Light bouncy front end in sweepers

[Pasta Burner]

So I finally got the ole 87 out into the canyons rather than just around town and to from work.  I put progressive springs and oil in earlier this year and it was an amazing improvement around town, no more bottoming the forks and fear of washing out.  Today I got a real ride in and noticed that between the 55-75 mph mark in a curve the front end seems light.  Not like it’s going to slide out but not planted either.  I can’t attest to how it felt before the spring change because I felt too uneasy to push it hard.  Just wondering what would cause this and how to adjust it.  Maybe more air in the ass end?  Was running 4psi up front and 15 rear, one up no luggage other than tool bag and water jug.

[skydoc_17]

Hey Tom,

When you purchased your Progressive Fork Spring Upgrade, there should have been a pair of white PVC pieces of pipe in the kit. These pieces of "Shim" can be cut to adjust the firmness of the spring action in the front forks. They go on top of the washer that is on top of the new spring, and under the fork tube cap. This is the "Preload" for the new fork springs. By what you are describing, it sounds like you left these preload shims completely out. I dress out at about 185 lbs. and I used 1/2 of the shim in each fork. If you are heavier, you will use more of the shim. This was a bit of a trial and error thing for me, before I found the right amount of preload shim to use for my weight. To be honest, I purchased two schedule 80 (Gray colored) couplers and made my final adjustment with these once I found the correct length. The wall thickness of the schedule 80 couplers was quite a bit thicker, and I felt much better about using a plastic shim against a metal spring. They have been in for 7 years, and are still going strong. The white schedule 40 pipe that comes with the kit will do the job though. This will firm up the front forks in the sweeper turns nicely, but it does make the around town driving just a bit harsher. Once you have the length of the shim by using the white pipe, I would be happy to make you a set of custom brass spacing shims for your forks for the price of the material, time and shipping cost. When I do my fork seals this winter, I plan to use a set of the brass preload shims myself. 

You will know if you have too much shim in because your teeth will clunk together when you hit a pothole! LOL!! I started out with the entire shim installed. (Teeth Clunked) Then I went to 3/4 of the shim, (still a bit to firm) then to 1/2 the shim and that was just about right for my weight. When I make up MY set of preload shims, I might add 1/32 of an inch to fine tune it even closer. 

Let me know if I can help you with a shim set.

Earl

[Pasta Burner]

@skydoc_17 You are absolutely correct Earl, I did not use the PVC spacers.  I used the “cap” as recommended by Prariehammer (may he Rest In Peace) and others.  So you are recommending I increase the preload?  Maybe start with an additional 1/2” and dial back from there?

here’s the thread from my install. 

 

[skydoc_17]

Hey Tom,

Without knowing your weight, I can only guess on where to start with the size of the shim pipe. If you start at 1/2 of the shim pipe, (NOT 1/2 inch of the shim pipe) and want to make it smaller, then you better weigh 150 pounds! No insult intended Tom, but after your wife caught me peeking in the living room window to see how much shim you needed to add to your fork springs, (LOL!!) If you weigh MORE than 185 lbs. then I suggest that you start with the entire shim and work down from there, unless you DO weigh 150 pounds! (I hope you take my little pun in the spirit it was intended!)

Earl

[Pasta Burner]

I’m hovering right around the 190 195 range right now.  185-190 is my target weight.  Been traveling a lot lately so eating out for weeks on end doesn’t help.  I’ll swap out the cap for the shims and see what happens.  Won’t report back for a few weeks though.

[Mach VIII]

On 8/7/2021 at 2:07 PM, Pasta Burner said:

@skydoc_17 You are absolutely correct Earl, I did not use the PVC spacers.  I used the “cap” as recommended by Prariehammer (may he Rest In Peace) and others.  So you are recommending I increase the preload?  Maybe start with an additional 1/2” and dial back from there?

here’s the thread from my install. 

 

I'm quite interested in this topic.  I have been confused about what spacers, parts, and how much oil to use after reading through a ridiculous number of posts/threads. Some of it seems to spring (pardon the pun) from inconsistent naming of parts. Earlier this year (while completing my service & restoration) I opened up the forks to replace the fork oil.  To my delight, I found that the previous owner had installed Progressive springs up front.  I believe I found my forks to be set up like the top spring in this picture - using only the threaded fork cap, the spacer with the fat o-ring, and the spring.  There may have been a washer in there too, I can't remember.  I believe I tried making and adding some PVC spacers, but there was no way I could get the fork caps down and get the threads started, so I left them out (I'm healthy and able-bodied enough to do such a job, so that wasn't the problem).  While I'm sure the fork oil replacement was helpful, I find the front end to "wallow" when pushing the bike through the twisties.  I can touch down pegs, but it doesn't feel all that planted up front when leaned over at speed.  That was certainly disappointing, but then I don't really know what to expect from such a big bike.  This sounds like what Pasta Burner is experiencing as well.  I don't notice the bike diving excessively, which is good, but better cornering would be very much welcomed.

[Squidley]

Another thing to consider if it hasn't been mentioned in this thread is the fork brace. The stock yamaha is a bit anemic, there was an aftermarket brace produced that beefed up the front forks where they come together at the top of the tube. Not sure if that still available, but it made a decent difference with the front forks twisting in hard corners.

[Mach VIII]

30 minutes ago, Squidley said:

Another thing to consider if it hasn't been mentioned in this thread is the fork brace. The stock yamaha is a bit anemic, there was an aftermarket brace produced that beefed up the front forks where they come together at the top of the tube. Not sure if that still available, but it made a decent difference with the front forks twisting in hard corners.

Good point.  I did, however, install a Superbrace on mine and am having those issues.

[Pasta Burner]

Hey @Mach VIII it’s going to be another few weeks before I get to play with it, but will report in with any experience.  Please do the same if you decide to mess with yours sooner rather than later.

[Mach VIII]

Will do, but you're likely to get to it before me.  I've got some other home and bike projects to get to first.

[Marcarl]

14 hours ago, Mach VIII said:

I'm quite interested in this topic.  I have been confused about what spacers, parts, and how much oil to use after reading through a ridiculous number of posts/threads. Some of it seems to spring (pardon the pun) from inconsistent naming of parts. Earlier this year (while completing my service & restoration) I opened up the forks to replace the fork oil.  To my delight, I found that the previous owner had installed Progressive springs up front.  I believe I found my forks to be set up like the top spring in this picture - using only the threaded fork cap, the spacer with the fat o-ring, and the spring.  There may have been a washer in there too, I can't remember.  I believe I tried making and adding some PVC spacers, but there was no way I could get the fork caps down and get the threads started, so I left them out (I'm healthy and able-bodied enough to do such a job, so that wasn't the problem).  While I'm sure the fork oil replacement was helpful, I find the front end to "wallow" when pushing the bike through the twisties.  I can touch down pegs, but it doesn't feel all that planted up front when leaned over at speed.  That was certainly disappointing, but then I don't really know what to expect from such a big bike.  This sounds like what Pasta Burner is experiencing as well.  I don't notice the bike diving excessively, which is good, but better cornering would be very much welcomed.

I can understand what you were going through with trying to get the cap to thread. I use a t-bar with the proper sized socket, forks allowed to fully extend and then I have to put my shoulder into it as I carefully start the threading process. I used only 1/2 the available spacer and found that to be taxing enough to get things together, but it can be done.

[Mach VIII]

I'd like some clarification on some things.  Those that are using the PVC spacers - are you using these IN ADDITION TO the factory spacer that has the fat o-ring (the one that is 1-2 inches thick), OR INSTEAD of that factory spacer?  Sorry I don't know what else to call that part.  The factory setup (as shown above) has what are, to my eyes, 2 spacers - a short one with the fat o-ring and the long thin metal tube.  I know not to use the thin metal tube spacer.

Second question, what is the actual length of the PVC spacers provided by Progressive? I don't have them, so references to 1/2 or 3/4 of the spacer length do not have any meaning to me without the original length measurement as reference.  Thanks.

[Marcarl]

2 minutes ago, Mach VIII said:

I'd like some clarification on some things.  Those that are using the PVC spacers - are you using these IN ADDITION TO the factory spacer that has the fat o-ring (the one that is 1-2 inches thick), OR INSTEAD of that factory spacer?  Sorry I don't know what else to call that part.  The factory setup (as shown above) has what are, to my eyes, 2 spacers - a short one with the fat o-ring and the long thin metal tube.  I know not to use the thin metal tube spacer.

Second question, what is the actual length of the PVC spacers provided by Progressive? I don't have them, so references to 1/2 or 3/4 of the spacer length do not have any meaning to me without the original length measurement as reference.  Thanks.

The metal OEM pipe will be history. An 1.5" pvc spacer is a good measure to start from. There should be a good amount of umph needed to get the screw cap to get threaded, if it goes on easy, make one a 1/2" longer.

 

[Bob K.]

On 8/14/2021 at 7:18 AM, Mach VIII said:

I'd like some clarification on some things.  Those that are using the PVC spacers - are you using these IN ADDITION TO the factory spacer that has the fat o-ring (the one that is 1-2 inches thick), OR INSTEAD of that factory spacer?  Sorry I don't know what else to call that part.  The factory setup (as shown above) has what are, to my eyes, 2 spacers - a short one with the fat o-ring and the long thin metal tube.  I know not to use the thin metal tube spacer.

Second question, what is the actual length of the PVC spacers provided by Progressive? I don't have them, so references to 1/2 or 3/4 of the spacer length do not have any meaning to me without the original length measurement as reference.  Thanks.

I checked my notes from my 2005 installation of Progressive springs.  The PVC spacer was 1 1/4" tall.  I didn't use it.  Instead, I installed the OEM metal spacer with the o-ring that Prairiehammer referred to as the "cap" in the above photo.  It is approximately 1" tall.  I'm 175 pounds.

That shorter OEM round metal piece is indeed called the "cap" and the original longer spacer is called the "guide".

Even with Progressive springs, a Superbrace, and a Furber Fix (steering stem washer replacement), I don't like this bike in higher speed sweepers either, especially if there are bumps.  It's worse at lower speeds.  The front end seems bouncy and untrustworthy.  There seems to be a lot of uncontrolled weight up front in the steering assembly, forks, calipers, tires, etc as if the forks are undersized and not stiff enough for this bike.  I notice this if I'm at a stop and I give the handlebars a rapid, sharp jerk to one side or the other: I can feel the oscillations in the handlebars until the momentum dissipates.  Problem is, this is my first big bike and it has been my first big bike for 20 years, so I have nothing to compare it to.  Maybe this is just normal for a bike with 1980s technology and engineering.

Following intently.

Edited August 15, 2021 by Bob K.

[skydoc_17]

Hey Guys (and Gals) lets crunch some numbers for a moment and see if we can come to the same conclusion I came to about the front forks of the First Gen. Yamaha Venture Royale.

With the VMAX weighing in at around 579 pounds, and having 40MM fork tubes, and the Venture Royale weighing in at 785 pounds, and having, (you guessed it) 40MM fork tubes to say that the front end on the Venture Royale is on the "Light Duty" size is, in my opinion an understatement! Now Yamaha attempted to deal with this issue with the introduction of the Yamaha Royal Star Venture, but at 41MM the front forks on the Second Gen. are laughable at best! Of course, the riding style of the Second Gen. is different from the riding style of the First Gen. (In my opinion) A set of 50MM front fork tubes on a First Gen. would have suited me just fine. (1 9/16" vrs. 1 15/16") Considering that the First Gens. used the same fork lowers that were used on the XS1100 (which were 39MM lowers) Yamaha had enlarged the fork tube bore in the lowers as far as they dared to go in the 80's, early 90's. If they would have gone to a 50MM upper fork tube (as they should have, given the increased weight of the bike) that would have required the recasting of the upper and lower triple trees, the lower fork tubes, not to mention the increased 50MM upper fork tubes, which at the time, would have been the largest fork tubes that were ever used on a production motorcycle in their product line. (And still is to this day!) Plus you would have added 10 pounds to the weight of the bike, with ALL of it being on the front end. With my own personal riding style being that of "I am only vertical when I am at a stop light", I have learned to embrace the "horror" of the sloppy front end of a First Gen. in those sweeper turns where parts of your bike that should not touch the ground sometimes do. I have often though of adding a "Mid Brace" between the top of the lower fork tube travel and the bottom of the triple tree to see if that would firm up the front end. If there was some interest in this from the other forum members, I may try to introduce one as I plan to retire in early 2022 and will be able to turn all of my attention to my "Little Shop By The Creek". Feel free to comment on this upgrade that I plan to at least make for my 87'VR, and if it pans out, I will add one to my 89'VR as well. If you are so inclined, maybe I will add one to your bike as well. As a Machinist, I have lived my life making my bikes "Better". If the upgrades were solid, I offered them to the other forum members. Many have used them, some have not. If there was another front end from ANY other motorcycle on the planet that would improve the high speed handling of a First Gen. I would have figured out a way to adapt it to my 87'VR. (And believe me I have looked!) ALL of the sport bike front ends are WAY to short, and can't handle the extra weight of the First Gen. So, short of adding a totally custom Olins, multi-thousand dollar front end to a bike I paid $800.00 for, "I am stuck with what I got", so to speak. 

I hope I didn't steal this thread with this post. These were just my thoughts, for what they were worth.

Earl

[Mach VIII]

Bob K. - Thanks for the detailed information.  Curious names Yamaha chose to use for some of these parts, but so be it.  So if I'm reading your information correctly, there's only 1/4" difference between the factory "cap" and the PVC spacer that Progressive provided.  While that might make some amount of difference, I don't expect it to be worlds difference in terms of feel/handling with such a slight increase in preload.

Since it is easy to do, I might try using the CLASS to add a few more pounds of pressure up front and increase the preload that way.  It's cheap and it's easy, so worth a try I suppose.  From what I read in other threads, most with Progressives are running with the minimum pressure up front (4 PSI as I recall), or on the "LOW" setting which is a few PSI higher.  Anyone else experimented with this with results they can share?

Skydoc, I have no doubt you're correct in your assessment of the spindly front forks.  This is something that seemed to plague all Japanese bikes at least until the mid to late 1990's when beefier forks began showing up on sportbikes.  Of course it's taken longer for that to spread out to other models.  I have no idea if a "mid brace" would improve things or not.  If you try it though, I'd be keen to learn of your results.  I'm certainly envious of your skills and access to tools as a machinist to create custom parts.  I'd try it myself, but only limited by my lack of skills, lack of training/experience, lack of access to tooling, and lack of ready access to materials. LOL

Edited August 17, 2021 by Mach VIII

[saddlebum]

I have progressives but still make minor adjustments on the class to fine tune it to were I want it, take air out on rough roads and add a little on smooth roads and hard surface twists. Do I have a sweet spot ? Can't say as I have found it yet. On the other had we don't have a lot of challenging twisties here and often the ones that are often have fine gravel or sand so you don't often push the limit.

[Pasta Burner]

Just an update after finally getting home from extended business travel this summer and getting some miles on.  I’m currently of the opinion to leave the spring and spacer install as is and adjust with CLASS.