Commando suspension setup

Hi Carbon

I have NJB on 4 bikes. I did the Maxton set up for the forks & they suggested the complete package.
Still learning.
Pembrey a few years back I had standard forks & long Hagons & the bike handled fine. They always say change one item at a time so that you know your base setting. I have started moving my footrests back & my clipons to the front of the forks to give me more room as the Seeley is a small package.
I definitely need more track time.
Chris

If you are having problems with your Maxton suspension, have you contacted them and explained whats wrong? I have always found Richard to be very helpful and keen to get any issues sorted out quickly.

Hi Carbonfibre

They are going back as soon as the brackets have been welded on the frame for my Maney exhaust.
all the best Chris

What did Richard have to say when you explained what was wrong, and have you checked all the details on the spec sheet you filled in to help Maxton build the correct shocks for your application, were all spot on?

Carbonfibre said:

What did Richard have to say when you explained what was wrong, and have you checked all the details on the spec sheet you filled in to help Maxton build the correct shocks for your application, were all spot on?

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You dont need hi-tec cartrides with fancy data sheets, Luke Notton [Pat Greens Access team] thrashed the field in this years lansdowne Bonhams race,with Duncan Fitchett close third, also Austen Kear first and Jack Ebb second place in the pallet force championship. What did they all have in common? My simple adjustable flow control units, enough said.
www.lansdowne-engineering.com

How does you simple flow control system deal with the requirements of low and high speed damping? Personally I have found the difference between modern cartridge forks and older type designs to be very noticeable, but if your system can provide the same levels of performance at a far lower price, then it seems like the ideal set up to have for road or race use.

Pressure differences , as the forks are compressed at a faster rate the ports respond to control the flow, original norton dampers produce approx 40 psi internal pressure, sudden braking will produce over 350 psi in the Lansdowne set up.

ludwig said:

Cheesy said:

..So the race tech cartridge emulators are probably a good idea ..

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RT valves are out . do a search

Cheesy said:

Im still surprised that no one sets sag, ..

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I certainly do ..

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I realise that the RT valves are not a drop in option but the required modifications dont seem too difficult with a lathe and mill on hand and maybe some donor damper rods and check valves.

I thought that you would be one of the few to set up your bike properly, what sort of sag measurements are you running?

john robert bould said:

Pressure differences , as the forks are compressed at a faster rate the ports respond to control the flow, original norton dampers produce approx 40 psi internal pressure, sudden braking will produce over 350 psi in the Lansdowne set up.

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Pretty much the same as 1980s Marzocchi forks then............a big step forward from the 1950s set up in the stock Norton forks certainly!

Question,what should the springs with differently wound sections be refered to as ?

Spring makers refer to them as progressive rate or variable rate springs.

Quote from Wiki
"Progressive rate coil springs – A coil spring with a variable rate, usually achieved by having unequal pitch so that as the spring is compressed one or more coils rests against its neighbour."

Exactly.............but as very few "progressive" springs have coils that touch even when suspension is at full travel, the word "progressive" is in most cases related purely to marketing.

NJB shocks seem to have damping designed to work with the strongest rate springs likely to be fitted, which makes for harsh slow suspension action, with little compliance over rough road surfaces. Not a major problem on road machines, but pretty dangerous on road race machinery being used seriously.

Can't express how pleased I was on the extra leaning clearance in race like cornering and the extra soft compliance of Peel's front sag set 2 inches down with me on it for 4 inches of spring action. I threaded the damper rods further down from top so can pre set spring load some what over the factory fixed tension. Could also put in a rather weak spring spacer for factory sag level and then slice a bit off factory spring and put in a harder spring for no bottoming on most big bumps. BTW with Gregs kit you can DIY progressive dampening rate too.

I'm not yet sure what to do on rear springs and shocks but will experiment with 15" long ones to level Peel 2" higher with 80-120 rate springs to start with. Looking at the Production Racers I see they have mounted shocks vertical but don't know why. Want to fit Ohlins with adjustable everything but they cost up to $1800 so not first time out on lesser 15" gas pressure reservoir shocks.

Cheesy — You asked about sag settings. I set my sag on the front to approx 20% of the total fork travel (standard Roadholders). Before I did that, the stiction was so bad that I could not get a reliable figure for the sag. so I overhauled the forks to minimise play and friction and finally got fed up with the standard damping and fitted Lansdowne dampers - 100% better. I set the preload by shortening the springs slightly and fine-tuned it with spacers of the appropriate length. With 19 inch 4.10 Avon Roadriders front and rear, the bike steered and handled as well as I thought it should.

I found that even with almost no sag on the rear or with some sag, it made little difference. I also found this to a certain extent with my Seeley that had the old type Maxton rear shocks (Maxton-modified Konis, which were excellent). I set the static sag on the Seeley to 5-7 mm and set the preload on the rear on the Commando so that there was a few mm of 'give'' (so that the shocks were not 'topping out') and it was fine, but I also used softer springs. I have a new set of Maxtons on the rear of the Seeley now and I won't be able to find out how good (or bad?) they are until next season. I am a bit anxious, having heard some less than complimentary remarks about them.

Carbonfibre said:

Exactly.............but as very few "progressive" springs have coils that touch even when suspension is at full travel, the word "progressive" is in most cases related purely to marketing.

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Koni used to offer a progressively wound spring.
But then what did they know about suspension....

Ya can't coil bind factory Roadholders because they bottom on damper tube first, nor the rear shock also because internals foul first so its essentially unheard of for any craft to coil bind its springs before something else solid stops short of this. Tighter coils move more the the open coil area of the progressive springs, duh.

You can't coilbind factory roadholder springs, and would not want to (!!) because, with linear springs, the whole thing would have to be SOLID to be coilbound..... !!

I can recall having to unload/stretch a spring to remove a bit of paper caught between the coils, so progressively wound springs can touch coils together. Only it wasn't in the front forks....

hobot said:

Ya can't coil bind factory Roadholders because they bottom on damper tube first, nor the rear shock also because internals foul first so its essentially unheard of for any craft to coil bind its springs before something else solid stops short of this. Tighter coils move more the the open coil area of the progressive springs, duh.

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You are are right there Steve.

Ugh thanks John but have experienced fork hydo lock after over filling and then only after being fooled as fine for a 1/4 mile till - air pumped out woohooie!

I'm getting to point to take Peels forks apart for a final going over and nip up. I could send one of her special custom springs to someone to measure as example to reproduce. They were developed by seasoned expert not me. Seem to have softer than factory initial compression of couple inches then about factory for an inch
then rather stiffer the last inch.

I'm confused on lowering front to corner better as fork extend on leans and it sure seemed to help my security to press it over hard under power. Don't know if lifting Peel's rear will counter that effect or make front hook up too much for me.