NX250 fork spring mods
Verfasst: Sa Jan 04, 2020 7:50 am
Unlike the rear shock, the front fork isn’t too bad – at least with an rider of average weight. The main downsize is too much negative suspension travel (or "sag") with the side effect that the NX is pretty unstable on the kickstand and easily tips over. The sag is measured with the rider sitting on the bike – in my case with a stock fork its 7cm or 34% of the total way of travel. Too much – usually something between 20 and 30 % is recommended.
The fork of the NX250 sags so deeply because the short top springs are so soft. These are very unusual for Honda forks, otherwise rigid spacers are used. My guess is that the only purpose of the top springs is to lower the fork.
So I tried a couple of aftermarket fork springs. Remarkable: none of them have the same length as the stock springs. It looks like that, even though the manufactors claim that the springs were specifically made for the NX250, they were taken from some other bike.
Negative consequences: the aftermarket springs are either too long or too short, so you have to either made some spacers or use massive force to screw in the fork plugs.
No wonder that almost all of the (expensive) aftermarket springs are not really much of an improvement – White Power and Promoto are still too soft and Wirths are way too hard. Maybe the Wirths work better with a riders weight of more than 100kg – but I haven’t tried that.
The best of the bunch i.m.o are the Hyperpro https://www.ebay.de/itm/KIT-MOLLE-FORCE ... SwPAlcnOBU, but they are also the most expensive. They work pretty well even at higher off-road speed. The hyperpros came with 25 grade fork oil, the others with 15 oil, if I remember correctly.
Since I was pretty disappointed with the aftermarket parts I was looking for an affordable alternative and stumbled over these adjustable fork plugs https://www.ebay.de/itm/1-Pair-37mm-CNC ... Swj61cg3c7 . With those the sag can be adjusted between 19 and 29%. It works even (with 15 grade fork oil) better when the short top springs are replaced with 8.5cm (~ 3.5'') long spacers (thickwalled aluminium, outside diameter of 1 1/4''
or 32mm). A length of 70mm is sufficient for lighter riders
The fork of the NX250 sags so deeply because the short top springs are so soft. These are very unusual for Honda forks, otherwise rigid spacers are used. My guess is that the only purpose of the top springs is to lower the fork.
So I tried a couple of aftermarket fork springs. Remarkable: none of them have the same length as the stock springs. It looks like that, even though the manufactors claim that the springs were specifically made for the NX250, they were taken from some other bike.
Negative consequences: the aftermarket springs are either too long or too short, so you have to either made some spacers or use massive force to screw in the fork plugs.
No wonder that almost all of the (expensive) aftermarket springs are not really much of an improvement – White Power and Promoto are still too soft and Wirths are way too hard. Maybe the Wirths work better with a riders weight of more than 100kg – but I haven’t tried that.
The best of the bunch i.m.o are the Hyperpro https://www.ebay.de/itm/KIT-MOLLE-FORCE ... SwPAlcnOBU, but they are also the most expensive. They work pretty well even at higher off-road speed. The hyperpros came with 25 grade fork oil, the others with 15 oil, if I remember correctly.
Since I was pretty disappointed with the aftermarket parts I was looking for an affordable alternative and stumbled over these adjustable fork plugs https://www.ebay.de/itm/1-Pair-37mm-CNC ... Swj61cg3c7 . With those the sag can be adjusted between 19 and 29%. It works even (with 15 grade fork oil) better when the short top springs are replaced with 8.5cm (~ 3.5'') long spacers (thickwalled aluminium, outside diameter of 1 1/4''
or 32mm). A length of 70mm is sufficient for lighter riders