| Author | Message | ||
     Dr_gumpert |
So me an the misses were riding, and every time the suspensiom would compress, like accelerating, going over bumps, or just going up an incline there would be this insane vibration throughout the bike, and to be honest it felt like it was hurting the bike. Does anyone have an idea why it would be doing this? | ||
| Hughlysses |
If the rear suspension compresses completely, you'll feel all the engine vibration that is normally kept away by the rubber isolators. I've noticed an increase in vibration on my bike when riding 2-up when the suspension compresses, but nothing like "insane" vibration. I'd (1) make sure you have the suspension adjusted properly for the load according to the manual, particularly the rear pre-load and (2) if that's OK, check the condition of the isolators. One of them may be badly deteriorated. | ||
| Desert_bird |
Is this first time you've experienced this? "Insane vibration" sounds disconcerting. It's a part of life with me when riding heavily loaded or w/pillion, especially on deep dips at speed. Not insane but definitely noticeable. I found a slight correlation with the condition of the front isolator, but it seems something unique and normal to XB design. Part of the "character" of the bike. Some pillions actually don't mind that vibration ... The rear isolater seems pretty bombproof on these bikes. I haven't heard of many people changing them out. Perhaps they haven't chimed in. I second Hughlysses' suggestion on making sure that your rear shock is not bottoming out. Good place to begin is to make sure you are getting all the rear preload you should. If not then you can refill the preload adjuster. The hydraulic oil in that adjuster tends to disappear. It's an easy 15 min job. DB (Message edited by Desert_bird on March 30, 2016) | ||
| Electraglider_1997 |
Check your tires for cupping because that can make your bike feel like you are riding down a railroad track. | ||
| Reepicheep |
When I had my 9sx I made fun of all the guys buying the free spirits tensioner. When I got my Uly, I felt what they were trying to fix. Don't get me wrong, I still make fun of them, but I no longer discount the problem they wre trying to solve. Drill the mounting bolts for your tensioner out a couple of steps up with a step drill and reinstall. See if that makes things better. | ||
| Electraglider_1997 |
You could always solve the problem by riding a GoldWing. Nah, that gives you a whole new set of problems. | ||
| Hughlysses |
Good place to begin is to make sure you are getting all the rear preload you should. If not then you can refill the preload adjuster. The hydraulic oil in that adjuster tends to disappear. It's an easy 15 min job. Good point by DB. You can tell the state of your adjuster by backing it off all the way and then starting to turn it back in. You should start to feel resistance within no more than about 4 turns. If you don't, some of the fluid has leaked out and you're not getting the full range of pre-load adjustment, which will make it much easier for your rear shock to bottom out under load. There are a couple of threads here about fixing it, but here's the basic procedure: First, support the back of the bike so no load is on the rear shock. Then disconnect the hose from the remote pre-load adjuster. Take something like a small screwdriver, stick down in the hole in the adjuster, and gently push the piston all the way down. Now fill the opening to the top with oil; jack oil and fork oil have been used. The type oil doesn't seem to be critical. Carefully reconnect the hose, avoiding spilling the oil before you re-tighten the fitting. Now try your pre-load adjustment. You should start to feel resistance within 2 or 3 turns. | ||
| Sagehawk |
I put a lowering collar in my 12x over new years weekend and took the extra time to refill the oil. Before, almost 8 turns to see any resistance. Travel on cylinder was around 1/4". Took two times of refilling to get it right, but now I feel resistance within 1 turn. Travel on cylinder is now 3/8". Still playing with preload as to having the lowering collar in the bike. World of difference, it has made! | ||
| Tootal |
I always felt the vibration you're feeling comes from the belt getting extremely tight when you bottom out. That's what Reepicheep is talking about. I still haven't done anything with my idler but it's on the list! | ||
| Arry |
I'm not positive, but I think the belt would be at it's slackest point when the suspension is bottomed out. | ||
| Crempel |
I experienced this some time back with the missus on the back too. I talked to Al at AmericanSportBike about it and he confirmed that it is the suspension bottoming, causing you to feel the vibration of the engine through the frame. I had also thought it was belt related because it felt just like I imagine the teeth of the belt would feel like if they rubbed over something. If Al is still around, you should call him and ask him about this. Still sorry we are losing him as a resource. That guy has forgotten more about Buells and motorcycles in general than most of us will ever know. | ||
| Ourdee |
As I have read it, we aren't loosing his help. He is just getting out of the parts business. He wants to be more like some of us that ride around and have fun. Al, Feel free to correct me if I'm wrong. | ||
| Woodnbow |
I had that bottoming vibration on my 08 with the original motor/trans. Now it has an 09 transplant and there's no vibration at all under the near bottoming conditions but the motor vibrates significantly more under all conditions than the original. Not enough to fuss about but it's there. | ||
| Etennuly |
I did some serious research into this problem as me and the Misses are kind of over the GVW numbers for the Uly. What I found, making several passes through a local dip in the roadway, was that the engine mounts were bottoming out. What you feel is the pulses of that lump being loaded through the frame at full compression. I thought it was, and was concerned about, it being the belt also. By testing it with the engine shut off and at different RPM levels I found that the vibrations were strictly from the engine pulses at full bottom out of the engine mounts. So it is not really a concern except that your front isolator may be going bad. | ||
| Chopperbob |
I just bought my Uly two weeks ago. Riding it home, two up and with the bags packed, this bike vibrated when bottoming out in dips. Has anyone got a source for a beefier rear shock? The bike handles fine with all 3 shock and fork adjustments turned up for max load, but it definitely bottoms out in dips. | ||
| Natexlh1000 |
The suspension is all Showa so theoretically, you could find out what our stock spring's Showa number is and find if they have one the same length with a higher capacity. | ||
| Hughlysses |
Chopper bob- see my post above about checking the condition of your preload adjuster. There's a good chance that's the issue with your Uly. | ||
| Al_lighton |
I don't think it's the belt, I think it's just a combination of the rear isolator and the shock loading. If you look at a tube frame Buell, the rear wheel/swingarm/shock/engine assembly is mounted across isolators completely from the main frame/seat subframe/steering assembly. Only the heim joints join the two assemblies through a (mostly) rigid connection. If you load a tuber too much, the isolator doesn't isolate as well, and if the isolator bolt heads bottom against the isolator, they'll get a bit more rumbly. But nothing like the Uly effect that folks have described. But XBs aren't just like the tubers. The shock bridges the two isolated assemblies, so when the engine is dancing around a bit on the isolators, the shock is dancing a bit with it. But when you really load that shock, it doesn't dance as nicely and will transit more vibes. The rear isolator as it gets loaded more heavily will also transmit more vibes. The two together can get really rumbly compared to a tuber or other Xbs. The biggest difference between the Uly and the other XBs WRT this effect is the length of the seat. The rear load with the greater moment arm will more heavily load the rear, increasing the rear shock and isolator load. All 100% my opinion from what I've observed. I don't have any proof of this. But I don't run a spring loaded idler myself and am not a believer. As a related aside, I had someone come into the shop once complaining about pulsing in the front end during braking, a pretty common occurrence when the brake rotors are coated with uneven deposition layer. But this particular Uly had a really clean looking rotor. I rode it a bit and was confused at first, because it definitely pulsed badly on braking. But like Vern's test, I did a bunch of braking with the engine off, and all the pulsing when away. Under hard braking , the front iso was compressing completely and transmitting engine pulses to the rider. This is the same effect as what happens in the rear when the rear gets loaded too heavily. Al | ||
| Smorris |
i'm reading this wondering about an odd problem i have encountered. this past fall one of the last outings i whacked the throttle a couple times to get a nice wheel stand, i too experienced a shudder feel and i think a sound as well. did not encounter on hard corner exists but just when showboating a wheelie. i was headed toward the coil springs in the clutch shell but haven't gotten there yet. what do you think Al? could it be front iso? rear iso? or shock? one reason haven't gone to the clutch shell coil springs is that i am unaware of any way to diagnois, as i understand they are all differing lengths and pressures | ||
| Natexlh1000 |
What coil springs are you talking about? The only springs I know of in these clutches are diaphragm style? There aren't any cush-drive type things either. Are you bottoming out the rear suspension when you put all the bike's weight on it? | ||
| Al_lighton |
I've not heard of these type of sounds emanating from the clutch "cush drive" springs. They are generally reliable, though I know of some cases where the springs failed and parts of the springs ended up in the primary. There is no fix for them in such a case, you have to replace the basket. A wheelie loads up the rear of the bike similar to two up loading, so I'd suspect the sound is the same one that folks hear when heavily loaded in the rear. So it's likely the rear isolator fully compressed and transmitting engine vibes into the main frame. Nate, tubers don't have the coil springs in the back of the clutch basket, but all XBs do. | ||
| Smorris |
thanks for input. i'm going to refill shock resovoiur and see if that is quick fix. if the rear iso is fully compressing is that an indicator it is nearing the end of it's life and should be replaced | ||
| Natexlh1000 |
Whaaaa! I have been living a lie! I need to see my service manual. I thought tubers,sportster, and XB motor primaries were pretty much same||same. | ||
| Smorris |
It isn't in service manual and you can't see it in parts book except the convex areas where the coils are located radially, i think there are 6 coil springs. the xr1200 has the same shell but none of the other sportsters |
