Coil Shock for Focus JAM2 (Gen1 - Shimano)

steve_sordy

Wedding Crasher
Nov 5, 2018
8,361
8,587
Lincolnshire, UK
I have never ridden a bike with a coil shock, but I would expect a coil shock on the Focus Jam2 to have the same advantages/disadvantages as if you fitted it to a Focus Jam, or indeed any other similar travel/type of bike. :)
 
  • Like
Reactions: Gio

sputnik275wce

Member
Patreon
Feb 23, 2019
24
18
Switzerland
I have never ridden a bike with a coil shock, but I would expect a coil shock on the Focus Jam2 to have the same advantages/disadvantages as if you fitted it to a Focus Jam, or indeed any other similar travel/type of bike. :)
Thanks for the answer! Unfortunately its not that simple. It depends on how much the bike is build for linear or progressive damping. ?
 

Eckythump

Well-known member
Founding Member
Jan 16, 2018
832
680
North Yorkshire
Not sure how it will work on a Jam2 with the suspension design initially being digressive to the sag point then progressive for the rest of the travel. Might be a bit mushy until it ramps up.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,361
8,587
Lincolnshire, UK
Thanks for the answer! Unfortunately its not that simple. It depends on how much the bike is build for linear or progressive damping. ?

A very good point! As I said, I've never ridden a coil shock. With the Focus Jam2, I find that I am going through the shock travel much more than I would expect when compared to the fork travel. On my last three clockwork bikes I have had an imbalance of that sort between fork and shock. Sometimes it was the fork that was not progressive enough, sometimes the shock. Either were easily fixed by the use of spacers to alter the volume of the air spring. But with the Focus, I'm taking my time before doing anything to the shock. On almost every ride I'm finding the stanchion "O" ring right at the end of the travel. But so far I haven't felt any bangs or any other bottoming out symptoms. What I do believe is that because the shock is sitting into its travel a lot more than the fork, the bike orientation makes steep climbing harder and occasionally impossible. Making the shock more progressive and therefore more supportive would solve that problem.

Focus say this:
"The linkage is designed to give a digressive rate until the sag point at 30%; then the stroke becomes progressive until the end of the travel. This is said to give sensitivity at the beginning of the stroke to gain grip, and then ramp up to provide support during the mid-stroke, as well as to prevent bottoming-out on bigger hits."

I don't experience the "ramp up to provide support during the mid-stroke" but I do notice the "prevent bottoming-out on bigger hits."
 

R120

Moderator
Subscriber
Apr 13, 2018
7,819
9,185
Surrey
Olly Wilkins has a coil on his analog Sam, saw him riding it at Peaslake last week. He is sponsored by X-Fusion, so may be one of these? Or more likely a prototype:

VECTOR HLR

MRP Hazzard is available with progressive springs, and is designed for bikes where a linear coil would not be ideal.

Hazzard
 

R120

Moderator
Subscriber
Apr 13, 2018
7,819
9,185
Surrey
Heres is OW's bike

Screenshot 2019-03-27 at 16.58.54.png
 

sputnik275wce

Member
Patreon
Feb 23, 2019
24
18
Switzerland
A very good point! As I said, I've never ridden a coil shock. With the Focus Jam2, I find that I am going through the shock travel much more than I would expect when compared to the fork travel. On my last three clockwork bikes I have had an imbalance of that sort between fork and shock. Sometimes it was the fork that was not progressive enough, sometimes the shock. Either were easily fixed by the use of spacers to alter the volume of the air spring. But with the Focus, I'm taking my time before doing anything to the shock. On almost every ride I'm finding the stanchion "O" ring right at the end of the travel. But so far I haven't felt any bangs or any other bottoming out symptoms. What I do believe is that because the shock is sitting into its travel a lot more than the fork, the bike orientation makes steep climbing harder and occasionally impossible. Making the shock more progressive and therefore more supportive would solve that problem.

Focus say this:
"The linkage is designed to give a digressive rate until the sag point at 30%; then the stroke becomes progressive until the end of the travel. This is said to give sensitivity at the beginning of the stroke to gain grip, and then ramp up to provide support during the mid-stroke, as well as to prevent bottoming-out on bigger hits."

I don't experience the "ramp up to provide support during the mid-stroke" but I do notice the "prevent bottoming-out on bigger hits."

A very good point! As I said, I've never ridden a coil shock. With the Focus Jam2, I find that I am going through the shock travel much more than I would expect when compared to the fork travel. On my last three clockwork bikes I have had an imbalance of that sort between fork and shock. Sometimes it was the fork that was not progressive enough, sometimes the shock. Either were easily fixed by the use of spacers to alter the volume of the air spring. But with the Focus, I'm taking my time before doing anything to the shock. On almost every ride I'm finding the stanchion "O" ring right at the end of the travel. But so far I haven't felt any bangs or any other bottoming out symptoms. What I do believe is that because the shock is sitting into its travel a lot more than the fork, the bike orientation makes steep climbing harder and occasionally impossible. Making the shock more progressive and therefore more supportive would solve that problem.

Focus say this:
"The linkage is designed to give a digressive rate until the sag point at 30%; then the stroke becomes progressive until the end of the travel. This is said to give sensitivity at the beginning of the stroke to gain grip, and then ramp up to provide support during the mid-stroke, as well as to prevent bottoming-out on bigger hits."

I don't experience the "ramp up to provide support during the mid-stroke" but I do notice the "prevent bottoming-out on bigger hits."
My ring is always completly at the bottom of the stanchion. I also put some more psi into the damper. It got poppier but the ring is still all the way down.
 

sputnik275wce

Member
Patreon
Feb 23, 2019
24
18
Switzerland
Olly Wilkins has a coil on his analog Sam, saw him riding it at Peaslake last week. He is sponsored by X-Fusion, so may be one of these? Or more likely a prototype:

VECTOR HLR

MRP Hazzard is available with progressive springs, and is designed for bikes where a linear coil would not be ideal.

Hazzard
Thanks! I will have a look at the mrp hazzard??
 

Eckythump

Well-known member
Founding Member
Jan 16, 2018
832
680
North Yorkshire
My ring is always completly at the bottom of the stanchion. I also put some more psi into the damper. It got poppier but the ring is still all the way down.
Have you added any volume tokens? I put in 2 of a possible 3 to get it how I wanted. A lot cheaper than a new shock.
 

Keisari66

Member
May 1, 2019
57
28
Finland
Decided to get the dbcoil inline. Now I don’t know what the eyelet size should be, there’s open eye 15mm too but I don’t think that’s what I need. The size is 210/55 with 25x8mm hardware right?
 

sputnik275wce

Member
Patreon
Feb 23, 2019
24
18
Switzerland
Decided to get the dbcoil inline. Now I don’t know what the eyelet size should be, there’s open eye 15mm too but I don’t think that’s what I need. The size is 210/55 with 25x8mm hardware right?

You should ask Focus directly, they always gave me satisfying answers...
 

Keisari66

Member
May 1, 2019
57
28
Finland
Bumped into a problem :| Cane Creek DBinline coil with valt 2.25” spring and after install it’s touching the frame... what’s the next step?

C327D512-D54D-45F4-BBBF-7DD421F758AF.jpeg


BA03EDAA-1233-4427-8C93-5D7D96830A17.jpeg
 

khorn

E*POWAH Elite World Champion
Patreon
Jul 19, 2018
980
1,054
Denmark
Actually when it gets compressed it moves further away from the frame.
Agree with regards to the leverage factor, however when you compress a spring it will expand a bit sideways and/or even go into a slight arc.

That setup will rub the frame for sure but it’s your bike and it’s a free world so do whatever you like ;)

Karsten
 
  • Like
Reactions: S D

EMTB Forums

Since 2018

The World's largest electric mountain bike community.

518K
Messages
25,443
Members
Join Our Community

Latest articles


Top