HAGON Progressive springs

Just received a set of Hagon progressive fork springs for an SK4 but the more I read the instructions the more I'm reluctant to take the forks apart...

So here are a few questions:
1) are these springs any good? Suppose it's a bit late to ask now, but it would be good to hear from anyone who's tried them.

2)how do you change the springs? Is it simply a matter of removing each fork leg at a time, loosening the fork cap bolts and taking out the spacer washer and spring?

3) there is no mention about how much oil should be put in each leg, but instead it says to leave an air gap of 120mm. I know that the manual tstes 488ml for an SV650S but it also states that the should be an air gap of 94mm.

4) is the 7.5 fork oil the best one for an 11 stone rider?

I've only ever fiddled with an 'X' model, but...

Originally Posted by Italianjob

1) are these springs any good? Suppose it's a bit late to ask now, but it would be good to hear from anyone who's tried them.

2)how do you change the springs? Is it simply a matter of removing each fork leg at a time, loosening the fork cap bolts and taking out the spacer washer and spring?

3) there is no mention about how much oil should be put in each leg, but instead it says to leave an air gap of 120mm. I know that the manual tstes 488ml for an SV650S but it also states that the should be an air gap of 94mm.

4) is the 7.5 fork oil the best one for an 11 stone rider?

1 - Dunno
2 - Much as you say, but loosen the cap BEFORE undoing the bottom yoke clamp bolt and AFTER you undo the top yoke clamp.
3 - Always fill with fork oil only by measuring the required air gap - with no spring in and the fork compressed. Best to start with a larger airgap as you can add oil with a syringe. I reckon 1cc = approx 1 mm in the fork tubes. The smaller the airgap, the sooner compression damping kicks in. A very small airgap will make the front end feel very hard.
4 - Most people go for heavier oil than the factory specified weight, which for an 'X' model is 10W.

[northwind]

I ran with 15W in mine with the Ohlins springs, and it was just a little too heavy. If I were doing it again I'd use 12.5.

You'll need at least a paddock stand and jack to do it- and personally, there's no way I'd remove a fork leg without serious support.

not a good idea to do it yourself. the fork oil must be mill perfect on each fork on mine i used a 95 mill air gap with 10w oil with a preload spacer of 40 mill. as for the springs any spring have got to better the the oe. http://www.socalsvriders.org/downloa...p=getit&lid=58 try downloading this file it the chassis part of the sv k4 workshop manual. it should guide you through it

sorry that link dosent work but if you go to the first part of the address and then go to the downloads section and download the chassis part. the oil weights only go up in 5 ie 5/10/15 you could mix them to get different weights

[21QUEST]

Originally Posted by mac650s

not a good idea to do it yourself. the fork oil must be mill perfect on each fork on mine i used a 95 mill air gap with 10w oil with a preload spacer of 40 mill. as for the springs any spring have got to better the the oe. http://www.socalsvriders.org/downloa...p=getit&lid=58 try downloading this file it the chassis part of the sv k4 workshop manual. it should guide you through it

Why?

Get you self a Haynes manual or download the Suzuki one.

As for the oil weight/air gap I would go with what Hagon recommends.

Cheers
Ben

[Sid Squid]

It's an easy job, nothing at all to be wary of.

Some things to note:

1) Loosen the upper yoke clamps and clip on clamps, then loosen the fork caps a turn or so with the forks still on the bike, much easier, adopt the same procedure to tighten them again.

2) When tightening the fork caps, don't lean on them, they're light alloy and have a very fine thread.

3) The final air space depends greatly on the volume of the spring, if the new springs are made of thicker and/or more turns of wire, a lower fork oil level will be necessary in order to preserve the same air space, check with the spring maker if you're in any doubt, different models of SV have use different oil levels, make sure you're using the right one.

4) Standard oil is 10W. If you're using heavier springs, heavier oil is appropriate. The great majority of people are using 15W oil, if you're 11/12 stone it'll most likely suit you well, (I think Northy's a dwarf or something).

5) It's best to set the oil levels as accurately as possible, however the SV fork is a bit crude at best so no need get obsessive.

[northwind]

Originally Posted by Sid Squid

4) Standard oil is 10W. If you're using heavier springs, heavier oil is appropriate. The great majority of people are using 15W oil, if you're 11/12 stone it'll most likely suit you well, (I think Northy's a dwarf or something).

Nah, it was just that I had a hard-front conversion in the winter

Someone said it's essential to get the air gap spot on... I don't agree with that at all. In fact, I'd say a bit of experimentation with the air gap can give you some interesting results. IMO it's one of those things where there's no magic numbers, and you may well find you prefer a different level from stock. Not massively different, mind!

For example, loads of people use PVC tubing to make new preload spacers. PVC tube's got much more volume than the stock metal tube, and so the air volume is cut. How many of those compensate with the oil level? Not very many, I reckon.