Morning all. I purchased a brand new 190×50 Fox Van RC rear shock for my trusty HL 5 spot last month for what can only be described as a criminally small sum. The only problem is the coil fitted to it is 400lb and my 13 stone overfaces it slightly and so I’ll need a heavier coil.

My question is what the hell is the length of spring should I buy? The coil on the moment is 2.45 (far longer than the stroke length) a mate has the same shock but his coil length is 2.37, I’ve seen them for sale on the classifieds with 2.25 coils on them get 50mm is roughly 2″.

I’m purplexed, so much so that I am using the purplexed smilie for the first time. ❓

I usally go by the stroke and weight 50mm stroke is usually around a 2.25″ stroke , and what weight you need, I’m running a 2.25 x 550lb spring on my Orange 5 14 stone , I think TFTune have a spring calculator on their web site.

I’ve tried the TFT tuned calculator, I’ve got a good idea of the spring weight that I need its the length of the sping that I am not sure about.

I’m wondering if you fit a lighter but longer spring in to a shock does that mean you have inbuild preload and so the coil will act like that of a heavier weight setting.

Coil length does’nt make any difference.Buy it based on stroke and spring weight.
Pre-loading does not make shocks ‘stiffer’ btw.

there are 3 measurements you need to worry about with coils

1. spring weight – this needs to be right, and will be a function of your bikes suspension design, your weight, and the shock you are using. Use the TF tuned calc for guidance.

2. stroke length – this is how far the spring can compress before it becomes coil-bound (ie: the coils bang into one-another and it wont compress any more). The spring you use must have a stroke length of *at least* the stroke length of the shock you are using it on.

ie: 50mm stroke shock needs a spring with a stroke length of *at least* 50mm (about 2 inch), but you could use a longer one if…

3. free length – how long is the spring when uncompressed – ie: will it fit on my shock, is it physically too long to fit.

what you will find is that springs designed for say a 190x50mm shock will have stroke lengths varying from about 2in to 2.4in depending on the spring weight, as a stiffer spring will be thicker coils therefore will have a slightly shorter stroke than a lighter one designed for the same shock. (increasing the free length would be one way to get more stroke, but then it might be too long to fit the shock body.)

hopefully that makes sense…..

You probably need somewhere between a 500lbs and 550lbs spring, and stroke length must be at least 2in, I think you will find 500×2.25 will also fit, but heavier springs with that stroke may be tight on a 190mm shock body.

I might have a suitable spring in the loft, ill check tonight for you if you want, you can try it out if I have got one cos it’s always worth riding a bit as the spring calcs only work as a guideline, personal pref and riding style could mean you need to go softer/harder.

Matt

Cheers Matt, that is exactly what I needed to know. I was pretty sure that I could use a Cane Creek 500×2.25 shock based on coils I have tried in the past and as they are only 20 quid from TFT I’ll probably go for one of those. I also have a couple of heavier 2″ Romic coils been sat there for an age I might have a play with.

JonR what was the criminally small sum and are there any more for this meagre fee? I want a 190 x 50 for my covert..

Cool, glad that made sense!

re: Romic coils – they are normally a bigger internal diameter due to the size of the Romic shock body, so may not fit on the fox shock without a reducer collar at either end.

I know more recent Fox Van shocks are a bit bigger than the old Vanilla RX/RC but make sure you check before trying to use one as you don’t want the spring sliding around and sitting off centre – bad things will happen if it does.

Matt

Toys, I’m afraid it was from an ebay seller who had bought the wrong size and the auction didn’t even get one bid so I emailed with a lower offer and he took it. That said I think Vortex Racing was selling a similar shock at a very reasonable rate on the classifieds. Yep, this is the one.

http://singletrackworld.com/forum/topic/fs-%e2%80%93-tyre-coil-shock-rotors-front-mech-700c-wheel-saddle-piccies-1

Matt, I’ve got the old Romic shock body as well so I’d be mounting them on that and having a quick blast about just to see how the heavier spring weight feels. Cheers for the advice, its been invaluable.

Yeah

thanks Jonr

“That said I think Vortex Racing was selling a similar shock at a very reasonable rate on the classifieds. Yep, this is the one”

😳 Sorry thats now awaiting fitting to my bike!

oh arse.. Have fun. I have it on ebay alert now so I’m sure to get a cheapy sooner or later.

I’ve got a brand new Elka for sale (200×57) if anyone is interested.

E-mail me: mikek@skylinecad.plus.com

too long for me.

Mikey – how much are you asking for the Elka?

Erm, around £350 ono. They retail for £470. It’s brand new and never even been fitted.

Sorry, sounds like a good price but way beyond my budget 😥

No probs.