GSX1400 Owners .org

Technically Speaking => Suspension => Topic started by: Speedy1959 on Friday, 06 July 2018, 08:46 PM

Title: linear or Progressive ?
Post by: Speedy1959 on Friday, 06 July 2018, 08:46 PM
Half thinking of biting the bullet and replacing the fork springs when I refurb the guides / seals etc next week.

As the title asks..
Linear or Progressive ?

Hyperpro or Hagons ?
My bike never sees track days so dont expect Ohlins type performance !

Basically is it actually worth spening the extra on springs ?
Title: Re: linear or Progressive ?
Post by: seth on Friday, 06 July 2018, 08:52 PM
Can of worms linear or progressive .
:popcorn:

For info I have hagon progressive in 2 of the 14's and they improved/stiffened up the forks
I have hyperpro progressive for the other 14 but they'll be in the bking forks I'll be fitting to the b/w 14.
Both kits come with everything you need including info on amounts of oil .airgap and the fork oil itself .

:cheers:
Title: Re: linear or Progressive ?
Post by: Speedy1959 on Friday, 06 July 2018, 09:32 PM
As always I thank you for your valued expertise Seth.

s
Title: Re: linear or Progressive ?
Post by: grog on Friday, 06 July 2018, 09:42 PM
Your question Speedy, worth spending on springs. My answer is yes. I fitted Wilbers progressive. I did get forks set up at same time, wilbers oil also was used. Hard to know what worked but total package was chalk n cheese.
Title: Re: linear or Progressive ?
Post by: Hooli on Friday, 06 July 2018, 10:36 PM
On the other hand I've ridden a 14 with progressive springs back to back with a standard one (both with recently serviced forks) and the only difference was a bit less dive under heavy braking.
Title: Re: linear or Progressive ?
Post by: RickC on Friday, 06 July 2018, 10:42 PM
I fitted linear Racetech FRSP S3732095 to mine, I found it hard to get any other linear springs.

The Racetech ones are for K1-K3 models at 315mm, later models are 340mm, I had a spacer made up for mine.

There are lots of options for progressive springs which is probably a good reason to go for progressives.

Title: Re: linear or Progressive ?
Post by: gsxbarmy on Saturday, 07 July 2018, 02:49 AM
Quote from: Hooli on Friday, 06 July  2018, 10:36 PM
On the other hand I've ridden a 14 with progressive springs back to back with a standard one (both with recently serviced forks) and the only difference was a bit less dive under heavy braking.

Same on mine when I had it. Really makes no appreciably noticeable difference to the 14.

My advice Simon would be to save your money spending out on springs, and, once you have had your fork oil changed, take it to a suspension specialist (like Maxtons) to get your suspension properly set up, normally costs about £80 or so, but is probably the best £80 you'll spend on the bike https://www.maxtonsuspension.co.uk/

And then it won't really matter which springs you have (BTW I think they have progressive as standard anyway.....but don't quote me on that) as the handling will be transformed and setup exactly for you. Just fitting new front springs won't make a jot of difference IMO
Title: Re: linear or Progressive ?
Post by: Andre on Saturday, 07 July 2018, 05:12 AM
I would ask the suspension specialist which oil he recommends.

To me the biggest difference is that linear springs are easier to adjust than progressive springs. With the right progressive springs you get a more comfy ride while they stiffen up the more travel the fork does (prevents them from hitting bottom during dive - a very bad thing).

Given your weight (100 kg?) I don't think you need new springs. My suspension specialist says the same as Barmy, the originals are progressive, but less than after markets like Wilbers. He also said that I (100 kg) don't need other springs.

To determine if you need other springs, you need to set sag(s) correctly. Then put a cable tie on a stanchion. Go for a longer ride during which you should take a bunch of corners and also do some heavy braking. Then measure how much spring travel you had. If less than 10 mm left, get stiffer springs. If you use half or less travel, get weaker springs. It all depends on your weight, riding ability, and roads taken. Street rides are always a compromise. There is no "best".

Instead of letting a mechanic do the work, save that money (as well as the money for the springs and oil) and let a suspension specialist do it. There are some other "tricks-of-the-trade" he might apply to make you happy. They usually have so much experience that they do it right if you bring him just the fork legs.
Title: Re: linear or Progressive ?
Post by: grog on Sunday, 08 July 2018, 06:32 PM
not sure mine handles any better, probably doesnt. since i had it set up by susp. guru, no more brake dive, no more twiddling with adjusters. they are now just front forks in my bike, those adjusters did my head in, tried lots of changes, was all over my capability. best mod ive done, never look at or think about adjusting. suits me. much smoother over bumps also a great thing.
Title: Re: linear or Progressive ?
Post by: Tony Nitrous on Sunday, 08 July 2018, 06:58 PM
From MCT Suspension...

(https://gsx1400owners.org/forum/proxy.php?request=http%3A%2F%2Fi64.tinypic.com%2Founkp2.jpg&hash=3cb53787dbfa8f5993877da639929db7162f95fe)
Title: Re: linear or Progressive ?
Post by: Speedy1959 on Wednesday, 18 July 2018, 05:37 AM
Update to this thread..

Today I fitted a set of Hagon Progressive fork springs along with their recommended Rock oil  SVI10 fork oil.
The new fork springs are about 10cm longer than the originals (see photo) because the bikes original spacer is NOT used with these fork springs

I haven't been out on her yet as I am in the process of refreshing the lower front forks with some Satin Black Acrylic paint.. I have to say I am bloody impressed with how well its going on!
Did 3 light coats this evening with half hour between coats (Can says 15 mins).. Its a lovely warm evening so perfect for spraying.
Will put up a photo of my attempt at spraying when the forks are back on the bike..
Title: Re: linear or Progressive ?
Post by: Notty on Wednesday, 18 July 2018, 06:28 AM
well done Simon - cant wait for the ride report !! :)
Title: Sophies Ch0ice
Post by: Speedy1959 on Friday, 20 July 2018, 03:13 PM
Thursday evening and Sophie is back together.
My spring pre-load was wound in to the max on the old springs and still they were pretty soft.
Now the pre-load is on number 5 and its a fair bit firmer, but in a good way.
Point is I now have a choice which way to adjust the springs..
New oil is a thicker 10W and so still playing around with the compression and rebound.. But Compression is eased off back to the standard factory setting at the moment.
Rebound is 6 clicks out...
I am not far off at that.