Commando suspension setup

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John suggested most Commandos will have been crashed at some stage, which in some cases is going to mean a much steeper head angle.............., I would agree about the crash damage, and maybe these bikes handle a good deal better than something that hasnt been crashed, which still has the stock chopper type geometry?
 
Carbonfibre said:
John suggested most Commandos will have been crashed at some stage, which in some cases is going to mean a much steeper head angle.............., I would agree about the crash damage, and maybe these bikes handle a good deal better than something that hasnt been crashed, which still has the stock chopper type geometry?
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You obviously know more about Commando steering than the factory did.
Tell us your experience with Commandos to make such nonsense statements ??
 
Good point Daveh about Commandos liking 19" and narrow.

I've never worked it through, logically, I get why rebound damping is essential but when it comes to compression damping, why is damping better than a progressive spring?
 
99% of "progressive" springs are designed for buyers who have no idea how a true progressive spring works, and are not concerned they have purchased a part that doesnt work.
 
It is my understanding that after considerable testing(trial and error) the Brits adopted 27 degrees as being the ideal compromise steering head angle to enable the suspension to absorb both braking and road surface forces. They then set about controlling stability by setting an appropriate trail and to a lesser extent wheelbase. By decreasing the steering head angle the braking forces are not transmitted as well to the suspension and the bending forces on the legs are increased, but bumps will be better absorbed by the suspension. But I guess this is mostly theory. I have just returned home after a run through Kangaroo valley (with its many corners), on my gsxr600. The steeper head angle, although it is supposed to turn faster into a corner, doesn’t seem to make the bike handle any better than my commando, and in reality my cornering speeds are generally higher on my commando. Maybe its just what I have been used to.
Ando
 
Ando — you are not the only one who has experienced this. On paper, we would think there would be a big difference but I guess it might be because standard bars give you more leverage than clip-ons and you have those narrow section tyres, both helping turn-in. The Commando wheelbase is 1440 mm, which is quite sporty, so it is capable of carving a tight turn and doesn't drift — at least not with a rod-end head steady! I thought my 750 Gixxer should perhaps have steered more quickly than it did, but the stock rear tyre is too wide so I have gone down a size to 180 and dropped the forks a few mm.

Dave
 
Now's ya getting into why I'm so nutzo on fullly linked Commando. A bit OT for springs but right on point to have most fun w/o a scare or crash. One of the most annoying things about the balloon tired sports bikes and un tammed Cdo is when they do break loose they don't just slide at same lean angle they trip down to low side or spin bike by sliding front or rear and crash unless able to recover by flat tracker wide crossed up slide, which could still be into the dtich or oncoming.

On the sharp steering angle moderns it seems to cause them to jitter judder and jump trying to counter steer sharp and leaned on power. Some fight to stay down others fight to pick back up, ugh. This can turn into tank slapper a damper can delay but then interferes with tire road following or pilot recovery action at some point not all that much faster/harder around - ugh.

At least a regular Cdo is pretty darn neutral to this, that is don't resist staying down or flinging back up, just may wobble up to crash if lumpy surface/wind gusts have time to build up the resonaces.

One strange thing to add in my delights with Cdo's, tammed or not, over a rigid sports bikes is Cdo's can take higher instant loads and not tang like a bow string. That is you can fllp them to max angle and radius faster harder than moderns in tights that rebound meanly or just let their balloon tire edge profile fly out from under. The down side of Cdo compared to more rigid bikes is they can't hold the same leaned loads as long in sweepers or hinging builds up. This shows up most in the free way like places where hp means more the torque response out of apexes.

Spring wise, more I feel the front lift and the rear squat the more secure i am to haul in tighter harder on my Cdo's or sports bike balloon tire coward.
 
ludwig said:
xbacksideslider said:
..I've never worked it through, logically, I get why rebound damping is essential but when it comes to compression damping, why is damping better than a progressive spring?
Click to expand...
Lots of info on the web .
like here :
http://www.gostar-racing.com/informatio ... set-up.htm
And here :
http://www.tonyfoale.com/Articles/Springs/Springs.htm
or here :
http://www.sportrider.com/tech/146_9608_tech/index.html etc ...
Read about suspension setup till your head explodes ..
"The reason why there is so much debate and controversy regarding suspension set up is because it is a personal experience and depends on how and where you ride your motorcycle. " (quote)
Click to expand...

Thanks Ludwig, the SportRider link was most helpful; what I get now is that the SHAPE of the bump is what compression damping can adeptly handle; fast/sharp bumps are not differentiated by a progressive spring.


R
 
ludwig said:
xbacksideslider said:
..I've never worked it through, logically, I get why rebound damping is essential but when it comes to compression damping, why is damping better than a progressive spring?
Click to expand...
Lots of info on the web .
like here :
http://www.gostar-racing.com/informatio ... set-up.htm

And here :
http://www.tonyfoale.com/Articles/Springs/Springs.htm

or here :
http://www.sportrider.com/tech/146_9608_tech/index.html

etc ...

Read about suspension setup till your head explodes ..

Main problem with suspension set up is that most riders simply dont have a clue about this, and a fair few on older TS bikes have spring rates which are far from suitable, as as one size fits all dampers which are not adjustable ans in most cases come fitted with springs which are far too hard. Most modern sports bikes come with suspension which is reasonably effective for road use, but in may cases wont work anywhere near a well as it could, due to riders not being able to set it up properly.



"The reason why there is so much debate and controversy regarding suspension set up is because it is a personal experience and depends on how and where you ride your motorcycle. " (quote)
Click to expand...
 
So do you CF have any actual advice on what springs may be more suitable for Commandos ?
Or is this more airy fairy stuff, with no experience of Commandos.

I'd comment that Koni offered those variable rate springs for Nortons in their last versions of variable damping koni rear shocks. Think they were rated at something like 75-90 lbs (can't find the sheet, can't be sure those numbers are correct from memory). Think the orig Girling Commando springs were 120 lbs ?
 
Rohan said:
So do you CF have any actual advice on what springs may be more suitable for Commandos ?
Or is this more airy fairy stuff, with no experience of Commandos.

I'd comment that Koni offered those variable rate springs for Nortons in their last versions of variable damping koni rear shocks. Think they were rated at something like 75-90 lbs (can't find the sheet, can't be sure those numbers are correct from memory). Think the orig Girling Commando springs were 120 lbs ?
Click to expand...


Unfortunately selection of the correct spring rate, and dampers suitable for any one particular rider on a specific bike, is something that is the province of a suspension expert. There is an awful lot of confusion over suspension, and unless you are satisfied with the performance provided by one size fits all suspension parts (often very poor) a custom made adjustable set up will be required, and even then some degree of knowledge will be required to fine tune this properly. Its a bit like carb tuning..............and does require a certain touch.

Finally in regard to springs a true progressive part will have coils which are very nearly touching at one end when the spring is uncompressed, but not completely sure that the use of these is appropriate, as while they will certainly provide progressive action when compressed, the opposite effect will occur during extension, which may not help handling to any great extent?
 
Carbonfibre said:
Finally in regard to springs a true progressive part will have coils which are very nearly touching at one end when the spring is uncompressed, but not completely sure that the use of these is appropriate, as while they will certainly provide progressive action when compressed, the opposite effect will occur during extension, which may not help handling to any great extent?
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You must be joking - these current breed of MX bikes can leap 30 ft in the air, and comfortably land without maiming the rider - you think progessively wounds springs aren't used there ?? !??

Linear springs are old school, move with the times...
 
YZ450F is a pretty up to the minute MX bike, and comes fitted with a KYB shock complete with Ti spring: http://www.oemdirtbikeparts.com/2006-YA ... 416-34.htm I visited the workshop of Dixon Racing a while ago, and cant say I noticed progressive springs on the works bikes either!

Maybe you need to let Yamaha know they are still using old school technology on their bikes, and I am sure they would welcome your help, as they are obviously at a big disadvantage to all the other MX teams who are currently using progressive springs on their machines?
 
Progressive springs haven't been used in any serious competition applications for some while, but I guess those selling them are not likely to be shouting that from the rooftops!
 
Carbonfibre said:
John suggested most Commandos will have been crashed at some stage, which in some cases is going to mean a much steeper head angle.............., I would agree about the crash damage, and maybe these bikes handle a good deal better than something that hasnt been crashed, which still has the stock chopper type geometry?
Click to expand...

You cannot be serious. That is one of the most stupid things I have seen in a long time. Maybe you can line up the Volvo with enough precision to make sure the steering head stays in line but I'm afraid that talent isn't in the rest of us.
 
A titanium spring ?
That is just getting weird.
The ultimate marketing exercise. ??

Typical dirt bike spring - available brand new now.
Selected at random from vast hordes of similar things.
Commando suspension setup
 
john robert bould said:
Looks like old CF as all the trump cards again :lol:
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Suspension setup in MX bikes is like hairdressing styles - changes every week.
Wonder what next weeks flavor will be ?

And somehow I can't see too many folks fitting $2000 sets of Ti fork springs into their Commandos. But I could be wrong, there are lots of [ Deleted before LAB got to it ].

P.S. This was flavor-of-the-month some years back, more for road use though.
Springless, air does all the work.
Picked it up for a song...

Commando suspension setup
 
As far as I am aware it is only the KTM PDS system that uses progressive springs, so yes they are used in serious competition but only by one manufacturer. Titanium springs have a pretty good weight advantage if that is your thing. Air shocks can work but they have their own set of problems, stiction being a pretty significant one, very noticeable on a mountain bike, they are light though.
 
BUT all the silly M-X belcrank linkages were described as RISEING RATE .

Progressive rate springs will give a less jarring ride , if properly selected.
Like my Triton . :D 8) :p

If I were you blokes , Id forget all about it , and go Hi Tech , with HANDLEBAR STREAMERS , instead . :D :shock: :roll:
 
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