Front suspension questions
Thread Starter
Senior Member
Superstock
Joined: Jan 2006
Posts: 402
From: Florida
Front suspension questions
When I ride into a driveway I get a "BANG" sound and feeling as the front wheel crosses the road to apron transition bump. It feels like the tire has suddenly gone flat and I hit the rim. 
With the bike standing still, I can compress the forks quickly enough to barely dupplicate the sound. I put tywraps on the forks to gauge the fork travel while riding. The tywraps emd up at 1 1/5 inches from the bottom of the tripple, and 2 3/4 of an inch up from the resting state measured at the fork seal. I do not think this indicates bottoming (???). The bang comes in the last inch or so of travel.
Is this something common to the SHawk
Thanks
With the bike standing still, I can compress the forks quickly enough to barely dupplicate the sound. I put tywraps on the forks to gauge the fork travel while riding. The tywraps emd up at 1 1/5 inches from the bottom of the tripple, and 2 3/4 of an inch up from the resting state measured at the fork seal. I do not think this indicates bottoming (???). The bang comes in the last inch or so of travel.
Is this something common to the SHawk
Thanks
Senior Member
SuperSport
Joined: Mar 2005
Posts: 758
From: Laurel, MD
One of the best modificatons you'll make is to get weight-matched springs for the forks.
The fork springs are very soft. So, depending on your weight, yes, its a common problem.
www.racetech.com is one source.
The fork springs are very soft. So, depending on your weight, yes, its a common problem.
www.racetech.com is one source.
Senior Member
SuperSport
Joined: Dec 2004
Posts: 764
From: Nananimo, B.C.
Re: Front suspension questions
Springs alone wont fix what your talking about. I believe your referring to hydraulic lock that occures when too much fluid is trying to go through too small a valve therefore it feels like its bottoming out.
You need:
1) weight matched springs
2) Racetech compression valves which allow more fluid to flow
You need:
1) weight matched springs
2) Racetech compression valves which allow more fluid to flow
Thread Starter
Senior Member
Superstock
Joined: Jan 2006
Posts: 402
From: Florida
Re: Front suspension questions
I have looked at both Racetech and Traxxion Dynamics and found the springs and valves I'd need. Are there any others to consider?
A lot od folks seem to prefer Racetech is there any benefit from one or the other.
I've also seen a piece about reshaping the damper needle with a bench grinder to give a full taper and lose the square off. This seems a bit extreem, would it really make much difference? Have any of you done this with significant success?
Wieghing about 178 and will be riding mostly street, any suggestions on fork oil wieght. I'm not looking for razor sharp (stiff) track handling, I want to be able to ride for an hour or so with out getting pummeled by the bike. I do have places to play in tight twisties but this would not be the norm.
Thanks for the input.
A lot od folks seem to prefer Racetech is there any benefit from one or the other.
I've also seen a piece about reshaping the damper needle with a bench grinder to give a full taper and lose the square off. This seems a bit extreem, would it really make much difference? Have any of you done this with significant success?
Wieghing about 178 and will be riding mostly street, any suggestions on fork oil wieght. I'm not looking for razor sharp (stiff) track handling, I want to be able to ride for an hour or so with out getting pummeled by the bike. I do have places to play in tight twisties but this would not be the norm.
Thanks for the input.
Moderator
MotoGP
Joined: Dec 2004
Posts: 2,553
From: South Texas
Re: Front suspension questions
Bird,
Ohlins also offer springs.
My superhawk forks came with the rebound rod mod and racetech springs. I later added the racetech compression valve. It's been too long since my last 98 with stock forks to accurately compare the two on just the rod mod aspect but they are worlds apart in operation and smoothness.
I doubt many folks would tear apart the forks and ONLY do the rod mod. I'd suspect they would also drop in springs, fluid and/or valves while the had everything apart.
You'll need to run the wt oil that's recommended by the suspension folks you settle on.
Aloha, dude.
Ohlins also offer springs.
My superhawk forks came with the rebound rod mod and racetech springs. I later added the racetech compression valve. It's been too long since my last 98 with stock forks to accurately compare the two on just the rod mod aspect but they are worlds apart in operation and smoothness.
I doubt many folks would tear apart the forks and ONLY do the rod mod. I'd suspect they would also drop in springs, fluid and/or valves while the had everything apart.
You'll need to run the wt oil that's recommended by the suspension folks you settle on.
Aloha, dude.
Senior Member
SuperSport
Joined: Mar 2005
Posts: 758
From: Laurel, MD
Well lets start with a couple of questions. How much do you weigh? And what is your sag with you mounted on the bike?
In all liklihood your problem is not hydraulic, its mechanical. If so, the springs will fix it for about a fourth of the combined cost. Then you can properly evaluate your damping. You may just determine that its perfectly adequate.
While you are at it, consider 10w fork oil.
In all liklihood your problem is not hydraulic, its mechanical. If so, the springs will fix it for about a fourth of the combined cost. Then you can properly evaluate your damping. You may just determine that its perfectly adequate.
While you are at it, consider 10w fork oil.
Thread Starter
Senior Member
Superstock
Joined: Jan 2006
Posts: 402
From: Florida
Re: Front suspension questions
The scale says 180lb.
As for the sag I will need to recruit some help to check it properly so hopefully I can get that this week end. I'll let you know what I find.
Allthough I may end up going to the upgraded springs, valves, and rod mod, I think Jim has a good point in checking one thing at a time.
Thanks for the reminder on Ohlins springs.
The more choices the better.
Aloha
As for the sag I will need to recruit some help to check it properly so hopefully I can get that this week end. I'll let you know what I find.
Allthough I may end up going to the upgraded springs, valves, and rod mod, I think Jim has a good point in checking one thing at a time.
Thanks for the reminder on Ohlins springs.
The more choices the better.
Aloha
Thread Starter
Senior Member
Superstock
Joined: Jan 2006
Posts: 402
From: Florida
Re: Front suspension questions
LOL.
I am already Shocked and awed at the sinking feeling of the stock set up.
I hope to be rebounding with joy using the improvements you have suggested.
I appreciate the advice and candor I find at this forum and hope I can keep up WIT all of you.
I am already Shocked and awed at the sinking feeling of the stock set up.
I hope to be rebounding with joy using the improvements you have suggested.
I appreciate the advice and candor I find at this forum and hope I can keep up WIT all of you.
Thread Starter
Senior Member
Superstock
Joined: Jan 2006
Posts: 402
From: Florida
Re: Front suspension questions
Hooray!!!
I figured out what I need to fix my suspension.
It is a very special spring that makes the ride much smoother so you can go much faster.
Has anyone ever used this kind of spring???
Does it work as advertised???
I figured out what I need to fix my suspension.
It is a very special spring that makes the ride much smoother so you can go much faster.
Has anyone ever used this kind of spring???
Does it work as advertised???
Thread Starter
Senior Member
Superstock
Joined: Jan 2006
Posts: 402
From: Florida
Re: Front suspension questions
As luck would have it, I was able to ride the 1999 F4 that was in the shop when I was working on my forks a couple weekends ago. I checked for accident damage (bent or mis aligned forks) changed to a heavier fork oil wt and increased the oil level. Some temporary improvement was achieved, and bottoming is not as harsh.
Aside from the adjustable compression setting and 2mm larger tubes both bike's forks appeared very similar inside and out. The F4 fork springs are closer to my weight.
Coming off the side stand the F4 does not drop down in the front like the Super Hawk does. Sitting on the F4 I instantly noticed the seat moved down under my weight (compliant), while the Super Hawk's seat doesn't seem to move at all. Interesting that both bikes are sprung oppositely. On the road the F4 is a dream. Over bumps the rider and chassis float while the suspension does all the work. No getting bounced off the seat and thrown about. Maintaining a steady throttle was no effort over potholes, construction plates, and rough roads. Now I have a benchmark for the next phase of suspension work on the SHawk. Springs should be here any day now. I think they are coming by row boat.
Aside from the adjustable compression setting and 2mm larger tubes both bike's forks appeared very similar inside and out. The F4 fork springs are closer to my weight.
Coming off the side stand the F4 does not drop down in the front like the Super Hawk does. Sitting on the F4 I instantly noticed the seat moved down under my weight (compliant), while the Super Hawk's seat doesn't seem to move at all. Interesting that both bikes are sprung oppositely. On the road the F4 is a dream. Over bumps the rider and chassis float while the suspension does all the work. No getting bounced off the seat and thrown about. Maintaining a steady throttle was no effort over potholes, construction plates, and rough roads. Now I have a benchmark for the next phase of suspension work on the SHawk. Springs should be here any day now. I think they are coming by row boat.
Moderator
MotoGP
Joined: Dec 2004
Posts: 2,553
From: South Texas
Yeah, I had an F4i for a short while a couple years back. Here's what I did:
https://www.superhawkforum.com/viewtopic.php?t=1949
https://www.superhawkforum.com/viewtopic.php?t=1949
Thread Starter
Senior Member
Superstock
Joined: Jan 2006
Posts: 402
From: Florida
Re: Front suspension questions
Darn it Bling!
I had all but put that mod out of my mind. Now you got me thinking more seriously of the F4 front. My back would love loosing the clipons, and I'd have a good use for my extra dive weights. I'll strap them to the upper fairing mount to balance the weight distribution change. Ah Nirvana!
:wink:
Very nice job BTW!
I had all but put that mod out of my mind. Now you got me thinking more seriously of the F4 front. My back would love loosing the clipons, and I'd have a good use for my extra dive weights. I'll strap them to the upper fairing mount to balance the weight distribution change. Ah Nirvana!
:wink:
Very nice job BTW!
Thread
Thread Starter
Forum
Replies
Last Post
luiggispeed
Technical Discussion
3
Aug 16, 2005 09:00 PM
