2010 Evo - Some Suspension Questions

[jml]

Hey all,

Short version: How often would you recommend replacing the front fork spring in these forks?

Long version: After 10 hours of riding I'm starting to pick out certain things I know feel kind of wrong. My first find was definitely the rear suspension. I'm currently overweight (100 kg, looking at getting down to ~80 kg) and this is way too much for the rear spring to handle. With nearly maximum preload the bike is still settling into around 97mm of race sag and out of spec with static sag, which from what I've read tells me the spring needs to be replaced with something stiffer, the rear is just too sloppy and gives me little spring/support for basic log hops.

While I'm investing in the rear I thought I might fix the front up, how often do people recommend replacing the front fork spring? The aftermarket springs seem to be stiffer (>95kg) riders, so I might invest in the stock spring as this is my target weight.

Regards,

[dan williams]

Unless your bike is stored with the suspension fully compressed your stock springs should last for many years. A 2010 is not likely to be a candidate for new springs. Having said that I have put the stiffer front and rear in my 2013 because I am also a Clydesdale at 100kg. I'm sure, unlike myself, you are all muscle. I got the springs from Saunders Extreme. Yes I also cranked up the preload first time with the new springs. The suspension compressed what looked like the proper amount standing on the pegs in the parking lot. Once I got in the woods the bike was unridable.

Is this your first trials bike? I'm not asking that to be a jerk. It's just not uncommon for new trials riders to be very uncomfortable with how soft a properly working trials suspension is. Most of the experianced guys will talk about how the suspension tracks over rocky turns or whether it sticks on steps or how the front to rear balance affects ability to hold a line. I never hear them talk about sag.

If you're having trouble getting lift over an obstacle it usually has more to do with throttle control. The typical error is to keep the throttle on which keeps the rear suspension compressed causing it to pound the rear into the obstacle. If you watch a good rider ride over a log their throttle is essentially off when the rear wheel makes contact.you will also notice the rear suspension is uncompressed. With full preload on even the stock springs your suspension won't track small bumps at all and that will seriously affect your ability to find traction in the slick.

[dan williams]

Oh yeah, forgot to mention backing off the preload made the new springs work fine. In fact the reason for using heavier springs is so you can use less preload but that's a whole long theoretical discussion I don't care to type into a phone.

[jml]

Thanks for the reply Dan

Part 1: The suspension compressed what looked like the proper amount standing on the pegs in the parking lot. Once I got in the woods the bike was unridable.

Part 2: Is this your first trials bike?

Part 3: If you're having trouble getting lift over an obstacle it usually has more to do with throttle control.

So a 3 part response;

Part 1: I've noticed when I'm on my bike and others, the rear squats really low (this is a picture of me on a Scorpa 125). On my Beta the rear mud guard is even closer, the bike looks like a chopper! I understand that the bike is suppose to be soft, but if most of the suspension travel is taken up by my weight there isn't going to be much for soaking up the bumps right?

Part 2: Yes this is my first trials bike, But i've also ridden a Scorpa 125 and GasGas 270 for half a day. The 270 If I recall wasn't too bad as it might have been setup for a slightly heavier and more experience rider.

Part 3: I'll try and be more mindful of that next time I'm out on the bike.

Edited August 5, 2014 by jml

[feetupfun]

The photo of you on the Scorpa is showing rear suspension that looks pretty well spot-on for sag.

In trials, having only a small amount of "bump" travel when you are riding flat ground is irrelevant to how it works in the section, because you should be unweighting before hitting things. I would worry a lot less about static sag with you aboard. I'm about that same weight too and find the standard springs on all the modern bikes I have ridden to function perfectly for me.

If the rear is going down too far on the Beta and other bikes with the standard suspension settings, maybe you are not positioning your body correctly. There should be no forces acting on your arms when you are standing up and the bike is at equilibrium

[vonhazza]

I had a problem with my 09 Beta rear spring but have since replaced with a Heavy Duty one, I am about 125kg and it works well for me, the front forks I have only played with the spring tention and dampning ajustment and that feels fine as well.

Cheers Steve,

Edited August 5, 2014 by vonhazza

[dadof2]

Easiest way to stiffen the forks a little is put a little more oil in, ie reduce the air volume.

I once went up a few Kgs per mm on rear spring stiffness on an MX bike because I was a bit on the heavy side and could not set the sag according to book. Bike was a pig to ride, far better when i went back to standard spring and had shock revalved by pro circuit.

[heffergm]

I'm a recent trials convert as well. If you're used to riding Enduro bikes like I have been, toss out all the suspension tuning know how that went with them. Basically, it's all about weighting on a trials bike. Body position and using your legs to absorb hits. At first I thought the suspension was awful; I think I referred to it as a wet noodle. But basically I just stink. You'll get the hang of it, leave the suspension alone.

[jml]

Most of my calculations have been based on what was recommended in the "Learning Trials" DVD by Jordi Pascuet. It recommends the following:

Total extension - Rider on Bike = Race Sag
Total extension - Bike freestanding weight = Static Sag

Recommended values:

Front Forks: Rider on the Bike = 5-6cm sag (Static sag Range=1-1.5cm)

Rear Suspension: Rider on the Bike = [Min]6cm, [Max]8cm sag (Static sag Range=1-2.0cm)

My Numbers:

Front Forks: Race sag: 7cm (cannot add anymore preload) & Static sag: 1cm

Rear Shock: Race sag: 10cm (cannot add anymore preload) & Static sag 1cm

[lineaway]

You should take the fork apart and make sure you do not have a broken spring. I have not heard of any on the Evo, but it is not that rare on a trials bike. And springs do wear out. The old gassers would totally sack out in a year of riding with two springs when most of the bikes were running one. Also you are chasing numbers that mean little for most trials riders. Yes, you are on the heavy side. But it is more important that the suspension works together front and rear than anything else.

[dan williams]

Heh heh this is like mixing a band. Newbies will say, "I can't get the ------ loud enough." When you tell them to turn down the other instruments they just look at you like you're an idiot. It sounds to me like having your forks at full preload is making the chassis do odd things in regards to head angle and loading. Remember if one suspension isn't compressing the other will compress much further as the inertia of the frame tries to rotate around the axle of the wheel with the non compliant suspension. You should be bottoming out the front and rear occasionally, a couple times each loop and even if you're riding bunny sections you should bottom out on the loop trail if you're going at a good clip.. If you're not then you're not using all the travel you should. Too stiff forks will force the rear to compress more on hits and effectively increase the trail of the frame. that can lead to some very weird handling during transitions from one camber to another. Another thing that is common to a new rider is to have their bars too far back to slow the steering down or too far forward thinking it will hold the front end down on climbs. This is a largely personal preference setting but it is important because it affects your entire perception of the bike. Having the bars too far forward will cause you to compensate by sticking your can far back which works against you in a climb. Having them too far back causes you to stand up a bit too straight rolling your hips forward and messing up your ability apply force to the bars and pegs to control the bike. It takes some time to figure out the right position. When you ride with other more experienced riders look at their bikes and see how they are set up for your area. See if you can snag a putt on a few and get to feel how a suspension should work rather than go by just look. See if you can get a good trials tuner to work with you to get your bike set up. Just note that the best riders are not always the best wrench operators. Some of these guys can ride a trashcan through a section and still look like they're on a factory bike.

It's a learning process. It takes time so don't stress over it. Even after almost 30 years of doing this it still takes me about 3 months to where I feel properly adjusted to a new bike. And yes the phrasing is intentional as I have to settle into the bike as it is adjusted to my liking.