Replacing suspension fork spring


New Member
Aug 14, 2016
Hi All, This is my suspension fork... Suntour NRX D HLO. 63mm. Hydraulic Speed Lockout / Preload

I'd like stiffer suspension than what my fork offers now. My idea is to change to a stiffer spring to achieve that. I wrote to Suntour asking about this. This was their response... "It does not appear as though spring kits are available for the NRX forks."

Are stiffer 3rd party springs available for my fork or is a whole new fork my only option? All comments are welcome, thanks!

(btw, Preload is already set to max!)
A 63 mm fork - any 63 mm fork - is NOT a performance item.
If yours is bottoming out you’re either heavier than the bicycle designers expected, or you’re riding the bike harder than the bicycle designers expected.
Your options are limited.
Air forks are good, as it’s easy to increase pressure to cope with heavier rider/harder riding.
But I’m not aware of any air forks in that travel range.
There are some Rockshox forks that can be fitted with spacers to reduce travel. 100-to-80 mm is doable, I know that. Your bike would probably survive going to 80 mm travel. Or maybe a 100 mm fork can be detuned to 60 mm.
TBH, your easiest/safest option might be another bike, more suited to your style of riding.
From what I found online, the Suntour NRX D HLO appears to be a low-end fork designed for hybrid road bikes. That's probably why parts are not available for it, it's not designed to be optimized to the rider the way higher-end MTB fork are. It's only designed for smoothing bumps in the road, not bashing around off-road, which is why the travel is so limited. Dabac's suggestion of getting a bike better suited to your riding style (or your size, if that's the issue) is probably your best bet.