Lowering the front end on a GS650?

[csw55]

Hey guys! I'm new to the forum, so I'm not familiar with the search feature. So I'm gonna come out and ask my question here:

I'm turning my gs650 into a boberish rig, and I have lowering the rear end figured out, but I'm reeeeeally wanting to lower the front.. I'm sure It's possible, somehow, but I was just wondering if anybody had any info or links that'd be helpful.

I found this guy's bobber online (gs650) that I absolutely love, and noticed the front end on his bike is significantly lower than stock... I'll post a pic of his and mine to let you compare. Thanks in advance for any help!

Mine:



His:

 

[wymple]

You can drop it some by bringing the forks up a little in the trees. Easily reversible if you don't like it.

 

[csw55]

You can drop it some by bringing the forks up a little in the trees. Easily reversible if you don't like it.

I'll probably try that first. Thanks for the input! I just noticed you're from SE Iowa. I'm from around the Knoxville, Oskaloosa, Pella area. Where are you located?

 

[wymple]

Just below Mt Pleasant, near Salem

 

[tkent02]

Shorter forks, shorter fork springs, smaller wheels.

 

[trippivot]

difficulty scale of 1-10 it is a 4

difficulty scale of 1-10 it is a 4

have you replaced your own fork seals before? it is that simple to internally lower them. Zip off the underside bolt and remove the upper spacer, the main spring then the lower dampening rod.

What you do is put a spacer under the dampening rod. -- you do not have to remove the main chrome tube from the lower slider -- if you do you probably have to replace the seal. Do the work over a oil drain pan because all the fork oil is going to come out.

PVC plastic tube is the standard spacer material. 1" 2" 3" your choice -- the 2nd thing to remember is to increase the upper spacer the same amount as the under (lowering) spacer.

As a side note the kick stand will probably need to be shortened.

 

[csw55]

have you replaced your own fork seals before? it is that simple to internally lower them. Zip off the underside bolt and remove the upper spacer, the main spring then the lower dampening rod.

What you do is put a spacer under the dampening rod. -- you do not have to remove the main chrome tube from the lower slider -- if you do you probably have to replace the seal. Do the work over a oil drain pan because all the fork oil is going to come out.

PVC plastic tube is the standard spacer material. 1" 2" 3" your choice -- the 2nd thing to remember is to increase the upper spacer the same amount as the under (lowering) spacer.

As a side note the kick stand will probably need to be shortened.

Thank you so much! I'm out of state, so I won't be able to try it until early next month. the seals in the forks need replaced anyways, so I'll probably just rebuild them, and do the mod while i'm in there. I'll be sure to take pictures. Thanks again!

 

[Steve]

Also keep in mind that your suspension travel will be reduced by the same amount that you lower it. :-k

If you lower it 2", your stock 4" of travel will be reduced to 2". Unless you change the spring rate (stiffen it considerably), you will be bottoming out an anything bigger than an expansion joint in the pavement.

You will soon see why these are "show bikes" not "road bikes". :-\\\

.

 

[csw55]

Also keep in mind that your suspension travel will be reduced by the same amount that you lower it. :-k

If you lower it 2", your stock 4" of travel will be reduced to 2". Unless you change the spring rate (stiffen it considerably), you will be bottoming out an anything bigger than an expansion joint in the pavement.

You will soon see why these are "show bikes" not "road bikes". :-\\\

.

:-k hmmmm. good point.. I guess i'll be researching some stiffer springs lol!

 

[Steve]

Sonic Springs has multiple rates for most bikes (and the owner of the company is a member here

).

Might check on the rates that are available, maybe even have a chat with Rich Desmond (the owner) to see what he suggests.

Keep in mind that cutting coils off the spring will increase the rate of what is left.

.

 

[wymple]

Sliding the forks up in the trees maintains the suspension travel, tho.

 

[csw55]

Sliding the forks up in the trees maintains the suspension travel, tho.

That's true, but I don't want fork tubes sticking up past the bars. I might do a little of both to achieve the desired drop. Thanks for the help, guys!

 

[csw55]

This may be a dumb question, so please don't snap at me. I'm dissasembling my gs650 forks, to cut the spring, and add the spacer. Well I don't know how to get the spring out . On the top, theres the air valve, and on the bottom, its just a seal (at least i think). Does the spring and dampening rod come out the top of the fork, or the bottom?!? Again- I apologize if this is a stupid question, but I'm a stupid person haha. Thanks for any advice. Here's what the top of the fork and the bottom look like.

 

[csw55]

Nevermind. I forgot I owned a repair manual for the bike. hahaha. For anybody reading this, and having the same issue I ran into:

You press down on the air valve, which will allow you to get to a keeper/snap ring. pull that ring out, then boom, spring comes right out.

I'll update this thread with the finished product when I get them back together and on the bike.

 

[Steve]

Nevermind. I forgot I owned a repair manual for the bike. hahaha. For anybody reading this, and having the same issue I ran into:

You press down on the air valve, which will allow you to get to a keeper/snap ring. pull that ring out, then boom, spring comes right out.

Yep, in that first picture you posted, you can see the gap in the retainer ring at about the 4 o'clock position.
Press on the disk that holds the air valve to release pressure on the ring, pry it out. :encouragement:

.

 

[csw55]

Done!

Done!

I finally got around to doing the job! I machined a couple spacers at school (i'm in a machining program) out of aluminum. A lot of people i see online use 1" OD 3/4" ID pieces of PVC, and even though I'm sure they'd work fine, i just felt more comfortable using aluminum. I wasn't sure how low to go, but I eventually decided on 2.5".
Here's a pic of the spacers after I machined them on the CNC.

You'll need to cut about the same amount as the spacer off the top of the spring. I cut 2.25" off the spring, that way I had a little preload.

Here's the first fork I did, next to the other stock fork.

And here's how she looks now!

 

[Steve]

Looks very good. :encouragement:

Hope it works as well as it looks. :-k

I am glad it's your bike, it would never fit me.

.

 

[hillsy]

Seeing as you have lost some travel in your forks, you might want to make up some spacers for the upper springs and cut off a few more coils.

The fewer coils you have in the springs, the stiffer they become.

 

[csw55]

Seeing as you have lost some travel in your forks, you might want to make up some spacers for the upper springs and cut off a few more coils.

The fewer coils you have in the springs, the stiffer they become.

Could you explain? I guess I'm not sure what you're meaning.

 

[Crankthat]

I think what he is trying to say.
You have less travel/room for your front end.
More likely to bottom out/jar and cause damage or failure.
Less coils but space taken up with spacers will cause stiffening of springs=less likely to bottom out/jar as the now stiffer springs will flex less with impact and thus less chance of reaching the bottom out point.
Not sure if he is correct in that but it makes sense to me.
How stiff is too stiff though?