Hyperpro progressive fork springs.

[Dellinger]

I've been planing on doing an overhaul on my 08 xb12 scg forks before the spring. I've watch alot of Isle of Man TT videos. (stop making jokes and pay attention) I noticed there were bikes using the Hyperpro progressive springs.

The videos were way smoother to watch, less bouncing around... I started reading a bit and figured what the hell for $150 shipped. Ive wasted way more money in the past on useless crap than this. If they suck I can get rid of them but if they don't, I'll have a better handling bike because of'em.

I'll probably get them in the mail in a couple weeks. I don't see me waiting that long to get them in the forks, when I do I'll give a review.
http://hyperpro.com/en/springs/

 

[ToneTheMoan]

I would be interested to see what you think of them just out of interest, and do a pic of the hyperpro`s next to the standard springs it would be interesting to compare them! Obviously i wont need them as i am such a brilliant rider!! ha ha ha :up:

 

[Zerocwl]

hmm interesting. would like to know what you think of them. did you get rear too or just front?

 

[Dellinger]

Just the front springs. I plan on doing a 43mm S/R full ride height front end swap next year and if I like the springs I may order one of their complete rear shock units instead of the factory one. Suspension is the key to fun safe riding at speed...
http://www.epmperf.com/hyperpro-motorcycle-shocks.htm

No matter what, I'll be replacing the entire suspension on the bike next year. I may save'em for a future Scg build for my wife, sell'em or trade'em with a member here for a set of 43mm tubes to rebuild with another set of their springs. I got all the seals and bushings from ASB, just waiting on the springs.

 

[oh9bolt]

https://www.google.com/search?q=bue...droid-verizon&sourceid=chrome-mobile&ie=UTF-8

 

[Dellinger]

http://vi.raptor.ebaydesc.com/ws/eB...265&category=178042&pm=1&ds=0&t=1456081045739

These are the ones I purchased.

09bolt, I read the old reviews from the search and I had concerns about the kit lowering my scg height bike lower. This set of springs are made specially for this low model, you would think it's properly engineered. I'll find out soon enough. I'm a heavier rider too so a fresh review on the low springs with a heavy guy testing'em should be good for the forum...

When I go full R/S height next year I'll be using new forks, lower triple, side stand and full rear shock. Not sure if that was one of your concerns or just search results...

 

[Dellinger]

WOW!
Just took the first ride after the form rebuild. This isn't a worthless upgrade. First thing I noticed is how the front end glided over my crappy street which was worse before. I replaced the bushings, seals and oil with the stuff in the kit. Putoline was the brand in the kit. If you live in the UK you get their brand. The U.S. Distributed may offer their oil, IDK. I got mine off eBay, a seller out of Italy had them for $150 shipped. I'll post pics of them up against the stock springs.

 

[Dellinger]

the one on the top is the Hyperpro, the other is the stock spring from the 41mm Scg fork.


I was nervous because the new spring is 1/2" shorter but doesn't affect the front end height.

 

[Cooter]

Verrrry interesting. Did you have to give them your 'fully dressed" weight? I would LOVE to know the spring rate difference between the two.
Thanks for posting

 

[Dellinger]

I didn't give any weight. They are similar to stock over all just the resistance changes more over the length of the compression. The spring is made out of silicone chrome which is bad a$$. All my guns have springs made out of this stuff. AR-15 springs are tested to 1,000,000 compressions without change.

 

[Cooter]

I would guess the Buell factory springs are silicone chrome too. Monroe shocks used to quote that suspensions cycle over a million times per MILE:horror: Albeit at a much shorter stroke than the 6" or so a buffer spring moves every time the BCG cycles in an AR-15. It's the amount of the springs wire twisting that dictates life cycle.

I'm positive the progressive rate is higher than the stock progressive rate, just because they are a 'performance upgrade'. HyperPro doesn't need to please the grandma commuter who bought a Firebolt to get church on Sundays . I'd just like to know how much higher, considering they don't have any made specifically for any different weights, just factory spec.

That explains why they have a physically shorter free height, yet retain the same loaded static dimension. The higher spring rate will compress less (at the same weight).

Ironically thats the only job springs do (hold weight), they don't affect damping at all, and there's only so much pre-load adjustment you can make to get the correct static dimension without making your own spacer. Just throwing questions out there. I like to crack out on suspension theory, almost as much as engine theory. Wheres my :dork: emoticon? Haha..

 

[Dellinger]

Honestly the stock spring looks like they're made out of the same stuff and are progressive as well. The coil spacing is the main difference. They feel softer in the first inch but get harder as you try to push. The cut sheet that came with the spring called for a lower oil level too. 140mm. I think my manual said 108 or 9mm for the Scg.

 

[Cooter]

The different oil level spec is interesting. The fork leg should have the same static height dimension before and after. Hmmmm.

In my experience(*) fork oil levels are dictated by how much oil the fork leg can hold at full compression, without hydraulic locking the leg. So a little less is fine but a smidge too much and you'll limit the compression travel in a not so nice way...

If I ever need to re-build forks that don't have an oil level spec'd I have a method that works perfectly (so far haha). Instead of installing the spring, extending the fork tube, and adding oil to the set dimension (that I don't have)... I will install the spring, compress the fork tube, and add oil up to the top (I actually go -4mm for fork cap clearance when installed). That way there's no way the leg can hydraulic lock, and theres the most amount of oil you could fit anyway. Remember the oil only really needs to cover the damper completely once it's purged, but more is good for cooling.

I've checked that method against spec's (even for Buells) and it works perfectly. Compress the tube, add to full, extend the tube and bang! it matches.

 

[Cooter]

And further more!

(Oh Lord I know) The physically shorter spring should take up less volume, thereby requiring more fork oil. Even though the factory level spec still wouldn't change.

 

[motoguy]

In my experience(*) fork oil levels are dictated by how much oil the fork leg can hold at full compression, without hydraulic locking the leg. So a little less is fine but a smidge too much and you'll limit the compression travel in a not so nice way...

If I ever need to re-build forks that don't have an oil level spec'd I have a method that works perfectly (so far haha). Instead of installing the spring, extending the fork tube, and adding oil to the set dimension (that I don't have)... I will install the spring, compress the fork tube, and add oil up to the top (I actually go -4mm for fork cap clearance when installed). That way there's no way the leg can hydraulic lock, and theres the most amount of oil you could fit anyway. Remember the oil only really needs to cover the damper completely once it's purged, but more is good for cooling.

I've checked that method against spec's (even for Buells) and it works perfectly. Compress the tube, add to full, extend the tube and bang! it matches.

Thanks for the tip!

 

[Cooter]

Re-reading that I failed to be clear that is for the maximum amount of oil allowed, making the stiffest fork possible. Less air = higher spring rate.
If you want a softer spring rate, reduce the amount of oil in the fork. More air to compress = lower spring rate.

The Ol' Dave Moss zip tie should answer what rate you need for your weight, riding style, type of terrain, etc.

 

[motoguy]

Re-reading that I failed to be clear that is for the maximum amount of oil allowed, making the stiffest fork possible. Less air = higher spring rate.
If you want a softer spring rate, reduce the amount of oil in the fork. More air to compress = lower spring rate.

The Ol' Dave Moss zip tie should answer what rate you need for your weight, riding style, type of terrain, etc.

Regarding USD forks, for your method you're only filling the bottom fork leg, correct? Not letting it overflow into the top tube as well and filling all the way to (-4mm from) the cap threads? The fork seal remains "dry" as you're filling the tube, correct?

 

[Cooter]

The whole point is to have less oil in it than can hydraulic lock at full compression, so the fork needs to have all the parts in it and tubes compressed into each other. Remember, this is a replacement theory if you do not have MFG specs and the maximum amount of oil you can ever put in the fork, for the stiffest spring rate before changing the springs themselves.

 

[motoguy]

Thanks! That makes sense. I like that the Buell manual has you measure the level with the forks compressed, which is far easier than bikes I've dealt with in the past which want them measured at full extension.