I have ordered the CCDB, and it's on the way. I know it takes sometime to tune. I'm not to intimidated about all the adjustments. I understand low and hi speed compression. Low and high speed rebound I got a small understanding. I've been reading old post it, mainly the thread about PUSH and there slow rebound. One question I have is CCDB rebound like the Vivid? On the vivid low speed was just the first 20% of travel and high speed is the last 80%, is CCDB like this. Or is it just mainly deeper into the travel only? Also is it possible to have a low speed event when the shock is deep into its travel? Also by reading it sounds like you can alter where you want the high speed kicking in by adjusting the low speed rebound. Sorry if this sounds retarded, just want a little knowledge on the rebound before I start adjusting.
CCDB low and hi speed rebound.
- Thread starter Optimax150
- Start date
I'm not exactly sure of how the inner workings off the CCDB go about but by definition shaft-speed damping is not effected by how deep the shock is in it's stroke. So a low or a high speed event could happen any time independent of where the stroke is at. AFAIK, that's what HSC, LSC, HSR and LSR mean but a lot of companies use the terms for hype rather than accuracy.
I try not to think of it from a technical aspect and just try and connect it directly to how it makes the bike behave in real life situations. For me LSC and LSR were quite easy to tune. Lighten it up until your bike stopped bobbing. The CCDB is incredibly sensitive so the tiniest amount of bob is visible. I've got mine down to a range of a few clicks between solid pedaling on one and more comfortable lazy-riding on the other.
HSR and HSC not quite as easy. Basically try and fiddle with it until it tracks well in the very rough stuff. HSR sweet spot is a dangerous find. I find the easiest way to find it is to make it faster and faster and until you start getting bucked on the hard hits. With the fast HSR it should have the suspension recover pretty quick. With HSC, harden till it stops bottoming harshly or tracks adequately well. With the high speed stuff I have a hard time figuring out if the bike is squirmy because the HSC is too hard (hydro locking?) or light (bottoming) or the HSR is too fast (bucking)/ slow (packing up). All just advice from experience so take it with a grain of salt.
Tuning your CCDB from scratch is hard. I'd suggest finding a post or emailing malcolm and asking where a good place to start would be for your frame then go on from there. No other shock has had as noticeable change in performance per click as the CCDB in my experience. With a pretty good number of clicks that gives a big range for adaptability of the shock and also a big range for not having it quite right if you don't know where the sweet spot is for a frame design. 2c
I try not to think of it from a technical aspect and just try and connect it directly to how it makes the bike behave in real life situations. For me LSC and LSR were quite easy to tune. Lighten it up until your bike stopped bobbing. The CCDB is incredibly sensitive so the tiniest amount of bob is visible. I've got mine down to a range of a few clicks between solid pedaling on one and more comfortable lazy-riding on the other.
HSR and HSC not quite as easy. Basically try and fiddle with it until it tracks well in the very rough stuff. HSR sweet spot is a dangerous find. I find the easiest way to find it is to make it faster and faster and until you start getting bucked on the hard hits. With the fast HSR it should have the suspension recover pretty quick. With HSC, harden till it stops bottoming harshly or tracks adequately well. With the high speed stuff I have a hard time figuring out if the bike is squirmy because the HSC is too hard (hydro locking?) or light (bottoming) or the HSR is too fast (bucking)/ slow (packing up). All just advice from experience so take it with a grain of salt.
Tuning your CCDB from scratch is hard. I'd suggest finding a post or emailing malcolm and asking where a good place to start would be for your frame then go on from there. No other shock has had as noticeable change in performance per click as the CCDB in my experience. With a pretty good number of clicks that gives a big range for adaptability of the shock and also a big range for not having it quite right if you don't know where the sweet spot is for a frame design. 2c
I agree with Wa-Aw about HSC and HSR.
Wa-Aw makes some very good points for tuning the CCDB. I would add that if you don't have specific initial tune recommendations for your frame, the settings in the CCDB manual (stock settings an aftermarket CCDB is shipped with) are not a bad place to start.
There is big difference between compression and rebound as it pertains to low speed vs. high speed: on the compression side, the force comes from impacts and the terrain so you can have events that trigger high speed or low speed events anywhere in the shaft, although typically if there is enough energy in the event to drive the shock shaft almost all the way to bottom out, most likely it will engage the high speed circuit.
Things are different on the rebound side. The driving force of the rebound circuit is only given by the spring (air or coil): deep in the travel there is a lot of energy to dissipate while earlier in the travel there is less energy. This is one reason why it is important to have a decent amount of preload on the coil (as Malcolm will remind you) because that's the driving force for the rebound circuit on small bumps.
This also means that high-speed events on the rebound side happen when the shock starts rebounding from deep in the travel. If you break it down, at the of the compression side, the shock is compressed a certain amount and it's not moving for a split second (zero shaft velocity). The spring is loaded and starts driving the rebound. There is an amount of energy to dissipate given by how much the spring is initially compressed and the shaft will initially accelerate going from LSR to HSR and finally back to LSR (of course this just means that the poppet valves on the HSR circuit will open in parallel to the LSR needle, there is always oil flowing through the low-speed circuit). Where that transition happens depends on the amount of preload on the poppet valve (HSR).
This is also the reason why rebound shaft speed has much less variability than compression shaft speed and the rebound damping circuit doesn't need to handle as broad a range of velocities. In a fork (leverage ratio 1:1) I have measured shaft speeds as high as 3-4m/s depending on the speed of the rider, how they ride, the trail, while on the rebound side, shaft speeds rarely exceed 1m/s and the distribution of rebound shaft speed only depends on the amount of travel used.
There is big difference between compression and rebound as it pertains to low speed vs. high speed: on the compression side, the force comes from impacts and the terrain so you can have events that trigger high speed or low speed events anywhere in the shaft, although typically if there is enough energy in the event to drive the shock shaft almost all the way to bottom out, most likely it will engage the high speed circuit.
Things are different on the rebound side. The driving force of the rebound circuit is only given by the spring (air or coil): deep in the travel there is a lot of energy to dissipate while earlier in the travel there is less energy. This is one reason why it is important to have a decent amount of preload on the coil (as Malcolm will remind you) because that's the driving force for the rebound circuit on small bumps.
This also means that high-speed events on the rebound side happen when the shock starts rebounding from deep in the travel. If you break it down, at the of the compression side, the shock is compressed a certain amount and it's not moving for a split second (zero shaft velocity). The spring is loaded and starts driving the rebound. There is an amount of energy to dissipate given by how much the spring is initially compressed and the shaft will initially accelerate going from LSR to HSR and finally back to LSR (of course this just means that the poppet valves on the HSR circuit will open in parallel to the LSR needle, there is always oil flowing through the low-speed circuit). Where that transition happens depends on the amount of preload on the poppet valve (HSR).
This is also the reason why rebound shaft speed has much less variability than compression shaft speed and the rebound damping circuit doesn't need to handle as broad a range of velocities. In a fork (leverage ratio 1:1) I have measured shaft speeds as high as 3-4m/s depending on the speed of the rider, how they ride, the trail, while on the rebound side, shaft speeds rarely exceed 1m/s and the distribution of rebound shaft speed only depends on the amount of travel used.
Last edited:
Thanks for the info. Sounds like I can choke out the high speed rebound if I add to much low speed rebound. As for a starting point, a person told me that stock settings is pretty good for my frame. It's a scythe, but he is running a shorter shock than me. I think the settings might be a bit different.
Great explanation of what everything does direct from Cane Creek. I have a 2011 Demo 8 which I bought a CCDB for and Cane Creek sent me the set-up guide. I started with the base tune and felt a bit too much pop on jumps at Whistler. Adjusted the HSR per the guide and it solved the excessive pop problem. Definitely worth following.
http://ww2.canecreek.com/products/suspension/double-barrel/base-tunes
http://ww2.canecreek.com/products/suspension/double-barrel/base-tunes
Thanks, I already read it, actually a few times. I just wanted to understand low and hi speed rebound more. Looks like I got some experimenting to do.
When you get it, wind the slow speed circuits all the way in and bounce the bike, then wind it off a little and try again. Just did it to check something and i learnt a few things.
Why?? To do the drop test? I occasionally do the drop test but I ignore it. Sometimes my back wheel bounces sometimes it doesn't. Depends on how I got my shock set up that day. Or you want be to do it to see something cool?
First off-What bike do you ride? It would be helpful if we knew the leverage ratio etc.
Second-You can't "choke off" the Hi/Low speed rebound compression by adjusting the other settings on a double barrel. On a shock like a Rc4 or vivid the high speed compression/rebound adjustments can affect other settings due to the shim stack type designs. Also with a shim stack, the adjustments do very little as far as giving you a range of adjustments hence the need for different tunes according to what frame, leverage ratio etc. A double barrel is completely different. All four circuits are independent from each other and do not affect one another because oil is continuously circulated through each independent channel.
Edit-just read you are on a scythe. I am assuming but it is similar to a vpp design with a progressive curve at the end of the stroke right? I am on a 2011 demo so I don't have a good basis to give you as far as a starting point. I would email Malcolm or find someone with a similar setup to you.
You are right it is progressive at the end. I wasnt really asking for a starting either just for a bit more understanding of rebound.
Low speed rebound is going to control rider input- pedal bob, mid stroke wallow etc. High speed rebound is going to control fast breaking bumps, riding over rocks/bumps at a fast speed etc. Don't think of it as low speed controls x% of travel and high speed controls the last 1/3 of stroke etc. The double barrel is completely different than a shim stack shock. Best example is to run low speed wherever you want and keep it there and high speed wherever you want. Ride a rocky section fast with or without a lot of high speed rebound then try it again with the opposite. You will see that no matter what your low speed rebound is set at it won't affect how the suspension reacts through braking bumps rocks etc. Probably goes without saying but make sure you have at least 1 turn of coil preload. Also, people post videos of themselves bouncing on the bike in the parking lot or just messing around and using that as a setup test. This might give you a starting point for low speed compression and rebound but there is no way that you can simulate what a hand dyno can do or real riding conditions. Hope that helped.
Optimax150 -
My thoughts are in this thread, which you've read but might be worth a re-skim.
nybike1971 covered everything very well above, but I'll try add a few things:
Firstly no, running more LSR won't 'choke out' the HSR, but if you run too much LSR the bike will tend to sit deeper in the travel (because as nybike mentioned, LSR / HSR can be considered as beginning stroke / end stroke for the most part due to the spring controlling shaft speed in that direction).
The basic rules for tuning rebound are to make sure the back is always slightly slower than the front (everywhere in the stroke basically) to prevent bucking, and my personal suggestion is to start with moderate LSR settings (say 5-6 clicks in) and primarily use the HSR to get the rebound doing roughly what you want - once that is done you can add a little more LSR if needed to make the rebound curve more linear (so that the beginning stroke isn't hugely faster than the mid/end stroke, which although can aid in traction/pop in more advanced setups, can also cause strange kicking sensations off jumps if you go too far).
This is really no different to a single-tube shock, except 'setting the HSR first' is done by the manufacturer in configuring their shimstack / base-tune, and the end user gets to adjust the LSR afterwards. On the CCDB you get to do both.
The reason for this is simply because that's how speed-sensitive dampers work, there are two flow paths in parallel with one path being restricted - in the CCDB's case that is by a spring-loaded poppet valve, in some suspension it might be metal shims or a compressible plastic tube, but the principle is the same either way. When you increase restriction on one path, it increases flow through the other. In practice this means that you need to run a certain amount of HS damping otherwise the poppet (secondary parallel flow) will start opening up too easily and reduce damping in the mid-speed region where you need support (even though you might have run enough LS damping to *think* that it's well supported).
What the CCDB does do a little differently is force a lot more oil through the piggyback adjusters by nature of the twin-tube design, so it gives you a wider range of external adjustment, so as you pointed out it doesn't have the need for frame specific tunes - this has benefits and drawbacks of its own.
My thoughts are in this thread, which you've read but might be worth a re-skim.
nybike1971 covered everything very well above, but I'll try add a few things:
Firstly no, running more LSR won't 'choke out' the HSR, but if you run too much LSR the bike will tend to sit deeper in the travel (because as nybike mentioned, LSR / HSR can be considered as beginning stroke / end stroke for the most part due to the spring controlling shaft speed in that direction).
The basic rules for tuning rebound are to make sure the back is always slightly slower than the front (everywhere in the stroke basically) to prevent bucking, and my personal suggestion is to start with moderate LSR settings (say 5-6 clicks in) and primarily use the HSR to get the rebound doing roughly what you want - once that is done you can add a little more LSR if needed to make the rebound curve more linear (so that the beginning stroke isn't hugely faster than the mid/end stroke, which although can aid in traction/pop in more advanced setups, can also cause strange kicking sensations off jumps if you go too far).
This is really no different to a single-tube shock, except 'setting the HSR first' is done by the manufacturer in configuring their shimstack / base-tune, and the end user gets to adjust the LSR afterwards. On the CCDB you get to do both.
That's actually not true, the CCDB does not provide damping in a magically different way to a conventional single-tube damper. The circuits are not 'independent from each other', and indeed do 'affect one another' at least in the same direction of travel - i.e. HSC affects LSC, HSR affects LSR.
The reason for this is simply because that's how speed-sensitive dampers work, there are two flow paths in parallel with one path being restricted - in the CCDB's case that is by a spring-loaded poppet valve, in some suspension it might be metal shims or a compressible plastic tube, but the principle is the same either way. When you increase restriction on one path, it increases flow through the other. In practice this means that you need to run a certain amount of HS damping otherwise the poppet (secondary parallel flow) will start opening up too easily and reduce damping in the mid-speed region where you need support (even though you might have run enough LS damping to *think* that it's well supported).
What the CCDB does do a little differently is force a lot more oil through the piggyback adjusters by nature of the twin-tube design, so it gives you a wider range of external adjustment, so as you pointed out it doesn't have the need for frame specific tunes - this has benefits and drawbacks of its own.
Correct but the range of adjustment that a design like a double barrel provides is way larger than that of a shim stack/internal floating piston. Redundant but like we both said eliminating the need of tuning to leverage ratios etc. I honestly can't tell that my low speed comp is affecting my high speed and the same with rebound. However I am on a horst link bike and have not ridden anything but my demo for a long period of time. I have ridden a few vpps and morewoods (very low leverage). I didn't get to adjust the settings on other bikes though.
Here is a good video of how the internals work:
http://ww2.canecreek.com/products/suspension/double-barrel/technology
Not trying to be a dick or start an argument UDI but Cane Creek claim the adjustments are independent from each other. However I am just a paramedic and a bike mechanic not an engineer.
Here is a good video of how the internals work:
http://ww2.canecreek.com/products/suspension/double-barrel/technology
Not trying to be a dick or start an argument UDI but Cane Creek claim the adjustments are independent from each other. However I am just a paramedic and a bike mechanic not an engineer.
Last edited:
Yeah, I think you see that kind of terminology in a lot of suspension marketing material these days so I'm not saying it's a ridiculous claim or anything - but like I said, in the same direction of travel, the dampers work in parallel (i.e. oil can flow through LSC and HSC circuits simultaneously) which means that there certainly will be crossover.
You can test what I'm referring to by closing a chosen LS adjuster completely, and then comparing how it feels with its respective HS adjuster fully open vs. fully closed. You'll notice that even if you compare both scenarios at roughly the same shaft speed it'll likely feel different.
It's not an issue at all, as I said it's just the nature of most speed sensitive dampers and something to be aware of when tuning.
You can test what I'm referring to by closing a chosen LS adjuster completely, and then comparing how it feels with its respective HS adjuster fully open vs. fully closed. You'll notice that even if you compare both scenarios at roughly the same shaft speed it'll likely feel different.
It's not an issue at all, as I said it's just the nature of most speed sensitive dampers and something to be aware of when tuning.
Udi- thanks for the reply. I was waiting for you to chime in, you being the suspension expert. Yes I read that thread and actually started reading it again. Looking foward to messing with it see the range myself.
One more question somewhat off topic. How would you run you're rebound in soft loose conditions with off camber corners? Fast or somewhat slow?
One more question somewhat off topic. How would you run you're rebound in soft loose conditions with off camber corners? Fast or somewhat slow?
I think the general rule with rebound is to keep it as fast as you are comfortable with (while sticking to what I said before about keeping the rear slightly slower than the front). Usually you'd set the rebound to suit your spring rate and taste, and then not change it hugely for different tracks.
I think if loose / offcamber is predominant then you'd want it slightly on the faster side, but you can slow it down if it's kicking/bucking you too much off jumps, or popping back at you too quickly in a bermed corner. Problem is that most tracks have a combination of these things and more so I think it's better to have one rebound setup that will work well for most scenarios you'll encounter.
Personally I set and forget rebound for the most part, and run more compression (mostly on fork) if the track is steeper, or back it off a bit for flatter tracks + if my hands are getting wrecked.
I think if loose / offcamber is predominant then you'd want it slightly on the faster side, but you can slow it down if it's kicking/bucking you too much off jumps, or popping back at you too quickly in a bermed corner. Problem is that most tracks have a combination of these things and more so I think it's better to have one rebound setup that will work well for most scenarios you'll encounter.
Personally I set and forget rebound for the most part, and run more compression (mostly on fork) if the track is steeper, or back it off a bit for flatter tracks + if my hands are getting wrecked.
Actually, as Udi said, the CCDB still has exactly the same crossover of LS and HS circuits as any other design. Most modern high end bicycle damper designs consist of two basic components (for each of compression and rebound):
1. A fixed-aperture low speed circuit that is always open at a certain size (may be externally adjustable but while you're riding, it stays wherever it's set)
2. A variable-aperture high speed circuit that is basically a normally-closed (NC) valve, that remains closed until there is enough pressure built up due to the resistance of the damping fluid moving through the low speed circuit.
The amount of force required to initially open the HS circuit (determined by the preload on the valve, whether that be shims, a poppet, or whatever) is what determines the force and velocity where the HS circuit starts allowing oil through and thus contributing to the damping force. However, what this means with any conventional spring-preloaded HS circuit, is that there is SIGNIFICANT overlap between the LS and the HS adjustments, in that backing off the HS preload in turn reduces the damping force at a speed which could still be considered to be "low speed". There is no way around that with the shocks currently on the market (although there are dampers that can get around this... but they're not on the market
).Whilst the CCDB is an amazing damper with some excellent attributes, its major selling point is its EXTERNAL adjustability. If you wanted to look at maximum overall versatility/range of tuning options, there is no going past shimmed dampers if you're willing to consider revalving them (or one step further, shimmed + boost valve a la RC4). While the CCDB's adjustment range is wide and very usable for a lot of riders on a lot of bikes, it doesn't mean that you can use external adjustments to do exactly the same things you can do with internal valving mods - which are a little harder to do with poppet valves than shim stacks.
With off-camber/loose stuff I'd recommend quite a lot of HSR, adjusting the LSR in order to reduce the bucking effect of tyre slip. In my experience on off-camber stuff (and assuming your setup isn't miles off the mark to begin with), the greatest loss of traction comes from the macro effects of the rider's weight getting bucked upwards/forwards too much, rather than the micro effects of the tyre following the ground super precisely. The small variations in grip that arise from the wheel following the ground slightly better or worse are smaller than the variations you get from a tyre being suddenly weighted/unweighted, which typically causes those unrecoverable rear wheel washouts.
That doesn't mean your suspension should be super slow, but full fast is typically a bit unstable and prone to causing tyre washout on off camber stuff. Predictability means grip. Keep in mind that your compression settings will have some effect here too.
What Steve said makes sense, I'd go with that over my rushed suggestions. I think in those low traction situations, tyre choice / setup and technique seem to have bigger effects than suspension setup anyway - which is why I hinted at setting your bike up to cater for everything else you might encounter as well.
That's what I was thinking. I ran my suspension setup like that for a wet sloppy course and worked out good. I also back off on my hsc but add a little lsc.
I was just asking for ideas and to compare setups. Not afraid to try different setups, also keeps riding interesting.