Trying to Lower my bike 1/2 Inch without buying Parts

[WingMan71]

Loving my new-to-me 2018, and have already fixed my windshield and bar reach problem. The Madstad windshield fixed the wind problem and the bar risers fixed the reach problem.

But, I'm short with a 30" inseam, so on to my next problem...

I'm almost flat-footed at stops with my riding boots on, but not quite. So, I'm trying to get the bike as low as I can without resorting to buying and replacing parts.

Today I adjusted the rear shock to it's "lowest' setting, meaning the shock is extended to its maximum allowable length by moving the adjusting rings. There are about 1.125" (2.86 cm) of adjusting threads on the stock rear shock. Mine was set at the mid-way position when I bought the bike. I was able to move the adjusting rings toward the top of the existing threads with the shock on the bike! "How", you ask. Well... with a 20" long screwdriver and an impact hammer. I loosened the locking ring from the left side, moved the rings up, then tightened the locking ring back up from the right side. Pretty easily done actually. I moved the rings up a good 1/2 inch (1.27 cm).

Here is their final position after the adjustment. (Yes, I was able to align the yellow index marks when finished so I can tell if the rings are staying put.)



So, my question is:

"CAN'T I NOW MOVE THE FORKS UP IN THE TRIPLE TREE THE SAME AMOUNT TO BRING THE FRONT END DOWN TO MATCH?"

What say you?

 

[dduelin]

You should be able to slide the forks up about 18 mm (~11/16”) and not hit the fender against the radiator stay. My forks are lowered this amount and the fender extender barely rubs the radiator stay under heavy braking however I do have about 5/8” inch more preload than stock.

 

[WingMan71]

You should be able to slide the forks up about 18 mm (~11/16”) and not hit the fender against the radiator stay. My forks are lowered this amount and the fender extender barely rubs the radiator stay under heavy braking however I do have about 5/8” inch more preload than stock.

I think I'll move them up 1/2 inch to match my drop in the back. Hopefully that's all I'll need to get fully flat-footed at stops. Thanks.

 

[Rabbit]

Boots with thicker soles would help too

 

[WingMan71]

Boots with thicker soles would help too

Yup, already have those or I'd be worse off yet.

 

[Rabbit]

Yup, already have those or I'd be worse off yet.

Then you need to invest in those platform shoes from the 70s. No bike too tall then!

 

[dduelin]

This is when I usually say it's not necessary to flatfoot a motorcycle in order to safely/enjoyably ride it. Various methods of lowering introduce the possibility of dangerous handling or the surprise of touching hard parts down when cornering. I feel it is better to learn short-legged coping skills and ride unmodified to height machines. That is just my inseam challenged opinion and realize it’s not for everyone.

 

[Rydinon]

Forget the platform shoes - go stiletto heels.

Seriously, while I am not very familiar with the NC's suspension, looking at the service manual and from what I know about rear shock absorbers in general, those rings simply adjust the preload on the shock's spring. If you unscrewed the rings, you lessened the preload so that the bike will drop lower when you are aboard. (This is what I think you did.) In suspension terms, you have increased the sag of the bike - the bike drops lower when loaded. You have taken up more of the available suspension travel before you even start moving, leaving less travel before the shock locks up from a bump in the road. If this happens when you are leaned over in a curve, the rear end could 'hop' - a disconcerting feeling (to say the least).

Raising the forks will bring the bike back to level for a static situation and will probably not have any adverse effects.

 

[670cc]

Forget the platform shoes - go stiletto heels.

Seriously, while I am not very familiar with the NC's suspension, looking at the service manual and from what I know about rear shock absorbers in general, those rings simply adjust the preload on the shock's spring. If you unscrewed the rings, you lessened the preload so that the bike will drop lower when you are aboard. (This is what I think you did.) In suspension terms, you have increased the sag of the bike - the bike drops lower when loaded. You have taken up more of the available suspension travel before you even start moving, leaving less travel before the shock locks up from a bump in the road. If this happens when you are leaned over in a curve, the rear end could 'hop' - a disconcerting feeling (to say the least).

Raising the forks will bring the bike back to level for a static situation and will probably not have any adverse effects.

If you adjust the shock/spring rings to lower the rear, it will lower the rear of the bike whether the bike is loaded or unloaded (if the shock is not at it’s physical limit on the unladen bike). You are simply changing the mounting point of one end of the spring with reference to the frame. Yes, reaching the end of suspension travel becomes more likely on bumps the more you lower it. The spring rate is unchanged.

Raising the forks an appropriate amount brings the steering geometry back towards where it was.

 

[WingMan71]

Then you need to invest in those platform shoes from the 70s. No bike too tall then!

Ha, don't laugh, I wore those back then!

 

[WingMan71]

If you adjust the shock/spring rings to lower the rear, it will lower the rear of the bike whether the bike is loaded or unloaded (if the shock is not at it’s physical limit on the unladen bike). You are simply changing the mounting point of one end of the spring with reference to the frame. Yes, reaching the end of suspension travel becomes more likely on bumps the more you lower it. The spring rate is unchanged.

Raising the forks an appropriate amount brings the steering geometry back towards where it was.

I'll be fine with my half-inch lowered bike.

1. My riding weight, with all gear on, is 145 lbs.
2. I'll never ride this bike 2-up.
3. I won't ever have loaded luggage on the bike.
4. At 75 years old this week, I'm a very conservative rider. (My days of ripping through the twisties are over.)

Thanks for all the replies!

 

[br549rick]

I'll be fine with my half-inch lowered bike.

1. My riding weight, with all gear on, is 145 lbs.
2. I'll never ride this bike 2-up.
3. I won't ever have loaded luggage on the bike.
4. At 75 years old this week, I'm a very conservative rider. (My days of ripping through the twisties are over.)

Thanks for all the replies!

thank you, sir, for your service to our country it is appreciated.

 

[Rydinon]

If you adjust the shock/spring rings to lower the rear, it will lower the rear of the bike whether the bike is loaded or unloaded (if the shock is not at it’s physical limit on the unladen bike). You are simply changing the mounting point of one end of the spring with reference to the frame. Yes, reaching the end of suspension travel becomes more likely on bumps the more you lower it. The spring rate is unchanged.

Raising the forks an appropriate amount brings the steering geometry back towards where it was.

"If you adjust the shock/spring rings to lower the rear, it will lower the rear of the bike whether the bike is loaded or unloaded...You are simply changing the mounting point of one end of the spring with reference to the frame." I'm not sure if we are both saying the same thing. If the OP relaxed pressure on the spring, that is removing preload - which holds the bike up at a given height.

The real proof would have been if he had measured the sag before making the change - both with the bike alone and with the rider on the bike. And then comparing it to the sag afterward. If the bike's reference point - say bottom of the license plate - dropped lower when he climbed aboard after tweaking, then he increased the sag. The whole point of using preload is to position the bike while laden, with about 2/3 of the shock's travel yet to go before lock-up.

 

[Donk]

Easiest and fastest way to lower your bike 1/2" would be to let the air out of the tires

 

[670cc]

"If you adjust the shock/spring rings to lower the rear, it will lower the rear of the bike whether the bike is loaded or unloaded...You are simply changing the mounting point of one end of the spring with reference to the frame." I'm not sure if we are both saying the same thing. If the OP relaxed pressure on the spring, that is removing preload - which holds the bike up at a given height.

Maybe it’s just a terminology choice thing, but there is no way to “relax pressure” on the installed and laden spring by adjusting the rings. The weight of the rider and bike compressing the spring is the same. Until a shock travel length is reached, the length of the spring is still the same, and the spring force pushing back on the bike is the same. The way to relax pressure on the spring is to unload the bike.

On an uninstalled (on the bike) spring/shock, the shock is fully extended, and adjusting the rings, pushing on the spring against the shock limit does compress the spring, hence the name preload. When the spring/shock is installed on the bike, and the bike loaded, the shock is not at limits. Adjusting the rings then does not compress the spring, it changes the ride height by altering the mounting point of one end of the spring. I think of preload as done when installing the spring on the shock body. Once installed, the “load” of the bike replaces the “preload”, the shock is not at travel limits, so the adjustment rings now affect sag/ride height. I really wish the term “preload” would go away, because is causes a misunderstanding of the function of the spring adjusters.

The real proof would have been if he had measured the sag before making the change - both with the bike alone and with the rider on the bike. And then comparing it to the sag afterward. If the bike's reference point - say bottom of the license plate - dropped lower when he climbed aboard after tweaking, then he increased the sag. The whole point of using preload is to position the bike while laden, with about 2/3 of the shock's travel yet to go before lock-up.

I agree on the sag comments. Some measurements would ascertain if the adjustments accomplished the goal without too much compromise in available suspension travel.

 

[Rydinon]

I really wish the term “preload” would go away, because is causes a misunderstanding of the function of the spring adjusters.

Then everyone could use their own terminology instead of learning what one word means and how it affects the shock's performance. (to bad we don't have an emoji for sarcasm)

 

[WingMan71]

Well...
Here's what Penske Racing Shocks says:

"The more preload, the HARDER the suspension is. The lower the preload, the SOFTER the suspension is.
But, preload and sag intertwine. Winding on preload RAISES the suspension, and removing preload LOWERS it.
If the ride height is too high, there is too little sag. A motorcycle riding near the top of its suspension travel might feel stiff and uncomfortable. If the ride height is too low and there’s too much sag, the motorcycle might feel unstable and move around too much.
As you can see, sag, spring rates, and preload all play a part in the perfect setup for your physical makeup, needs, and preferences."

Here's the full article:
Penske Racing Shocks - Motorcycle Spring Preload

 

[670cc]

Well...
Here's what Penske Racing Shocks says:

"The more preload, the HARDER the suspension is. The lower the preload, the SOFTER the suspension is.
But, preload and sag intertwine. Winding on preload RAISES the suspension, and removing preload LOWERS it.
If the ride height is too high, there is too little sag. A motorcycle riding near the top of its suspension travel might feel stiff and uncomfortable. If the ride height is too low and there’s too much sag, the motorcycle might feel unstable and move around too much.
As you can see, sag, spring rates, and preload all play a part in the perfect setup for your physical makeup, needs, and preferences."

Here's the full article:
Penske Racing Shocks - Motorcycle Spring Preload

When people read the first two sentences, they might immediately think that the preload adjustment makes the spring softer or stiffer, but in reality the spring rate is fixed. If you want a softer of stiffer spring, you’d need to replace it. Later in the paragraph, they do properly touch on raising and lowering, and sag and nearing suspension limits, which is where the feeling of softness and stiffness might come into play.

Trying to explain suspension adjustments and outcomes in one paragraph requires some simplification and vague explanations.

 

[WingMan71]

Trying to explain suspension adjustments and outcomes in one paragraph requires some simplification and vague explanations.

Agree. That's why I posted the link to the entire article.

Also agree that preload adjustments do not, and cannot, change the spring rate. That's fixed.

That said, moving the preload adjusters on a rear shock does in fact change the compressed length of the spring. That's one measurement I did take, and the 1/2" move of the adjuster rings resulted in a 1/2" change in the length of the spring. If this weren't true, then preload adjusters would be useless.

 

[670cc]

Agree. That's why I posted the link to the entire article.

Also agree that preload adjustments do not, and cannot, change the spring rate. That's fixed.

That said, moving the preload adjusters on a rear shock does in fact change the compressed length of the spring. That's one measurement I did take, and the 1/2" move of the adjuster rings resulted in a 1/2" change in the length of the spring. If this weren't true, then preload adjusters would be useless.

If the adjuster changed the spring length, then the shock was against the travel limit. Did you make this measurement with you on of off the motorcycle? If you were sitting on the motorcycle at some mid suspension travel, not against any stops or restriction, it is impossible for the adjuster to change the spring length. If you move one end of the spring, there is no more force on the other end than there was before (bike and rider weight unchanged), so the other end of the spring moves, too, keeping the length the same with no difference in compression.