[heloego]

So I finally get to do a couple more mods to my '12 C5.

   Want to install progressive shock from our host, but have a minor issue...
   Here's the "stock" shocks installation. There is about 1/4 inch clearance between the spirings and the loop on the frame behind the tool box:

Here is the install using the Progressive Shocks. I had to force the top mount into position to allow the bolt to be inserted, but now there is no clearance between the shock spring and the frame. The spring is in full contact with the frame.


  Maybe it's just the A&P in me but I have to ask...
  I know I can elongate the upper mount lug mounting holes to give me the clearance I need at the spring, but I'm concerned about possibly compromising the integrity of the upper mounting lug.
   So has anyone else encountered this, and will I be OK elongating the holes enough to gain some clearance between the spring and the frame?
   Thanks in advance!

[upintheair]

Since it is not an aircraft, would it work if you inverted the unit?  It appears that the external shape if the spring is tapered.  I agree that elongation is not the best idea, from my A&P experience.

[rtillery02]

Odd, I installed the progressive upgrades from our host onto my 2012 C5 Classic & had ZERO problems or any issues at all with installation clearance. I'll have to check, but I think mine may have been the heavy duty ones.     

[Kevin Mahoney]

The joys of hand welded frames, some with no jigs. I think you will be OK if you elongate the mounting hole a bit

[Vince]

     Changing the shock angle by elongating the hole should work OK, but then you have another issue.
Even a slightly different angle will load the shock differently and it will work differently than the shock on the other side. This imbalance may cause handling inconsistencies. Modify both shock mounts to get the same angle on both.

[mattsz]

The joys of hand welded frames, some with no jigs. I think you will be OK if you elongate the mounting hole a bit

     Changing the shock angle by elongating the hole should work OK, but then you have another issue.
Even a slightly different angle will load the shock differently and it will work differently than the shock on the other side. This imbalance may cause handling inconsistencies. Modify both shock mounts to get the same angle on both.

Wonder what the odds are that the shocks are at the same angle now? 

[heloego]

   Compared to the stock units these things are massive industrial strength family sized. Both shocks fit the same way. No clearance at the frame/spring, so at least the lugs are in sync.
   I agree with Kevin re frame construction. That and the larger diameter spring combined to produce this problem.
   I am not going to elongate the holes, as I would have to nearly file them all the way to the aft edge of the lugs just get the clearance I need. Currently, with the bolts installed the springs are actually bowed due to the contact with the frame. That's too much metal removal and would, I believe, seriously weaken the lugs.
   Inverting them won't work. The current contact point is 3.5 inches (88mm/8.8cm) from the upper bolt hole center. Measuring up from the bottom mount stud center is also 3.5 inches (88mm/8.8cm)so the spring and spring boss normally on the bottom would also contact the frame at the same point on both sides.
   Unless there is a truly viable option available I don't think I have a choice but to return them and for now stick with the stock shocks.
   I'd be perfectly happy with a store credit (for other cool stuff) and since the shipping was free for the order that included them I have no problem paying shipping back to CMW.
   Beautiful shocks! They just won't fit my particular C5. 

[Blairio]

Why don't you try inverting the spring, rather than the whole shock? This would require safely dismantling and then reassembling each suspension unit, but may solve your problem.

[suitcasejefferson]

I see no way those shocks are going to fit. I can see the bend in the spring were it is being pushed back by the frame. I would definitely not do any modifications to the frame. Not only could that affect the integrity of the frame, but it is just not good mechanical practice, for bikes or airplanes. I would not feel good about riding around on a bike with a butchered frame.

[Ice]

Hagons. They will fit and can be sprung to suit any rider. You might ask Ducati Scoty for his insights.

[JVS]

Just thinking here and might be completely wrong..

But, did you install the new shock on that side with the existing one in place on the LH side? Maybe there is a mismatch of spring tension, i.e. a high pre-load setting on the left side of the bike, that is pulling the swing-arm harder (upwards) as compared to your new shock on the right. The new one might be set at the lowest or lower pre-load setting. Or, it might be the other way around regarding the pre-load (stock is on low, and new is on high).

I would suggest you support the swing-arm, remove both the stock shocks, and then install the new ones by having them at the same pre-load setting.

[heloego]

JVS: Photos were taken with both progressives installed, same settings on each.

Blairio: Inverting the spring would yield the same results.

SCJ: I strongly agree. This particular bike just won't allow it. And any hacking, hammering, filing, etc. to get them to fit would just be wrong.

[Rattlebattle]

I see no way those shocks are going to fit. I can see the bend in the spring were it is being pushed back by the frame. I would definitely not do any modifications to the frame. Not only could that affect the integrity of the frame, but it is just not good mechanical practice, for bikes or airplanes. I would not feel good about riding around on a bike with a butchered frame.

My thoughts exactly. Send them back.

[heloego]

   I'd already contacted Tim at our host, so he's aware of the fit. He asked for pics and I sent a couple to him.
   All I'll need now is an RMA. I'll call again tomorrow.

   Thanks everybody for your input.
   Like BH says, "Enfield people are good people!"

[HUdson51]

You may try enlarging the upper mounting hole to the rear a bit to provide clearance for the spring. Fabricate a filler out of a washer to just fit the empty space created by the enlargement to prevent any movement of the upper mount.