Handling improvement for 5th Gens

[vic28222]

I have a 99 VFR800 that I have owned since it was nearly new and I love it but it has always turned in a little slower than I would prefer in the twisties when riding at a pretty good pace.  Another way to describe it is to say the steering has always felt a little heavy to me.  I assumed the rear spring was not up to the load and that I should get my shock rebuilt, revalved and a proper spring for my weight and was just about to do that.  To establish a baseline I got a friend to help me and we measured the sag, front and rear, and to my amazement, everything was right where it should be!  The front was 39mm and the rear was at 25.  I backed off one level of rear preload and the rear went to 29.

 

I have dropped the front of other bikes over the years to get them to turn faster but that has always made it harder to get the bikes on their center stands.  I'm  77 now and I need things to get easier, not harder!  I have read about people shimming the rear shock to raise the rear to accomplish the same so I decided to look into that.  I found that NAPA Auto sells two body shims that are perfect for doing this.  One is 1/8" thick and the other is 1/16th" thick and they are both slotted so you can install one or both without removing the shock.  https://www.napaonline.com/en/p/NCP2641037?impressionRank=2  ($0.79 each) and https://www.napaonline.com/en/p/NCP2641038?impressionRank=1 ($0.59 each).  

 

I installed the 1/8" thickness first, by itself and found that it dropped the rear wheel to where it was only 1/4" off of the ground when on the center stand and that the bike leaned about as far as I wanted it to when on the center stand.  My best guess is that when stock it leaned about 9 degrees and that it now leans about 15 degrees.  I think if you put the 1/16" shim in there too that your center stand would not lift the rear tire and the bike would lean too far when on the side stand.  Someone said that you could go to a 4mm spacer but I don't think so.  1/8" = 3.18mm.

 

To install one shim is very simple and only takes about an hour or two.  First, put the bike on its center stand and remove the seat.  Then loosen the bolts that hold the front of the tank in place about 1/2".  Now remove the two bolts holding the rear of the tank down.  Raise the rear of the tank several inches and put rags or something soft on top of the rear of the airbox to hold it up.  I cut about 8" off of the end of a pool noodle and used it to hold the tank up.   Now remove the bracket that holds the pivoting piece the tank bolts to.  Then remove the large rubber flap that covers the area and then remove the larger bracket the smaller one bolts to.  Note:  When you do this last step there are two different sized nuts/bolts involved.  The large one is a nut and is the nut that holds the shock to the shock cross member.  The other one is a bolt and simply holds the other side of the bracket in place.  When you remove the large nut you will notice that your rear tire goes to the ground but the stud remains above the cross member enough to put the nut back on easily.  If you get a good flashlight you can see that the top of the shock mount has dropped about 3/16" below where it normally is when pulled up tight.  At this point it is very easy to slip the thicker shim into place with the slot going around the shock's mounting bolt.  Tighten it all back up putting brackets and rubber flaps back as they came off.  Now your rear tire should clear the floor only about 1/4".  This leaves the center stand fully functional and it makes it even easier to put the bike on the center stand.  

 

I took the bike out for about an hour and ran some twisty roads and some higher speed interstates.  The bike feels noticeably lighter and quicker to turn in and yet was rock solid at 100 mph.  I hit a few small bumps at high speed and introduced some small but rapid steering inputs to see if I got any indication of instability and I didn't.  Now I cannot guarantee that you will have the same results so if you make this modification to your bike, ease back into riding it to insure that it feels safe to you.  But I will say that for less than 2 hours of time and $0.79 in parts, the result is very nice.

 

I do not claim having found out about this on my own. This has been mentioned many times in the past but not recently and not in this level of detail.   I just want to share how easy it was, where you can get the part needed and how much it improved the handling of my bike.  It is still not a 600cc race replica in handling but it is substantially better IMO than it was.  

 

Vic

PS.  Adding the 1/8" spacer raises the rear somewhere in the ballpark of 12mm which is roughly 1/2".  In the world of suspension mods, this is a substantial change.

[bmart]

Sounds like you made an improvement that you like. 

 

What were the bike only sag #s front and back? 39mm front is a bit more than normal. 

 

Many folks raise the rear (shims or adj shock) and lower the front quite a bit without any degredation in handling. 

 

For reference, here's what I'm running now. The '98 is perfect (for me) and the '00 is less so as I can't find a cheap shock I like, so I also ran three shims (NAPA 665-3230 for $7) and am sucking up that the damping is dreadful. 

 

Rear shock length:

'98 330 mm (5 mm more than stock)

'00 329+mm w/3 shims

 

Top of triple to flat top of fork cap (stock is 39mm)

'98 45mm

'00 43.5mm

 

Rear sag rider/bike only in mm

'98 31/14

'00 31/10

 

Front sag rider/bike only in mm

'98 33/26

'00 33/25

 

Hope that this helps!

[vic28222]

Front and rear sag with just the bike on the ground, no rider, was in the 0-5mm of sag.  While my front sag was within the normal range at 39mm, I can easily raise the front with more preload BUT the front end feels good at this point and my objective was to sharpen turn in w/o compromising stability.  So I left the front alone and raised the rear.

[bmart]

0-5mm bike sag is very low...so your spring rates for your weight are probably off a bit. 

 

Glad you're happy! (I wish I was with my '00!)

[vic28222]

Actually bike only sag should be in the 0-5mm range.

 

BTW, while I inserted one 1/8" thick shim you inserted (3) 1/16" shims so you added 1.6mm more than I did.  If you had not dropped your front end, your rear tire would have been on the ground when the bike was on  the centerstand.

[vic28222]

This is what RaceTech recommends for Free Sag as quoted by Cycle World.

 

[bmart]

That's certainly one opinion...but goes against long standing knowledge of 8-10 free rear and 20-24 front by most suspension gurus. (there a hint in the note you posted, 'If the suspension does not drop at all, you need a stiffer spring.')

 

I'm cheap, so close enough is close enough for me unless i'm buying springs anyway!

 

I'm glad that you like it, but i'm not getting an oil debate! 🙂

[vic28222]

BMart, there is always one of you on forums like this.  You say you don't want to get into an oil thread and yet you have been questioning and goading me over what I have said from the start.  And none of it served any purpose but to inflate your ego by suggesting you know more than the next guy. 

 

The main message I was trying to send is "IF" your 5th gen VFR seems slow to turn in there is a very inexpensive and easy way to help it some.  I never purported to be a suspension guru but what I did use as my knowledge baseline was what RaceTech and Cycle Gear had to say  and that was good enough for me.  Sure there are other opinions out there and those other opinions may in fact be better if you are tuning your bike for a big race at Barber or Laguna Seca but that is not what I am trying to do.  My bike felt a little slow to turn in and I wanted it to turn more willingly on the street.  That's all. 

 

Let's give this a rest.  It serves no purpose and may well distract a reader from my basic initial intent.  Again, that is "If your 5th Gen VFR does not turn in quickly enough for you, here is something you may want to try.  It is super cheap and very simple to do."

[bmart]

I don't understand your accusation. I'm glad that you like your setup...as I said a few times. 

[stuartb3502]

6 hours ago, vic28222 said:

Let's give this a rest.  It serves no purpose and may well distract a reader from my basic initial intent. 

You’ve done that yourself mate. Hopefully you were just having a bad day and will now apologise. Otherwise I suggest you start a blog and post with commenting disabled. You’re not well suited to a discussion forum. 

[ShipFixer]

On 2/24/2023 at 4:45 PM, vic28222 said:

The main message I was trying to send is "IF" your 5th gen VFR seems slow to turn in there is a very inexpensive and easy way to help it some.  I never purported to be a suspension guru but what I did use as my knowledge baseline was what RaceTech and Cycle Gear had to say  and that was good enough for me.  Sure there are other opinions out there and those other opinions may in fact be better if you are tuning your bike for a big race at Barber or Laguna Seca but that is not what I am trying to do.  My bike felt a little slow to turn in and I wanted it to turn more willingly on the street.  That's all. 

39mm is 35% sag.  What @bmart is nicely saying in a round about way is that by using spring sag to slightly steepen head angle to "sharpen steering" you are paradoxically adding squishiness in hard corners and turning with a softer spring rate.  While it will sharpen handling when the fork is relatively static, it's going to reduce handling at the performance end where it really matters. 

 

I know from his other threads that since he roads races a lot, he likes the knife edge feel of a hard linear spring - cause he actually corners and needs a quick handling bike.  As we get faster on bicycles or motorcycles, we like more of that precision up front that comes with a stiffer rate.  So he like most knows what happens you do what you are suggesting.  I use progressives from Hyperpro so I have a bit of the best of both worlds but my static sag is ~30mm and the bike stays up in the travel over real world (not track) roads.  Importantly, my fork does not dive and lose handling precision at speed.  Any speed, for that matter.  I have had RaceTech linears in there and I know what the knife edge feels like for initial turn in, but on progressives I have nearly the same amount of precision, the same once in the turn, but no amount of ruts or potholes in the middle of a turn will matter.

 

The right way to do what you are trying to get to is to separate the two variables.  Keep the right spring rate for your preferences and experience level, and drop or raise the fork tubes in the triple clamp to get the right rake or head tube angle you want.

 

I realize from your first post this is exactly what you are trying "not" to do.  However, a 5mm drop in fork tube length is going to be something like 2-3mm drop in chassis height above ground, etc.  I have never, ever noticed a difference in center standing my bike regardless of where the fork tubes are.  

 

 

[vic28222]

Look, I was not trying to say anything other than A) if you have a 5th gen VFR and B) it does not turn in as quickly as you like, then C) you can sharpen the steering somewhat by simply and easily adding a $0.79 shim available at any of the thousands of NAPA stores all around the USA.  I made this change and it had a very nice affect on the handling of my bike.  Many people raise the fork tubes in the triple trees by some number like 5-8mm and that sharpens the handling.  You can also raise the rear by an equivalent amount and get the same result.  To me raising the rear was both easier and preferred because I am a 77 year old man and raising the rear makes getting the bike on the center stand easier.  To me, at my age, easier is always preferred if all else is equal.

 

Before making any change to a bike's suspension, virtually all suspension gurus suggest you should measure and set your sag first.  To do that you have to have some basic knowledge on how to do that and you have to have some target numbers to work toward.  I used an article in Cycle World that explained step by step how you set sag that quoted RaceTech's method. https://www.cycleworld.com/sport-rider/suspension-setup-guide/#:~:text=For street use%2C you should,along with your preload setting.   The article also gives some guidance on what sag numbers should be front and rear for both street riding and track time.  According to CW/RT, the front should have a minimum of 25mm sag for the track and a minimum of 30mm for street riding.  The article said specifically if you have MORE sag in the front than that not to worry about it unless you are bottoming the front out.  The CW article did not give a maximum sag figure.  I  also read what Penske had to say about setting sag and they say that sag should be set to 30-35mm for the track and 35-45mm for the street.  https://www.penskeshocks.com/blog/how-to-properly-set-your-motorcycle-front-suspension-sag-why-it-matters#:~:text=Depending on your riding style,comfort%2C and overall ride quality.

 

My sag number of 39 on the front is right in the middle of 35-45mm and my rear sag of 27.5mm was close enough for me especially because the bike was already a bit slow to turn in and lowering the rear to hit the 30mm number would adversely affect the results I was looking for.  I said that the front felt good at 39mm and what I wanted to do was raise the rear more.  And that is what I did using the shim method.  

 

My initial purpose was to share a simple and inexpensive way to make a 5th Gen VFR handle a little sharper on the street.  Since the parameters and methods used were well supported by Cycle World, RaceTech and Penske, I don't see the purpose of debating all the minutia that has come since.  The concern I have over debating largely immaterial issues such as whether rear free sag is 0-5mm or 5-8mm or whether adjusting sag with preload affects spring rate is that someone without much experience will become confused over what is "right" and do nothing.  The article was simply written to the street rider who feels his 5th Gen is handling a bit slow and it offered him/her a quick, easy and cheap way to go about changing that.  

 

 

 

 

[VFR750F3]

If you really want it to turn get some Pirelli Supercorsa or Rossa Corsa tires.  You can play all you want with Sag numbers but a crappy tire is a crappy tire.  I had some Michelin Pilot 2 or 3 road tire back in the day on my RC51 it would not turn.   I always ran wide. I threw them in the garbage.  The tire profile of these new high performance tire dictate how quickly you will turn.  A older tire that has squared off will not turn.  Tire pressure is also very important.  I have Supercorsa on 2 of my bikes Rossa Corsa on another.  On of my friends with a RSV4 tells me the new Michelin Power 5 is a upgrade to the Pirelli.  It has these tiny dimples on the chicken strips to expel water.

[vic28222]

On 2/24/2023 at 10:02 PM, bmart said:

I don't understand your accusation. I'm glad that you like your setup...as I said a few times. 

Sorry to have jumped you over your input regarding suspension setup.  I never really intended to get into the finer nuances of suspension setups.  Rather I was trying to focus on a simple, easy, quick and cheap modification that helps a 5th Gen turn in a bit better while street riding.  I felt obligated to go through the process of setting sag before doing anything else since to do otherwise would be a sin. 

 

It just got under my skin that you wanted to get into topics I considered well beyond the intent of my write up and did so in a way that, to me, suggested that you know more than I do.  For instance, saying that my front sag was outside of a healthy range (although Penske and CW/RT agree with my sag figures) and then asking for my free sag figures and saying that 0-5mm which I used went against something like "long standing knowledge of 8-10/20-24mm free sag ... most suspension gurus" or something close to that.  Again you said my figures were wrong and I should learn from you even though I got my figures from CW/RT and Penske and I haven't a clue who is in your list of "most suspension gurus."  Maybe I was having a bad day and took your input as a case of "I know more than you do" and furthermore I interpreted it all as missing the point of my piece.  Then when you said you were not going to get into an oil thread after, in my opinion, that is exactly what you had just turned my simple piece into was the straw that ........ well, you know how that goes.  

 

If I misinterpreted your intent, I apologize.  Maybe I was having a bad day.

 

Vic

 

PS.  I have been riding for over 65 years & rode enduros for 13 years.  I have ridden in every state in the lower 48, have ridden in British Columbia and Nova Scotia, in most of the northern half of Mexico, the full length of Baja and in Spain, France and Italy.  And I still ride regularly and have three bikes in my garage now.  This is NOT to say that I know all there is to know but it is to say that I have been around the block a few times.

[vic28222]

1 hour ago, VFR750F3 said:

If you really want it to turn get some Pirelli Supercorsa or Rossa Corsa tires.  You can play all you want with Sag numbers but a crappy tire is a crappy tire.  I had some Michelin Pilot 2 or 3 road tire back in the day on my RC51 it would not turn.   I always ran wide. I threw them in the garbage.  The tire profile of these new high performance tire dictate how quickly you will turn.  A older tire that has squared off will not turn.  Tire pressure is also very important.  I have Supercorsa on 2 of my bikes Rossa Corsa on another.  On of my friends with a RSV4 tells me the new Michelin Power 5 is a upgrade to the Pirelli.  It has these tiny dimples on the chicken strips to expel water.

Tires do matter for sure.  I have 60+K miles on my VFR and have been through virtually all of the Sport Touring tires and some are MUCH better than the others.  At one point I had a Michelin Road 2 on the front and a 3 on the rear and it was awful!  The bike did not want to turn!  I think the best tire I have had was a set of Metzler M3s IIRC and loved them but the rear was gone in 3500 miles and the front didn't make 6K.  If you ride a lot, that gets too expensive for my blood.  Right now I have a new set of Dunlop RoadSmarts on it now and so far they seem fine for a ST tire.  I have never tried the Supercorsa or Rossa tires but I hear they stick like glue and wear like the Metzler I had did.

[bmart]

2 hours ago, vic28222 said:

Right now I have a new set of Dunlop RoadSmarts on it now and so far they seem fine for a ST tire. 

Me too (find common ground!). I wish that they still made the 2s, as I like them better than my 3s. They're more than adequate for any tipe of street riding and even a novice track day. 

[bmart]

2 hours ago, vic28222 said:

Maybe I was having a bad day and took your input as a case of "I know more than you do" and furthermore I interpreted it all as missing the point of my piece.  Then when you said you were not going to get into an oil thread after, in my opinion, that is exactly what you had just turned my simple piece into was the straw that ........ well, you know how that goes.  

 

If I misinterpreted your intent, I apologize.  Maybe I was having a bad day.

No worries! We're all trying to help each other. Forum communication makes it harder sometimes. I was joking about the oil threads. Current oils are all pretty good...just like tires. Suspension is much the same, whether "right" or not. 

 

I rode a friend's Tracer 9 the other day. I would have thrown the suspension out before ride #2, but he loves it. My best track day buddy likes his set up pretty rigid. I actually like my soft. We swapped bikes a few years back. He got off the track before completing a lap saying that my bike was unrideable. lol I felt like his had welded bits instead of suspension...but we ride nearly identical times. 

 

Crazy sport...

[vic28222]

15 minutes ago, bmart said:

Me too (find common ground!). I wish that they still made the 2s, as I like them better than my 3s. They're more than adequate for any tipe of street riding and even a novice track day. 

Nice!  I hear the 4s are even better but they are more expensive.  No complaints so far from me on the 3s.

[vic28222]

19 minutes ago, bmart said:

No worries! We're all trying to help each other. Forum communication makes it harder sometimes. I was joking about the oil threads. Current oils are all pretty good...just like tires. Suspension is much the same, whether "right" or not. 

 

I rode a friend's Tracer 9 the other day. I would have thrown the suspension out before ride #2, but he loves it. My best track day buddy likes his set up pretty rigid. I actually like my soft. We swapped bikes a few years back. He got off the track before completing a lap saying that my bike was unrideable. lol I felt like his had welded bits instead of suspension...but we ride nearly identical times. 

 

Crazy sport...

Speaking of oil, a friend of mine in Houston is a retired chemical engineer who was on the team that developed Shell Rotella T full Synthetic.  He use to ride a VFR too and they used his bike to test how well the additive pack in Rotella T would hold up in a VFR.  At 10,000 miles the Rotella T was just beginning to look like it should be changed and Mike ran his bike pretty hard.  In a conversation I had with him he said if you are running Rotella Full Syn and you change your oil any more often than every 5,000 miles or once a year you are wasting your money and good oil.  I have run Rotella T Synthetic in mine for the last 50,000 miles following his guidance and mine has yet to burn an ounce of oil between oil changes.  You are right though, there are many good oils out there now so run whatever makes you feel good!