| Author | Message | ||
     Court |
Jerome: One element of "good news" is that nothing you do to that belt tension is going to make the belt break. The 7 Kevlar strands were once demonstrated to dealers by hanging a HD FLHTCU by ONE of the strands. In another instance, 1/4" holes were drilled at small intervals along the belt and the bike was hammered. No can do. The ONLY (subject, of course, to me being wrong yet again) that belt will break is the "rock twinsxt the belt and the pulley" gig. Yes, I know there will be exceptions. I have not heard back but will keep you posted. Court | ||
| Ralph |
 bighairyralph | ||
| Mikej |
Ralph, Let me guess, somebody twisted it while or before they put it on. I've heard that twisting them is another way to get the belts to break prematurely. | ||
| Ralph |
Mikej, how about he twisted the throttle. bighairyralph | ||
| Mikej |
Ralph, I worked with a guy outwest who had a hot twin, the only things H-D on it were the tail-light and one other small item. He claimed it would also bust belts, but I don't know what kind of power it produced. Who's bike is that, and what kind of power is the engine producing? | ||
| Court |
I'm not sure who'd bike it is...but IF "power" broke the belt I can tell you it's in excess of 400 RWHP and 500 '/# torque. | ||
| S2no1 |
Egads, I'm blind, I'm blind. Somone tell me what mining companies handle chrome. Based on the usage on that motorcycle I need to buy some stock. Wait, that may not be a good idea. Someone might melt down that bike and flood the market with chrome decreasing the value of my investment. Arvel  | ||
| Slodog |
Anyone try 25/53 sprockets with an aluminum swingarm, I put the swingarm on my S1 and i am going chain drive, anyone have an opinion on if it will clear. my 23/50 combo is not working, my chain is rubbing my swingarm the wrong way. ANYTHING..would be appreciated. PLEASE HELP.. I DON'T LIKE THE BELT. | ||
| Jmartz |
Slodog: I have a Custom Chrome 24 at the shop being holed up with an electric zapper (too hard for drilling). It is nearly identical in diameter as the 27 teeth pulley. I have seen postings that a 25 will fit but since the chain is thicker (verically speaking and thus larger in diameter when forming a partial circle on the pulley) it sure seems that there isn't any more room in that area. I believe a 24/52 or 25/53 will still carve groves on both the SA and SA block due to the inherent slop a chain must have but the "damage" is not significand nor structurally damaging. Jose | ||
| Ralph |
The 25 WILL fit, a 26 would need a little clearance grinding. bighairyralph | ||
| Chuck |
Hey Court, Guess what I broke today...seriously considering a chain, now. Who makes sprockets for these things? I thought those cams I put in, helped things; but, man . . . . . . I never dreamed I could get 400 RWHP  | ||
| Court |
Chuck: Don't fool yourself. I'm unconvinced (but also unsure and AM going to find out as soon as one of the Buell dudes gets back from testing) that POWER can break a belt. Good news is that the chain conversion is not rocket (no pun intended....well,perhaps a small one)science. My personal observation: But GOOD sprockets AND chain. Arvel: Careful. The Hunt's already tried that. Court | ||
| Blake |
Neglecting FOD (foreign object damage) as instigator, what causes a belt to break? Tension right? A liberal 1000 FT-LB at the rear wheel (near 100 FT-LB @ crank times overall ratio of near 10 for 1st gear with USA final drive) times 3 for inertial loading (dumping the clutch) gives 3,000 FT-LB at the rear axle. Divide that by the rear pulley's radius and you get approximately 7,000 LB belt tension. Belt too tight? So tight it won't let the swingarm reach overcenter wrt axis defined by pulley centroids? The belt in effect becomes an extremely inefficient tension member of a rigid rear suspension. If the angle included between the swingarm and the axis defined by the pulley centroids ends up under max load (like when hitting a big bump or dip) around 1 degree, the belt will be seeing almost 12,000 LB for every 200 LB of dynamic overshoot loading (dynamic overshoot loading being the portion of the rear axle load not being carried by the rear suspension). Take that angle to 1/2 degree and the factor jumps from 60 to over 100! A 200 LB DOL then results in 22,000 LB belt load (11,000 LB tension in top and bottom)! Can you say "SNAP!"? In the highly unlikely case where the peak DOL and drive tensions coincide, (well maybe when launching a wheelie over a speed bump?) your too tight belt would see 18,000 LB in the top (drive portion) of the belt, and 11,000 LB in the bottom! How about 1/10th of a degree? The belt would be seeing nearly 120,000 LB for every 200 LB DOL. Plus consider that this excessive belt load also has to be endured by the right side swingarm bearing and the front pulley drive shaft/bearing. I'm just dividing the DOL by the SINE (ratio of opposite to hypotenuse legs of the pulley centroids to the swingarm triangle). Do ya see Court's point about the belt not breaking due to power? Overtight is WAY bad! Loose is good. (This is for drive belts, not women!)  Blake (afflicted with trigonoreah?) | ||
| Bluzm2 |
Blake, You're scaring me!!! This engineering stuff is like dirty talk for me! Screw it, I'm buying some books so I can keep up with you! Like a area radio talk show host says "You learn more here by accident than anywhere else by design". I couldn't agree more. Actually I can follow most of your stuff with no problems. Either I really should have been an engineer or you would make a very tallented prof. Hmmm, probably a bit of both. Thanks Aaron.. BluzM2 | ||
| Blake |
Got a picture. Wanna see it? Here it is...  The geometry isn't to proportion or scale, but it illustrates the situation well enough. I simplified, the DOL would actually need to be shown perpendicular to the swingarm axis. I goofed and drew it vertical. | ||
| Chuck |
Ralph, Jmartz, Please help  What's your latest finding on chain conversion? My belt popped yesterday; and I won't try abusing another. A friend wants to buy my stock rear pulley, anyway...so chain conversion, for me, may be slightly cheaper. Ralph, how many chain links are needed to get around the 25 / 52 sprocket combination? And does the 25 countershaft sprocket give you enough engine clearance? What spacers do you recommend? My bike is a 2000 M2; and from your photos, I know my rear wheel is different from yours. Thanks in advance. Would like to get parts on order tomorrow if I can. My Buell is way more cool to "drive" than my mini-van  | ||
| Court |
Chuck: Talk to Cap....this guy is good....very good. Blake: Nevermind....it'll never pass the filter. Court | ||
| Jmartz |
Chuck: Ralph has tried the the 25 trans sprocket and you should go with that for maximum clearance. A 56 rear will yield a 2.24 2ndary ratio, slightly "weaker" than stock (less acceleration, more top end). A 57 would be 2.28 sightly "stronger" than stock (2.26). A 140 link chain will do. Because chains need to run with more slop than belts it is almost certain that there will be some contact with the SA block and possibly the SA (in aluminum late model bikes) but I don't think this will be harmful. You may construct a nylon rubbing block to be positioned on the SA block but there is no easy way to protect the SA itself as the contact is sort of sideways and not on a flat surface you coud drill and tap. I had a machinist build me a 1/4 inch spacer for the trans pulley. In '95 HD went to a 3/4" wide spline and all present day replacement pulleys and sprockets remain at 1/2" thickness. Alternatively (the hard way) you could change the oil seal and spacer to a pre '95 or better yet pull the spacer and have a machinist build you a 1/4" longer one. I am personally not inclined to replace the oil seal with 5th gear still in the trans, but that's just my personal opinion. Jose | ||
| Chuck |
thanks for writing back, Jose. Cap called me last night with a "solution". We agreed on the 25 / 57 combination. He is putting a kit together for me, now, with everything I will need. One cool thing about the conversion . . . I don't have to pull my swingarm to replace the "worthless" belt | ||
| Ralph |
Chuck, what Jose said. I used a 25 in the front and 52 in the rear. Cap is running a 53. I made the spacer for the front so your kinda on your own there. I got the longest standard chain (120 links?, can't remember) and cut four off for the right fit. I also built a rub block for the swing arm block and the swing arm itself. It will be about impossible to drill and tap the block on the bike for mounting a rub block. I don't see any reason for the necessity of a rub block on the swing arm block. The chain will eat some and then leave it alone. The swing arm I did on the bike with an angle head drill. The swing arm doesn't have the thickness or mass of the block and when the suspension is unloaded the chain would smack it a good one. I'm in the process of lowering the bike to get some more clearance. I had some serious geometry changes with the White Power shock combined with the aluminum swing arm. I would strongly suggest getting ahold of Cap. He's very knowledgeable and just down right smart. He'll also have the right spacer for you so you won't have to come up with one. Sorry I can't really give you any absolute answers but I'm still developing my set up. The last thing I want to do is give you the wrong way to do things. Or tell you how to tune your carb bighairyralph | ||
| Blake |
No, but you'll be cleaning and lubing and cleaning and lubing and replacing. Is it really that tough to pop out the right side isolator and slip the new belt on? YES!!! It is!!! Except on an X1. How 'bout putting the same removable joint on the other Bikes?! BUELL!!! Are you listening?! | ||
| Ralph |
Hey, Blake maybe they could. Gee, wouldn't it be neat-o-keen? Gosh, maybe they could even make both sides removeable to ease isolator service. Naw, there's just no way. bighairysarcasticralph think s2 baby | ||
| S2no1 |
Ralph, I feel for the isolator impaired. Arvel | ||
| Chuck |
Ralph, thanks for writing back...Artful, to answer your questions from the "general discussion" : a new belt is over $150. Someone above said $165. That amount of money will buy several sprockets. The lack of a "cush drive" may present its own problems; but my brain won't allow me to focus on more than one problem at a time. My bike has "mild" cams and had 4514 miles on it, when the belt broke (it now has 4516 after pushing for 2 miles). Anyway, did I deserve this "fate"? Well...yes...probably. I abuse my bike on a daily basis, "flogging" the engine and driveline, whenever the "coast is clear", sometimes using the clutch to help launch the front end, skyward...Only trouble is, I don't have the self-discipline to give up these "bad" hooligan habits: so, I'll try something different for a while. If nothing else, the sprockets will look, way cool | ||
| Jmartz |
Still Chuck, your belt should have lasted longer. Hoser from Calgary does just that (frequent wheelies) and I am the terror of my neighborhood. My bike has 38,000+ miles and I can't see any wear on the belt or pulleys. I have a set of pulleys in the shop being lightened. When I get them back I'll post a picture. I estimate the loss of 3 lbs. overall. I like the idea of a chain and have begun collecting some parts for a kit but the chain slap issue needs to be resolved before I do the conversion. I was hoping to arrive at a final drive ratio (about 2.5) that would produce 85 mph at 4000 rpm in the baker 6th. jose | ||
| Chuck |
maybe, I just got a "dud" | ||
| Jmartz |
I agree | ||
| Ralph |
Probably. My belt went over 36,000 with no problems. But, I never did a wheelie Really...I'm telling the truth....honestly....stop laughing.... bighairyralph | ||
| Chuck |
. . . . . . or . . . maybe my bike is just more powerful than all of yours | ||
| Ralph |
Uh, sure Chuck, you bet. Just like I never pull wheelies. bighairyralph |
