Bonneville America Forums Forums Technical Forums Performance Mods Progressive** LOWERING** front springs

Fisrt off not sure if this should be in this catagory or "general" but my thinking is if done properly it's a performance enhancing mod.

Anyway after getting my forks completly disassebled, (thanks to all and especially Z for the great "how to" vid)I noticed that the spacers suppiled by Progressive were the wrong size. In the kit they shipped out the spacer is only 4" long and for the America/Speedmaster application the spacer should be 6.12" for a 1" drop and 5.12" for a 2" drop. These said PVC spacers DO REPLACE OEM spacers, also to do this properly you must remover the dampner to ADD the required springs. Here again 1 spring for 1" drop and 2 springs for 2" drop. Yes you ADD, meaning the OEM spring on the dampner stays in place.

At first I thought that I must have ordered the wrong kit but upon speaking with Progressive this am they have been sending out this kit with the wrong spacers. They didn't say how long it has been this way but are in the process of correcting it. So my suggestion is if you have lowered your front and it's not exactlly what you expected you may need to go back and measure the spacer to make sure it is the proper length.

If the math don't change, a 4" spacer would be a 3"+ drop. That would SURELY be noticed, and/or unacceptable to anyone who's bought one.
Something's fishy.

thanks for the PM Matt, i knew about adding the two springs to the oem one 2 get the 2" drop but not the spacer part, will need to check the ones i still have in the box and measure those suckers.

I have used these lowering kits before and they are counter intuitive. At first blush the idea of adding springs to make the bike lower seems wrong, but its not.
You can do the install with the forks on the bike ( IMHO it's easier). The is a chart on progressives web site (and I recall on fast eddys as well) that shows you the correct spacer length for your bike. You likely will have to cut down some spacers to suit. The kits are somewhat universal.

I've been thinking about this all morning now and, OOOPS. Yep I guess you really don't need to completly disassemble them, the only thing on the bottom of the tube is the dampner seat. So yeah, now I see why it would could be done still on the bike.

But if I never took it completly apart I wouldn't have ever make my nifty drift tool.

with the forks on the bike and front wheel off. you can easily loosen the dampner screw, located in the axle bores. you will need to brace the lower fork with a screw driver or bar to counter the torque, but it is an easy 1 man job.
You may want to remove the from
remove the dampner thru the top of the fork tube (after the spacer and spring)using a telescoping magnet. change out your springs and spacers, slide it back down the tube, replace the dampner screw and torque to spec. add oil in specified amount. replace top caps.

Gents, I installed a set of Pro Springs many, many miles ago, 45,000. I'm curious what the life expectancy might be for the springs?

44,999 Miles.

Honestly , that's a good question and I have no clue.

I know the oil degrades over time, and that can be easily changed but I would imagine that the springs would wear also and not have the same rebound as when originally installed.

I wonder if you can do a compression test, comparing the old spring to a new one?

If the springs are of the Chrome Silicon variety, they will supposedly do up to a million cycles. They were developed for Nascar engine valves (if what I read a few years back is true) and found their way into mil-spec gun actions, high mile diesel engines and a host of other mechanical devices. For an actual definitive answer, I would write Progressive's engineering department for a metallurgical makeup and expected spring cycle life. In the old days, springs were made of O-1 or Improved Plow Steel, but as one could expect, we have come a long, long way from there.