Plunger suspension ride height adjustment

[pauldridge]

Just getting my '53 SQ 4 MK II back on the road after a 2 1/2 year slumber. The plunger suspension seems to be in decent order, but I find the ride height is so low that my stock-mounted pipes drag the ground even under the most minor lean in a turn. My 205 lbs fat ass doesn't alleviate the situation any.

According to Waller, the only adjustment is using stronger springs from a Sq 4, which I already have, of course, and D'fly seems to only list a single spring for ALL the plunger frames.

Please see the attached photo of my UNLADEN plunger suspension. Does this look right?

Any and all solutions would be welcome.. perhaps some sort of spacer/shim under the spring?

'53 Plunger Suspension unladen ride height

[simon.holyfield]

Are those wishbones really higher at the back than at the front Phil? If so, there's something wrong.

Mine are not far from level, but they are definitely lower towards the back. Perhaps the springs are wrong or have collapsed?

[roger.fellows]

Do you have rear footrests Phil? If you're not intending to use them it's probably worth raising the silencers by drilling a lower hole in the bracket.

It'll be useful to do that even if you can get better ride-height by correcting the suspension.

We can't see where the suspension cap fits from this photo.

[pauldridge]

Thanks for the responses. To Roger, I did consider moving the silencer strap up a bit, just hated to leave bare metal on my new, chromed mounting tab. And, no, I don't have the passenger pegs installed, and never intend to carry a pax.

Here are additional photos of the entire suspension, both sides, On each side, the wheel/suspension saddle sits about mid-way of the available travel, as you can see. It seems like the at-rest position should be to allow more downward travel of the frame? I guess I could try new springs, but D'fly shows them as "on order only"

And, yes, for the observant, I did note from the photo that one of my axle adjust nuts is loose.. corrected after the photo was taken!

Finally, what is the suggested procedure for adjusting that bolt through the trailing portion of the suspension yoke? Waller doesn't seem to mention it.. obviously it is designed for adjustment.

You can see larger images by clicking on each photo

[roger.fellows]

Hi Phil, the suspension units look correctly assembled to me. It looks as though you've bent the silencer brackets inwards which helps a little.

I think I can see the knurled washers each end of the cross-tube on the sliding member. If you can rotate at least one of each pair by hand that's correct.

There might be a tad more cap showing than I would expect, but not enough to make a significant difference.

I'd go with Simes' suggestion of investigating the springs. I don't have access to mine to compare just now.

Looking at photos of members' bikes on the club website, there is quite a variation in the at-rest positions of the slider with overlap between weight on and weight off.

Might there be room for auxiliary springs between the spindle and main springs if you find something that fits?

[Simon.Gardiner]

I'd say that suspension was letting the bike sit much, much too low. Have you got something in upside-down??

Here's a pic I nicked from another Square that had details posted here (I 'borrowed' it to show the rear brake cable routing but I think it also shows the suspension with the weight of the bike).

SG

[roger.fellows]

I always get confused about which way the brake operating arm should be with different arrangements, but downwards invites self-servo over bumps for some set-ups. Will your brake cable clear everything on full bump?

PS This was in the composing while Simon G was posting. That's a very smart cream, the rear brake arrangement is obviously different in the position of the cable-stop.

PPS: there's a bit about up/down and cables on Draganfly's site.

[roger.fellows]

Are you able to force the slider most of the way to the bottom of the travel, Phil?

[pauldridge]

Yes, after conversing with a US owner, I put the bike on the rear stand which showed then about 3/4 inch reveal of that lower flat spring.

Hard to imagine anything assembled backwards as the spring seems to be symmetrical, nothing much else in there?

[roger.fellows]

Just being picky, I wouldn't expect to see what looks like a crimped washer under the head of your spindle bolt. Is it there by design?