Topic: Hmmmm, I have been told to cut the springs

[Really?]

Hey Y'all.  A few of you have suggested to me to cut the front springs a couple inches to lower the front end further than sliding the tubes up the tree's.  I can dig that.

I cannot find springs already cut and Progressive does not have any.  I read through the forums here looking for a description or a picture of what they did to cut thier springs.

How are y'all cutting the springs?  Straight cut or making it flat across the top/bottom of the springs like I have seen on uncut springs.  Are y'all cutting the top or bottom (if it matters)?

What is your method and what are you cutting them with? 

I wonder what the spring rate is changed to once they are cut.

[mlinder]

In my opinion. cutting springs is not a good idea.
look at the ends of the spring they are flat to spread out the load... and you will lose stiffness.... which is low on stock springs (which I think you have).
Why do you want to cut them? (havent seen the thread where people are telling you to cut them.)

[turboguzzi]

sorry, have to ask, who told you to cut the springs and what are you trying to achieve.

Although it's true that by cutting the springs you will:

1. lower the front end
2. have a stiffer spring rate

You will also reduce the available fork travel to absorb bumps, more chances of fork bottoming.

there will also be plenty of "free stroke" unless you put a spacer under the damper rod.

I did shorten them on my racer (for stiffer rate) but also added a spacer under the fork cap to maintain the right static sag.

I cut them with a grinder, bent the end so it touched the last coil and then ground the last bit flat. be sure to put the cut end at the top so it doesnt rub inside the tube

TG

[Really?]

I want to bring the front end down 2-3 inches.  I have slid the forks up the tree already to just about touching the bars.  The rear is already down two inches and hoping this rim order comes in so I get work on getting down a bit more on the 16" rim.  Seat foam has already been cut down.

The wife is inseam challenged.

http://forums.sohc4.net/index.php?topic=40612.msg418423#msg418423

[KingCustomCycles.com]

I cut every set on every bobber I build.  I remove 1-2 inches off the top of each spring with a muffler cut-off tool or die grinder with cutting wheel, if you prefer.  I cut at an angle and try to keep things as flat as possible. They will bottom more readily but with no rear brake either, I ride rather conservatively. 

[chrislib]

Mine are cut 1.5in. I cut the coils and then used an angle grinder to flatten the cut edge so the spring sits flat against the cap at the top of the fork. I`ve been riding the thing all summer with no ill effects, i.e. poor handling,bottoming out etc (altho I am a pretty conservative rider). If I were building the bike for performance or doing a resto I would not cut anything but my bike is neither so...

[dp2275]

i shortened stock 750 springs by 2" and installed them in cb500 fork tubes which are already almost 2" shorter than stock.  also slid the tubes up in the triples.  total lowering is around 4"...i do have some travel, but shes fairly stiff as it needs to be to prevent the headers from sittin on the ground 

[Really?]

I saw that pic during my searches on this subject, that is waaay low.

The fender does not hit the pipes when it bottoms?

[dp2275]

I saw that pic during my searches on this subject, that is waaay low.

The fender does not hit the pipes when it bottoms?

it would be close if it bottomed ALL the way, but the fender is also sitting an inch up off the tire.  there is more clearance than appears in the picture but im moving the fender mounting points so the fender tucks in closer to the tire anyways and then there shouldnt be any problems even under full compression.  the fender also gets a little close to the bottom of the headlight bucket..

[754]

Giga, you coud rake your frame..or make highpipes.. my frame is less than 5 inches off the ground.

 If you can fab you may consider the following, cut and lower the frame in the oil tank area, and make a new seat.. this will  require modding the oil tank, frame, and making sidecovers..

..or just build headers that are higher up..

[Really?]

Hey 754, you are a scary dude, JK.  You are putting ideas in my head and now I wonder if I can even get them accomplished.  I am not a fabricator but yanno, wish I had some of that talent.

• Let's see rake the front to drop it some, I have seen some and they look really nice.
• Have the frame cut and lowered under her backside.
• Make a new low seat.

Her inseam challenges would be over, so would a bunch of money I would assume.  I love the idea and my brain is a mess now, lol. 

[heffay]

giga... does your wife actually operate the bike?

i don't see what the problem is if all she does is sit behind you.

[Really?]

Hey, nope she does not operate the bike.  It was purchased for her to operate and me have a whole lotta fun making it that way and modding it.

I would not 2up this bike as I am spoiled to my XVZ12DN when it comes to that.  So, this would be a 1up bike but maybe take the kids around the block a few times too young to go any further.

Hopefully, someday, we can both ride together on our own bikes.  She is fine on the back of my bike but she would like her own too.

Oh, do not get me wrong, I will prolly ride the k5 too.  Once i get to a point with hers, I will want one for myself (I do already).

[heffay]

did you just say you're making a lowered bike for no one to operate?     

if you're wife will not be on it... why lower it for her?
if you're the only one on it... are you vertically challenged as well?
i don't think you're kids will be able to reach the ground for a while.   

[mystic_1]

If you're particularly ambitious, check out the www.hondachopper.com site and research a process that's come to be known as "Konging a frame".  It involves cutting up and rewelding the frame from the rear shock mounts to the downtubes, to give you something like this:



which can then be turned into something like this:



Some links to more info:

http://hondachopper.yuku.com/topic/8791/t/Konging-a-frame.html

http://www.hondachopper.yuku.com/topic/6205/t/konged-frame.html

http://www.negwebdesign.com/x/sohc750/kong/

http://konga750.blogspot.com/


There are some downsides to this approach that must be considered, and don't even think about it unless you're supremely confident in your welding, fabrication, and engineering abilities.

cheers
mystic_1

[Really?]

She does not operate it yet, she will when I can get it low enough for her.  I am not vertically challenged, I can handle a 32+ inch seat height.

She is good for a max 27" seat height.  This frame and seat is so wide it lowers her seat height ability.

[Really?]

Konging the frame looks like a kewl idea but someone else will have to do it.  Not looking for the chopper look though.

I want to keep what I think I am going for ( i could be wrong considering all the different views on styles) - cafe/bobber/old school mix.  Something I think I have seen a lot in the SOHC4 gallery.

[speedy gonzalais]

I wouldnt advise cutting the springs your self or getting any1 else to do it, I doubt you will get both springs exactly the same lenth and i think the cut ends will bend thru time and cause other problems as they wear. come to think of it the word dangerous just popped into my head. any right minded person wouldnt want to endanger there own life let alone suggest it to some one else!

[mystic_1]

• Let's see rake the front to drop it some, I have seen some and they look really nice.
• Have the frame cut and lowered under her backside.
• Make a new low seat.

Konging could accomplish all three of these things, you don't have to build a chopper to use the technique.  Just lower the seat rails without extending the front downtubes.

Of course, simply getting shorter front forks would probably be way easier.  You could also put sleeves on the damper rods to lower the shocks, similar to the Progressive Suspension front lowering kits for Harleys., look into those online for inspiration.  Do believe you'd have to cut the springs or get shorter ones to make that work.


mystic_1

[fuzzybutt]

get a set of cycle-x short for tubes and some shortened shocks, a cafe seat would also work for lowering the seat height as they usually use very little padding

[Really?]

get a set of cycle-x short for tubes and some shortened shocks, a cafe seat would also work for lowering the seat height as they usually use very little padding

I have emailed Ken and Sue at cyclex a couple times to see if they would cut a set of springs for me to go with these -2 tubes.  The reason for asking them about the springs is if he can build what he does, I would expect him to do the job of cutting them right.  But, I have not had a response from them.

I know they are backed up with recent issues but I thought they would have responded in some way other than none.

Done the 11" shocks on the rear already.  16" rim has arrived, still waiting on the spokes.  I have had a couple inches of foam removed from the seat too.  The wife wants to keep the king/queen.  She has seen the cafe seats and has been spoiled to the sofa on my XVZ12DN (she has fallen asleep back behind me a few times).  If and when the frame is konged, I will have to be quite inventive on the seat, lol.

[Triffecpa]

Cutting fork springs is not a dangerous or risky thing to do.  (Assuming that you don't manage to cut your finger off in the process).  You can grind the cut end flat on a bench grinder.  I've done it lots of times and they won't even consider my application for the Rocket Scientist club.

If you are going to shorten the forks, getting shorter tubes really isn't necessary.  Disassemble the forks and put a solid spacer into the bottom of the fork tube (the length of the spacer dictates how much shortened the fork will be) and then reinsert the damper rod and top out spring.  Reassemble the forks and then put your old spring in the top.  Mark it so that you get about an inch of preload on the spring with the cap installed.  Cut it with an angle grinder using a cut off wheel.  You can put a flat metal washer on top of the spring if you're worried about sharp ends etc, but generally grinding the end flat will alleviate any problems.  The springs are pretty captive inside the fork.  There isn't going to be lots of moving around of hard parts to wear anything out. 

Cut off the end of the fork spring that has the closely spaced coils.  The forks will be stiffer than before. 

Tracy

[heffay]

^ listen to that last guy!  i just rode his bike on the track this weekend and he's a definite tuner/race setup guy!  

and, my opinion?... he's right... grind it down, good as new.

[Really?]

Hey Tracy, thanks for the lowering steps on the forks.  Although, how that part works like that, I cannot quite grasp yet, I have so see it I guess and pictures I have seen does not make me see it in my mind.

Anyway, got a couple questions.  The spacers, what should they be made out of?  Read here http://forums.sohc4.net/index.php?topic=19405.msg202853#msg202853 that PVC pipe was used.  Will this hold?  Also, will I need a longer bolt?  Last question, with this setup, what weight oil would you recommend?

It would be interesting to make this work on the cheap.  Well, I guess I need a die grinder.

[754]

This should have been mentioned,

When the spring is cut the end should be heated and rebent in a manner that allows the spring to be ground flat, with it having contact most of the circle.. ie.. like the stock ends..


CB 450 forks are around3/4 inch shorter than CB 750 forks, and should have shorter springs.

I forgot why you did not want to slide them up a few inches, early 750 needs barbacks, but 77/78 I think allows them to go waaaayyyy up..

[heffay]

i have no problem sliding the forks up or down... my opinion, that's what they were designed to do more so than modifying parts.

i kinda like the looks of forks jammed up in your face.     if they don't go much or at all over the height of the controls, then there's not much of an issue here.

[Really?]

I think I have read the 550 are also a bit shorter.  I have slid the tubes up the tree's, I think I measured an inch, and they are really close to the bars.  I want to get a bit further down, more like two to maybe three inches.

[mystic_1]

The spacers, what should they be made out of?  Read here that PVC pipe was used.  Will this hold?

Here's how they do it at Progressive Suspension, Inc:




Installation instructions:

http://www.progressivesuspension.com/pdfs/updates/3055-110HarleyForkLowerKit.pdf

mystic_1

[Really?]

Yea, Mystic, you are right.  I know it is used for the preload.  I have PVC in the forks with the progressives on my XVZ12DN.  Now that you reminded me Mystic, I will try PVC for the Damper/Lower part of the tube.  Thanks!

[Really?]

Followed the image link, I hadn't seen those kits.  Too bad they do not make them for us.

[mystic_1]

Well, our forks are similar, so you could probably just double-up on the rebound springs like Progressive does.




Scavenge some off some used forks, or maybe someone here has a spare set you could nab.


mystic_1


Edit:

www.cmsnl.com sells them new:



mystic_1

[Really?]

I just looked that the pdf you linked.  Now it makes sense and I can visualize what I need to do.  

That second image is kewl, I hadn't found that one.  I can see where adding the additional rebound spring would work too.  This whole thing just got a whole lot easier looking!


Thanks a ton Mystic!

[Triffecpa]

yes, PVC pipe will work for the fixed spacer.  I use 20wt oil in the forks.  I pull the springs out, collapse the forks and fill them with oil to within 4" of the top of the fork tube.  Re-extend the forks, put the springs in and caps on and you're good to go.  If you find that the forks compress to the point where hard parts hit hard parts (ie wheel hits the pipe etc) then add a bit more oil to the fork.  You can adjust the fork to the point where it will hydraulically lock before things hit that weren't designed to touch.

TR

[Really?]

Thanks a lot for that finalization of the process and that great tip for the hydraulic lock.  If anyone needs to lower there forks, this has got to be the perfect thread!

Thanks again Tracy!

[754]

20 wt, seems light. I prefer heavier oil and a stiff fork action, when the bike is really slammed, you dont want a lot of travel.. a speed bump could give you a  nasty surprise

I never really built mine to go around corners fast..

[Triffecpa]

754. you might be right about heavier oil.  I typically build my stuff to roadrace and you want controlled action, but you do need the forks to move thru their stroke.

Tracy

[Really?]

I want to verify what I found in the manual is right for the torque on the allen bolt at the bottom of each fork.  I think the manual said, if I read it right, 32.5 to 39.8 ft. lbs.  Did I find the right torque setting?

Well, it appears someone else has been here before me as the tubes that were on it were 1" shorter than stock.  The springs stick out just under an inch from the top of the tube so it looks like I won't have to cut the springs, kewl.

Tower helped me figure out that missing inch.  http://forums.sohc4.net/index.php?topic=43545.msg452378#msg452378