Reducing fork height with shorter springs

[Nissbird]

Hi,
Reducing fork height with shorter springs - does anyone have experience of this? Specifically using Wilbur 40mm shorter springs.
Regards

 

[Nikolajsen]

No, I have not.
But please be aware, that you WILL change the behavior of the bike. And 40mm is a lot

 

[Nissbird]

With the rear lowered 40mm as well, I do not think the dynamics will alter at all.

 

[Nikolajsen]

With the rear lowered 40mm as well, I do not think the dynamics will alter at all.

Åh..didn't know that you also will lower the back.
That will help a lot on behavior

 

[Madhatter]

be cheaper and easier to lower them (forks ) in the triple clamps , loosen the bolts a bit and slide the forks up , 25mm at first maybe a little more if needed . remember there is sag and compression when you sit on the bike. then you can do a lowering link out back to balance the bike.... 25mm is about an inch plus the inch you get by the low seat position , that's about 50mm or 2 inches lower . I would try that before replacing the fork springs .

 

[Nissbird]

Done all that

 

[EricV]

The geometry doesn't work that way. Inverted forks, that are not the same O. D. for the entire length. You won't be able to safely slide the fork tubes up into the triple trees 25mm, nor do you want to.

1" lowering links in the rear need 13mm fork raise to balance the geometry again.

Forget about shorter fork springs. Better still, seat work and taller boot soles.

And yes, I have lowered a Super Ten and know what I'm talking about.

 

[Madhatter]

I guess that slams the door shut on that problem, really , thicker boot soles.... sad to be inseamed challenged I think.... Harley makes their living on those...

 

[EricV]

I guess that slams the door shut on that problem, really , thicker boot soles.... sad to be inseamed challenged I think.... Harley makes their living on those...

Or simply accept that maybe it's time for a different bike. Lowering a Super Ten 40 mm will pretty much destroy the bike in terms of what it's designed to do. Even at 25 mm lowering links, bottoming out mid corner if the pavement was anything but smooth was not all that uncommon.

I know several short inseam riders that ride tall bikes and just have learned to slide off one side when they come to stops. Yes, they have to plan their stops and sometimes it's tricky. I know another handful of riders that do have thicker soles. Either thru a cobbler or boots that come with thicker soles. I'd do custom seat work first. You can easily get another inch lower than the factory low seat.

A wise man once told me: "Don't try and make the bike into something it's not." It's never going to be light. It's never going to be a 24" seat height bike. 30" seat height is probably not realistic.

 

[The Ferret]

Narrowing the seat helps a lot, without losing the overall height/comfort.

 

[Madhatter]

so ,curious here, what is your inseam nissbird ? all that's left to suggest other than buy a trials bike and mount a seat on it , would be to trim the tread off the tires , might get a quarter inch there...

 

[Madhatter]

we ain't helping much....

 

[Nissbird]

Thanks for the comments gentleman.
This is my second ST, I like riding this bike more than any other bike I have owned and am quite happy to ride all the daylight hours I can get. However at 5' 6" in height and weighing only 11.5 stone (161 lbs in US speak) and with a "stark bollock" naked inside leg of 29.5", controlling the bike at traffic lights and junctions is precarious and fraught with danger especially kitted up and with my Wife as pillion. Yes, short guys can ride these bikes no problem, but 275KG with legs fully stretched and on the balls or even toes of their feet is too risky IMHO.
Previously I dropped the forks 10mm and the rear 20mm to get the seat height down from 845mm to 830mm and in combination with some excellent Sidi Canyon Boots made it possible for me to get the balls of both feet on the ground which has been sufficient until my trips to Scotland highlighted:
• That I consider myself particularly fortunate to have not developed a hernia
• Forgot to take the chain lock off the front wheel and found I couldn’t hold it when I tried to take off and consequently dropped it on pebbles
• Bike blew over in a gale at a petrol station due to its upright posture on the side stand

To rectify the above and because I do not ride off road or crank the bike right over, I have decided to:
• Lower front 40mm – have purchased Wilber front springs £143 + fitting
• Lower rear 40mm - make some dog bones – I’ve done it before on a previous post
• Get the seat reshaped.
• Reduce side stand by 40mm(shall have to check the geometry first)
• Remove main stand

I could buy another bike but it won’t have the things a ST gives me. I challenge all to name another bike with the same spec and ergonomics as my XT1200ZE but has a 40mm lower seat?

 

[Checkswrecks]

Thanks for the comments gentleman.
This is my second ST, I like riding this bike more than any other bike I have owned and am quite happy to ride all the daylight hours I can get. However at 5' 6" in height and weighing only 11.5 stone (161 lbs in US speak) and with a "stark bollock" naked inside leg of 29.5", controlling the bike at traffic lights and junctions is precarious and fraught with danger especially kitted up and with my Wife as pillion. Yes, short guys can ride these bikes no problem, but 275KG with legs fully stretched and on the balls or even toes of their feet is too risky IMHO.
Previously I dropped the forks 10mm and the rear 20mm to get the seat height down from 845mm to 830mm and in combination with some excellent Sidi Canyon Boots made it possible for me to get the balls of both feet on the ground which has been sufficient until my trips to Scotland highlighted:
• That I consider myself particularly fortunate to have not developed a hernia
• Forgot to take the chain lock off the front wheel and found I couldn’t hold it when I tried to take off and consequently dropped it on pebbles
• Bike blew over in a gale at a petrol station due to its upright posture on the side stand

To rectify the above and because I do not ride off road or crank the bike right over, I have decided to:
• Lower front 40mm – have purchased Wilber front springs £143 + fitting
• Lower rear 40mm - make some dog bones – I’ve done it before on a previous post
• Get the seat reshaped.
• Reduce side stand by 40mm(shall have to check the geometry first)
• Remove main stand

I could buy another bike but it won’t have the things a ST gives me. I challenge all to name another bike with the same spec and ergonomics as my XT1200ZE but has a 40mm lower seat?

I love the enthusiasm and "can do."


Just watch for bottoming on the skid plate (assuming you have one) in the corners.

 

[EricV]

Nissbird - After you do this and realize the consequences, then return it to the 20mm lowering and correct the side stand, you will realize one of two things. You're either in the market for a R1200GS Low suspension, Low seat bike, or you will be spending some more time at the gym to build strength.

I have a 29" inseam, 17.5 stone and typically my bike is well loaded with extra fuel, a gallon of water and a full pannier of tools, etc, plus the other pannier full of clothes. Not quite as heavy as having a pillion. I wear Gaerne G Midland boots and only get my toes or sometimes the ball of my foot down at stops. I also have custom suspension at stock height levels, no lowering there. (Touratech/Ohlins) and a custom Russell Day Long seat. The seat moves me up another 25mm over the stock seat.

Nothing you have described warrants lowering the bike at all. With a 20mm lowering, you're doing something else wrong if that wasn't enough. This is my second Super Ten as well, Gen I in '11 and now a Gen two earlier this year. Neither bike lowered. I did lower by 25mm dogbones and 13mm drop in front for my wife to ride. She did fine with that and is 5'6" and 10 stone. She decided not to buy a Super Ten and got a R1200GSA Low/Low instead. (Twice the bloody cost!) She loves that bike and rides it well, even in Enduro Pro mode which moves the suspension up quite a ways.

You have ignored the first response to being inseam challenged. Get a custom seat! One that gives you a lower height.

Sorry to beat you up M8, but you are heading for an unpleasant situation. We all have the odd drop or tip over. Being able to flat foot when stopped won't help when you have loose pebbles and odd angles, it will still go over. Pillion challenges sometimes mean for extra struggle at stops. I understand that. Extra attention and planning and good communication go a long way to account for this.

You will do what you will do. All I'm saying is that you will regret dropping the bike 40mm. And speak to a proper suspension shop before you order your springs. Dropping the front 40mm with shorter springs is not going to maintain the proper geometry. Not to mention spring rate impact. The bike will have very slow turn in with 40mm shorter springs in front and 40 mm dogbone drop. Which means longer dogbones, but not 40mm longer.

Best of luck and I hope I'm wrong and it's brilliant for you.

 

[patrickg450]

I love the enthusiasm and "can do."


Just watch for bottoming on the skid plate (assuming you have one) in the corners.

stole my thunder.........

I am short, bad short. I lowered my bike with Jaxon's links. I then lowered the tubes in the front clamps as much as you can (safely) and it was only about 7/16, I believe less. I hear these folks that lower it like inch to inch and a half, and I am like WTH???? I have no idea what they are speaking of.

Now on to Big Bad Bob's point. I tried another lower seat and was able to return my bike to stick links. The people at ACD have thanked me, I killed that thing. Jaxon's bash plate will be next as I doubt they will give me another one.


PG

 

[Nissbird]

No skidplate Checkswrecks

Thanks for your take on this EricV, its much appreciated, especially about the shorter spring and longer dog bone behaviour but I'm determined to try it, if I don't like it I can always change it back.
At 17.5 stone you are 50% heavier than I am and I believe better able to handle a tall heavy bike.
The springs are coming and Wilbers UK will be fitting them for me. Regarding the dog bones I did this earlier:

http://www.yamahasupertenere.com/index.php?topic=20797.msg298920#msg298920

The ratio is 1:3.57, so theoretically an increase from the stock of 118mm to 128.7mm will give me a 40mm difference, if not I shall just laser cut some more.
I will measure the height of the rear wheel before and after to check

 

[Nissbird]

Hi EricV,

At 245 lbs you have a 1:2.47 ratio with a ST and at 161 lbs I have a 1:3.76 ratio.

Shown like this I think demonstrates your chances of holding it up are considerable better than mine.

 

[Overlander]

At the end of the day experimentation is the name of the game.

 

[EricV]

Yes, I am fat.

I do have a much stiffer spring on the shock and the 30mm Ohlins kit in the forks. My bike is taller than stock. Still, I see your point. Much is about the balance point. After that, we all struggle.