I just don't get the endless posts on performance upgrades

Re: I just don't get the endless posts on performance upgrad

ludwig said:

Larso1 said:

..It is still my experience that for every performance upgrade I make, the power increase is modest and there seems to be an equal and opposite loss in reliability, for the most part. Increases in heat (from higher compression) especially create reliability problems at the cylinder head ... Reduced reliability and cost are the two factors that I have issue with..

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All true , but there is another way :
Loose weight ! .
Shedding 120 - 130 lbs equals 20 HP and will transform the bike .
While the benefits of increased HP can only be experienced when you are actually USING that extra power , the benefits of less weight can be experienced ALL of the time : better accelleration and braking , less stress on frame , engine , gearbox , drive train .. less wear , tires , chain .. , less heat , better handling , less fuel consuption , increased reliability .. even pushing the bike around becomes easier .
Altough not exactly cheap , loosing 100 lbs is likely a lot cheaper than trying to gain an extra 10 HP .

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I did this with my project bike, it is 110 pounds lighter than the stock bike that I borrowed the motor from. It was pretty shocking to feel the acceleration difference and ligtness in handling.
The acceleration advantage diminishes as you go faster, at some point it is a battle between the hp of your engine and wind resistance, weight is no longer a factor, but this is at far beyond legal speed.

The other advantage of light weight is lower rider fatigue. I found that six hundred mile day on the light bike was about the equivalent of 400 miles on the heavy version, as far as body aches and pains and general weariness when riding challenging roads.

Glen

Re: I just don't get the endless posts on performance upgrad

Lighteness Is Rightness yet lightness can cost and involve efforts as much as engine mods that may pay back less. Rule of Thumb is 7.5 lb off worth an extra hp up - acceleration wise and braking too. Wartorn and Ludwig are stars to follow down the light path away from factory utilitarian state. Its another feature that helps alot on off road handling that pays back in spades on secure pavement flings. To get what I want out of Peel implies about 1 hp per lb of bike/rider combined and even better than that may be her torque pound to mass pound ratio. Wheels spun and unsprung mass pays off the mostest per oz removed and can cost and involve as must a speical crank shaft. Restless souls/minds soon bored with plain Jane projects but of course Commandos may not be all that excites you in life to devote to and its pretty hard to beat what Norton sold to get nice highs from the easy operation besting modern traffic and sharing the highs a Commando of any sort delivers everywhere.

Re: I just don't get the endless posts on performance upgrad

hobot said:

To get what I want out of Peel implies about 1 hp per lb of bike/rider combined and even better than that may be her torque pound to mass pound ratio.

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Huh? You are going to get 500+HP out of a Norton? Am I missing something here?

Re: I just don't get the endless posts on performance upgrad

Ugh definite dyslexic misprint of my mind ahead of fingers. Meant to state:
1 hp per 4-ish lb of bike/pilot combined. Peel and me may come under 500# total in full faired caged charging ligthed and weaponized Peel, so possible to pair down to under 450# for real battle advantage. So please note everyone hobot now convicted of claims of more hp than number of lbs, ugh. GP's and 9+ sec drag bikes have ~1 hp per 3ish lb of bike alone. I abhore wheelies and know dropping nose way low sure helps leap forward instead of sitting smoking. Fairly similar 920 Jim dyno'd got upper 80 lb ft so add ateast 50% more for boost and go look up torque to mass of elites. Torque = acceleration, hp is how a high speed ya can keep pulling too is all. Fact of the matter is no stock cycle can carry me to my desired fantasy level before gone. Endless posts on dream machines makes our world go around eh.

I've got most what I need on hand to reproduce past Peel's oddball Combat power combo, so wondering how cheap of parts can be used, though would have to keep rpm 1000 less as that good stuff being used in next Peel. Need crank, and cam drive mainly and maybe a barrel as enough left overs from Peel era to finish. Then what to put engine in, chopper, trike or Cushman or a boat just not in aircraft thank you.

Re: I just don't get the endless posts on performance upgrad

hobot said:

I abhore wheelies and know dropping nose way low sure helps leap forward instead of sitting smoking.

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This has been going through my head with all the talk about reducing weight and increasing HP.

My BSA back in the 70's was built up. Never dynoed it but couldn't keep clutch working cause it burned them up. I had heavier springs and whatever upgrades I could do back then but clutch was a weak link. It was a Hornet with no battery and was very light. When the clutch did work it was hard to keep the tire from spinning....so not sure how light a bike with performance upgrades could be before something else comes into play and messes things up.

Hobot not sure why you want such a beast...seems like a drag bike rather than a rider.

Re: I just don't get the endless posts on performance upgrad

FWIW, weight affects acceleration but has virtually no effect on top speed - that becomes a function of aerodynamics vs HP.

So how does one reduce a COmmado's weight by 100 lbs and still have a motorcycle?

Re: I just don't get the endless posts on performance upgrad

There is such a thing as 'the law of diminishing returns', often success comes down to 'what you do with what you've got' as it does in other enjoyable past times. There are two ways to go with a motorcycle if you want performance. You can have a bike with heaps of top end power and set the geometry up for 'point and squirt', i.e. the bike runs wide in corners, but accelerates like buggery. Or you can develop more torque use higher gearing, and use and use geometry which causes the bike to tighten up it's line in corners. If you use the top end motor in a bike that tightens it's line, you get the hi - side . If you have the torquey mid-range motor and high gearing, and the bike runs wide, you have no advantage. For racing a lighter nimble bike is always better than a heavy over-powered monster. For touring a Honda Gold Wing is popular. So you have a choice to make about how you want to use your bike - racer or tourer. A compromise bike is never as good as a bike which is specialized for it's intended purpose. It all comes down to 'whatever blows your hair back'. I love my Seeley 850 on a race circuit, however as a road bike it would drive me insane - a BMW boxer would be superb.

Re: I just don't get the endless posts on performance upgrad

hobot not sure why you want such a beast...seems like a drag bike rather than a rider.

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hobot has been struck by lightening with the rump rod and two whimpy helpers, so tight decreasing radii can be taken like a drag racer floating front all acceleration felt as straight back into rear axle thrust not any side loads till I let go of forks and throttle for the whiplash release rebound to neutral right out of there. Where other cycles are at least traction states is where/when Peel can SPIKE Acceleration G's. I've described how pissed off/surprised/shocked in my own drive way on Gravel to end up twice out of seat no matter how I tried, well guess what pulls even harder on tarmac! If I was 'careful' smooth on peg scraping leans she'd pull a sideways wheelie not spin nor loose grip. If I gave her a bit more she'd spin to either drift lazy flat tracker style out wider to get better longest straight zone in a turn or a lot harder and trip out completely into a low side that next instant hi sides and depending on when/where I cut the low side short determines where the sling shot aimed and how far it flys, all the while twisting in flight
of vetical COG to land on a smashed down patch that can take a frame bending amount of torque as tire rebounds too with the front slamming down momentum resisting stupid wheelie out of there. Peel allows evolving the 'Slow down to Point then wait a bit to Shoot" style into "Ricochet Rabbit" controlled crashing. Its takes serious power/mass to pull this off so seek way Mo Pow at apex to get even more thrills. I like bee line much as anyone but its so boring compared to adding accelleration vector at 90' ontop the straight sprint G's. Brain vision draining so fighter pilot breath control needed and requires way more pilot effort than just the hanging on enough to work throttle power steering. Peels hooks up so far over - side ways loads almost completely in line of suspension as when upright, [until front lifted out of conflicting effect > TWACK me off road orgasm]. No steering damper can allow fork motion as fast and far and furious as Peel requires so thank goodness for basic Commando innate self centering stability. Ever see a sail boat boom snap across deck in a tack, motorcycle forks do that too but it so upsets others, poor things. In milder sweepers I call it "Faceting a Turn" as even Peel can't accelerate on tire edge as more upright, so another way to go around pretty similar is just keep increasing power so any time tipped a bit off center automatically trips out instantly [like a real dragster would] then while still increasing power tip back up for more thrust and repeat as needed through about any lines around ya like or need to go around parking lot cones in the way. Non of the above involves any brakes nor any instants not accelerating just slower lower G's on the trip out instants and a bit longer no G's weightlessness relaxing while flying to catch breath for next instant injection of Adrenalin. Strangeness of Peel is only time I can feel her as a motorcycle under me it durring air time, iso's can isolate so relieving to touch back down on Gravel or pasture - freaking uncanny I tell you yet flabbergastingly fantastic. Note full extended air muscles here but will suck down rather lower than stock at least as low as Seely lean fouling racers. Air and water tanks in plain view here.


Basic body plan angle with Full Fairing crash clearance being measured/provided for.


Most lean limited angle with Drouin and cage on. Note the natural straight steering fork fall into. When put - ie: over powered into this state and front still loaded the front is trying like crazy to plow into road twisting front or bike in direction desired with the front axle angle to frame forming a hinge axis that pitches bike harshly into a lifting hi side reaction, which force is directed into twisting up frame against rear axle-tire traction being powered up to low side spin out but then cant because more than the whole mass of rider/pilot is being acceleration loaded down into smashing a wider rear patch so can power on more till point I can't focus clearly on the paint line turn in power cut fork let go breath taking sling shot ZING all the rest is just the 1st stages of launch to hit 2nd stage gravity escape speed. If ya picture this on THE Gravel, easy to see how rear could be swung around front patch w/o letting off, well its way way easier on tarmac doing it through sharply decreasing radii, like Brer Rabbit say's "Oh Please Please do anything to me but Please Please don't thrust me into decreasing radii patch with pinned trhottle. hehehe. Peel craves what corner cripples crash doing.



Oh yeah Peel had total neutral handling, ie: only takes mild effort to change fast to any lean angle [by ordinary ways] but once set nil effort to stay at set angle even sliding outward on both tires, stayed same angle no issue to trip out or hi side, then only takes same amount of effort to change to new angle and relax again letting the hoss head for the barn on its own like Alan on his Seeley says his takes over for him and faith enough to just let it... This is how I take THE Gravel sweepers with some spirit, before any leaning I'm in gear to spin tire and let the spin out [before entry] begin the lean and rear swings out some so crossed up and then resist any further tire spread by feathering smooth spin up and feathering/holding forks to just road follow the direction-path Rear Ruling the Roost is Rocketing us along. 5 yr on last Peel, about 8 yrs now next edition.

Re: I just don't get the endless posts on performance upgrad

I could never drive worth a dang on gravel. Rear always wanted to come out from under me with the slightest throttle. Lighter bikes were worse...knobby tires helped

Re: I just don't get the endless posts on performance upgrad

Your my hero Hobot, I hope to someday be able to put words together the way you do. I kinda get a picture in my head as I read your posts and wonder how you do it, I look forward to your reports on how this machine does in the gravel. :wink:

Re: I just don't get the endless posts on performance upgrad

Dennis I never feel I got a good grip on THE Gravel travel and can assure you if any tire texture-grooves or knobs helps then it ani't really THE Gravel, which only tire pressure and compound softeness matters, as nothing to grip to dig in on, any digging in just hits hard base lubed with hot dust by then. No one me or anyone does well on THE Gravel, just mostly lucky to get off of it each and every time. Only thing worse is when it turns to mud then always instant crisis. I hit that stuff fast as I can to hydro plane over it, it lucky, I can keep a slight rear tire power so not to either drag or to accelerate or Wipeout SPLAT! Last mud patch low sided C'do on L knee/hip to hi side on to R elbow shoulder to pop out of the mud back on mere wet [ah] Gravel like UFO snatched me probed pounded then shot back on still wobbling cargo like nothing out the ordinary happened, but evidence by hole over L knee and scuff R elbow rain suit. THE Gravel is my Guru, my Demon, my Savior, my Terror, my Master, my Teacher my Teaser and Tempter. Ain't re loaded camera program in 'puter for the most recent shitty skid marks picitures leading to poor SuVee down it in.

Re: I just don't get the endless posts on performance upgrad

mike996 said:

FWIW, weight affects acceleration but has virtually no effect on top speed - that becomes a function of aerodynamics vs HP.

So how does one reduce a COmmado's weight by 100 lbs and still have a motorcycle?

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I'm not sure exactly how to accomplish this with a Commando but like to try this and a few mild performance enhancements. I will do this on something other than my near stock MK3 which runs very well and makes more power than it seems it ought to already, so it would be stupid to take it apart. I'll probably buy a wreck for this experiment.

I would start by taking it down to the nubs and then chucking out all nonessentials. Get rid of the heavy centre stand and side stand, fabricate a lightweight one from aluminum. Change out the wheels for something much lighter. The stock seat needs to go, it weighs a ton. Same with the steel or fibreglass tank.
I would not go quite to the he extent Ludwig has gone to save weight, just too much work, so total savings might be more like 80 pounds. There are some areas I would avoid, such as using bicycle tubes to save weight. I know that this has been successfully done,but for safety reasons and to avoid the general annoyance of flats, I would still run a good Michelin leakstop tube, provided wheels are old style spoked and require tubes. Tubeless would be ideal for weightsaving.
Other than that, replace non critical steel bolts and washers with shop made aluminum 6061, replace critical steel bolts with Ti bolts and just really strip the bike down to it's essentials.
With my Vincent project I started with the motor and trans and then looked very carefully at the weight of every item as I fabricated or installed it. It is really quit amazing how much weight is in unecessarily heavy brackets and such. For example, an Altette horn that the collectors love weighs about six pounds and produces a sound like a sick cow in heat. I found an airhorn with built in compressor that weighs less than a pound. A collector bought my Altette on ebay for $230, he is welcome to it!
Lighting is another area of potenwtial weight savings. LEDs with their own lense are much brighter than conventional tail/brake signal lights and can be had in an all in one unit that weighs only a couple of ounces.
I used a very light electronic speedo/tach unit that does away with heavy speedo and tach cables plus their drives,gets rid of one instrument and the heavy holders. It also has 1/4 mile ET and zero to sixty functions plus a ton of other good stuff. All in one unit that weighs a few ounces.

Glen

Re: I just don't get the endless posts on performance upgrad

During the muscle car era with the h/p races between manufacturers, as the years advanced the cars never got any faster because they added creature comforts for the older crowd buying the cars. This added weight and the added horsepower could not keep pace. Duntov fought the putting of the big block truck engine in his Corvette. A 64 GTO post sedan weighed in at 3200 lbs and a rated 348 hp I believe. It was a quick combination. That yields a 9.2 hp to weight ratio. A Commando weighs in at about 410 lbs and has 60 hp. That yields a 6.8 horsepower to weight ratio. Having driven both, I would say they are comparable in acceleration over the quarter mile. Bikes it seems just cannot put the power to weight advantage to the best use. Both run a 13 to 14 second quarter mile in stock condition. If you add passenger weight of say 180 lbs to each vehicle you get 9.7 hp/weight for the GTO and 9.8 for the Commando. There it is, almost the same. The other poster was correct about shedding weight rather than adding horsepower. Each 7 lbs you shed frees up 1 hp. Wow. If I got back to my weight in the 70's I would pick up a free 26 hp. Good thing I run a 19 tooth sprocket . Thankful to Norton for all that low end grunt. Scary when you were young and skinny and silly. Now a god sent when you are old and fat and senile. Well getting there.

Re: I just don't get the endless posts on performance upgrad

As someone posted on the Triumph Daytona forum, Cagers (car drivers) diet for reasons of Vanity, Sportbike riders diet for power to weight ratio :mrgreen:

Re: I just don't get the endless posts on performance upgrad

We have a lightweight-Commando-guru here, maybe Brent will dazzle us with numbers/data.

Vince

Re: I just don't get the endless posts on performance upgrad

I haven't read all the replies to this thread, but I agree with the OP, a Commando is nice, but if you want to go fast, get something else. If the mods are made to make it more reliable, I'm for that, if the mods are to make it faster than it was and money is no object, then that is OK too, but tweaking a 40 year old bike to run with modern machines has as much chance of success as me winning the 100 meters in the olympics, let alone being part of the starting lineup. That being said, putting cash into your bike is surely more satisfying than seeing your broker taking his cut just as your savings are melting away to nothingness :wink:

Life is short, enjoy it while it is time 8)

Jean

Re: I just don't get the endless posts on performance upgrad

aceaceca said:

Each 7 lbs you shed frees up 1 hp. Wow. If I got back to my weight in the 70's I would pick up a free 26 hp. Good thing I run a 19 tooth sprocket . Thankful to Norton for all that low end grunt. Scary when you were young and skinny and silly. Now a god sent when you are old and fat and senile. Well getting there.

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That's funny

Re: I just don't get the endless posts on performance upgrad

worntorn said:

As someone posted on the Triumph Daytona forum, Cagers (car drivers) diet for reasons of Vanity, Sportbike riders diet for power to weight ratio :mrgreen:

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Its a lot easier to gain 200 bhp by buying a new bike, than by any amount of dieting !?!?
If you want to go really really fast....

Re: I just don't get the endless posts on performance upgrad

Yes, but when you already have the 200 hp bike, you need to diet for further gains. And his comment was intended as a joke!

Re: I just don't get the endless posts on performance upgrad

plain and simple...if you break down on your norton more than likely u can repair it on the side of the road and continue...break down on a new jap crap and you need a college education plus a computer to fix it
thats my thoughts anyway