rear spring

Vintage Veloce

Vintage Veloce

pro rider
Joined
Oct 7, 2020
Messages
1,088
Location
San Diego
The 2020 manual claims the rear spring is 180mm long.
And the rate is progressive from 100 - 150 N/mm (571 - 857 lb/in)
Since the diameter isn't stated, I roughly measured the spring on my rear shock.
It seems to have an 80-85mm OD (outside diameter) and the wire is about 12.2mm OD.
So that means the spring diameter to the wire center on both sides is approx 72mm.
And the ID (internal diameter) is about 60mm.

A bit of web searching revealed these single rate H&R springs for cars with an ID of 60mm and 180mm length:
Screen Shot 2020-10-21 at 9.27.56 PM.jpg

Now the question is what rate to try. My rear shock is too stiff. So I certainly want less than 150 N/mm, I think.
But I'm not sure how to pick... any advice?
 
how much do you weight? you should just get a Nitron R1 or R2 and be done with it.

It's worth the money if you're into spirited riding, increase handling = increase safety.

It's also a really easy to swap in and out (15mins) and resale value for aftermarket shock is really good, you'll get some of the money back, while you gain the benefit of superior suspension that is correct for you weight in the mean time.
 
Sisco said:
how much do you weight? you should just get a Nitron R1 or R2 and be done with it.
Click to expand...
I'd have the same spring rate question with a new shock too. I figured I'd try a spring first and figure that part out.
I'm 165 pounds (65 Kg) with full gear. And it seems the 2020 has some different suspension pieces than the earlier years.
 
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When you buy Nitron the dealer should set you up with the correct spring rate, I know Nitron 800lbs spring rate is for 75-80kg rider without gear.

pretty sure the rear shock for 2020 are interchangeable with earlier model 401 and RC/Duke 390 since the length of the shock are all the same.

Really wouldn't recommend changing the stock progressive spring to a non progressive because you can't adjust the comp and rebound to suit it and it will probably bounce you off the road.

Just do it right the first time, get the Nitron R2 independent adjustment for comp and rebound.
 
Yeah... I've replaced shocks before... and they have always come out too stiff. I think all these shops tune for fat racers! ;-) Actually, I think it is just "safer" for them to go stiffer than to risk the suspension being too soft. And many guys think stiffer is better.

My 2020 Svart 401 is WAY too stiff. It sags through the soft top of the spring and then its a rock. Sag is set roughly correct, I've been playing with that.

The 2020 shock may be the same dimensionally as the 2019, but the 2020 does have adjustable rebound. Yes, it's still a pretty cheap shock, but if the spring rate is too stiff, none of the damping settings help.
I'm not afraid to experiment with springs. I figure even if I buy a whole shock I'd be doing the same thing. And at the end, if I decide I need a new damper too, I'll have a better idea what spring rate to start with. ... Maybe. It's an experiment.
 
I am not convinced that the spring is the problem, is it not the valving in the shock itself which makes it feel so stiff?

I changed mine and am happy with it.

For me it was less because of the spring, more so because of the shock, otherwise I would have just bought a spring for far less money's.

I say shock because it was pretty soft and would bottom out, but on a pothole it felt like ... well... less comfortable than I prefer;)
 
Vintage Veloce said:
. I've replaced shocks before... and they have always come out too
Click to expand...

When I ordered the hyperpro I had to tell them my riding weight so they could put it together for me.

One more thing, a bit more subjective, it makes the bike feel like riding a bike with a much higher price tag.
 
Yeh I agree, the stock rear shock was way to soft, I bottom out even on the street, I swap it with yamaha r1 rear shock, now its better, I think the stock shock doesnt much adjustment, now I feel like to replace front forks with 2021 one.
 
The experts I spoke to said that the piston size will make a difference, I'm not sure what the stock piston size is but stay away from KTech Razor R because the piston size is 35mm which is tiny (smaller than stock) Rod sizes is also different between Nitron R1 (14mm) vs R2 (16mm) maybe that's a factor as well, YSS and Ohlins piston size is 45 mm and significantly bigger than the Nitrons.

The K-Tech is 14-35MM piston
Nitron R1 is 14-40MM
Nitron R2-R3 is 16-40MM
YSS is 16-45MM
Ohlins is (probably 16?) -46MM

Nitron R1 vs YSS

1604203432076.jpg

Stock vs Nitron R2

1604203476268.jpg
 
- Hyperpro
16mm / 46mm
Progressive Spring

From the website:
3D Shock Emulsion.
Options: La, Hpa

  • Hyperpro schokdemper / schokbreker
  • Diverse instelmogelijkheden (zie details).
  • Voorzien van progressieve veer.
  • Nederlands kwaliteitsproduct.

Google Translation:
3D Shock Emulsion.
Options: La, Hpa

Hyperpro shock absorber / shock absorberVarious adjustment possibilities (see details). Equipped with progressive spring. Dutch quality product.
 
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I've heard that a progressive shock spring is great when you have big variance in rider weight... like if you carry a passenger sometimes. Or you are making a motorcycle/shock that needs to work for many different rider weights. But if the the rider's weight does not vary, supposedly a single rate spring makes it easier to set up the dampening to match.
 
Vintage Veloce said:
I've heard that a progressive shock spring is great when you have big variance in rider weight... like if you carry a passenger sometimes. Or you are making a motorcycle/shock that needs to work for many different rider weights. But if the the rider's weight does not vary, supposedly a single rate spring makes it easier to set up the dampening to match.
Click to expand...
Problem solved with hydraulic preload adjustment :)
 
Sisco said:
Problem solved with hydraulic preload adjustment :)
Click to expand...
Preload doesn't help if you have the wrong rate spring, It only changes the ride height and position of the swing arm (and linkage, if any) in it's arc. Regardless where you set the preload, you end up at the same point of spring rate.
Here is a description from Race Tech's Bible.
preload 1.jpg
preload 2.jpg
preload 3.jpg
P
 
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Yes I know, if you care about correct sag setup then it should adjusted when you carrying passenger. This is super easy with hydrolic preload, but I wouldn't bother without it because it's a PITA to adjust preload without it.
 
I'll never have a passenger on this bike... I removed the rear pegs. :cool:
Ah, I get it, you are suggesting the hydraulic preload adjuster if you have reason to regularly change the preload?
My point was that a progressive shock springs is good if you are riding both with and without a passenger.
But FWIW, some think that if it is always a solo machine, many thing a straight rate is better, provided it is the correct rate for the conditions.
 
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