steering head

:?: My 74 Norton Commando roadster was involved in a right side impact accident, bending both fork stanchions. I replaced them both as well as the handle bars.
the bike rides well, but I can see a definite rise of the handle bars to the left , the left being slightly higher than the right, the bars are new and straight . My thought is the head stock is bent, can it be straightened or would I need a new frame ? Thank you for all your inputs in this problem.

Gidday Gra

it is indeed likely you may have damage.

If you see evidence of visible damage, there is only one step if you have not the experience or equipment to do this. this stuff is not do it yourself stuff you can learn at Bunnings on a Saturday arvo .

the only course of action IS TO PAY A PROFESSIONAL. full stop.

the professional would probably inspect first. He/she would then be in a position to advise on further action. eg: throw away or repair. also should be able able to inspect steering heads too. And good professionals cost good money. Yer mates may tell ya, no wuzzas, break out the oxy and crowbar. Dont do this mate.

This is my humble opinion
Aussie bradley

Well there ya go Gra you have either lied to us about it riding well or are so brain injured in hospitial now you don't yet realize you've crashed again bad from the bent frame and now require a new brain as well as new frame. If not then it was a professiona frame bender that crash bent your frame in such a way its was bent some where else to perfectly compensate. Or*OMG it just don't matter but visually on as much skewing as you have and can simply un-professionally bend back cold til looks good and hands rest at same level side to side.

I thought I'd have to bend my Peel special stem back after finding bent/dimpled stem down tubes so imagined how to cheaply efficiently get it checked & done. I'd take to a weld shop that has a large vise to hold stem with contured wood blocks then with 2x4's or 4x4's ask staff to help support and lever through frame hard points/joints till visiually good again. Or run rods through the front and back iso tabs that run through stout angle iron verticals on robust base and use pipe through stem with or w/o bearings in to lever stem back square. The bearings are iffy to save as beating to remove or levering through them may slightly damage them though likely couldn't tell if not a professional frame bending stunt racer. Of course the only right way to do this is sent off somewhere to completely slice off stem and bend frame parts back then re-weld together and refinish w/o weaking while trying to hide the repair like a cat covering its scat.

If the steering head is bent enough so that one end of the handlebar is higher than the other, the front wheel will not be centered with respect to the down tubes. Put the bike on its centerstand on a level surface, point the wheel straight ahead, and have a look.

It is possible to straighten a bent frame, but it is a big job. And a little fussy.

Greg

Taking it to a specialist does seem like the best solution for most cases. Having said that, I've been riding a Commando with bent frame on the street for years now, with no noticeable problems. And it occasionally gets ridden really hard. I do plan to straighten it when I start rebuilding it, but until then, I just keep riding it. If you're not experiencing any handling difficulties, then you might want to just keep riding it. If it bothers you anyhow, it is certainly possible to straighten a Commando frame. No need for a replacement.

I've straightened a couple Commando frames, as well as modifying them for road racing, but I have a large steel surface table, and some fixtures I made to allow me to get them right. Unless you are pretty handy, and well equipped with facilities, I wouldn't recommend trying it yourself. Some years ago I took a frame (not a Norton) to a professional here (Dr. John) for straightening, and was really impressed with how easily, and cheaply, they sorted it out.

If you include your location in your profile, someone can probably recommend a local shop.

Ken

The spine and headstock area are unlikely to bend but what tends to happen is, the two frame loops that go down and under the engine get pushed like a parallelogram to one side. right down to the back of the gearbox area. You will find it difficult to replace the front iso bolt through the engine mount if this is the case. The wheels will not line up because they are out of line in the vertical axis. (I rode my fastback like this for 30 year in ignorance) I would look for a simpler explanation to your problem first, like the top yoke or steering stem being bent. If you can take your hands off the bars and it doesn't dive in the ditch, ignore it

gripper said:

The spine and headstock area are unlikely to bend but what tends to happen is, the two frame loops that go down and under the engine get pushed like a parallelogram to one side. right down to the back of the gearbox area. You will find it difficult to replace the front iso bolt through the engine mount if this is the case. The wheels will not line up because they are out of line in the vertical axis. (I rode my fastback like this for 30 year in ignorance) I would look for a simpler explanation to your problem first, like the top yoke or steering stem being bent. If you can take your hands off the bars and it doesn't dive in the ditch, ignore it

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I have a '74 frame I picked up for $20 that was advertised as bent. It obviously was in a front end collision as the fork tubes present were bent rearward quite a bit. The headstock is slightly twisted and the large diameter spine is bent at the point where the down tubes near the battery area connect. The good portion is the rear loop and the reason I bought it.

Something to consider, and not mentioned yet, is that the fork yokes may be bent, not the frame ?

I rebuilt a 'lightly' crashed 850 some years back (not me), and as obtained, the front wheel was
noticeably pointing to the left, with the handlebars straight ahead (once the bent handlbars were replaced).
Stripping the front end down and inspecting everything revealed the lower fork york was ever so slightly twisted,
and causing the misalignment. Attempting to straighten those yokes revealed they were surprisingly soft to bend,
but it was difficult to get the complex twist out completely, so I obtained another set of yokes.
This fixed the problem completely, everything seemed straight and true again.
Hopethishelps.

Alrighty another thread that's been paired down to a thinker's level hobby based on philosophical beliefs or pure faith vs tested experiences.

After all the decades reviews on the wide scope [other forums too] of non-prefect frames found I've still yet to hear how much is too much to actually detect in safety or handling so knowing life and funds are short I'd just bend the handle bars and forgetaboutit. Of course if trouble assembling from skews then mashing bashing beating bending prying levering and jacking to slice/dice/pin/rose bud welding should be sought out. Clip on's come to mind as reasonable solution for minds of refined Cafe perfectomundo's approval and if even noticed bu someone that nosey tell em the slightly different angle is to compensate for old race injury, letting em assume its you rather than the faulty Commando. Yokes, bearings and stanchions should be renewed close to perfection even in hobot bent cycles. May not want to let forum know what path ya tactfully take.

If you run a string line around both wheels and can get them both in line, nothing much else matters. If you want perfect handling you need to put the frame in a jig and start measuring and using the Porta-power. The guys who do this for a living are usually pretty good at it. It can be a bit fiddly, trying to do it accurately.

Reminds me of my misspent youth - we had a bent frame and no money, so . . . we used a 4 foot level and steel studs as straight edges to discover where we wanted to bend it back, lashed the frame to a telephone pole with tie down straps and went at it with a 6 foot steel digging bar and an oxy-acetylene torch. Came out OK.

Ugh, Al wishful myths w/o facts or experience, Commandos did not ever come with both wheels in same line with stem/spine, nor did a bunch of other famous brands, so that don't matter much but what does is the squareness of the 4 holes cradle mounts in, which is easiest to judge by trouble to assemble then jig up for corrective controlled brute forcing if needed. The good part of me knows this instant case should use this opportunity - excuse to take it down to frame and crank shaft for long term labor saving and public approval even if not practical cost effective, that's basic best advise to please everyone but the unrefined black sheep.

We've seen how you ride twisted canyon road xbackslider and some your dubious hard riding history so going by the best advise implies your successful crude brutishness is dangerous risky practice here.

Someday I may have to make up a Cdo with adjustable frame so wheels can be set out of road travel line, out of center line, toed in/out and leaned either way plus shift power unit significantly either side with the above factprs and some bent yokes and stanchions and stiff bearings to play with to nail down what matters most and what don't but for looks. CoG side to side don't make much difference as I've found out testing 50 lb in one hard bag and plenty of testimony online forums claiming same thing, no problemo. Lots of things matter to safety and handling but that's basic rake, trial and swing arm angle, shock and fork height stuff beyond a mere bit of crookedness.

Again not to be mis-understood I and everyone else *kows* the only uncontroversial incontestable best advice is to always is use this and every opportunity to take it down to crank and work back up or just scab along best as can and don't mention it publicly. GT Enterprises is most famous Cdo frame worker last couple decades.

hobot said:

Commandos did not ever come with both wheels in same line with stem/spine,

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Says who ??
I know we have had this discussion before, but...

I recall rebuilding a lightly crashed 850 some years back,
and simply lined everything up roughly along the spine frame's backbone.
Worked well, steered well....

Power units including the rear wheel center are all factory built some what L of center, how much varies so maybe a few were made so badly they ended up all centered. I'm not expert but rode crooked craft enough to know its more tire wear or drive train strain that suffers most rather than dangerous handling at least a thrilling bit over legal. Regardless of anyones history knowledge the facts reported that impress me besides my own are its only visual or assembly that clues someone like me into finding frame faults so then boils down to what is worth to ya to make more perfect if only thing that will be detectable is appearance. Oh yeah about the crooked craft part, most wern't mine but d/t my hard earned nut case reputation was asked by locals to hop on and access on where to attack first. Harleys cafe's to Honda heaps, ugh.

Alignment don't matter near as much as stability if ya can twitch its loads to one main direction and hold em till can flip em stable the other way does pretty good, if THE Twitch don't send ya over the top. Found out today why the banchee quad I test rode turned into out of control straight line flat tracker about 60 on THE Garvel and raised front doing dougnuts in pasture to flip it over on me- swing arm was broken so front half could twist opposite rear half, ugh yet a thrill ride with a small leg scar I'll never forget. I could too easy see crippling injury on those uncontrollable beasts - no wonder they can't lick cycles on BaJa events. Got filled in picking up anti-swing arm slide deflection devices for Peels experimental centered rear wheel. Asked about the ravine runs in tool/die shop back woods, told totally ice storm destroyed by layers of tree falls, hm. Scary.

Thanks for all the great reply's to my damaged commando alignment issue. I have rode the bike over 600 miles with this condition and no steering or handling issues. I am leaning towards the suggestion from ( Rohan ) regarding the possibility of bent fork yokes. The accident happened last year traveling at 50mph a big 100+lb dog ran into the front forks at a right angle to the bike, the dog was chasing something so was running fast. I don't know the formula to figure out speed and side impact load plus estimated weight. The fork stanchions had an 1 inch of bend to both. By the grace of God I did not go down , I managed to come to a safe stop using the rear brake only. The total damage to the bike was bent forks snapped right footrest, bent gear shift and dented front fender and badly bruised foot (dog impact) I had boots on that saved me from a broken foot or worse. With the help of my friend guiding, I rode the bike home slowly taking back roads for 40 miles . Would the fork yokes triple tree bend before the headstock ? ps I will try to post some pictures if I can figure it out. Thanks again for all the great advice.

Would the fork yokes triple tree bend before the headstock ?

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Depends on the forces applied and the direction, you are not going to find out until you start measuring, as the impact was coming in from the side its less common than the normal pure front end. I have a bent 750 frame from a straight front ender, its the rim, frame and stanchions that bent not the yoke. But from the side the yoke might give way first. The 2 thin front downtubes will give a clue, if they look straight then that would suggest the yoke is at fault.

Sounds like a good excuse to get yourself a set of beautiful CNW billet yokes

Grajaguar1 said:

Would the fork yokes triple tree bend before the headstock ?

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Possibly. The yokes on my '70 are quite soft and were easy (but time consuming) to straighten. If you still have one of the bent fork tubes you may have the lever you need to straighten the yokes.

In the same vein as 'measure twice, cut once', you do need to measure the frame or have a look at the bike to see why one handlebar is higher than the other. Fixing the wrong problem is frustrating. hoboT's experience shows that the bike does not have to be perfect to ride well, so you can do a fair job of judging the frame / front end straightness in your driveway with a couple straightedges, rods, squares, etc.

if the yokes are bent it would have been hard to fit the fork tubes. How did the front end go together ? If you remove the front fender and wheel you can put straight edges at the top and bottom of the assembled forks and see if they are they in the same plane. If not, the yokes are bent or the front end was not assembled correctly.

Greg

Greg

Deer impact into fork at combined speed about 65 bent Trixie stanchions to snap bike out from under sideway then bent under spine tube landing on me. Left hair in front tire bead 360' around and broke my neck plus other stuff. Yokes were fine so new stanchions fixed that and use shims on head steady to off set it more but never check stem squareness as can't tell any handling bother so just noting how strong the yokes compared to all the rest.

Replacing the stanchions was no problem nothing seemed out of alignment. Does this mean the yokes are fine? As I mentioned the bike handles fine no shaking or wandering, just the uneven bars . Maybe if the yokes are fine and the bike rides good I should just wait till I am ready to any future major work. I don't won't to tear it down to have the frame checked unless I see an obvious problem. On inspection of the frame I don't see any thing bent.