Rear shock springs sizes and interoperability?

[macribs]

So looking for rear shock and spring is a daunting task for me as a heavy rider. After checking with a couple of calculators I should use 900 lbs spring.

Found finally 900 lb spring. But all that is listed is this:

900lb x 1.60 stroke
900lb x1.83 stroke
900lb x 2.21 stroke


How can I know what rear shock will fit these springs? These are aftermarket springs. Are the "stroke" the length of the spring? Or the overall compression? Or maybe inner diameter?

 

[Punx0r]

The required spring rate to support your load depends in the stroke length (longer stroke = softer spring for the same load). IMO decide roughly what stroke shock you want (going to be dictated by your frame) and then check you can get an appropriate spring for it.

 

[macribs]

Well the shock length will be as close to 230 mm as possible. Eye to eye.
But I have no clue what to look for when getting a coilover spring to the shock. And those spring numbers are just confusing.

 

[Hillhater]

Those spring numbers mean nothing technically.
A spring is rated in lb/ins ( lbs per inch of compression) , free length, and compressed length.
And defined by its OD, ID, number of coils, etc etc.
I guess the " stroke " figure could be the difference between free and compressed length,..but that is only a guess.
You will also need to know what stroke you need on the shock to suit the frame action.

 

[Drunkskunk]

What bike is this going on?

The spring's stroke needs to match the shock's stroke. Also, the inner diameter of the spring needs to match the diameter of the shock body. They aren't all the same. The shock's stroke and length need to be matched to the bike, and the spring rate can only be calculated once you know the travel ratio for the bike's swing arm.

 

[macribs]

It is for a Vector frame.

 

[Drunkskunk]

ok, the longest spring there has a stroke of 2.21" or 56mm. That's a pretty short stroke, and would be about right for a short shock like a 7"/180mm. If you want a ~230mm shock, which does seem like a good size for the Vector, you'll need a different spring.

I think DNM makes a 230 or 240mm shock with a 900lbs spring option.

 

[motomech]

You might want to look for a new/used Fox air spring shock.
Both of mine work great for me and I weight 250 plus.
Even on my 13 year old Rocky Mountain, which offers little in a progressive linkage, the Float R has a supple ride and never bottoms out.
I did add Fox's Air Volume Tuning kit which stiffens up the last half of travel.
The rebuild kits are less than $20 and I only have to add air once a month or so.

 

[macribs]

Thx. I little hard to navigate to the correct Fox shock. There is Fox Float, Fox Float R, Fox Float RP, Fox float X, Fox Float X CTD and finally Fox Evolution Float CTD LV high Volume.

Not sure which to get and what sets them apart

 

[motomech]

Well, I think I can shorten the list.
About halfway thru the model line-up, rebound adjustment is added.
But, I don't even mess with the compression adjustment except to move it a little off the lowest setting.
The thing is, these mountain bike set-ups are so well thought out and the quality of componets is so high for the intended extreem usage, that even the lower-end stuff is plenty good enough for street riding.
I would look for a model bike that uses a linkage simlular to yours, with about the same travel, and see what Fox shock it uses.
Bikepedia is good for that.
The only other thing I might do once you find a model, is search it with the key words "Heavy'' and 'heavyweight" injected in.

Also, take a look a the Fox air spring tuning kit, they aren't so rude to say it, but these are for heavy riders.

 

[Punx0r]

Is the frame not designed for a specific length of shock?

 

[macribs]

It seems most other vector owners uses a shock-length of 240mm or so. Turning the top mounting upside down can add or subtract about 15mm. This bike has a rather uncomplicated swing arm and no linkage to add extra travel. You get as much travel as the shock allow. I will look over the Vector thread to find the recommended shock length. IIRC it is 240mm. Yesterday I could not find any Fox Float in that length, the longest Float I saw was 8.5" or 215mm - but I will search again, maybe I screwed up with the metric conversion :lol: :lol: The fox float evolution LV seems to have a larger air chamber. Is that the same thing as the kit you bought maybe?

Btw there is a Australian site, clickbike.com.au - anyone familiar with that site? Is it trustworthy?
They have great prices on brand new layowers. Both air shocks and coilovers. The coil/spring is not included. They also have Fox 900lb springs - but no sizing in length........think one of these shock might work well? From what I read on various forums it seems manitou has longer between service. And that will be a plus.

http://www.clickbike.com.au/#!product/prd1/1860161825/manitou-coil-shocks-(priced-from)

http://www.clickbike.com.au/#!product/prd1/1863726075/manitou-air-shocks-(priced-from)

 

[ozman]

Maybe you and i need the duel shock swing arm
I am 110kg
I think vector recommend a shock length of 190mm - 240mm depending on how tall you are

 

[motomech]

Not your avg. ebike.
Looks more motorcycle to me.
I think KTM offered a line of dirt bikes that used that set-up, no linkage.
Have you thought about contacting the suspension manufacturers directly and supplying them all the data and see what they say?

 

[macribs]

I know DNM has a 200$ shock/coilover that works well for this frame/swing arm. But I can't seem to find spring above 650lbs.
So I am worried that will not work.

I hope that klickbike site will answer my email soon. Maybe I will be wiser then. I asked them if they had had any FOX springs that would work for the manitou shock.

 

[Punx0r]

Yeah, you won't find an airshock (Fox or otherwise) that long. 240mm shock is going to be 3.25" stroke. Plenty of coil spring shocks in that length, though.

I'd be surprised if you needed a 900lb spring with 3.25" stroke. Check the suspension calculator again IMO.