Technical Discussion Topics related to Technical Issues

Exhaust Clearance Fix?

Thread Tools
 
Search this Thread
 
Old 05-25-2011, 06:36 AM
  #1  
OUCH... MY A$$ HURTS!!!
SuperSport
Thread Starter
 
joshuatest's Avatar
 
Join Date: Dec 2007
Location: Elba, Ny
Posts: 707
joshuatest is an unknown quantity at this point
Exhaust Clearance Fix?

Ok,

I've been searching for the last couple day's on what kind of options I have here.

Problem... That damn exhaust header pipe on the right side of the bike has made ground contact on many occasions during right hand turns at not so crash friendly speeds... My fear is that with the right camber of the road, that the pipe will actually lift just enough weight up to make me loose rear wheel traction for a moment, which would result if i'm lucky in a low side, or worse, if the tire regains traction, a violent high side...

This ground contact is typically only happening in race or closed course type settings where bike lean is at its most, but the fact that it happens at all is scary...

Yesterday I took my lower fairing off (RC51 fairings) and took the bike to a good friends exhaust shop, and we debated how we could fix the issue... From looking at the bike, I thought we could cut the header pipe, and kinda redirect it upwards from its current location, where it would pretty much be right where your oil level window is, but the problem with that, the oil line that sits just above the exhaust pipe now, would be right next to the pipe, and even with exhaust rapping, i still don't feel comfortable laying the pipe right there...

The other, and probably larger issue is the Y section is so close to the oil pan, that cutting and making it reconnect before the Y is gonna be a feat in its own...

Everything I have seen after market for full systems looks like it routes the same place... Some look like larger diameter tubing, which in my case would be worse...

My front suspension was sprung by greg, and I've had help setting it, so i should be properly set up there. My rear is stock, with it set on the stiffest settings, which isn't even close to right for my 218lb ***....

Has anyone had this issue come about?

I really like my bike, but I'm getting into track day's a few times a year, and with the type of riding I'm blessed with here in Kentucky, I'm thinking I might be better suited to just sell the thing and find me a bike that has proper ground clearance for the track...

Any idea's on getting that damn pipe moved? or do you think i'm its strictly a rear suspension issue? ---which i suppose it could be...
joshuatest is offline  
Old 05-25-2011, 06:51 AM
  #2  
Senior Member
SuperSport
 
mboe794's Avatar
 
Join Date: Jul 2008
Location: Twin Cities
Posts: 505
mboe794 is on a distinguished road
I had this problem when experimenting with fork height. Pulling the forks up too much was obviously the primary cause. Drop them a little, if they are raised, and shim the shock. Or stiffer fork springs to get the sag right, if you haven't done that already.
mboe794 is offline  
Old 05-25-2011, 07:06 AM
  #3  
Senior Member
SuperSport
 
mboe794's Avatar
 
Join Date: Jul 2008
Location: Twin Cities
Posts: 505
mboe794 is on a distinguished road
Looks like you already have springs. I missed that part on the first read. In that case you might wanna look into a shock from Jaime. I am very satisfied with mine, along with many other members here. I would imagine the added length that he incorporates into them with the correct spring should fix the problem.
mboe794 is offline  
Old 05-25-2011, 07:11 AM
  #4  
OUCH... MY A$$ HURTS!!!
SuperSport
Thread Starter
 
joshuatest's Avatar
 
Join Date: Dec 2007
Location: Elba, Ny
Posts: 707
joshuatest is an unknown quantity at this point
Originally Posted by mboe794
I had this problem when experimenting with fork height. Pulling the forks up too much was obviously the primary cause. Drop them a little, if they are raised, and shim the shock. Or stiffer fork springs to get the sag right, if you haven't done that already.
Greg did my forks, based on my weight. I did slide them just slightly up when reinstalling, but that was based on them being stiffer, to get same ride height. They are probably only moved upward about 1/4 inch max... do you think they are to far?

My rear shock is something I'm sure I need to deal with, but when considering the cost of the rear shock, some rear sets, and possibly exhaust work to solve my problem, I keep debating if I should just sell and buy a bike more suitable for the track, which I have a feeling i'm gonna spend more and more time at...

there is a 03 RC51 for $3600 locally I have debated just dropping the mine down to like $3000 and seeing if it would sell quickly... I've got Micron high mounts, scotts damper, RC51 fairnigs, Ducati 999 projector light, and one owner with 11k on it... Brand new 2CT's with about final 3 sessions of last track day on them...

I love the bike.... Don't feel that I need any more power, its delivery is right on! I think I would be pleased and disappointed with the RC... Its just a whole other bike. I just hate dropping more money into the SH to make it where i need it to be for my riding style when I'm sure i could flip flop bikes for less...
joshuatest is offline  
Old 05-25-2011, 07:23 AM
  #5  
OUCH... MY A$$ HURTS!!!
SuperSport
Thread Starter
 
joshuatest's Avatar
 
Join Date: Dec 2007
Location: Elba, Ny
Posts: 707
joshuatest is an unknown quantity at this point
looks like a trackday photo... have you had to get rearsets?
joshuatest is offline  
Old 05-25-2011, 09:23 AM
  #6  
Senior Member
SuperSport
 
mboe794's Avatar
 
Join Date: Jul 2008
Location: Twin Cities
Posts: 505
mboe794 is on a distinguished road
I wouldn't think 1/4 is too much. Mine is at about 1/2 an inch. With 1kg springs. Shim that shock! Either use some washer or cut a U shaped hunk of metal, about 6mm thick, to slide between the upper mount. Cheap and easy.
mboe794 is offline  
Old 05-25-2011, 09:24 AM
  #7  
Out of my mind, back in 5
MotoGP
 
Tweety's Avatar
 
Join Date: Nov 2006
Location: Skurup, Sweden
Posts: 6,109
Tweety is on a distinguished road
Originally Posted by joshuatest
Greg did my forks, based on my weight. I did slide them just slightly up when reinstalling, but that was based on them being stiffer, to get same ride height. They are probably only moved upward about 1/4 inch max... do you think they are to far?

My rear shock is something I'm sure I need to deal with, but when considering the cost of the rear shock, some rear sets, and possibly exhaust work to solve my problem, I keep debating if I should just sell and buy a bike more suitable for the track, which I have a feeling i'm gonna spend more and more time at...

there is a 03 RC51 for $3600 locally I have debated just dropping the mine down to like $3000 and seeing if it would sell quickly... I've got Micron high mounts, scotts damper, RC51 fairnigs, Ducati 999 projector light, and one owner with 11k on it... Brand new 2CT's with about final 3 sessions of last track day on them...

I love the bike.... Don't feel that I need any more power, its delivery is right on! I think I would be pleased and disappointed with the RC... Its just a whole other bike. I just hate dropping more money into the SH to make it where i need it to be for my riding style when I'm sure i could flip flop bikes for less...
Dude... doesn't matter what you weight, what you have done to your forks or shock... The basic problem is bodyposition, not the routing of the header... If you are scraping hard parts your bodyposition is wrong, as simple as that... That's the basic problem, if you want to deal with it or not, that's your issue...

As for dropping the forks 1/4 inch... Well I'd say 5 mm or so is the most you can drop the forks without changing anything else, before you create a clearance problem...

1/4 inch is 7 mm, so you are in the trouble zone... Either pull the forks back up, or raise the rear with a shim...

Those two things together will give you all the ground clearence you need... If you manage to scrape hard parts with that done, your body position is definetly wrong... Re-routing the header will only mean you find other things to grind, until you do have an off...

Also, the rear shock is an issue when you start doing track-days... I'd consider that more important than the rest of your list of upgrades... But that's just my opinion...

The right shock, setup for your weight will give you a couple of mm more clearance in the rear... If you go the route suggested and have Jamie help you, he will add the lenght of the shims with converting the shock unless you specifically opt out, so it's kind of a known "fix" for handling...
Tweety is offline  
Old 05-25-2011, 09:43 AM
  #8  
Banned
MotoGP
 
8541Hawk's Avatar
 
Join Date: Aug 2007
Location: Lake View Terrace, CA
Posts: 5,942
8541Hawk will become famous soon enough
Originally Posted by Tweety
Dude... doesn't matter what you weight, what you have done to your forks or shock... The basic problem is bodyposition, not the routing of the header... If you are scraping hard parts your bodyposition is wrong, as simple as that... That's the basic problem, if you want to deal with it or not, that's your issue...

As for dropping the forks 1/4 inch... Well I'd say 5 mm or so is the most you can drop the forks without changing anything else, before you create a clearance problem...

1/4 inch is 7 mm, so you are in the trouble zone... Either pull the forks back up, or raise the rear with a shim...

Those two things together will give you all the ground clearence you need... If you manage to scrape hard parts with that done, your body position is definetly wrong... Re-routing the header will only mean you find other things to grind, until you do have an off...

Also, the rear shock is an issue when you start doing track-days... I'd consider that more important than the rest of your list of upgrades... But that's just my opinion...

The right shock, setup for your weight will give you a couple of mm more clearance in the rear... If you go the route suggested and have Jamie help you, he will add the lenght of the shims with converting the shock unless you specifically opt out, so it's kind of a known "fix" for handling...
or yeah what he said......
8541Hawk is offline  
Old 05-25-2011, 06:10 PM
  #9  
OUCH... MY A$$ HURTS!!!
SuperSport
Thread Starter
 
joshuatest's Avatar
 
Join Date: Dec 2007
Location: Elba, Ny
Posts: 707
joshuatest is an unknown quantity at this point
I'm going to have to disagree here...

The bike is known for poor ground clearance, thats no secret.

As for the forks moved up, I didn't do this for cosmetic change, this was because the bike front end sat higher after having forks sprung, and this was suggested when I reinstalled them.

I'm in Ky, where we have some seriously blessed roads... Lots of hills and curves... And I'm not dragging pipe on just any turn, its when the camber of the road is just right.

For instance, at Nashville Speedway in turn 6 (i think) last right before turning left onto the back straight... The road comes up at you, so if i'm leaned in, as I cross the center of that raised section, my pipe drags...

I'm going to measure the amount of change in my forks... Can someone who has properly sprung front forks please measure the amount of tube above the tree for me? And I'll go ahead and shim the rear shock for now, and see about having it modified after June 4th's event.

I'm no professional, but I think my body position is pretty good guy's... I didn't buy the bike to do track day's on it, but after moving to Kentucky, the roads just talked me into riding harder!

Thanks for the help, if someone will post that measurement, I would appreciate it...
joshuatest is offline  
Old 05-25-2011, 09:16 PM
  #10  
OUCH... MY A$$ HURTS!!!
SuperSport
Thread Starter
 
joshuatest's Avatar
 
Join Date: Dec 2007
Location: Elba, Ny
Posts: 707
joshuatest is an unknown quantity at this point
Bike is on stand, top mount for rear shock is out, I'm gonna cut a spacer for it tomorrow...

I've been reading all night... It seems that the most common is adding 6mm spacer to the top mount of the rear shock... Is that the suggested amount? I've seen 5mm, 6mm, 7mm, ect.. I'm going to start by putting the front fork tubes back to stock location (if i can find that measurement, but i'm going based on how much i raised them)

I think i read on one thread that someone raised with 10mm rear shim, but left front alone... I have sprung the forks, so in theory i've already gained a slight raise in front, which is what raising the forks where meant to cure. I'm just not sure if I should leave the front alone with forks raised 1/4"', or put them back to stock position and run a 10mm spacer...

I've got some metal that would make a good 5mm spacer in the garage, but I've got a good friend who's a tool and die worker that I could drop it off with tomorrow and have him fix me up to any size....

Considering that i'm dragging metal... Which would you suggest...

(i'm planning to get shock modified, but have a event on the 4th i need the bike for, after that I think i'm good till Little Tally 3rd weekend of June.
joshuatest is offline  
Old 05-26-2011, 03:03 AM
  #11  
Out of my mind, back in 5
MotoGP
 
Tweety's Avatar
 
Join Date: Nov 2006
Location: Skurup, Sweden
Posts: 6,109
Tweety is on a distinguished road
Originally Posted by joshuatest
Bike is on stand, top mount for rear shock is out, I'm gonna cut a spacer for it tomorrow...

I've been reading all night... It seems that the most common is adding 6mm spacer to the top mount of the rear shock... Is that the suggested amount? I've seen 5mm, 6mm, 7mm, ect.. I'm going to start by putting the front fork tubes back to stock location (if i can find that measurement, but i'm going based on how much i raised them)

I think i read on one thread that someone raised with 10mm rear shim, but left front alone... I have sprung the forks, so in theory i've already gained a slight raise in front, which is what raising the forks where meant to cure. I'm just not sure if I should leave the front alone with forks raised 1/4"', or put them back to stock position and run a 10mm spacer...

I've got some metal that would make a good 5mm spacer in the garage, but I've got a good friend who's a tool and die worker that I could drop it off with tomorrow and have him fix me up to any size....

Considering that i'm dragging metal... Which would you suggest...

(i'm planning to get shock modified, but have a event on the 4th i need the bike for, after that I think i'm good till Little Tally 3rd weekend of June.
On the forks there is a groove for a lock ring... That sits at the top of the clip-on... That's your reference... When that's algined, you are back to stock in terms of how you have things mounted...

But I think you misunderstod me...

If you drop the forks, and do nothing else, your groundclearance is compromised... Yeah, compensating for correct springs is OK, but I highly doubt that's more than 5 mm... You "think" you are at 7 mm or there abouts... The way I see things, you should have taken a few measurements at stock, and then gone back to stock geometry... But yeah, I'm a bit **** when it comes to planning stuff...

If you drop the forks and raise the rear, you keep groundclearence at the same level... Do that instead of just dropping the forks, and you keep from decking out...

No, the bike isn't known for bad ground clearence... The groundclearence is actually about the same as with a lot of other bikes, but it's very well known for the fact that on other bikes you hit the peg feelers, and when you remove them you have a bit to spare... On the VTR, when you remove those, you hit the headers, and they don't budge, and you go over... On most other bikes there are less important and less solid things that hit first... Ie, not bad ground clearence per see, but bad effects if you push the margins...
Tweety is offline  
Old 05-26-2011, 04:31 AM
  #12  
OUCH... MY A$$ HURTS!!!
SuperSport
Thread Starter
 
joshuatest's Avatar
 
Join Date: Dec 2007
Location: Elba, Ny
Posts: 707
joshuatest is an unknown quantity at this point
Me and this bike departed way's after I only owned it for a few months, so the fork springs came as a result of trying to fix the reason it went into a head shake on me... I did take some before measurements, but its been a while, and to top it off, the bike was trashed when i began the process of rebuilding, which is when the forks got done by greg...

On to the more important question...

Which would you say you recommend as a starting point right now? I'm going to look around for a couple weeks for shock options, but if I don't find a decent enough price, after the Alpine run, I'm probably going to send mine to Jamie? to have it worked over...

I cant remember what spring Greg used, but it was based on a 200-220lb rider.

Do you think i'm better off with fork tubes pulled 5-7mm to regain stock ride height in front, and adding 5-6mm shim in rear? Or Adding 10mm shim in rear, and setting tubes to original location, keeping slightly higher ride height front?
joshuatest is offline  
Old 05-26-2011, 04:41 AM
  #13  
Out of my mind, back in 5
MotoGP
 
Tweety's Avatar
 
Join Date: Nov 2006
Location: Skurup, Sweden
Posts: 6,109
Tweety is on a distinguished road
Actually, I know the story... I have a pretty decent memory, and I remember the threads you have posted...

The best compromise in ride height, angle and steering geometry is to have the forks dropped around 5 mm and the rear up around 5 mm at the shock... Keep in mind 5 mm at tha shock translates too a lot more at the wheel based on geometry of the swingarm...

I doubt you will find anything close to what Jamie can offer with a modified F4i shock in terms of price/performance... But look around...
Tweety is offline  
Old 05-26-2011, 05:36 AM
  #14  
OUCH... MY A$$ HURTS!!!
SuperSport
Thread Starter
 
joshuatest's Avatar
 
Join Date: Dec 2007
Location: Elba, Ny
Posts: 707
joshuatest is an unknown quantity at this point
ok thanks... and your basing the 5mm drop on the forks based on the stiffer springs correct?

I measured last night and was actually about 9mm from lock ring to top of clip on, but I had remembered the lock ring being a few mm above the cilp ons from stock, but my memory isn't as good as yours

I'm going to adjust them tonight, and add the shim to the rear... Hopefully this rain will go away, so I can get a few miles in before the Alpine on the 4th...

From the reading, I'm gonna really like the fell of this slightly raised rear!

thanks for the help
joshuatest is offline  
Old 05-26-2011, 02:35 PM
  #15  
Out of my mind, back in 5
MotoGP
 
Tweety's Avatar
 
Join Date: Nov 2006
Location: Skurup, Sweden
Posts: 6,109
Tweety is on a distinguished road
Yeah, I'd say 5 mm for the stiffer springs should be a decent guess... Possibly a bit more, but not without raising the rear to keep ground clearance...

The groove whould probably be about ½-1 mm above the top of the clip-on with the ring resting on the clip-on, that is to ensure you mount the legs exacly the same height... So to simplify I just considered "zero point" where the groove is flush with the clip-on...

Yeah, I think you'll like it...
Tweety is offline  
Old 05-26-2011, 03:42 PM
  #16  
OUCH... MY A$$ HURTS!!!
SuperSport
Thread Starter
 
joshuatest's Avatar
 
Join Date: Dec 2007
Location: Elba, Ny
Posts: 707
joshuatest is an unknown quantity at this point
Ok... shot home early today, compressed 4 fender washers in the vice and welded them around the edges, then cut two sides to match the size of the upper shock mount. Grinded down, and ended up with right at 5.5mm shim for rear shock...

QUESTION #1 - With stock shock, and this shim, what preload setting would you think I should be on? I was at 7 prior to today to try and keep bike off the damn ground. I backed down to 6 now, figuring i've got more room to give. What do you think? I'm 1 turn back from fully turned on the bottom screw (dampening?) Rear feels stick, but has a little give when i bounce on it... I've played with the rear a good bit, and I think i like it stiffer compared to the weak soft settings this shock provides.

Second... My lock ring is now at 12mm from lock ring (probably +10-11 from stock) because i was measuring to top of ring... I tried the 5-6mm range, and it just feels nose high...I rode around the block and it just didn't feel like the bike wanted to turn in like I wanted it to. Went to 12mm and it feels much better. would you say i'm good here? Someone above mentioned being at 5-6mm shim with 1/2" raised in forks and was riding the track on them...

Wifey will be home in about an hour, and I'm going to go wake this thing up a tad and see how it responds... I am truely amazed on how much taller the bike feels with that small change...

oh... Can somebody measure from ground to lowest point on the header pipe for me? (bike standing up straight with rider in seat... Either somebody who is stock, or somebody who's modified and has successfully eliminated the pipe hitting the ground. I'm going to have wifey measure this for me when she gets here...
joshuatest is offline  
Old 05-26-2011, 05:16 PM
  #17  
OUCH... MY A$$ HURTS!!!
SuperSport
Thread Starter
 
joshuatest's Avatar
 
Join Date: Dec 2007
Location: Elba, Ny
Posts: 707
joshuatest is an unknown quantity at this point
At current settings, the wife says I have 5" from low point of exhaust to ground, with me sitting on bike straight upright...

Took a spirited, but short ride... Kinda crazy, the swing arm has different angle, making wheel base shorter, and I can tell!!! Accidental wheelie

It floated the front end in 2nd a couple times, which it hasn't done since having the -1/+2 and it still took the right kinda road to do it... I'm just +2 currently...

It handles good... Feels different, but its just because its taller i think. Buddy has a RSV Mille and it almost feels like that now, real tall bike...

Very happy...
joshuatest is offline  
Old 05-26-2011, 05:45 PM
  #18  
Senior Member
MotoGP
 
7moore7's Avatar
 
Join Date: Jul 2010
Location: Phoenix, AZ
Posts: 3,869
7moore7 is on a distinguished road
Originally Posted by joshuatest
Took a spirited, but short ride... Kinda crazy, the swing arm has different angle, making wheel base shorter, and I can tell!!! Accidental wheelie

Very happy...
I hear ya on the geometry changes. I'm pretty fresh with suspension setup still, but [slightly shorter wheelbase + slightly taller ride height = big difference in turn in]
7moore7 is offline  
Old 05-26-2011, 06:01 PM
  #19  
Out of my mind, back in 5
MotoGP
 
Tweety's Avatar
 
Join Date: Nov 2006
Location: Skurup, Sweden
Posts: 6,109
Tweety is on a distinguished road
The settings on the shock have nothing to do with ground clearance really... They can change ground clearance, but that's not what they are for...

The shock spring pre-load should be setup so that it sags some 20-25 mm when you sit on the bike... If there is no sag, back it off...
Then you dial in the dampening setting to where it doesn't bounce around... I can't for the life of me remember if the OEM shock has rebound or compression dampening, but it has one, missing the other... It's not that good in unmodified form...

Trust me, it feels fine on a too hard setting, until you push it a tad more and it starts to skip around... I'd say at your weight, 6'th is probably good, 7'th is probably a bit to much...
Tweety is offline  
Old 05-26-2011, 06:06 PM
  #20  
Out of my mind, back in 5
MotoGP
 
Tweety's Avatar
 
Join Date: Nov 2006
Location: Skurup, Sweden
Posts: 6,109
Tweety is on a distinguished road
Also keep in mind... 5 mm shim = ~1.6 * 5 mm at the wheel, so 8 mm actually... That's because of the swingarm pivoting in one end...

Also on the OEM shock... Setting it "right" is nigh on impossible... You'll have to settle for "not wrong"...
Tweety is offline  
Old 05-26-2011, 10:23 PM
  #21  
Senior Member
Back Marker
 
superbeater's Avatar
 
Join Date: May 2009
Location: Pac NW
Posts: 213
superbeater is on a distinguished road
Putting in a shim does not effect shock preload or settings for sag.
superbeater is offline  
Old 05-26-2011, 11:16 PM
  #22  
OUCH... MY A$$ HURTS!!!
SuperSport
Thread Starter
 
joshuatest's Avatar
 
Join Date: Dec 2007
Location: Elba, Ny
Posts: 707
joshuatest is an unknown quantity at this point
Originally Posted by superbeater
Putting in a shim does not effect shock preload or settings for sag.
It doesn't, however the preload on this thing does actually change the ride height, and because i was fighting to keep the exhaust from hitting, i was riding on 7 for preload, and sag pretty well stiff so to keep the tires lower than the pipe... With the added shim, and additional height now, I'm questioning if I should try to dial that preload and sag back a little... I'm gonna drop the preload to 6 and play with sag some tomorrow...

Bike feels like a whole new animal now...
joshuatest is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
inderocker
Everything Else
3
02-13-2008 02:48 AM
ghopki1
Technical Discussion
8
12-28-2007 11:31 AM
fundgh
General Discussion
16
11-10-2007 09:13 PM
Autarkic
Technical Discussion
7
04-23-2007 07:53 PM
mikenap
Technical Discussion
1
06-07-2006 07:01 PM



Quick Reply: Exhaust Clearance Fix?



All times are GMT -7. The time now is 07:05 AM.