Help with rear springs please

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davamb

davamb

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Hi All,

I've got Konis fitted at the rear of the Norton and to put it mildly, it's rather stiffly sprung. I've got it on minimum preload, but there's virtually no movement on the rear at all. I recall the DPO saying it really only felt comfortable with his GF on the back! Can anyone please advise the standard spring rate (or whatever other terms define the spring) so I can see if I can replace the existing ones.

Thanks.
 
Hello Dave,

I have the same problem with old Hagons.
I think they need more travel and modern spring rates etc. Probably better off buying modern shocks to suit, but then the front will show how bad it is. (and I'm too poor)

How much static sag does it have?
How much loaded sag? (you sitting on it)

Suggest going to a good suspension shop with your bike and talk to them,,,,,
Graeme
 
Hi Graeme,

how's things? How's the young feller's Pantah going?

Static sag = Loaded sag = 0. Guess there might be a couple of mm, but none to write home about. One of the DPO's "great scores". The front (Cerianis) seem ok, but the rear is set up for an elephant. Was even thinking of borrowing the 'zocchis of the Pantah just to see what a softer spring rate would feel like! If that gives some results was thinking of a trip to the local wrecker for some old shocks. The shocks were rebuilt, so the damping's fine, just no spring travel.

Bike money's a bit tight after a recent TRX engine rebuild, so trying to sort this (or at least improve it) on the cheap.
 
Dave if you have Ceranni front that's a good thing, at least better than the Norton forks.

The wreckers is a good place for these sorts of things.
Koni is now Ikon so springs should be available.

Melbourne

Toperformance
No 8 Trade Place
Vermont VIC 3133
Tel 03 9873 1722
Fax 03 9874 2200

Geelong

Pole Position 23 Gordon Ave
Geelong Vic 3220
Tel 03 5221 3433
Fax 03 5221 6892
email. Polepos@pipeline.com.au
NSW
Wholesale Suspension
129 Coreen Ave Penrith
NSW 2750, 02 4721 2112
www.wholesalesuspension.com.au
email. sales@wholesalesuspension.com.au

also at

Wholesale Suspension
1/47 Third Ave
Blacktown
NSW 2148.
02 9831 8825










ACT

Capital Steering
www.capitalsteering.com.au
3/75 Wollongong St.
Fyshwick
ACT 2609
Tel 02 6280 5243
Fax 02 6280 5962
Hobart

AUTOCRAFT
225 Collins St
Hobart
Tas 7000
Tel 03 6234 1044
Fax 03 6231 3887
Email autocraft@netspace.net.au
Darwin
L&S Springs & Suspension
1/2404 Stuart Highway 11 Mile, Pinelands, NT 0829.
Phone: 08 8931 3565
Fax: 08 8931 3575



Graeme
 
Good luck getting any help from Ikon. I called them last week with exactly the same problem on my classic race bike. They just asked me what springs I wanted. That's what I was asking them!

For the record, my 750 race bike has Konis with 132 springs on them. The 132 is listed as a 112 lb/inch spring and I find it far too hard. The next lightest in a linear spring is 60 lbs / inch which I think would be too soft. Ikon want about $100 for a set of springs but can't advise me which ones to fit.
They do have a decent tech data page on their website, so if you can find a serial number on the springs you have, you might be able to find a softer one on their website.
 
http://www.davequinnmotorcycles.com/cgi ... Hagon.html
Shocks are not returnable once they have been fitted though we will do up to two spring exchanges on twin shocks if original springs are returned in saleable condition (clean with no chips or scratches). We do not warranty the finish on black springs.
Hagons NITRO stainless steel twin shocks are the top of the Hagon twin shock line.
Help with rear springs please
 
Best to ring the fellows that sell the shocks not the dealer/importer.
Try Steve Wood at Suspension Improvements at 32080082 (Slacks Creek)
 
GRM 450 said:
Best to ring the fellows that sell the shocks not the dealer/importer.
Try Steve Wood at Suspension Improvements at 32080082 (Slacks Creek)
Click to expand...


Thanks.
I'll call him now.
 
davamb said:
Hi All,

I've got Konis fitted at the rear of the Norton and to put it mildly, it's rather stiffly sprung. I've got it on minimum preload, but there's virtually no movement on the rear at all. I recall the DPO saying it really only felt comfortable with his GF on the back! Can anyone please advise the standard spring rate (or whatever other terms define the spring) so I can see if I can replace the existing ones.

Thanks.
Click to expand...

It might be worth checking the shocks themselves. My Konis virtually seized up because a nylon like washer internally had perished & the resulting sludge mixed with the oil & caused them to hardly move. I managed to get them apart & rebuild them myself. Had to take an educated guess on how much & what sort of oil to use though. Mine have heavier springs as I usually carry a passenger & found standard ones too soft. They are still fine solo though. I think they are 150lb springs.

Ian
 
Thanks for the information everyone.
I think the next thing to do is to acutally measure the deflection with a known weight and establish the rate.
I find that 1 lb/in = 0.017kg/mm and thus the stock rate of 126 lbs/in is 2.14kg/mm so a medium bloke like me at 80kgs will compress a single standard spring by 37mm (or half that for two springs). Will be interesting to see what I get. I'll take off a shock tonight and demount the spring and see what I get.
Nortoniggy, I had the shocks rebuilt a year ago, but had no idea what the spring rate was then. Would have been nice if the rebuilder asked!
Hobot, would love a couple of those Hagons, but just don't have the bucks at the moment.
 
I think there needs to be an adjustment in the calculation because of the forward slope of the Commando shocks. Most vertically mounted shocks use about 100 lb springs but the Norton uses 126 lb springs. I once tried 100 lb springs on my Commando and it was way too light. I'm not up on my trig these days but I think it is an easy calculation.
 
I'm with ya there Batrider, but just want to try and establish what rate these springs are first. Got one shock off tonight and removed spring, but ran out of time to try and measure compression versus force - need an assistant to measure, will see if someone can help tomorrow at work. Back end sagged a cm or so with only the one shock/spring present, will also be checking out swingarm movement to make sure it's not binding there.
 
Hobot, would love a couple of those Hagons, but just don't have the bucks at the moment.
Click to expand...

its always only hobot here and its was only a spring source I was posting site for. I'm going to face what you'all are with Ms Peel. She's been on a diet and I can't eat enough to put on weight. The $125 15.5" long set on her now was just to get a rolling mock up - but the springs seem too stiff to me not to bounce my butt right off off in lumpy turns. I've talked to Ohlins and a few others to get a ball park sense for progressive springs 80-120 lb was what we came up with on 500 lb total bike rider. These cheap shocks are said to be rebuild able for valves and seals and springs to make them pretty good with the air/N2 feature till interesting me for heavy cargo or passenger.

http://forums.sohc4.net/index.php?topic=83200.0
Help with rear springs please


As too affording stuff, after INOA rally and heat wave here, i shot holes in Trixie's peashooters to run a couple bolts through to trap the Loud baffle rattles and ride w/o annoying everyone till next season or two when caught back up. If nothing else major sucks on me first. ugh. Lucked out I shot down some limbs before a small tornado went over head and took non-over hanging limbs down. A roof hit would of set back Nortons and PU and tractor a year or more.
 
Also be aware that Koni shocks have adjustable internal damping. Maybe they're cranked up?
 
Dampening should not have an effect on slow compress or release, just the speed ya can push em down and rebound. Rusted inside would add restriction too but don't know it that can happen or not in sealed shock.
 
You can use your missus's bathroom scales and a drill press to get a reasonable idea of the spring strength.

graeme
 
Excellent thinking Graeme, beats trying to stand on the damn thing and measure its length at the same time!
 
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