anyone tell me if a 72 750 frame will swap into my 74 850? My guess is yes, but...
Next, Forks are shot too. Anyone put on any modern forks and triples? And if so, what fits?
Pete

Frame, no problem.
 
ZX6, ZX9 fit with a little bit of work on the yoke stem.

TL1000 fits with a replacement custom yoke stem.

All of the above need the stem to be 1", and it will slip right into the Norton headstock bearings.

All of these use modern 1" hollow axle.

There is a critical fit of the modern multi-pot brake calipers to a spoked (laced) wheel, requiring a custom made hub & spacers for the calipers to clear the spokes. Cast wheels have a very narrow profile in the area where the calipers reside when the wheel is mounted up.
 
I used a 1992 GSXR 750 inverted frontend rotors and calipers. I modified a harley dual disk hub to fit the rotors. All laced up to a deep center alloy rim. I am running taprered neck bearings, so ones that fit the gsxr neck were easy to find. All I needed to do was machine a spacer, because I didn't want to shorten the gsxr stem.

Frame swap compatible?

Frame swap compatible?

Frame swap compatible?

Frame swap compatible?

Frame swap compatible?

Frame swap compatible?


Here is where I got too before the project stalled and I took another direction.
Frame swap compatible?
 
Other than the steering geometry being different try to use the 850 swing arm which has gussets where the forks joint the support tube (in front of the pivot bushings)
 
there is MORE to fitting a later front fork assembly than JUST the stem. you and bwollf need to look at the offset of the trees (yoke's) as THAT can have a DRASTIC effect on trail and handling as well as rake IF the later trees have a different offset from top to bottom. also the length will change ride height and THAT will also have an effect on handling as both rake and trail can change.

grandpaul said:
ZX6, ZX9 fit with a little bit of work on the yoke stem.

TL1000 fits with a replacement custom yoke stem.

All of the above need the stem to be 1", and it will slip right into the Norton headstock bearings.

All of these use modern 1" hollow axle.

There is a critical fit of the modern multi-pot brake calipers to a spoked (laced) wheel, requiring a custom made hub & spacers for the calipers to clear the spokes. Cast wheels have a very narrow profile in the area where the calipers reside when the wheel is mounted up.
 
bill said:
there is MORE to fitting a later front fork assembly than JUST the stem. you and bwollf need to look at the offset of the trees (yoke's) as THAT can have a DRASTIC effect on trail and handling as well as rake IF the later trees have a different offset from top to bottom. also the length will change ride height and THAT will also have an effect on handling as both rake and trail can change.]

I never said the geometry would stay the same. Didn't WANT it to, that's why the modern forks.

Modern yokes are way different from Commandos in the stem setback from fork tubes, resulting in quicker steering.

The attitude of the bike can be adjusted by simply raising the fork tubes up in the yokes; something you CAN'T do with Commando yokes unless you bore out the tops, cut a slit in them, and weld up pinch arrangements.

The three monoshockers I've built all handle quite nicely, thank you. I personally like the ride better than my Dunstallized Comabt, and WAY better than my Interstate.
 
If the rear shock mount plates / gussets under the front off the seat loop , have triangular / angled up aft gussets on the inner shock bolt mounting plates , it should be one and the same .

If both gussets kick up the same , near vertical , behind the bolt , the steering head is a degree steeper .
 
These forks (well clamps) increase the trail by 25mm give or take depending on sag settings etc

Frame swap compatible?
 
ludwig said:
grandpaul said:
.. something you CAN'T do with Commando yokes unless you bore out the tops, cut a slit in them, and weld up pinch arrangements..

Nonsense ..
Just fit shorter damper tubes..

He was describing adjusting the tubes not cutting them shorter and not having any adjustment (unless you keep going shorter). Adjustably means a range of settings. Read it more carefully before calling nonsense.
 
ludwig said:
swooshdave said:
..He was describing adjusting the tubes not cutting them shorter ... Read it more carefully before calling nonsense.
I said cutting the DAMPING tubes shorter , not the stanchions ...Read it more carefully before posting .

Still doesn't give you any adjustably. Try again.
 
Back to the ORIGINAL TOPIC.

I provided a positive. PROVEN (multiple times) answer.

Several other replies to the post are not only off topic, but argumentative.

Give it a bloody rest.
 
ludwig said:
From everything I ever red from you , I can only conclude that you haven't totalled a 100 miles on Nortons in your entire life .

I'm not an independently wealthy retired person who can take road trips to the Alps whenever I choose. I have done a 600+ mile ONE DAY trip on my Interstate, about four or five 200 mile round-trips (sometimes 2-up), and several all-afternoon rides where we didn't keep track of miles. That's only in the 6 or 7 years I've had it.

I do have vintage racing experience with dozens of races at tracks across the country, finished 5th in the championship in my class, in a field of 20 riders (as a rookie) so I know a thing or two about riding hard and what a good-handling bike feels like.

I have owned over 150 motorcycles (over 120 were indeed running bikes) in almost 40 years, so I have more riding experience than you know. The Texas hill country where I often ride has some of the most challenging riding anywhere, and I've never so much as put a tire off the pavement.

Your conclusions are completely incorrect and tiresome.

BACK ON-TOPIC, AGAIN...

My Blue monoshocker has done less than 800 miles, but all of them fun and totally without incident. In my opinion, the handling is quite predictable, stable and light.

The reports from the two client Nortons with modern forks is that one of them has seen regular track time at "The Streets of Willow" (Willow Springs' secondary race track) and it is a much better handling bike than a standard-forked Commando; the other one is mostly shown, but it is ridden by both husband and wife, and they have nothing but excellent regard for it (she even kickstarts it by herself with 1 or 2 kicks).
 
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