Blog: Honda CB1000R (2018) suspension settings

Confession time, it’s been thirteen years since I last fiddled with a bike’s suspension. That’s because most bikes have a set-up that’s good enough and I’d rather be riding than adjusting. Plus, my riding is less about perfect apexes and measured control as it is about survival and getting away with it.

The last bike to break that pattern was a 2005 Kawasaki ZX-6R. I was booked on a track day but at the last minute I cancelled (why pay a fortune to ride round the same eleven corners over and over again?) and, instead spent a day turning the Kawasaki’s rock hard suspension into something more capable and comfortable.

Thirteen years on and after 700 miles on Honda’s CB1000R there’s a niggle. I love the way this bike goes, steers and, mostly the way it rides too. But the back end is too soft and on a bumpy road I’ve had the rear shock bottom out three times now. I can’t remember the last time that happened on anything, never mind a premium-priced neo disco racer. So, with a day off, sunshine and a need to get this fixed, I’m heading to my favourite suspension testing circuit.

The B1190 from Horncastle to Bardney won’t feature in anyone’s ‘100 greatest biking roads’ feature. It’s not scenic, not that long and is peppered with difficult, sharp, blind, bumpy and downright nasty corners. It’s challenging but not especially fun. From Bardney, out to Baumber and then back to Horncastle is more open and enjoyable, but still bumpy and taxing on motorcycle suspension. A morning on those two will get me a set-up and then an afternoon on the neighbouring B1183 will help with the fine-tuning.

On standard settings the Honda feels ok at the front but very soft at the back. Like the design team spent all their money on the Fireblade-ish forks, so had to fit a budget rear shock to hit, er, budget. Bounce on the seat at some traffic lights and there’s a huge amount of travel with almost no resistance and not a lot of rebound damping either. So it’s somewhat surprising that when you attack some seriously challenging corners with a bit of gusto the CB actually copes really well.

But you can feel it moving about and it does bottom out.  Out with the C-spanner, 10p piece and screwdriver - let’s get going.

Rear preload

A grown-up would do something called ‘measuring sag’ with a tape measure. Sag is the distance a bike drops on its suspension when you sit on it. So, if your suspension has 50mm of travel and your weight uses up 20mm of that when you sit on the bike, then adding 20mm of preload to the spring will allow for that and means there’s much less ‘bounce’ (a technical term) and less chance of it either bottoming or topping out. On most bikes preload is adjusted by a collar on the shock absorber or a knob on a remote adjuster. Adding preload raises the ride height a little but it doesn’t make suspension stiffer (or softer when you reduce it). Some people confuse softness with amount of travel.

The CB1000R’s rear preload is set on position two out of eight. The approved ‘Rosie method’ of adjusting it is to increase the preload and then sit on the bike. When the bike only drops a small amount (another technical term), there’s enough preload. I suspect that Valentino’s technicians use something more complex, but they’ve got all weekend – I have to be home by four.

Adding a couple of clicks makes a big difference and the ride quality is still good. The bumps that bottomed out the shock half an hour ago are felt, but nothing more. Adding a couple more clicks (position six out of eight) means the bike now sits taller at the rear, only sags a tiny bit and is steering a little quicker too.

Front preload.

Unless you sit on the handlebars the front end of a motorcycle rarely drops like the rear. On the Honda it feels roughly ok, moving the same on standard settings as the rear is now moving after tweaking. I adjust it a little anyway because..., oh, just because… The adjuster is unusual, positioned on the right-hand fork leg, needing either the world’s widest screwdriver blade or a 10p piece to twist it. I give it a full turn clockwise (more preload), go for a ride, tow turns anticlockwise (so one back off standard) but it makes little difference either way – possibly because the damping on the forks is much more controlled.

Rear rebound damping.

There are two types of suspension damping; compression and rebound. Compression damping alters the rate at which the spring compresses, while rebound (sometimes called ‘tension’) controls the rate at which the spring extends back.

The Honda only has rebound adjustment at the back and the standard setting is one and a half turns in out of a four and a half turn total. Too little rebound damping means that when you hit a bump and the shock compresses, it springs back quickly like a pogo stick, kicking the rider out of the seat. Increasing the rebound to three turns, adds to the feeling of smooth control from the rear shock. It still soaks up the bumps, but now feels like it responds better and makes the transition from acceleration to braking smoother too as the weight transfer onto the forks extends the rear shock in a more controlled way. 

Rear compression damping

Even with the preload set it still feels like the Honda’s shock compresses slightly too far and too fast. It needs some additional compression damping, but there’s no facility to adjust it. So, when I hit a big bump or accelerate hard it still compresses the shock quickly. I could add more preload, but instead I start to wonder if there’s anything I can do with the front (which has compression and rebound damping adjustment). In theory adding some rebound damping to the front will slow the rate at which the forks extend when I let the brakes off, meaning less force transferred to the rear, which will help stabilise the bike on the way into a bumpy corner. I try it and it works in as much as the bike feels easier to turn and doesn’t want to run wide (although there might be other reasons for this – see next section). This is the weirdness of suspension adjustment – how much of what you feel is in your mind and how much is real?

Front rebound damping

When I brought my ZX-6R here 13 years ago the lightbulb moment was realising that me running wide in tight, blind corners wasn’t all because I’m a useless halfwit with no talent. Going too fast into a blind corner inevitably means holding the brakes on for longer than you should, which means the forks are compressed. Which is good because this sharpens the steering geometry and helps the bike turn faster. But, at the point you release the brakes the front end has a tendency to spring back up, momentarily turning your supersport race replica into a chopper, making it steer very slowly indeed, which is why you run wide in the corner.

There are two solutions; either brake earlier, release earlier and steer through the turn on settled suspension. Or, add some rebound damping to the front so that when you release the brake the forks extend back slowly and smoothly, allowing you to turn in on consistent suspension.

The knack with rebound is to not add too much. Do this and you’ll affect the ride quality because if you hit a series of bumps the forks won’t have had chance to fully extend back from one before you hit the next and that increases the chances of bottoming out and that is a very bad thing for forks to do.

The CB’s forks have nine and a half turns of rebound adjustment. I start off at four and finish with six and a half – slightly more than needed because I’m trying to add compression to the rear.

Front compression damping.

On a racetrack this is especially important because it controls the transition from acceleration to heavy braking. On the road it’s less so because none of us really brake that hard unless it’s an emergency. Compression damping on the road is more about ride quality – controlling the feel over bumps. As an experiment I try full compression, followed by zero compression. The bike’s steering and feel in corners is different, but both settings are ok. The biggest difference is in the way the Honda holds the road. On zero compression it soaks up the bumps better, but feels a little vague and imprecise in fast bends (high speed, not that much lean or transition between braking and acceleration) and a lot more ‘exciting’ (as in involving, feeling more like a sports bike, but not actually going any quicker) in the slow corners because the front dives more sharply and quickens the steering. On full compression, the Honda steers more accurately and wanders less but the ride quality is much more harsh. In the end I admit I don’t really care about the front compression and set it halfway. Somewhere in Honda’s suspension development dept a man in a white coat is crying.

At the end of a long day…

The settings I ended up with will almost certainly not be the right settings for you, or you or you at the back. We all ride slightly differently, all prefer different feedback and all prefer suspension to do different things. Even at the very highest levels of Moto GP, two riders on the same bike will use completely different settings to lap a fraction of a second apart. Put one team mate on the other’s bike and he’ll struggle to get within a second.

The key to setting up suspension is to ask the right questions about what your bike is doing and think about the feedback you get carefully.

Make detailed notes of everything you do so you can put it back to previous settings if needed and don’t be afraid to turn everything to full on or full off – most bikes don’t have a huge range of adjustment, so you’re unlikely to wreck it.

Listen to what your suspension is telling you. Think about what the feedback means and remember that the settings you get on one type of road might be different from what’s needed on another one.

So our Honda’s suspension is now much better for me, at least. What was really interesting though was after a couple of hours spent working on the set up with warm tyres and hot suspension oil (the CB doesn’t have a remote reservoir to cool the rear shock’s damping oil), I stopped for lunch for an hour and when I started again the set-up felt stiff, sharp and horrible. The oil had cooled down, thickened up and took about ten minutes back on the b-roads before it was working properly.

The Honda is a road bike and the rear shock is a compromise between comfort and just-about-managing-to-be-sporty. Now it’s set-up I’m happy to ride it fast and it no longer bottoms out (which was the biggest problem) and steers faster too.

Three things I like about Honda’s CB1000R+

• Strong, flexible engine
• Superb quickshifter
• Strong brakes

Three things I’m still to be convinced about

• Long distance comfort (pegs are too high for me)
• Expensive for the spec
• Rear shock is lacking next to the competition