Progressive Spring - rear shock modification - is it any good?

[Jagster]

I came across this listing on ebay and thought ...hmm....Not massively expensive, so rather tempting.
But....Is it any good?
Does it solve the harsh rear end over potholes etc....?

Has anyone out there fitted this kit? and if so, does it improve the ride?

Hyperpro Progressive Rear Shock Spring triumph Rocket 3 R 2021-2022 | eBay

 

[RazMan]

Seems like a good deal ....... if it isn't just Snake Oil My lower back would be interested to read any reviews before committing though

 

[2023R3GT]

I came across this listing on ebay and thought ...hmm....Not massively expensive, so rather tempting.
But....Is it any good?
Does it solve the harsh rear end over potholes etc....?

Has anyone out there fitted this kit? and if so, does it improve the ride?

Hyperpro Progressive Rear Shock Spring triumph Rocket 3 R 2021-2022 | eBay

The biggest challenge is the small amount of travel on the rear shock Have you increased the pre-load on you rear - and have you set the rebound and compression to suit your weight and riding style?

 

[dougl]

How much do you weight? Better to get a linear spring that matches your weight. You should be able to set the preload so that the static sag with you on it is 30% of the travel. If you can manage this, you should be able to set the damping to give a comfortable ride.

 

[Jagster]

The biggest challenge is the small amount of travel on the rear shock Have you increased the pre-load on you rear - and have you set the rebound and compression to suit your weight and riding style?

How much do you weight? Better to get a linear spring that matches your weight. You should be able to set the preload so that the static sag with you on it is 30% of the travel. If you can manage this, you should be able to set the damping to give a comfortable ride.

Thanks for your responses.
I have set the stock suspension to what I think might be the best I can achieve.
I have observed during my setting up of all the variables that the changes definitely made a positive difference, however, I think the problem is just a combination of the short travel and the unsprung mass of the tail end.
There's a lot of inertia to be tamed in a short amount of movement. Generally, the bike soaks up the majority of peaks & troughs along the road very well, and the bike doesn't wallow or feel too rigid.
The problem is when you run over a road surface with harsh bumps.
I will take on board you comments, however and play some more with the settings.

 

[2023R3GT]

The rear pre-load from factory is at it's minimum. If I remember there is 35 or 36 increments. I increased mine to 30 and then refined the comp/rebound. Compression and rebound has a range of 3.5 turns. Increments does not to be full turns, I've used 1/4 turns in some cases.

You want the forks and shock to compress close to the bottom-out position (20mm on forks). Rebound should come up and then settle in a single movement/bounce of about 3/4" on the Rocket and 1" on lighter bikes, same with the rear.

Make sure you get your tire pressure right vs ambient temp and riding style. The rear can get very hot...

 

[RazMan]

This is a video showing a good method to set up your R3 - it worked for me anyway

 

[Jagster]

I have used Col & Zig's settings as a staring point for my bike because my weight is similar.
It has made a very noticeable positive difference. The bike is more comfortable and handling is really sweet.
I will however try to develop/refine my settings further, as suggested by 2023R3GT.

 

[atomsplitter]

A progressive spring is useful for smoothing the spring action since the progressive part adds linear resistance to compression. It's the first part of the coils to compress followed by the standard coils. With a short travel shock (like on my Bobber) it's not recommended. I put progrssive springs in my 05 Rocket forks and they performed much better, but there was plenty of travel available. You can set the preload for minimum sag and that increases travel length. I did this with my Bobber by changing to a high end Ohlins rear shock and it still will bottom out but only on the most severe hits. The Rocket has twin shocks so you can increase preload to limit static sag. You can see how much preload I had to add to max out my travel length:

 

[atomsplitter]

There's one more point I'd like to add here about spring rate and static sag. The rear springs on 2.5L Rockets are linear, thus the newton-meters per millimeter are set. Setting the static sag for 30% of the total travel limits the travel to 70% of the length. Setting the sag to 15% means 85% travel, 10% gets you 90% and so forth. The travel length is the key here, meaning with limited travel length the shock has to absorb and limit the compression of the spring before it bottoms out. The spring is not going to change how the shock feels under compression, only the total amount of travel available. The shorter the overall travel the greater the compression damping needs to be to prevent bottoming and the resulting ride is harsher. Since you gain nothing by setting sag to 30%, set the sag for 15% and back off the compression damping since more travel is available and less damping is required, thus the ride feels smoother. You can also back off the rebound damping so it recovers to the full travel length faster. You may find yourself balancing forces between pogo stick and hard tail but once you find the sweet spot the ride is as good as it's going to get with OEM equipment.