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1Back to top Go down   K1100lt Rear Spring rate Empty K1100lt Rear Spring rate Sun Jan 16, 2022 6:25 am

K75cster

K75cster
Life time member
Life time member
I had occasion to carry a 100kg rider with me today, the rear bottomed out a few times on our B grade roads. Is there a heavier spring for the stock shockie? Or if not how would I go about getting a heavier spring. There is a place called Dumbrel Springs in Wallsend NSW about 40mins away, Would I just drop in with the shockie and say this bike now gets two riders over 100kg on it instead of the 2x75kg riders it was designed for? I need some heads ups so I can talk turkey with spring type people.



Last edited by K75cster on Sun Jan 16, 2022 6:26 am; edited 1 time in total (Reason for editing : spelling)


__________________________________________________
Keith - 1987 K75c with r100rt replica fairing and half of a 1984 K100rt 1992 K1100LT a blue one

The Clever are adept at extricating themselves from situations that the wise would have avoided from the outset - QUOTE from david Hillel in Out of the Earth.
    

2Back to top Go down   K1100lt Rear Spring rate Empty Re: K1100lt Rear Spring rate Sun Jan 16, 2022 7:18 am

moriarti

moriarti
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HI I take it that your normal setting is on the softest for solo riding. Did you reset to max before riding with your pillion rider. Having ridden 2 up loads of gear on board on rough roads without bottoming out. If you did set on MAX then i think your shock is more than a little tired and a new one is on the cards.


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1984 k100 rs red/black VIN  0004449
    

3Back to top Go down   K1100lt Rear Spring rate Empty Re: K1100lt Rear Spring rate Sun Jan 16, 2022 8:39 am

Rick G

Rick G
admin
admin
Any coil spring manufacturer worth their salt will be able to tell by measuring the spring diameter, wire diameter and number of turns and make one a bit heavier. It may only need one less turn in the same length or sumptin like that.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 2004 K1200GT 1998 K1100 LT, 1986 K75 GS.
    

4Back to top Go down   K1100lt Rear Spring rate Empty K1100lt Rear Spring Rate Sun Jan 16, 2022 4:11 pm

Tom G

Tom G
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G'day Keith, Dumbrells at Wallsend have closed. I have no idea if they still exist or where they are. Cheers Tom


__________________________________________________
1986 K100RT Ex Police (Slightly modified)
2010 Suzuku DL650 V Strom
1992 R100R
    

5Back to top Go down   K1100lt Rear Spring rate Empty Re: K1100lt Rear Spring rate Sun Jan 16, 2022 7:18 pm

Dai

Dai
Life time member
Life time member
https://suspensionsecrets.co.uk/how-to-calculate-coil-or-leaf-spring-rates/

The clown(ess) and I had a conversation about this on here, but I can't find it.


__________________________________________________
1983 K100 upgraded to K100RS spec, 1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

6Back to top Go down   K1100lt Rear Spring rate Empty Re: K1100lt Rear Spring rate Sun Jan 16, 2022 8:38 pm

K75cster

K75cster
Life time member
Life time member
Thanks Dai that will come in handy, OMG Tom! how could they disso when i need them, but thanks for the heads up. Rick Thanks I also thought they who wind springs did them with a greater pitch and same wire dia, We still have single stage damping on these bikes don't we. Moriati you are closer to the truth than even I expected. I come here cap in hand to advise that I'm on the 3rd of 4 notches for the spring, (oh dear) and 3/4 on the s/h of the shockies dampener. SO I have moved the spring up one more to the top and have adjusted the dampener to hard. Still we are both over the 100kg mark so surely I should get a heavier spring made for it. However I'm yet to read the site Dai put up and discover which works best with springs, but had it in mind that single stage dampening needed single stage springing with just the last quarter of a stiffer stance in springing (basically to handle our whumps mid corner that we especially install in corners here in Oz) to counter that lst little bit.

Lastly the flat bit on the spring wind that acts as a contact as the windings close up. That bits important isn't it? The old Koni I have doesn't have it. It is off the K75, just wondering possibly some spring engineers design these things to not tough when the shockie is bottoming out. Seems an odd thing to do.


__________________________________________________
Keith - 1987 K75c with r100rt replica fairing and half of a 1984 K100rt 1992 K1100LT a blue one

The Clever are adept at extricating themselves from situations that the wise would have avoided from the outset - QUOTE from david Hillel in Out of the Earth.
    

7Back to top Go down   K1100lt Rear Spring rate Empty Re: K1100lt Rear Spring rate Sun Jan 16, 2022 10:31 pm

Point-Seven-five

Point-Seven-five
Life time member
Life time member
You say you have a stock shock and spring on your bike.  If it was original then I would think the shock and the spring are both well past their "best by" dates and should probably be replaced.

There are several sources for aftermarket suspension parts.  I have replaced the shock on my 16V K100 with a YSS unit.  They're very reasonably priced, and the purchase process includes questions about rider and passenger weight, gear, and riding style.  Once you answer the questions they select the shock and spring.  The results were excellent.


__________________________________________________
Present:
1994 K75RT
1991 K100RS


Past:
1988 K100RS SE
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

8Back to top Go down   K1100lt Rear Spring rate Empty Re: K1100lt Rear Spring rate Tue Jan 18, 2022 2:15 am

K75cster

K75cster
Life time member
Life time member
Yes .75 that sounds like the path to take. Thanks.


__________________________________________________
Keith - 1987 K75c with r100rt replica fairing and half of a 1984 K100rt 1992 K1100LT a blue one

The Clever are adept at extricating themselves from situations that the wise would have avoided from the outset - QUOTE from david Hillel in Out of the Earth.
    

9Back to top Go down   K1100lt Rear Spring rate Empty Re: K1100lt Rear Spring rate Tue Jan 18, 2022 4:07 am

Stan

Stan
Life time member
Life time member
All of this discussion reminds me of the the move from bench seats in cars to bucket seats. They were comfortable, but it depended on the size and weight of your bucket. Get the best combination for your bike.


__________________________________________________
1983 K100 basic vin 0003960 colour red  GONE
1987 K100RT vin 0094685 colour, orange peel, sorry, pearl..GONE
F800R black
    

10Back to top Go down   K1100lt Rear Spring rate Empty Re: K1100lt Rear Spring rate Tue Jan 18, 2022 6:33 pm

K75cster

K75cster
Life time member
Life time member
G'Day Stan. Yes and this old girl handled the one bucket just fine. I'd probably not had an issue if I had upped the spring and dampener rate to highest setting, but I missed it by one setting. Still now it has me wondering about the spring and damper setup, The spring goes from 16mm gap between coils to 3mm over 13 coils and that's way more than the 100mm travel available on the shaft. Also noted no bump stop. Still measuring all the gaps so I can go have a yack with a suspension specialist about whether the coils are supposed to touch at the same time the body reaches the shaft stop. Don't think I'll mention buckets to the suspension bloke though. Wink


__________________________________________________
Keith - 1987 K75c with r100rt replica fairing and half of a 1984 K100rt 1992 K1100LT a blue one

The Clever are adept at extricating themselves from situations that the wise would have avoided from the outset - QUOTE from david Hillel in Out of the Earth.
    

11Back to top Go down   K1100lt Rear Spring rate Empty Re: K1100lt Rear Spring rate Tue Jan 18, 2022 7:08 pm

Point-Seven-five

Point-Seven-five
Life time member
Life time member
It might help if you can post a photo of your shock and spring.  If it is an increasing rate spring the gaps between coils will get progressively smaller going from one end to the other. 

With a progressive spring, the smaller gaps will close before the wider ones gradually making the spring stiffer.


__________________________________________________
Present:
1994 K75RT
1991 K100RS


Past:
1988 K100RS SE
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

12Back to top Go down   K1100lt Rear Spring rate Empty Re: K1100lt Rear Spring rate Tue Jan 18, 2022 7:42 pm

K75cster

K75cster
Life time member
Life time member
Piccies
K1100lt Rear Spring rate K1100l11
K1100lt Rear Spring rate K1100l10


__________________________________________________
Keith - 1987 K75c with r100rt replica fairing and half of a 1984 K100rt 1992 K1100LT a blue one

The Clever are adept at extricating themselves from situations that the wise would have avoided from the outset - QUOTE from david Hillel in Out of the Earth.
    

13Back to top Go down   K1100lt Rear Spring rate Empty Re: K1100lt Rear Spring rate Tue Jan 18, 2022 8:29 pm

K75cster

K75cster
Life time member
Life time member
On it's highest setting I have 102mm of available spring travel, and 98or100mm of shaft travel. So if everything compresses in a big whump of a bump, I seem to be 4mm out and I'm missing a bump stop. Maybe a 4-5mm spacer would have the springs and shocky closed at the same time. I'll have to check spacings with a proper gauge.


__________________________________________________
Keith - 1987 K75c with r100rt replica fairing and half of a 1984 K100rt 1992 K1100LT a blue one

The Clever are adept at extricating themselves from situations that the wise would have avoided from the outset - QUOTE from david Hillel in Out of the Earth.
    

14Back to top Go down   K1100lt Rear Spring rate Empty Re: K1100lt Rear Spring rate Tue Jan 18, 2022 11:16 pm

Point-Seven-five

Point-Seven-five
Life time member
Life time member
Are you sure the shock is not upside down?


__________________________________________________
Present:
1994 K75RT
1991 K100RS


Past:
1988 K100RS SE
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

15Back to top Go down   K1100lt Rear Spring rate Empty Re: K1100lt Rear Spring rate Tue Jan 18, 2022 11:30 pm

Rick G

Rick G
admin
admin
That's an Original Showa and correct mounting.
Keith send it up to RAD shocks in Brizvegas, he will be able to reco it, last I heard $200 and $50 more for a shaft rechrome. Everybody I have heard says only good things about him.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 2004 K1200GT 1998 K1100 LT, 1986 K75 GS.
    

16Back to top Go down   K1100lt Rear Spring rate Empty Re: K1100lt Rear Spring rate Thu Jan 20, 2022 3:42 pm

K75cster

K75cster
Life time member
Life time member
Thanks Rick, yes It could do with a refurb. I am somewhat puzzled by the fact there are no witness marks on the shock body where we bottomed out. bearing in mind I cant find my callipers and am only eyeballing the measurements, The spring must be going spring bound before the shock body meets the nut under the top mount.
I had visions of it shagging the seal in there but without witness marks to suggest it has made contact, maybe the springs have taken the brunt of the fully compressed suspension.


__________________________________________________
Keith - 1987 K75c with r100rt replica fairing and half of a 1984 K100rt 1992 K1100LT a blue one

The Clever are adept at extricating themselves from situations that the wise would have avoided from the outset - QUOTE from david Hillel in Out of the Earth.
    

17Back to top Go down   K1100lt Rear Spring rate Empty Re: K1100lt Rear Spring rate Fri Jan 21, 2022 7:07 am

Holister

Holister
Life time member
Life time member
You could try Chivo in Holroyd Sydney. He'd be a bit closer. I've found him to be reliable and reasonably priced.


__________________________________________________

1989 K100RT     VIN  0097367 (naked)  
1996 K1100RS   VIN  0451808
 K1100lt Rear Spring rate Austra12    Fuel:  95 Octane
Engine Oil: Nulon Full Synthetic 15W50
Gear Box Oil:  Nulon Synthetic 75W90
    

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