| Author | Message | ||
     Berkshire |
"...it would have a tough time pushing that with taller gearing. I wouldn't want to be without the power you'd lose there. You'd also lose power through all the gears (since they'd all be 'taller')." I've been thinking about that... It recently occurred to me that with taller gearing, you'd stay in each gear longer before having to shift up. For example, with the stock setup you have to shift to 4th at about 65, and 5th at about 80. With 11% taller gearing you'd stay in 3rd up to 72. If 4th is 20% taller than 3rd, then you'd actually have 9% better acceleration from 65 to 72 with the taller gearing. But then you'd have 11% better acceleration from 72 to 80 with the stock gearing, since you'd be in 4th either way. With the taller gearing you'd stay in 4th to 89, so you'd actually have better acceleration from 80 to 89 with the taller gearing. But then you'd have better acceleration from 89 to 96 with the stock gearing, since you'd be in 5th either way. With the taller gearing you could go faster than 96, if you had enough power to push that much air out of your way. If what I'm thinking is correct, then the stock gearing would be better up to your normal 1-2 shift, but then the advantage would shift to taller gearing, and then back & forth as you go up through the gears. Since the initial advantage goes to the lower gearing, the taller gearing would always be trying to catch up in a drag race - but it's not a "total loss", since the advantage switches back & forth at various speeds. If you slow to 65 for a corner, then you accelerate out in 4th with stock gears - but with taller gearing you come out in 3rd. That's what I'm thinking, anyway... | ||
| Reuel |
You understand correctly! Just ask LaFayette. That's what he did. | ||
| Gearheaderiko |
Well, yeah. Thats why people prefer chains for racing. You can more easily 'fine tune' the gearing for the track and engine tune. Generally taller gears would give up something on acceleration (or you'd lose more than you'd gain, all other things being equal). The Blast hits a wall at 90mph. Getting beyond that can be time consuming, so using taller gears for a higher top speed is pointless (unless you 'upgraded' the engine). Doubtful that taller gearing would give any advantage in drag racing or just straight acceleration. Take it a step further. Whether you run 1/8 or 1/4 mile drag racing how you gear it makes a difference. Gear it low for 1/8 mile and you're fine if you hit top speed at the traps. But with the same gearing on 1/4 mile, you'd lose running that same top speed for the last 1/8 mile of the course, while the taller gearing would eventually pass you. | ||
| Fast1075 |
Actually in drag racing, you gear it for the best possible 60ft...with gearing tall enough to be JUST past the power peak at the 1/4 mile mark...for 1/8 mile you just shift fewer times. That eliminates one whole extra set of data you need to collect for performance interpolation. Cuts your set-up time and tuning passes in half. this is of course assuming you are competing in bracket racing on a regular basis. Throw in throttle stops, stutter boxes and nitrous it becomes a whole 'nuther head game. | ||
| Reuel |
I know what nitrous is, but what are throttle stops and stutter boxes? Is it that obvious that I only know the first thing about racing? | ||
| Fast1075 |
Reuel, no disrespect intended...I'll trade yah straight line skills for cornering skills  Have some to spare??? In drag racing there are 2 types of races...heads up, where both bikes take off at the same time...first one to the finish line wins...basically this is Pro type racing...run what ya brung, hope you brought enough. The other type is Bracket or E.T. racing...where bikes of different performance levels race against each other...the riders "predict" how quick they will run and the slower rider gets a head start equal to the difference in time between them...say my bike runs 9.00 seconds...your bike runs 8.50 seconds...when we race, I get .50 seconds head start...in theory, we will both cross the finish line at the same instant...in reality, the slower bike is a sitting duck at the finish line because the faster bike is closing at a higher MPH...in other words the the bike coming from behind has an advantage...BUT you dont want to be the quickest bike there...you end up sitting on the starting line watching the opponent go down track...it is very easy to blow the light and take off too soon...then you are eliminated... What you do is make the bike take longer to go down track...just a bit longer than the rest of the field... take your fast bike...add nitrous if you dont already have it...and put on a throttle stop...with a throttle stop...you take off normally..then at a preselected time down track, the throttles close to say...1/4...they stay closed for a predetermined lenght of time...then open..a bit down track another timer stages in the nitrous...watching the race...you and the opponent take off at about the same time...after say one second, your bike throttles down...the opponent takes off like a rocket, leaving you behind...after say 2.5 seconds, your throttles open back up and you start to gain on him...1 second later the nitrous timer kicks in and you add another 75-100hp...now warp drive kicks in...the opponent is coming near the finish line running, say 125 MPH...he cant see you, he cant hear you because he cant turn his head enough...he thinks he has you beat so he rolls off the throttle a bit to be sure he does not break out (remember he predicted what he was going to run, and if he runs quicker by even .001 seconds, he will be disqualified)...he is running 125 and slowing...you in warp are running 155..by the time he hears or sees you it is too late...you blip the throttle and beat him to the finish line by a wheel... That is deadly strategy....the nitrous is not needed....but if you don't have it you better have a King Kong Gorilla motor  | ||
| Reuel |
Well, I knew what bracket racing was, too, and figured there'd be a strategy to it beyond consistency. Didn't give it much thought until just now. Thanks! I like my cornering skills, so I'm keeping 'em! I wouldn't mind doing some drag racing, but find me a curvy road and set me free to see how close I can get to the ground without touching it, and I'm happy! | ||
| Berkshire |
I dunno 'bout all them tricks... I figure just cut a light and run your number, then the other guy will either break out or finish 2nd! OK, here's a trick: if you're the faster car and you catch the other guy before the finish, then ease up and just keep his front fender even with your door - they call that fender surfin'. If you're the slow car and you've got nitrous you don't use in time trials, then you can flip the fender surfer - set your dial a little faster so the other guy will catch you. He'll slow down to protect his dial, then you tap the bottle and nudge past him for the win. Anyways... I wonder how well the Blast pulley ratio works at the dragstrip? | ||
| Blastnyerass01 |
i can't find info on taller gearing anywhere, i'm looking to cruise down the highway at a lower rpm. is there anything that can be down as far as gearing goes? | ||
| Gearheaderiko |
Yes or no depending on what you want to spend. 2000 Blasts had taller gearing, but the pulley was very prone to breakage so it was recalled. 2000 pulleys are almost impossible to find and its a risk using one. An XB 12 engine sprocket can be installed, but you'll also need to add a new primary chain and according to someones research here, also an XB primary cover and adjuster. You can change the inner transmission gearing, but that involves splitting the engine cases. Convert to chain drive. No bolt on kit is available though. The Blast is also a little underpowered for taller gearing. You may get your desired goal of lower highway rpms, but you certainly wont gain a higher top speed without engine work. | ||
| Onecos |
Belt Alignment Question I think my belt needs alignment. I can hear it rub on the plastic guard. Looks like 1/4 of the belt is off the rear wheel sproket. See Pic. How do I align this?  | ||
| Gearheaderiko |
Alignment is non adjustable. Instructions are usually to look for worn or damaged parts. I cant really tell from the picture but it may be 'normal' or passable "but keep an eye on belt wear". Some have spaced the rear sprocket out to move the belt closer to center. I'm sure the factory would highly disapprove of this method given their being adamant about always replacing sprocket bolts and washers. Its also possible to move the spacing of the wheel by shortening the axle spacer on the sprocket side and adding a spacer on the rotor side. If the belt isnt showing extreme and/or abnormal signs of belt wear, I wouldnt worry about it. | ||
| Berkshire |
Its also possible to move the spacing of the wheel by shortening the axle spacer on the sprocket side and adding a spacer on the rotor side. Would moving the wheel to the right totally screw up the bike's handling? I had a similar idea: get the wheel widened only on the left side and change spacers to move the wheel to the right to re-center the tire. That would help belt/pulley alignment as you've described, and also give a wider rim (possibly for 1/2 the regular wheel widening price?) - but I wonder if moving the wheels center of mass (The heavy spokes, as opposed to the geometric center defined by the tire bead lips) would generate some kind of weird off-kilter gyroscopic voodoo or something? | ||
| Gearheaderiko |
I doubt you'd be able to notice any difference moving the wheel 1/4" to the right and 1/4" is probably the most you could move it without having to modify the sprocket cover or delete it. Personally, I think those that have spaced everything out so the belt runs exactly in the middle have 'issues'! You could also modify the front pulley to offset it, but again the clearances are so tight, you cant go far. I think its pretty rare when somebody actually does have a belt alignment issue and there arent damaged parts involved. They'd still charge you full price for the widening! | ||
| Onecos |
I looked at the possibility of altering the spacers. Not easily done as the disk brake will also need to be spaced. I could possibly move it 1/8 inch. No noticeable wear on the belt. I'll drive it till it fails and then consider chain drive modification. Blast on!!! | ||
| Reuel |
It'll last 15K+. Mine makes noise for the last 2 belts. Do your research before you go chain. I believe the pully was made so wide so that if something became amiss, like a bearing failure, the belt will not slip off the inside. | ||
| Berkshire |
Whatever thickness you subtract from the spacer on the right, you'd have to add between the caliper bracket and the swingarm so the total would be the same. The caliper would then move with the wheel, and the allen-head bolt that keeps the bracket from turning would need to be replaced with something longer. I was thinking more along the lines of 1-1/4" to 1-1/2" of additional wheel width, meaning 5/8" to 3/4" of change to spacers, and either a different sprocket or cut down the stock one for swingarm clearance, and the belt would ride mostly on the part that isn't getting used now. I noticed the stock setup already seems to be weight-biased to the right side. The wheel spokes are "dished" to the right, and the spokes are open on the left side and closed on the right, so there's a lot more metal on the right. There's also the bosses to attach the sprocket, the bolts, and the sprocket itself - as far as rotating mass is concerned, it's part of the wheel. The left side has the brake rotor and the hub comes out farther, but that's much closer to the center so I don't think it counts toward gyroscopic effect as much. Anyway, if the stock setup really is as weight-biased to the right as much as it looks like it is, then maybe it means that there's no such thing as gyroscopic effect, or it doesn't work in a way where left/right bias makes any difference. ...or maybe it DOES work that way, and the stock setup is pushing the limit of how much you can get away with, and any more would give squirrely handling, I dunno. Some custom choppers have wide rear tires, wide drive belts, and wide primary belts, and the result is a primary drive that sticks WAY out - I remember hearing something about a gyroscopic effect from the way-offset primary drives making it hard to turn the bike one way, or maybe it tried to turn itself when the revs got up, I don't know - but it didn't sound good... | ||
| Robi |
Hello, I want to see if I understand the questions and answers, as I seem to be having the same issue (except my belt has not broken – at 9,500 – not sure about previous owner – I just started riding it). Issue: The belt does not ride the center of rear sprocket, in particular, it is riding toward outside edge against outer plastic of sprocket. This outer plastic seems to be what is keeping the belt on. Sub-issue 1: Belt wear along edge. #8 wear if compared to page 1-19 thru 1-20 of service manual. Sub issue 2: plastic edge of sprocket "frays." From reading the forums, my understanding of resolutions are (please correct): 1. There is no alignment possible. This type of wearing is normal. Keep your eye on it. 2. Adjust spacers etc, to bring rear wheel/sprocket further right, thus bringing belt more center. a. Question: what does this do to balance and safety? b. Question: if rotation of wheel is what pulls belt to outer edge, and if outside sprocket plastic edge is what keeps belt on; what would prevent belt from moving further out if wheel is aligned to bring it to center? Won’t it just walk itself outward to the plastic edge of the sprocket again? 3. Adjust the positioning of the engine a. Question: Mentioned briefly in another thread I believe, is this a valid option? b. Question: Can someone explain this in detail? Thank you | ||
| Swampy |
The front sprocket/rear sprocket alignment are fixed by the design of the swing arm being mounted to the engine. (The simplicity of this machine is so amazing) There is nothing to adjust the belt placement. I think that using spacers on the rear axle would be the way to go. Whatever comes off the right side goes on the left side. The Plastic cover certainly has a purpose though, probably to keep the belt on the sprocket.... Oh yes I forgot.....Hi Girlfriend! (Thats for the benefit of the wife, who has told me more than once "Tell your girlfriend I said Hi" everytime she sees me typing on the computer) | ||
| Fast1075 |
Ever run a belt sander? The adjustment knob does not move the rollers side to side to center the belt...the adjuster allows you to adjust the rollers for parallel...the belt on the bike is very similar..if the belt is tracking off the side, the two sprockets are not parallel. Further explanation...if the outside surface of the rear sprocket is worn, it is smaller in diameter than the inside surface...result...belt runs to outside...if the belt is stretched on the inside edge (see it all the time in power transmission)it will try to track off the pulley...if the rear axle bolt is the tiniest bit closer to the swingarm pivot on the right side than the left side, it will track off....if the right side swing arm bushing is worn..it will track off..if the right side wheel bearing is loose, it will cause misalignment...and track off. If the axle is a bit bent...it will track off...anything that prevents perfect parallel alignment is a possible cause... | ||
| Swampy |
Well yes, that goes without saying! | ||
| Gearheaderiko |
"Hi Girlfriend! (Thats for the benefit of the wife, who has told me more than once "Tell your girlfriend I said Hi" everytime she sees me typing on the computer)"Oh, uh, Hi!? followed by uncomfortable silence. I think we're married to the same woman! | ||
| Gearheaderiko |
Robi: Repositioning of the engine is not possible. Altering the spacing of the rear wheel is not going to cause any problems in handling (none which you'd notice). Your belt is probably normal and nothing to worry about. The belt is the one thing EVERYBODY seems to notice and comment on, from wiseacre comments to instilling paranoia about its placement and size. I cant seem to recall anybody whose had a rear bearing problem mention anything about abnormal belt wear associated with it. Not that it isnt possible, it just doesnt seem to be that critical (in a practical sense). | ||
| Robi |
Swampy - thank you, and hello as well. Fast1075 - never ran a sander, but your explanation makes sense to me. Specifically, I totally see about the outer edge wearing more will cause its diameter to shrink. Thank you. Erik (I think that is your name) - I have recently taken the wheels off (with assistance from neighbor), and put them back on w/ new tires (by myself). The belt was riding toward the outside when I bought it (used). Questions: a. Since I put the wheels on myself, should I lift it again, and slide everything out and put back together? b. Should I look into spacing it (Note: I am not technically, or "shop" savvy)? c. Calm down, and just keep an eye on it? -------------------------------------------------- -------------------------------------------------- ---------- Follow up question, re: belt noise I road some country/city roads for about 30 miles yesterday. I was practicing figure 8's, 2nd day riding last night. I fell and drop the bike on the right side. (+) Pro: I'm glad to have fallen for my first time in a parking lot. (-) Con: Felt like an idiot the whole time because the 8's were tighter than I needed to do, but I was so impressed on how nimble the Blast was, that I just kept going tighter and tighter. Known damage: (1) right front blinker (replacement in stock); (2) right break handle (bent, but functional); (3) few scrapes. Calipers, rotors seem fine. Road to work, no problems. ISSUE: I'm hearing a noise from the belt (when off, and rolling manually; no noticeable sound when riding). Like a "binding" (the best I can describe). QUESTION: a. could this have been cause by the fall some how (in other words, is such damage likely)? I was only 1st gear, and turning within 2 parking spaces (this thing seems almost as maneuverable as a BMX bike - of course I fell though). b. Is this noise a signal of possible belt failure? c. Is it normal, and I should just calm down and keep an eye on it? I hope all my questions make sense, and thank you for your help so far. | ||
| Reuel |
If it's that strange squeeking noise, just enjoy it. It goes with the excessive idle vibration. | ||
| Robi |
It's more of a "creaking" noise. As I push the bike (say into, or out of, the garage), I hear the “creaking,” which seems to be coming from the belt. Yesterday (and this morning) is the first time I heard it. Yesterday it did get a bit of riding, but also I had the fall. If I had to wager on the best analogy, I’d say, it sounds like a taught rope (or leather strap) on a ship. As the boat sways, you hear the tight rope (or leather strap) . . . “creak.” [But I guess that's not far from "strange squeeking"]. That’s the sound I hear from the back wheel, as I roll it. And it’s not continuous. It sounds for about ¾ of the turn of the wheel. Again, since I heard this just yesterday, it’s a little bit of a concern to me. a. Though the drop (to me) was shallow and at low speed, did I potentially bend something that is putting excessive (or more) strain on the belt? or b. As you [Reuel] said, this is normal, and chill out. I appreciate the diagnostic skills you experts have, considering most of the prognoses are through reading someone’s poorly descriptive explanations. So, I guess I expect (or hope) either: (1) don’t worry about it; or (2) “yeah, I know exactly what’s happening, and here’s what to do.” Otherwise, unfortunately, I’ll give myself an ulcer. | ||
| Ezblast |
Check your wheel bearings. EZ | ||
| Robi |
What should I look for? a. Will they be bent/mishaped? b. Just replace since I don't know how old they are? c. If I grease them, do I need to take them out? Or is there a way to grease them while they are in? | ||
| Ezblast |
just jack up wheel, spin to see that it spins true and make sure there is no side to side movement. EZ | ||
| Robi |
Sounds good. Thank you. |
