Suspension Question

[bark]

Hi,

So, I've been 'finally' riding my Sherco on the weekend. Its a 2006 Sherco 2.9. I bought it used a couple months back and have finally had a chance to ride it yesterday. I rode it in the back (paved) alley just trying out the whole slow turns & balance thing. It was allot of fun. Let the learning begin.

Question... when the front wheel is unloaded, it seems kinda 'clicky' as tho the steering stem is loose but I don't think the stem is loose. It feels like at the bottom of the stroke that the suspension enters a different zone. I noticed it first when trying to pull the wheel off the ground. It felt like something snapped. But, then when just trying to pull the front end with the brake on, its like something shifts. Its really odd. You can actually see the front wheel take a shock load when it happens, it quite repeatable.

The rear suspension also seems to have a distinct difference in stiffness when pushing on the 'seat' when standing next to it. Its super easy to push then just hits a much, much stiffer portion of the stroke. Again, I don't think its a problem, just looking for understanding.

I'm used to enduro bikes where things are much stiffer and there are no discontinuities. I don't think these are problems but, at the same time, I'd like to understand them. I think the bike is bone stock. Its basically mint having been ridden by a relaxed, beginner rider. There's no scratches are anything on the bike anywhere.

Thanks,

Bark

[copemech]

Hi,

So, I've been 'finally' riding my Sherco on the weekend. Its a 2006 Sherco 2.9. I bought it used a couple months back and have finally had a chance to ride it yesterday. I rode it in the back (paved) alley just trying out the whole slow turns & balance thing. It was allot of fun. Let the learning begin.

Question... when the front wheel is unloaded, it seems kinda 'clicky' as tho the steering stem is loose but I don't think the stem is loose. It feels like at the bottom of the stroke that the suspension enters a different zone. I noticed it first when trying to pull the wheel off the ground. It felt like something snapped. But, then when just trying to pull the front end with the brake on, its like something shifts. Its really odd. You can actually see the front wheel take a shock load when it happens, it quite repeatable.

The rear suspension also seems to have a distinct difference in stiffness when pushing on the 'seat' when standing next to it. Its super easy to push then just hits a much, much stiffer portion of the stroke. Again, I don't think its a problem, just looking for understanding.

I'm used to enduro bikes where things are much stiffer and there are no discontinuities. I don't think these are problems but, at the same time, I'd like to understand them. I think the bike is bone stock. Its basically mint having been ridden by a relaxed, beginner rider. There's no scratches are anything on the bike anywhere.

Thanks,

Bark

I think you may be referring to the slack motion in the floating front disc. There are inserts under the retaining bolts that allow some clearance and movement. This is normal.

Of course the rear linkage is progressive, and I normally find that the rear spring set to no more than an inch of static sag(weight of bike only) is about right. It should float lightly within 0-1 range unless you are heavier, then you might kick it up a bit less.

The rear linkage should be cleaned and overpacked with waterproof grease on a regular basis and any questionable parts replaced. At best, the normal clearances in the linkage will translate into a bit of freeplay at the end of swingarm when unloaded.

Hope that helps,

[micm]

Cope, why do you set the back suspension with an inch of static sag. Does this mean when the bike is stationary with no rider that you could lift the back of the bike up by an inch on its suspension. The 0-1 range you mention that is the 'floating' inch? Why have any sag in a bike at rest with no rider - excuse my ignorance!

[bark]

Thanks I'll check those things out. I'm pretty sure that there is presently more than 1" of static sag.

Thanks,

Bark

[copemech]

Cope, why do you set the back suspension with an inch of static sag. Does this mean when the bike is stationary with no rider that you could lift the back of the bike up by an inch on its suspension. The 0-1 range you mention that is the 'floating' inch? Why have any sag in a bike at rest with no rider - excuse my ignorance!

Well, all I can say in brief is that there are lots of suspension dynamics involved, and more is not always better! Jacking up a spring too much reduces its sensitvity and reaction under acceleration when traction is needed most, may reduce the ability to fully compress it to gain rebound off the jounce rubber when you need it and soo fourth. Then too much can also become a pogo stick!

Seems all bikes have a certain amount of static sag and a MX bike can be a good example as they are really long in the throw! They may have 2-3 inches of sag off the start, which just floats over things as it all works over the whoops and yet traction unbroken because they don't "top out" easily and work within their range.

As my basic understang is that the factory springs on most all modern trials bikes are set for the "average" 150-175 lb rider, I do know a few riders that could do with a heavier spring, yet few bother with it. Even if done, the baseline would not really change.

[nzralphy]

Always set front & back suspension to 1/3 sag when in the normal riding position. Check it often as springs go slack.

As said above.... there should also be a 6-12mm sag without a rider - if there isn't you should get a stronger/weaker spring to suit your weight.