Where is your rebound set on the Deluxe?

Have you ridden a different bike that didn't feel like it was bucking you on bumps?

Are you riding these bumps stiff legged or seated?

 

I second PhillipJ's sentiment that it's worth looking at your rebound settings, if it's too slow it could be packing up and causing chatter, if it's too fast it could make your back end too bouncy and that could cause the feeling of getting bucked. It's also worth looking at your front suspension settings, if your fork is too soft it could also make it feel like your getting bucked. If you exhaust all those options you could have your shock tuned by a shop that specializes in that. Fluid Focus is supposed to be good for tuning or you could go with Avalanche Downhill Racing for a fully custom rebuild on your shock.

 

The bucking sensation sounds like my 2018 DPX that was notorious for hsc spiking. I'd get one of those Mara Pro that are on sale.

 

Yeah, it sounds like the ‘bucking’ you’re referring to is called ‘spiking’ and it’s generally caused by too slow of a rebound…

 

It sounds like you're wanting to improve the small bump compliance of the shock - personally I found with my Super Deluxe that there's a very narrow sweet spot for air pressure. Even a very small increase in air can pressure makes the bike feel harsh and chattery. Now, if you're running the shock firmer than recommended to adjust the BB height then that's probably going to cause an issue - the shock is simply too firm. You might want to add some air can tokens if possible. These increase the ramp up of the air spring which means you can lower the pressure slightly to improve the beginning stroke but the shock will ramp up much more harshly as it progresses through the travel so it won't blow through quite the same.

As you've suggested you could effectively reduce the damping effect with a lighter weight oil or alternatively get it custom tuned. It could even be that the shock comes with a stock tune that's a bit over the top for your bike. Just be aware that if you're going down the oil change route you need some specific tools in order to do this. Fine if you do all of your own servicing but for a one off it's probably cheaper to send it in to a dedicated suspension company.

A few other things to try - check for friction in the linkage and do an air can service. These can make the shock feel much more active so it's worth a go.

This is all on the assumption that other settings are in the ballpark. As others have said if you're running rebound at either extreme then this can also have a negative effect.

 

In had the same issue with my Lyrik 160mm and my Monarch 3 rear shock. I replaced all internal o-rings and oil but no matter what the low to medium speed compliance on small or medium rock totally sucked. There were a few times heading down some rock gardens I almost lost my grip because it was so harsh and I wasn’t ready for it. Yet, slamming into big stuff both front and back suspensions were plush. After quite a few experiments I decided to completely remove the factory volume spacers (2 in the shock and two in the fork). I immediately noticed a big improvement and the harshness is completely gone. I had to up my air pressure about 5 PSI from before but that was it. Overall shock and fork travel usage ended up being pretty much the same after the change.

If you are doing jump parks this setup is obviously not recommended. I run trails and single track in the desert going over larger rock and some drops.

 

Thanks for all the responses, and suggestions. Some feedback/thoughts:

The "bucking" (maybe not the best term) I described happens when I'm seated and go over a something like a small hill (<1m). I'm pretty confident that it's due to the compression just being too slow, the rebound feels OK to me.

The trails I ride are mostly singletrack with some small drops and jumps, rock-gardens, and lots of roots; no bike parks nearby and no big jumps. (I should have bought a more XC focused bike, but I ride what I have)

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Now, if you're running the shock firmer than recommended to adjust the BB height then that's probably going to cause an issue - the shock is simply too firm. You might want to add some air can tokens if possible. These increase the ramp up of the air spring which means you can lower the pressure slightly to improve the beginning stroke but the shock will ramp up much more harshly as it progresses through the travel so it won't blow through quite the same.
....

I was thinking about going this route and have some spacers in my Amazon cart... what's giving me pause is that I'm not sure where in the suspension travel range the majority of my pedal strikes occur. If they occur deeper into travel then this would help but I think that they usually occur low-to-mid-travel (could be wrong though). I'm used to riding more old-school XC bikes with higher BBs. I've been trying to re-train my brain but there are curves in the trail where I really feel like I should be peddling and putting the power down instead of trying to keep the bike vertical so I don't hit a pedal. Between your and Scott_123 suggestions, I guess doing some trial and error with different spacer counts might be worth a shot.

.....After quite a few experiments I decided to completely remove the factory volume spacers (2 in the shock and two in the fork). I immediately noticed a big improvement and the harshness is completely gone. I had to up my air pressure about 5 PSI from before but that was it. Overall shock and fork travel usage ended up being pretty much the same after the change. ....

The bucking sensation sounds like my 2018 DPX that was notorious for hsc spiking. I'd get one of those Mara Pro that are on sale.

That looks fancy. I want to see if I can make the DLX RT work with some tweaking before I give up and drop another $300 on this bike. These parts are so expensive that replacing just a few components gets you dangerously close to the price of a new bike. Something like cranks, seats, are carbon bars I don't mind dropping money on, because I can move them to another/future bike (hopefully). If I get a different shock for this, it's probably the only bike I'll ever be able to use it with...

 

Thanks for all the responses, and suggestions. Some feedback/thoughts:

The "bucking" (maybe not the best term) I described happens when I'm seated and go over a something like a small hill (<1m). I'm pretty confident that it's due to the compression just being too slow, the rebound feels OK to me.

The trails I ride are mostly singletrack with some small drops and jumps, rock-gardens, and lots of roots; no bike parks nearby and no big jumps. (I should have bought a more XC focused bike, but I ride what I have)



I was thinking about going this route and have some spacers in my Amazon cart... what's giving me pause is that I'm not sure where in the suspension travel range the majority of my pedal strikes occur. If they occur deeper into travel then this would help but I think that they usually occur low-to-mid-travel (could be wrong though). I'm used to riding more old-school XC bikes with higher BBs. I've been trying to re-train my brain but there are curves in the trail where I really feel like I should be peddling and putting the power down instead of trying to keep the bike vertical so I don't hit a pedal. Between your and Scott_123 suggestions, I guess doing some trial and error with different spacer counts might be worth a shot.





That looks fancy. I want to see if I can make the DLX RT work with some tweaking before I give up and drop another $300 on this bike. These parts are so expensive that replacing just a few components gets you dangerously close to the price of a new bike. Something like cranks, seats, are carbon bars I don't mind dropping money on, because I can move them to another/future bike (hopefully). If I get a different shock for this, it's probably the only bike I'll ever be able to use it with...

Trial and error with what you already have is cheap. Pulling the volume spacers on the shock and fork are a breeze and cost nothing but a little time. Then get in the saddle for enough rides to see the results. You can also fool around with oil viscosity but I’ve found Rockshox knows best what weight should be. I‘ve tried different oil weights and ended up going back to what was recommended.