| Author | Message | ||
     Ratbuell |
so..if the swingarm is bolted to the frame, why does my fsm show this guy: lifting a bare frame off an engine...that's still attached to a swingarm and rear wheel? (not only do i own and work on three generations of my own personal buells...i used to work for a dealership. for six years. i'm familiar with how they're built.) | ||
| Ratbuell |
weird. sorry bout the double post, didn't catch that till now...way past the 60 minute rule. sorry for wasting bandwidth!  | ||
| Badrap |
So, does adding the belt spring tensioner fix the bad vibes I get when the bike is loaded 2 up and we hit dips in the road? Inquiring minds want to know. | ||
| Ratbuell |
since the vibes don't come from the belt...and when you hit a dip you are UNloading the belt tension...i would seriously doubt a spring tensioner would affect the 'dip-vibes' one way or the other. | ||
| Svh |
I keep hoping that someone that has actually purchased one of these could answer Badraps question but no one ever seems to. | ||
| Ratbuell |
that in itself seems to be an answer to me... | ||
| Mbest |
OK kids, some fuel for the fire.... '08 uly with zero bearing or belt issues for the first 22,319 miles. The original belt looked to have some excessive cracking on the back side, probably from a rock or other debris getting eaten. My service writer offered to replace it under warranty, fine by me! Got the 2nd generation belt and it snapped in 2236 miles, then the current gen belt. 3106 miles later lost the rear wheel bearings. Back on the road with new bearings and lost the belt 1178 miles later. New current belt and found almost failed rear bearings 6233 miles later at a routine tire replacement. Lost the last belt 4683 miles later. I then drilled out the holes on the factory idler bracket to allow it to drop down about a 1/4 of an inch to reduce the static tension on the belt from guitar string tight to about a stiff 1/2 inch up and down play. Then to expand on that, I pretty much copied the DHM tensioner and installed it on the bike. 16,776 miles so far with out any bearing or belt issues but I carry a spare on trips. Hey Badrap, I had the same vibration on the larger suspension travel dips on my bike as well. It's from a failing front isolator 99% of the time. Swapped a new one onto mine and I can't make it do it. And NO, I don't wheelie at every opportunity or pop the clutch drag race at every light... just sayin.. mike | ||
| Prowler |
"So, does adding the belt spring tensioner fix the bad vibes I get when the bike is loaded 2 up and we hit dips in the road? Inquiring minds want to know." "I keep hoping that someone that has actually purchased one of these could answer Badraps question but no one ever seems to." In my opinion, YES. Belt tightness seemed to be the issue on my bike. It was like I felt every belt tooth engage the sprockets (at times), now......smooth. Plus it just feels like it's easier to roll the bike around the garage now, this would indicate to me that the belt (as delivered from OE) is really, really tight. I've never seen a cogged belt set that tight in an actual running application elsewhere. | ||
| Shagg1970 |
I have had this tensioner on my 06 ulysses for about 10,000 miles of the 15,000 that are on my bike with no belt or bearing failures. It also does eliminate the vibes when riding 2 up and hitting a dip. I don't know how people think the belt gets looser when you compress the suspension, it should get tighter. If you compress the rear suspension the swing arm is going to rotate up in relation to the frame/engine and the rear axle will be farther away from the engine sprocket making the belt tighter. The tensioner can also be adjusted for spring preload. I run mine a little loose, if I accelerate hard and feel the belt skip I know its too loose and tighten it about 1 turn then its about right. for me I am very happy with the spring loaded tensioner. | ||
| Schwara |
Thanks Shagg1970 ... I was hoping to see more first hand accounts. | ||
| Motorbike |
What does the FS tensioner cost in US dollars? Thanks. | ||
| Electraglider_1997 |
Just my 3 cents. I've only had 1 belt break and that was at the 25,000 mile mark. The only time I think the belt is way too tight is when a new one is first installed. Then it stretches so that the next time you take off the rear wheel and subsequently re-install everything it is very easily done. The only question I would have since I am no belt expert, is the belt at all weakened with this initial stretching? The XR1200 Sportster uses the same tension wheel as our ULYs but the axle allows for adjustment like most every other bike. Sure must make a new belt install a breeze. I really do appreciate that I don't have to adjust the axle though, once the belt is stretched that is. Here is a very informative take, explanation, and account of the effectiveness of the tension wheel. Though it is done on the XR1200 it equally applies to our Buells since that is where the idler originated. This guy thinks the springloaded tensioner is a waste of money. http://mysite.verizon.net/vze6wmx4/id106.html | ||
| Svh |
Last I checked, 2 weeks ago, it was around $150 plus shipping. Thank you for the actual answer as to whether it gets rid of that vibration. | ||
| Prowler |
"This guy thinks the springloaded tensioner is a waste of money." Well, "this guy" whomever he is(?), is applying the concept to a bike that has axle adjusters to initially set belt tension. We, unfortunately, don't have that option. I'll keep my FS tensioner, thanks...... | ||
| Paint_shaker |
Ahhhh.... to spring or not to spring? I choose not to to on either my Uly or my Firebolt race bike. | ||
| Badrap |
Thanks for the reply. The only time the bad vibes are a real issue is when I have a passenger. It doesn’t happen very often riding solo. | ||
| Motorbike |
The only time the bad vibes are a real issue is when I have a passenger. It doesn’t happen very often riding solo. +1 | ||
| Eulysses |
Rat...you say the belt tension is less on compression. Would you agree that the bike empty is in "extension" and as it is loaded and hits bumps it passes through the midpoint of the Range of Motion which is the loosest then tightens again as ROM passes midpoint and further compresses? With the swing arm pivot point located rearwards of the drive pulley, belt tension is most loose when the axle is directly in line with swingarm pivot and drive pulley but tightens when rear axle is above or below centerline. Agree? Euly | ||
| Prowler |
I think Rat is technically correct, but the rear suspension is designed such that as suspension compresses, distance between axle centerline and drive sprocket centerline increases and engagement of tensioner pulley decreases at the same rate causing the belt to stay at the SAME TENSION within supposedly a 1/16" or so. Manufacturing and assembly tolerances cause this distance (and initial belt tension) to vary bike to bike by a small amount. Ideal was if the tension would STAY THE SAME from full extension to full compression. Tensioner pulley diameter and location is critical to maintain this "hypothetical same" tension. Much time and effort (I believe they used a computer program to come up with the best balance of reasonable pulley diameter and pulley location). My own perceived observation is: The increased travel of the Uly suspension causes "full extension" tension to be higher than the rest of the XB's, hence the first couple inches of suspension travel on the ULY, the belt is tighter than the rest of the travel to fully compressed. | ||
| Badrap |
Does anyone besides Trojan sell the FS tensioner? | ||
| Nipsey |
Trojan is it as far as I know - and they deliver great service too. I have had the sringy thingy for a couple of years and while there is no science behind my opinion - I like it. I have never broken a belt (but then I ride the Uly less than I should), Bearings are OK (but I changed them out to SKF's pre-emptively), and dammit it looks good too. I did get a second belt and practice changing, and the spring made that easier. In addition since installing it the spring, I have flawlessly performed open hear surgery, dated a fashion model, thrown three touchdowns for the Oakland Raiders, and have become a general bon vivant. | ||
| Badrap |
Eric's 2001 patent http://www.docstoc.com/docs/54176773/Motorcycle-Ha ving-Stationary-Belt-Tensioner---Patent-6866112 claims a belt length change of only .008" during suspension cycle. It also calls out the sprocket and pulley size that must be for the 9's gearing because my Uly has a larger sprocket and pulley. | ||
| Luftkoph |
Let me add so more fuel to this campfire,all my dirt bikes you set the chain play with the wheel off the ground,i suppose that is the furthest distance that is easy to do vs.compressing the suspension all the way to set chain play that would be difficult to do.But the further out from the parallel line of the counter shaft,swing arm pivot final drive sprocket the chain will get tighter either in compression or in rebound,yes no opinions please. Ive always had that vibe on a big dip,new belt old belt | ||
| Froggy |
Badrap, those patent drawings also show plumbing for the turbo charger that never made it into production | ||
| Nobuell |
I alway had the two up vibe when when hitting a dip. I think the buell design may theoretically only allow a 0.008" belt length change but the practical application has tolerance issues that can cause extremely high tension. My last new belt was extremely tight. I modified the tensioner bracket to achieve the new belt tension recommended by the belt manufacturer for similar industrial applications. I never experienced the two up vibration again. The shock spring settings are the same as are the weights. I believe the vibration is not the additional compression force on the swing arm pivot but is the additional side load due to belt tension. It is only a theory but I have not had the vibration issue since the pulley modification. | ||
| Motorbike |
Nobuell, that is interesting. Can you tell me exactly what mods you did to the tensioner? Do you have any pics? Thanks! Also, what should the belt tension actually be and how did you measure it? | ||
| Uly_dude |
Hey Al(Motorbike), I have the belt tensioner. It cost a $100 USD. Whether the belt gets loose or tight when the suspension is used, with this thing it doesn't matter. It's always the same tightness, not too much, not too little. In fact, if the belt did get more loose when suspension is compressed, that's a good reason to buy the Free Spirits tensioner also. The last thing I want to do is get broke down - anywhere. So I figure it's worth the piece of mind that I'm doing everything possible, within reason, to prevent that. To me, $100 is within reason. Also, I checked this thing out, it is not going to break. It's a very simple design that uses the pully from the original setup. | ||
| Motorbike |
And I see they now have the FS tensioner available in red too! I better save up for one. Thanks Uly_dude! | ||
| Eulysses |
Hmmm...the shock mounts to swing arm and frame...not to engine. So compression does not drive the shock into a hardtail status that would pick up or pull the engine against its mounts. It would couple the swing arm and frame...and the frame would not transfer the vibration IF the mounts/engine were in proper position. SOMETHING is pulling the engine against the mounts. I am thinking tight belt again...because it is the belt that connects to the engine...not the shock. Make sense? | ||
| Nobuell |
Motorbike, I could not find much information regarding belt tension from Goodyear but Gates has a very good manual on belt tension for their Polychain belts that are similar to the stock belt. Using the Gates data, a new belt tension should be 108 to 118 lbs for .375" deflection (top center pushing down). A used belt should be 78 to 88 lbs for the same deflection. When I changed my last belt, the tension was way over the new value. I slotted the left hand pulley bracket hole with a rat tail file. Slotting the top of the hole slightly allows the pulley to pivot on the right hand bolt relieving the tension. I slotted the hole a little at a time until I achieved the proper tension. Tighten the nuts when complete to standard torque. Since then, I have not experienced the two-up tight belt sensation previously referenced. To check the tension the belt, I used a small load cell and a tape measure. I had my wife hold the tape measure against the side of the belt and pushed down on the belt with the load cell. I could read the tension from the load cell and see the deflection on the tape measure concurrently. I believe the pulley arrangement to be a sound design. I believe the problem is a stack up of tolerances and variables regarding swing arm length, motor location and belt length that may over tension the belt. After a few thousand miles of operation, the belt tension is within the correct tension range for a used belt. |
