Comet suspension

[redbloke1956]

Hi to all, I have just fitted the Sam Mangano front springs and am concerned that I may have too little suspension movement left, the two attached photos are with the bike off any stands, I am straddling bike but with virtually no weight on seat.
To my untrained eye FF3 and FF4 top and bottom links look to have travelled to almost full extension?/ Contraction?/travel.
The front springs look to be almost bottomed out?
This is my first Comet so have nothing to compare it too.
Thoughts anyone??

Kevin
p.s. I have also noticed that when bike is jacked up, the rear of the front mudguard fouls the magneto cover just before the front wheel leaves the ground, is this supposed to happen?

 

[Martyn Goodwin]

Kevin,

Like you I also "invested" in a set of the S.M. front springs for my Comet and like you I was aghast at the unloaded suspension sag - so much so that they were removed with the original springs going back in. I should add that prior to the final removal of the S.M. springs I attempted preloading them with a very large washer stack in the botton of the FF16's - but even with the position of FF4 (the top saddle) returned to almost normal, the amount of suspension travel available was very little - so much so I was not prepared to even try a test ride! Those S.M. springs have been consigned to the crappy parts bin - maybe one day, when all my scruples are gone - I may try selling them off on ebay.

The front end on my Comet now has the original outer springs FF12/2 (inners are intended to be used only if you have a sidecar fitted) and a new Ikon (aka koni) shock absorber. Also I have had the Spring Case inners FF16AS hard chrome plated. I replaced a set of very old (and hard) Avon tyres with modern Metzler Lasertec units and the overall result is great.

If you are concerned about your original front springs being tired all you need do is check their free length; They should be around 15 3/4 to 16 inches.

Martyn

 

[Bill Thomas]

Hello Kevin, Don't ride it till you talk to David D In USA. the mudguard touching the engine is because of the front damper too long, Have you got long lower eyebolts ?. Think about fitting an hydraulic steering Damper, I think all Vins need them, Good Luck Bill.

 

[redbloke1956]

Hello Kevin, Don't ride it till you talk to David D In USA. the mudguard touching the engine is because of the front damper too long, Have you got long lower eyebolts ?. Think about fitting an hydraulic steering Damper, I think all Vins need them, Good Luck Bill.

Hi Bill, Thanks for the reply mate, I am not sure what you mean by "lower eyebolts", the front damper doesn't have an eyebolt or am I missing something?
Regards
Kevin

EDIT: OOPS I see what you mean Bill, No I have short eyebolts........note to self "wear glasses more often"

 

[Bill Thomas]

Hello Kevin, Is the mudguard fitted ok ? Does It look right ? It does from what I can see in your photo, I think you had that trouble befor you fitted the new springs, Don't ride it till that guard misses it . Give us a photo of the lower damper fitting, Cheers Bill.

 

[bmetcalf]

My lower stay touched the mag cowl also, but it was fitted by a previous owner, not the Works. One fix can be to flip the stay over. Ron Kemp suggested that I put washers on top of the front headnuts and under the bracket, dropping the front of the motor a little bit. I did this and it worked. Do follow Bill's advise, though.

 

[sidmadrid]

Looking at my Comet, I would say the bottom link is horizontal ish in a normaly loaded situation. Yours is pointing skyward.
Springs too short, springs too soft?
On another vein, my Comet had a serious frontal in its life. After the wheel rebuild the front mudguard touched the mag
cowl when the front was jacked up. On very close inspection found the girdraulic blades were bent. Straightened and tweaked them on a hydraulic press. Might be worth putting a straight edge down the centre line of the spindles. Sid.

 

[davidd]

View attachment 1594View attachment 1595Hi to all, I have just fitted the Sam Mangano front springs and am concerned that I may have too little suspension movement left, the two attached photos are with the bike off any stands, I am straddling bike but with virtually no weight on seat.
To my untrained eye FF3 and FF4 top and bottom links look to have travelled to almost full extension?/ Contraction?/travel.
The front springs look to be almost bottomed out?
This is my first Comet so have nothing to compare it too.
Thoughts anyone??

Kevin
p.s. I have also noticed that when bike is jacked up, the rear of the front mudguard fouls the magneto cover just before the front wheel leaves the ground, is this supposed to happen?

Kevin,

Do not Panic. Despite Martyn's post I might just add a few shims. The springs were designed to prevent "Tank Slappers" and were not designed to make the front end "look" a certain way. If the eccentric end of the link is not lower than the front end of the link you will encourage problems. A few questions: what damper are you using, what color springs and did you get instructions.

The mudgaurd fitting is a mechanical issue that does not have to do with the springs. It is brace placement or a damper set up issue. I hope it is not Sid's bent blade issue. I am happy to go into more detail, but it would be nice to know the set-up.

David

 

[bmetcalf]

David, your previous posts convinced me to install the springs. How about a link to the post? The spring rates matching between yours and standard at full compression was the convincer for me.

 

[Big Sid]

On the C forks link angle . I have found that for street riding and fast road work far improved fork compliance results from following these ideas . They admittedly differ from from Davids findings ill admit but really please owners of road bikes for the increased compliance and comfort .
With the rider poised lightly on the saddle balancing on his toes observe closely the angle of the upper link . This should lie with its FORWARD end just below horazontal , not above . This gives the maximum damped upward movement upon sticking a rough patch of road before jolting the bars . This is acheved and the ride made more supple by eliminating the inner spring on the left side , the length then regained by inserting a spacer above the remaining spring about half to 3/4s inch long . This may vary with rider weight and the spring length . This done only on one side .
Be sure the springs and inner and outer rubbing surfaces of the tubes are greased . Also that the spring boxes are not damaged , are a free sliding fit within each other . Remember that the D models used only a single spring and this is a bit longer , so this modification is not straying too far .
The ride comfort is much improved as is the handling all agree who have done this mod , or ridden those I have done . Sid .