Suspension Upgrade

Life Cycle

If wheels are your legs, then suspension is your joints. Anyone with bad knees or hips will tell you how important healthy joint function is. If you want to make the single-most significant upgrade to your bike, consider looking at the suspension. An upgrade is not cheap, but it’s often well worth the investment.

In my review of the f650GS, I reserved glowing praise for its suspension. It’s good for street riding, but not for much more, and not even for Montreal streets. Since I’ve been doing adventure riding that takes me off-road, I’ve noticed its limitations. I’d often bottom out and bash the skidplate or engine guard, the kickstand, the centre-stand. The underside of the bike was taking a beating. I also found the front to brake-dive on the street and jumping rather than riding over large rocks on the trail. Knowing new suspension is much cheaper than a new bike, I recently decided to upgrade the front and rear suspension.

Front Suspension

Iniminators

Ricor Intiminator Valves

The front suspension on this bike is traditional (i.e. non-inverted) damper rod forks. There’s no adjustment other than changing the weight of the oil, and I’d tried thinner and heavier oils and was underwhelmed with both. Still, if you’re looking for a cheap mod, try a heavier oil. (Stock is 10W.) I guess you could also try playing around with preload by creating new spacers, but preload wasn’t the issue with the front end for me. (I’m only 145 lbs./65 kg.)

The other option is to change the springs to either a heavier spring or a progressive spring. Someone I know who installed progressive springs was also underwhelmed with the results and is now looking into other options. I think progressive springs are a bit like handlebar risers: modifications made popular by word-of-mouth and DIY ease than by the results. (After listening to GS instructors and Chris Birch, I decided to take my risers off.)

From what I’d read, the only way to improve the front significantly on this bike is to change to a valve system using either Race Tech Emulators or Ricor Intiminators. These valves essentially replace the damping rods, converting the suspension to something akin to cartridges. I say akin, because unlike cartridges, there isn’t any compression adjustment at the triple-T. Still, I was hoping to alleviate some of the brake dive and firm up the front end over potholes and rocks.

I decided to go with the Ricor Intiminators, mainly for the ease of installation. From what I’ve read, the technology is very similar. Ricor were unfortunately undergoing some restructuring and I had to wait months for my order to arrive, but it finally did last fall. (The company now has a new owner and is shipping again.) Installation was as easy as draining the oil, opening the forks, pulling out the springs, dropping the valves in, and replacing everything. Ricor suggest 5W oil, and strongly suggest Amsoil 5W oil. Little did I know that not all 5W oils have the same viscosity. Unfortunately, Amsoil is not easy to obtain in Canada, so I went with Bel-Ray.

Intiminator Instructions

At first, I was again underwhelmed. Ricor claims that the Intiminators can determine the difference between chassis movement (i.e. brake dive) and wheel movement (i.e. bumps and holes in the road). I imagine the former is much slower than the latter, so it seems possible from an engineering standpoint, but I still had some dive. To be fair, it might have had something to do with my braking. I basically went out on the street and hit the front brake a few times. Proper braking involves shifting your weight backwards and coordinating with the rear brake to get the bike to squat. I’ve since come to notice a difference in braking and an improvement in, if not the elimination of, brake dive.

But that is not the main reason for the upgrade. Once I got the bike up onto dirt roads, I noticed a huge difference in its handling. For once, I was taking corners in the dirt at speed, weighting the outside peg with the front end feeling planted. It’s almost like the valves work better at speed. I wonder also if the oil gets thinner as it heats, which is why Ricor suggests the thinner Amsoil. I decided from this one ride that it was time to buy a neck brace since I was now not poking along on dirt in 2nd gear.

Rear Suspension

OEMRearShock

OEM rear shock

My stock rear shock had over 92K on it and had never been serviced! You can’t service the OEM shock on this bike easily. That’s because there isn’t a valve to re-pressurize it. I found someone who could tap a valve, but that plus regular service would be $450. I also needed a stiffer spring since, with all my gear, I’m under recommended SAG by about 2 centimetres, even with the preload fully wound. A new spring is $230. All totalled, I was up close to the price of a new shock, and one that is much better.

740HR1

Stadium Suspensions HR1

I decided to go with Stadium Suspensions, a local manufacturer in Quebec that specializes in off-road suspensions. Going with a service instead of mail-order from one of the big manufacturers meant I could get the shock custom built. Thierry at Stadium was super helpful. He asked for me to weigh my gear, which I found was 70 lbs.! I guess that’s a lot compared to the minimalists, but that included one pannier full mostly of food and another with cooking gear, since that’s how I tour. A third large wet-dry duffle on the back and all my riding gear meant a lot of preload. One nice feature of Stadium is that they were able to incorporate my OEM preload adjuster into the new shock, which is a nice touch. No messing around under the bike with a wrench!

I went with their mid-level shock, the 740HR1. The big advantage of the HR1 over their base model (and my OEM) is the remote reservoir for the nitrogen gas. In a conventional shock with oil and nitrogen in the same compartment, when the shock is working hard all day, such as with off-roading, the oil can heat up to the point where it starts to mix with the gas and froths, creating compression fade. And because my bike shares the same frame with the Dakar version, which has a remote reservoir, there was already a cradle on my frame for easy installation.

20200624_183239

Reservoir with compression adjustment knob and, just above, the OEM preload adjuster knob.

Yes, I have to loosen those ring clamps to change my oil filter, but that’s the price I will pay every 7,000 kilometres. It’s actually a pretty neat set-up. Tierry at Stadium had owned a 650GS so already had the designs for this shock on file.

Dialling In

I had three adjustments with this shock: preload, rebound, and compression.

Preload: There are a ton of videos online on how to set rider sag. Basically, you want to unweight the rear (using a centre-stand or pulling the bike onto its sidestand) and measure from the axle up to a fixed point. Then sit on the bike with your feet on the pegs (you might need to balance against a wall or, as I did, a fence) and measure again. Don’t forget to wear all your gear. The difference between your first and second measurement should be about 1/3 of the stroke. My bike has a 165mm stroke, so I was aiming for about 55mm. Stadium had chosen the perfect spring rate and it was exactly on the mark. Nice!

I generally leave the preload at Base unless my wife decides to come for a ride. I haven’t toured with the new shock, but I’ll be setting SAG again with all gear loaded before I head off.

Rebound & Compression: The way Stadium explain it, rebound is how easy or hard it is for the shock to extend; compression is how easy or hard it is for the shock to—duh!—compress. To my surprise, when I started playing around with these settings, I found rebound more significant.

20200624_183333

Rebound damping adjustment on Stadium’s shocks. CW=faster; CCW=slower

Crank up the compression setting on the remote reservoir and you feel the bumps, for sure, but crank up the rebound to its hardest setting and you feel like you have no suspension. Perhaps that’s why Stadium suggests starting with the softest setting and adjusting upwards to preference. I found that at the easiest setting, the bike was bouncy. For Montreal roads and off-roading (pretty much one and the same), I’ve landed somewhere in the mid-range.

For compression, that’s a little easier. I keep it in the mid-range except for when I go off-roading. Then I make it harder (to compress), which saves some damage to my stands and engine guard and prevents the shock from bottoming.

I still had some adjustment to do on the front too. I found the shocks still a bit stiff for rocky terrain, so I mail-ordered some Amsoil 5W oil, and based on this advice from suspension guru Dave Moss, I measured using height rather than volume. I also put a little less oil in to, as he says, ease up the middle part of the stroke to adjust for my weight. Recommended height is 120mm and I went with 130. I’ve only done one day of off-roading with this set-up but the front end is getting better and better. I might try even less oil next oil change.

The season is young and there is plenty of off-roading still to come. In the weeks and months ahead, I’ll be tweaking the suspension more, including tire pressure, which is another important setting. Do I adjust every time I go off-road or, as Jimmy Lewis does, just keep it at 28 psi for road and dirt? Of course, no expense or type of suspension can make up for crappy skills, so I’ll be tweaking them too. At least now I have a bike that I feel confident to do some serious dirt riding on.

Have you ever played around with your suspension settings? Do you know what your recommended rider SAG is? If not, the RaceTech database has the info you need. Just use the Product Search feature; you’ll be surprised at how much comes up! Before you upgrade, just make sure you are getting the most out of your current system. Devoting a little time to this will result in many hours of more enjoyable and safer riding.

Scotch_BW_web

photo credit: Ray Bourgeois

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