JHS preload top caps for curvy and springs.

[Bad Intentionz]

I'm currently sorting out my front end and had a couple of questions.

When looking through some bits on the JHS website I saw the adjustable preload top caps and spacer/shim kit...

http://www.jhsracing.co.uk/~jhsracing.co.uk/public_html/archive/99-650/susp_steer.htm

Has anyone used or know anyone who has used these and are they worth the cash?

I also thought I'd add a poll on the thread as I've heard a lot of mixed feelings about progressive and linear springs, I thought this would be the easiest way to find out peoples thoughts on the subject

In advance... Thanks

[drag]

I have linears with 15W oil and a set of caps from robinsons, there dialed in about half way, and the whole front end feels a million times firmer

[Sid Squid]

Preload adjusters aren't necessary, once you've decided on a setting you probably won't change it, just use some suitable tube for your spacer, which you'll likely need to cut to an appropriate size anyway as most springs aren't supplied with spacers, and from your question I imagine you're considering changing springs.

[Bad Intentionz]

Preload adjusters aren't necessary, once you've decided on a setting you probably won't change it, just use some suitable tube for your spacer, which you'll likely need to cut to an appropriate size anyway as most springs aren't supplied with spacers, and from your question I imagine you're considering changing springs.

I take it I could just replace the standard spacer inside the fork tube with some tubing of the same type and lengthen it or should I use a seperate piece of tubing on top of the spacer to increase the preload?

next week I'll be putting new springs in. I've heard a lot of mixed opinions on what people prefer. I changed the fork oil the other week as it's never been done in over 20,000 miles. I put in 15w oil but it feels horrible. It seems like theres not enough rebound or something?

[Sid Squid]

I take it I could just replace the standard spacer inside the fork tube with some tubing of the same type and lengthen it or should I use a seperate piece of tubing on top of the spacer to increase the preload?
I'd use one piece, but yes.

next week I'll be putting new springs in. I've heard a lot of mixed opinions on what people prefer. I changed the fork oil the other week as it's never been done in over 20,000 miles. I put in 15w oil but it feels horrible. It seems like theres not enough rebound or something?
I'd consider 15W a dab stiff on standard springs.

[Bad Intentionz]

I'd consider 15W a dab stiff on standard springs.

Thats what I thought. how much would you recommend increasing the length of the spacer by each time, 5mm or so?

[Luckypants]

Spacer length will depend on the springs you fit. I'd assume you are fitting springs with resistance (dunno proper term) suitable for your weight? If that's the case, try the standard spacers first and see how the pre-load is with those - you can decide after trying this if you need longer or shorter spacers.

Pre-load is used to set the amount the bike sags under your weight, so there is no hard and fast rule on spacer length required. You are aiming to have a few mm (5-10?) of sag in the suspension under the bikes weight and 35-40 with you on board in full kit. Those are the numbers I favour for road riding, others use different numbers depending on riding style / preference.

[Bad Intentionz]

Spacer length will depend on the springs you fit. I'd assume you are fitting springs with resistance (dunno proper term) suitable for your weight? If that's the case, try the standard spacers first and see how the pre-load is with those - you can decide after trying this if you need longer or shorter spacers.

Pre-load is used to set the amount the bike sags under your weight, so there is no hard and fast rule on spacer length required. You are aiming to have a few mm (5-10?) of sag in the suspension under the bikes weight and 35-40 with you on board in full kit. Those are the numbers I favour for road riding, others use different numbers depending on riding style / preference.

Nice one, Thanks. I emailed Race Lab earlier on today. They do have springs (linear) suitable for my weight. They're going to see if they have them in stock and let me know.



Thanks to all for the advice.

[sv_rider1990]

sorry to thread jack but this has been buggin me wot is "better" or a favoured choice among curvey owners progressive or linear springs?

[Robw#70]

Progressive springs if your going to be happy to leave it at that, if you want to do more to the forks ie emulators, then you need linear as you cant set the damping for a variable spring rate.

Progressive springs are good at what they are intended for ie their progressiveness makes up for when there is poor damping and a cost effective fix, but ultimatelt linear and correct damping will perform better.

[Bad Intentionz]

If you want to do more to the forks ie emulators, then you need linear as you cant set the damping for a variable spring rate.

Progressive springs are good at what they are intended for ie their progressiveness makes up for when there is poor damping and a cost effective fix, but ultimatelt linear and correct damping will perform better.

Can anyone recomend a company that makes emulators and how much are they likely to cost???

[Luckypants]

Can anyone recomend a company that makes emulators and how much are they likely to cost???

RechTech do both the emulators and springs. I got both for my Curvy. Do a search on this topic and you will find reams of information.

Racetech emulators are also known as gold valves if you start looking for them for sale on t'internet.

[Bad Intentionz]

Thanks for that. I've found out that PDQ are distributers for race tech. I'll send them an email today and find out more. After some thinking, linear springs with emulators would be what im after.
Has anyone fitted these at all. I've read some bits online about it and theres mention of drilling parts. I havn't been able to find fitting instructions for the SV

[Luckypants]

Yes I fitted racetech springs and emulators to my 2001 curvy. Many folks on here have also fitted these parts, use the search function on this forum and you will find plenty of tips.

If you can use a spanner, you can do this mod. The SV forks are the same as pretty much any damper rod forks, so nothing special to worry about. The instructions that come with the emulators will tell you how to proceed.

[Bad Intentionz]

Nice one, Thanks. Shouldn't be a problem then. Really looking forward to getting the front end handling sorted now. Hopefully have everything ordered up in the next couple of days. Then lots of riding before lots more tinkering away on other little bits!