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Posted

Merits of coil on a bike that can take it. IE linear or progressive curve. 

 

HC - which bike?

Not clued up at all , does that mean the leaverage ratio os 1:1 ?

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Posted (edited)

Not clued up at all , does that mean the leaverage ratio os 1:1 ?

no. It means that the way the suspension is designed results in the shock being harder to compress as it moves through the travel (progressive) or the rate at which it moves through the travel remains the same (linear)

 

A regressive curve (force required to compress the shock at the end of the stroke regresses / decreases) is designed specifically for air shocks, as they ramp up by themselves due to (I think) Boyle's law. 

 

In numbers, on a bike with a coil shock with 500lb spring (spring requires 500lb per inch of travel)

 

Linear Suspension curve

 

1 in travel = 500lb

2 in = 1,000lb

3 in = 1,500lb

 

The travel is directly linear, as each inch requires an extra 500lb of force.

 

Progressive Suspension curve:

 

1 in travel = 500lb

2 in = 1,050lb

3 in = 1,600lb 

 

The force required to compress the suspension progresses / increases as you go through the travel

 

Regressive Suspension curve:

 

1 in travel = 500lb

2 in travel = 975lb

3 in travel = 1,400lb

 

The force required to compress the suspension regresses as you go through the travel

 

That's why coils don't really work well with regressive suspension curves - the compression rate of a coil is static at 500lb/inch, but depending on the design of the suspension, the resultant force needed to compress the shock may increase / decrease / do both.  

 

An air shock, however, has a progressive spring rate by its very nature, as the shock gets more difficult to compress as you go through the travel. If you're running it at a pressure that mirrors a coil shock's 500lb rating (ie you get the same amount of sag between the air & coil setups) you'll have the following result. 

 

Linear Suspension curve:

 

1 in travel = 500lb

2 in travel = 1,050lb

3 in travel = 1,600lb

 

Because the force you need to exert to compress the shock increases as you go through the travel, a linear spring rate with an air shock becomes progressive in nature as you move through the travel. This gives an element of "bottom out" protection. 

 

Progressive Suspension curve:

 

1 in travel = 500lb

2 in travel = 1,100lb

3 in travel = 1,750lb

 

With a progressive suspension curve AND an air shock, there's an even larger rate of bottom out resistance on a bike. This is where YT and quite a few others are, with YT having the most progressive suspension curve on the market, last I heard (read quite a few sources on this)

 

Regressive Suspension curve:

 

1 in travel = 500lb

2 in travel = 1,000lb

3 in travel = 1,500lb

 

With a regressive Suspension curve and an air shock, the bike's suspension curve is rendered linear in nature as the reduced force requirement of the suspension design is offset by the increased force requirement of the air shock. This is also why you can get a "linear feeling" air sprung bike. 

 

All the above is very simplistic, as hardly any bikes are purely linear or purely progressive or purely regressive, but there is one constant - a coil shock will not work nicely with a regressive suspension design. But they will work for bikes with a linear or progressive suspension design. 

 

Then there's volume reducing bands to consider as well, in addition to negative air chambers and different size air cans. Which make an air shock perform more / less progressively. Generally speaking, the smaller the air volume the more progressive it will be (which is why large volume air cans aren't good for fat bastards unless the suspension curve is really progressive in nature. 

Edited by Myles Mayhew
Posted

Not clued up at all , does that mean the leaverage ratio os 1:1 ?

 

No. Its just the how the suspension is able to progress along its stroke.

When an air shock compresses it becomes increasingly difficult for the shock to reach the end of its stroke because of pressure build up. So its compression curve is more progressive while a coil shock is more linear. 

 

So an air shock moving from its initial to mid stroke feels 'softer' than when it moves from its mid to end stroke. While a coil shocks progression through its entire stroke feels more predictable. Of course there are all sorts of nifty little tech solutions to help deal with this like spez's brain and MRP ramp control. 

 

That's just my basic understanding of how it works. I'm sure those more clued up could rectify me

Posted

Thank you Sir.

 

I kinda just wnated to kn9w why certain bikes aren't ideal for coil , the rest I knew (Well I feel like I now know it even better, if that makes sense)

 

no. It means that the way the suspension is designed results in the shock being harder to compress as it moves through the travel (progressive) or the rate at which it moves through the travel remains the same (linear)

 

A regressive curve (force required to compress the shock at the end of the stroke regresses / decreases) is designed specifically for air shocks, as they ramp up by themselves due to (I think) Boyle's law. 

 

In numbers, on a bike with a coil shock with 500lb spring (spring requires 500lb per inch of travel)

 

Linear Suspension curve

 

1 in travel = 500lb

2 in = 1,000lb

3 in = 1,500lb

 

The travel is directly linear, as each inch requires an extra 500lb of force.

 

Progressive Suspension curve:

 

1 in travel = 500lb

2 in = 1,050lb

3 in = 1,600lb 

 

The force required to compress the suspension progresses / increases as you go through the travel

 

Regressive Suspension curve:

 

1 in travel = 500lb

2 in travel = 975lb

3 in travel = 1,400lb

 

The force required to compress the suspension regresses as you go through the travel

 

That's why coils don't really work well with regressive suspension curves - the compression rate of a coil is static at 500lb/inch, but depending on the design of the suspension, the resultant force needed to compress the shock may increase / decrease / do both.  

 

An air shock, however, has a progressive spring rate by its very nature, as the shock gets more difficult to compress as you go through the travel. If you're running it at a pressure that mirrors a coil shock's 500lb rating (ie you get the same amount of sag between the air & coil setups) you'll have the following result. 

 

Linear Suspension curve:

 

1 in travel = 500lb

2 in travel = 1,050lb

3 in travel = 1,600lb

 

Because the force you need to exert to compress the shock increases as you go through the travel, a linear spring rate with an air shock becomes progressive in nature as you move through the travel. This gives an element of "bottom out" protection. 

 

Progressive Suspension curve:

 

1 in travel = 500lb

2 in travel = 1,100lb

3 in travel = 1,750lb

 

With a progressive suspension curve AND an air shock, there's an even larger rate of bottom out resistance on a bike. This is where YT and quite a few others are, with YT having the most progressive suspension curve on the market, last I heard (read quite a few sources on this)

 

Regressive Suspension curve:

 

1 in travel = 500lb

2 in travel = 1,000lb

3 in travel = 1,500lb

 

With a regressive Suspension curve and an air shock, the bike's suspension curve is rendered linear in nature as the reduced force requirement of the suspension design is offset by the increased force requirement of the air shock. This is also why you can get a "linear feeling" air sprung bike. 

 

All the above is very simplistic, as hardly any bikes are purely linear or purely progressive or purely regressive, but there is one constant - a coil shock will not work nicely with a regressive suspension design. But they will work for bikes with a linear or progressive suspension design. 

 

Then there's volume reducing bands to consider as well, in addition to negative air chambers and different size air cans. Which make an air shock perform more / less progressively. Generally speaking, the smaller the air volume the more progressive it will be (which is why large volume air cans aren't good for fat bastards unless the suspension curve is really progressive in nature.

 

Posted

After having another (not) awesome off at Hakahana it made me think more about protection.

 

The top two pics are of the mountain lite 2.0, and the bottom pic (showing the front pockets on manequin) are of the enduro lite 2.0. 

 

Mountain lite = 2l hydration and 1l cargo

Enduro lite = 2l hydration and 5l cargo

 

What do you guys think of the mountain lite? Is 1l of cargo space enough, or would you rather go for the enduro lite with 5l of cargo space?

 

Of course in the ideal world one would want both, 1 for shorter days and the other for longer days out. But which one of these would you choose if you could only choose one, and why? By the way, both have built in back protection - which is awesome in my opinion, and they both are stunning packs!

Posted

The top two pics are of the mountain lite 2.0, and the bottom pic (showing the front pockets on manequin) are of the enduro lite 2.0. 

 

Mountain lite = 2l hydration and 1l cargo

Enduro lite = 2l hydration and 5l cargo

 

What do you guys think of the mountain lite? Is 1l of cargo space enough, or would you rather go for the enduro lite with 5l of cargo space?

 

Of course in the ideal world one would want both, 1 for shorter days and the other for longer days out. But which one of these would you choose if you could only choose one, and why? By the way, both have built in back protection - which is awesome in my opinion, and they both are stunning packs!

I have the Enduro pack. most of the features are the same. I would recommend the Enduro as the 5l size is quite misleading. The pack is very sturdy and one have to pack all your equipment very carful.

Posted

The top two pics are of the mountain lite 2.0, and the bottom pic (showing the front pockets on manequin) are of the enduro lite 2.0.

 

Mountain lite = 2l hydration and 1l cargo

Enduro lite = 2l hydration and 5l cargo

 

What do you guys think of the mountain lite? Is 1l of cargo space enough, or would you rather go for the enduro lite with 5l of cargo space?

 

Of course in the ideal world one would want both, 1 for shorter days and the other for longer days out. But which one of these would you choose if you could only choose one, and why? By the way, both have built in back protection - which is awesome in my opinion, and they both are stunning packs!

2nd one without a doubt. 1l space is pitiful. You can always pack less in the 5l. Can't ever pack more in the 1l.

Posted

Just had to order a new lid and found 2016 TLD on clearance at CRC - A1's in all colours from about R950 - R1200...

What's the duties on helmets?
Posted

Just had to order a new lid and found 2016 TLD on clearance at CRC - A1's in all colours from about R950 -  R1200...

 

 

25%+14%+10% all in if I am correct..

 

Almost 2k then, still a good price but I scored one of them super comfy awesome new Leatt DBX 3.0 All Mountain helmets locally for around the same price.

Posted

Almost 2k then, still a good price but I scored one of them super comfy awesome new Leatt DBX 3.0 All Mountain helmets locally for around the same price.

I'm planning on getting on aswell. They look sick.

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