Bonneville America Forums Forums Technical Forums Performance Mods Progressive front springs

After almost a year I finally got around to installing my front springs the other day. I needed a second pair of hands and when Ed came over he assisted me. It was very easy, just loosen caps, pull springs and washer and replace springs and washer (tight coil side down). So my question is for anyone else that has done the standard replacement like this, NOT the lowering springs. I just put the stock spacer back in, it is about 6" long. The springs came with these real short, about 2", PVC spacers that I didn't install. Did anyone use just the short ones, or both or just the stockers?
I am working on dialing the suspension in correctly after reading the "Total Control" book by Lee Parks that someone here mentioned. Outstanding book by the way, explains road racing techniques and complete bike, suspension and ergonomic setups for stability and performance. Also just a plain old good read for safety and getting your head on straight for riding.
So, how about them springs and spacers?

I didn't use the short PVC spacers. I think they were for a different application....used to keep ride height at original.
I did cut some PVC pipe shorter than the stock metal spacers because I was going for a lower setup.
Front end feels a lot better now...I think you are going to like them.
BTW how's the build going? Breaking her in yet?

Hi, when my dealership installed the Front Springs, I had handed them the little 2" long spacers that progressive had included, even though the online website mentioned using the original spacers. When they were done with my bike, my front end was actually about 3/4" higher, and remains with the higher ride height than it ever did when I first bought the bike, so I'm assuming they re-used the stock spacers. I also had them put in 15W oil instead of the stock weight (8W or 10W), and have been very pleased with the results. The front end has alot less dive under breaking, and the bike leans over alot more aggressively because the front end "sets" sooner. Great Mod!!

My experience (replacing stock springs with Race Techs on my Trophy) is that if you want the ride height to remain basically the same you should take the original springs with the original spacers and lay them next to the new springs then add the amount of spacer necessary to make the two sets equal in length.

---- = spacer
ZZZZZ = spring

Original
|-----ZZZZZZZZZZZZZZZZZZZZZZZ|

New Setup
|_____________ZZZZZZZZZZZZZZZ|

_________ = amount of spacer to be added

If the final length of the new springs and spacers is much longer than the original all you will be doing is compressing (pre-loading) the spring too much and loosing suspension travel. The amount of suspension travel you have is equal to the space between the spring coils. Once that space has been used up, the spring is totally compressed and your out of travel. So on a single rate spring you don't want to have more than a few centimeters of preload, after that your just using up travel that you'd rather have for dealing with bumps and such.

Hope this makes sense,

Keith

This is not the first time I’ve read this on the POST & it frightens me...

The way 2 do the front end is WAY DIFFRENT than what I keep reading on this site.
The 1-2" Progressive lowering kit comes w/2 PVC spacers, directions, stickers, 4 springs (for below the damper), 2 Main springs & 2 washers.

*I'm posting the Kit in my gallery now*

The actual lowering starts below the damper push rod w/replacement of the existing stock springs to the progressive sm. springs (1 spring to lower 1") or (2 springs for 2").
The main springs & PVC spacers are pre cut to size for U in the kit. If the PVC spacers are not pre cut, they have a guide that shows the length for 1" or 2" lowering.

I've done a few front ends over the years & you need to disassemble (unfortunately) them completely if you want the performance that they have the potential to truly give you.

NOTES:
1. It wont take long, I can do it in an hour (messy job)
2. Get the Progressive Kit (10-1564) it’s only $80 4 God’s sake!

I’m NOT saying you can’t do it the LAZY WAY with spacers & springs…I’m just saying, get the kit & do it the right way.

Member
Gary James

Errah, I'm not trying to be a jerk but maybe it's your reading. Pat's post clearly states that he is NOT trying to lower anything just replace the stock springs which I would agree are too soft. My post above was to that end - a straight spring swap.

On the other hand, I agree with you 100% about lowering. If folks are lowering their front ends by putting in shorter springs and smaller spacers this is a bad idea. They should buy the parts to do it correctly.

Keith

Keith,
You beat me to it. I know Gary so i didn't want to come across as condesending. (me?? Never)
I also agree with using the full kit if lowering as it totally changes your suspension lift rates and all. I am no wizard at suspensions by any means, but I got me a book and I'm reading and learning!

I've got the progressive springs for my speedy too. I haven't put them in yet. It's not riding season here quite yet. I want to be able to make a proper comparison, so I'd like to take it for a ride with the stockers, then change em and go for another ride. I have not yet heard a review from anyone that has done the swap.

Pat... let me make sure I am understanding this correctly.
You left the forks on the bike.
You removed the top caps from the forks.
Then changed out the springs and replaced caps.

Has anybody changed the fluid? Can this be done with the forks on the bike?

In theory you could replace most of the fluid with the forks on the bike using some sort of siphon but honestly I don't think it would be worth the hassel.
Of all the stuff I just got through doing to my Trophy - valves, air filter element, new fuel lines, carb synch, bleeding brakes & clutch fluid, the fork oil & spring change turned out to be the one job that (for me) was actually far easier to do then I expected. It takes sometime and there are several steps but they are all pretty easy and it doesn't require much in the way of special tools or know-how.

If you want some pointers on how to do it just let us know.

Keith

slug,
Yes, it was as easy as that. 10 minute job. Raise front end off the ground first.
Remove bars, hold so they don't whack gas tank or spill front brake fluid (shouldn't be a problem though). I used my Ed for this, get another pair of hands to hold bars and make it safer.
Remove the big 22mm caps, carfeul they don't fly off the ends, hold tight when removing.
Remove spacer.
I used a piece of coat hanger to reach down about 12" and hook the spring and slide spring and the big washer out slowly as not to pull all the fluid up too.
Replace spring, tight side down, replace washer, replace long spacer. Replace cap, do other side, replace bars.
Beer break.

Thanks Dingua.
Thanks Jazzplayer.
I've changed fork oil quite a few times before on my other bikes. I was just thinking that if a person wanted to experiment with a few different types of fork oil, it would be a lot nicer if the forks didnt have to be removed every time.
O.K. ... it's true ... I'm lazy.

Well then you know the drill. IMO, outside of swaping in stiffer springs there isn't a whole lot else you can do for a reasonable price that will have a lot of effect. 10 weight oil seems like about the right grade to me for this bike. 15 weight might give you too hard a compression stroke and something lighter (8 or 5) would make the rebound too quick. You could mix 10 and 15 and get something around 12ish.
If I were going to experiment I might try raising the level of oil a little. It seems 166mm is low compared to the Thruxton(143) and standard Bonneville(120) but this maybe due to the amount of rake in the forks.

Keith

15W oil isn't all that bad, at least IMHO. When my dealership installed my progressive fork springs, I also had them put the 15W oil in; the handling is noticeably more comfortable, without being unduly harsh on bumpity bumpity surfaces, and is still reasonably plush. Now based on my mileage with the 15W, maybe the 20W would be a tad too harsh, but I think the 15W is just fine. And the roads here in LA / MS / AL aren't exacly baby butt smooth either. Regards to all :-)

So how much do the springs go for anyway? Not lowering, just springs? I think I've tapped my budget for this season, but maybe next year I'll pop for springs and rear shocks/springs.

I think about 60 bucks at mawonline.com

Hey not bad... Expeciallt considering all the good remarks people are giving them!

Dinqua,

The pic below is the new Progressive front fork springs (that are in your & my Speedys) next to the stock springs. I opted to install them with the tightly wound ends down (to displace more oil).


-BT

And they sure work great too :-) Some of the best $70 I've ever spent Thanks, bikebandit!!

Got mine today. Install and ride report pronto.

Easy 15 min. install. Makes a real differnce in the way the front end handles rough pavement. No more sharp jolts through the bars and less brake dive. Well worth the money ($55 from Motorcycle Accessory Warehouse).

So ya really just pop the caps, slide the old ones out, new ones in, replace the caps and done?

I just ordered some Progressive fork springs today. Since I'm close to 24,000 miles, I was going to replace the fork oil(book says every 4 years or 24,000 miles). I think I'll try the 15 weight. Has anybody tried a different height/amount of fork oil in the tubes?

Just got my fork springs and installed them. Wow! This is a nice mod! I never did like the front end dive under hard braking, but now....the bike is transformed. I haven't taken it on a long ride over bumpy roads yet, but if all I get out of it is the end to that hard dive under braking, I'll be pleased with the $70 I spent. The front end feels a bit higher, maybe 3/4 inch or so.

Your front end probably is higher, mine still is. When the my Speedmaster first came out after the install, I thought that the forks would "settle" in after a coupla hundred miles, well that didn't happen, and I figure I kept that 3/4" ride height increase. I'm not complaining, MORE ground clearance :-)

Probly feels higher cause your weight doesn't settle the springs as much...

You're probably right, but even on the side stand, no weight on her, I can see alot more fork than I used to be able to, The factory forks had less than 6k on them when I replaced them, and yes, even though I'm no longer possessed of a svelte and girlish figure, I don't think my bulk made the things sag :-) Like I said, no complaints, I can amaze some non-cruiser riders with how much lean She'll take without grinding the pegs.

good to know! They are definitly on my short list...

anyone know the part number for the springs.

Fork Lowering Kit: Part # is 10-1564

Fork Spring: Part # is 11-1145

I used the standard spring, not the lowering kit. I bought mine from BikeBandit.com. $70 and change after shipping is added.

I bet if someone wanted to they could make slightly shorter spacers out of PVC like someone did to lower their bike. That would take that 3/4 off there. As for me, I don't see a problem with a half inch more height... N o biggie.

Benny,
You really need to be careful with thinking like that. The suspension is supposed to be tuned correctly and altering just the spacer lengths may be a bad thing once you get to a certain point. Where that point is I don't know, but there are specific formulas (L1-L2/MaxL) or something like that. Spring travel/return rates distance etc are all variables. If you want I can post the suspension info from Lee parks' book. It has a really nice section on tuning the suspensions correctly for your style of riding and mentions the short spacer idea and why it is a bad one. If you shorten the spacers, you should shorten the springs with a differnt spring factor at the same time. (tinsel strength? I dunno, you're the real engineer)

One option could be to raise your fork legs in the top triple tree. It's not a visually pleasing fix, but it eliminates the whole cut-the-spacers thing.

You mean tensile strength? Ha yeah I hear ya. Personally, I'm not after a lowered look, so it's no boggie to me, and anyone who is, they offer a lowering kit, so I'd just as soon plug n chug with the replacements.