Fork Oil recommendations

I finally got time to work on the front forks. A number of members suggested shortening the spring spacer by 3/4" and changing to a 5 weight oil. I went to Home Depot and purchased a short length of PVC pipe, the same diameter as the spacer, and cut two spacers 3/4" shorter. Drained and replaced the fork oil with Honda 5 weight fork oil, 16 fl oz. per fork, per spec. Wow, what an improvement in ride. I'm 165 pounds and 5'6", and the front fork use to pound my arms. Now it rides firm but so much smoother. I would strongly recommend these changes.

In addition, I'm going to raise the fork in the triple clamp 1/2", to drop the front a little. Have others tried this? How far can you raise the forks without having the front fender hit something? Thanks all for the fork suggestions.

As a large and heavy person my problem is more a lack of damping that leaves me with cupped tires front and rear. Or am I barking up the wrong tree again?

I don't know. I am a small guy, 130 lbs and I get cupping on the front and rear as well. I also guess I have gotten used to the NT's suspension as I have no complaints with it. I think I have the rear set at position 6.

[...a lack of damping that leaves me with cupped tires front and rear....]

Usually, cupped tires are a result of insufficient air pressure. That being said, some tires seems to cup no matter what you do with the air pressure.

Raising the forks in the triple clamps by 1/2" is roughly 12 mm and that's how much mine are raised. I did it to compensate for lowering my bike.

Too soft leading to cupping? Thanks for the quick response.

Raising the forks will also change the way more the bike handles, from memory it quickens the steering so as you lay the bike over it will "fall into the corner" quicker

oldtimer said:

A number of members suggested shortening the spring spacer by 3/4" and changing to a 5 weight oil. I went to Home Depot and purchased a short length of PVC pipe, the same diameter as the spacer, and cut two spacers 3/4" shorter. Drained and replaced the fork oil with Honda 5 weight fork oil, 16 fl oz. per fork, per spec. Wow, what an improvement in ride. I'm 165 pounds and 5'6", and the front fork use to pound my arms. Now it rides firm but so much smoother. I would strongly recommend these changes.

In addition, I'm going to raise the fork in the triple clamp 1/2", to drop the front a little. Have others tried this? How far can you raise the forks without having the front fender hit something? Thanks all for the fork suggestions.

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I weigh 170 lbs. The front end does dive when braking, seems to be compliant enough over small bumps, but when hitting a sharp-edged bump ... OMG. Then it feels like the front end is rigid; almost like the front fork locks up, and the jolt is sent straight up my arms. If I want to switch to 5 weight oil and play with shorter spacers, what amount of sag should I try to achieve? Measured at the front from fork fully extended (unloaded) to fully loaded (bike + rider), or do I measure the difference between loaded with the bike's weight only, then add my weight?

Turbo DV8 said:

I weigh 170 lbs. The front end does dive when braking, seems to be compliant enough over small bumps, but when hitting a sharp-edged bump ... OMG. Then it feels like the front end is rigid; almost like the front fork locks up, and the jolt is sent straight up my arms. If I want to switch to 5 weight oil and play with shorter spacers, what amount of sag should I try to achieve? Measured at the front from fork fully extended (unloaded) to fully loaded (bike + rider), or do I measure the difference between loaded with the bike's weight only, then add my weight?

Click to expand...

This is how forks are designed to work. There is one small passage that allows oil to pass through soaking up the "small bumps" and a larger restricted passage that only works for larger bumps and therefore needs a certain fork displacement to "open up" the restricted passage.

Using lighter oil will take some of the harshness away from the larger bumps BUT I suspect it will also make the forks much less compliant for smaller bumps.

Maybe you need to investigate some of the aftermarket valves that can be fitted as these change the way the damping works.

Seagrass

DirtFlier said:

The Ricor valves fit snugly into the fork tubes and are sealed with an O-ring so they force as much oil as possible through the valve. By comparison, the Race Tech Gold Valves don't attempt to seal the outside. This is not a condemnation of the Gold Valves, just an observation. The Race Tech valves require that the damper rod holes be increased in diameter + additional holes added. The Ricors don't require modification of the damper rod. On my NT, the damper rods were already modified so I went ahead that used them with the Ricors.

I can't really say if this is good or bad (the extra oil volume) for performance but there is much more labor involved when installing Gold Valves.

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So, in the end, with the Ricor valves, ultimately you want to adjust the fork oil to the height specified in the manual, not the volume, correct?