Excuse the unusual rambled writing and the lack of pictures. I just didn’t have time to take any. I suppose there’s always time to do a proper write-up with some decent pictures when I put the bike back into street trim, when I’m not so pressed for time. With that said, here we go…
I almost didn’t do it, but then I made myself. I had a plan, I needed to stick to it, even though I’m currently a day behind schedule in race prep. It took me six hours to do the gearing change. SIX stinkin’ HOURS! I’m really getting tired of this mechanic’s gig. My mileage has dropped off significantly since I came up with this crackpot idea to go motorcycle road racing. I’m working more on my bike than I actually ride the thing. I should just slap a Harley sticker on my tail…
Work. Wrench. Sleep. Repeat.
That is not how it’s supposed to be…
Wrench. Race. Fight in the pits.
Ride. Eat. Sleep. Repeat.
There. That’s all I ever wanted to do. With a (huge) emphasis on RIDE. But it was the natural progression of things… it had to end up where it did. Eventually. The street isn’t my playground anymore. The street is boring. The street doesn’t challenge my will to learn and to improve. I need to move forward. I need to progress. I need to improve my riding skill. I need to get faster, smoother, better. But I digress, as I so often do…
I took the lowers off, then the sprocket cover. There was so much gunk under there, the chain was actually touching it; a redneck version of an automatic chain oiler. It took me two hours to get all the mess out of there and make it look like new again. What can I say? I’m a woman and women have to clean while we’re “in there”. I really can’t help myself either. I’m too anal to skip it. I suppose that’s why it always takes me forever to do stuff on my bike. I either get sidetracked or I need to clean something. Speaking of which, I also cleaned all the other parts that I had disassembled and made liberal use of anti-seize when I put all the stuff back together. Then I cleaned yet again. *sigh*
There is no way I could go up one tooth from stock in the front. There is no room, unless one gets rid of the internal chain guard, but then there’s a huge risk of ending up with a hole in the engine case should the chain ever break. No thanks, I think I’ll pass. I definitely could go down one more tooth though, to 15T.The safety washer that keeps the pinion nut from backing out is a pain in the arse to remove! First you have to somehow bend the thing down, away from the nut without scratching or bending or breaking something else, so that you may spin the nut off and remove the annoying washer and the sprocket; and when you’re all done, you have to bend the silly thing back against two of the six flat sides of the pinion nut. I’ll have to add this thing to my regular shopping list of consumable items, which already contains such things as oil drain gaskets, fairing screws and washers, lock nuts, spring clips, and rubber grommets. Once I finally bent the dreaded safety washer flat, I put the bike in gear, sat on it, and used the rear brake to hold the wheel in place while I loosened the nut enough with my breaker bar enough so I could spin it off the rest of the way with my regular ratchet.
The rear wheel is familiar territory to me, not that I ever took the actual sprocket off its carrier, but taking the wheel off doesn’t take me all that long anymore, I’ve done it so many times. Same with adjusting chain tension and alignment. I’m even starting to remember the fastener sizes and the torque values. The new 47T aluminum sprocket fit just fine. It looks like there could be clearance for running a sprocket all the way up to maybe a size 49T, maybe even bigger if I ditch the plastic chain guard. But this assumption can be easily verified with a few measurements, now that I have seen the final drive in its entirety and how the different parts relate to each other.
Today was definitely a day of firsts. I broke my first chain with the chain breaker kit I had gotten from Cycle Gear on Black Friday.
I also riveted my first chain, which was a little more difficult, since the instructions were a bit unclear and I had extra parts that they didn’t mention. But I figured it out by thinking my way through it. I verified that I actually made the pins spread once they were through the link, by measuring them with my digital calipers. They are comparable in size to the other pins in the chain, so I think I might be able to trust my handy work. The master link is stiffer than the others, but it does not kink, I checked that, too.
But it does have me a little worried. Same worry I went through with my first tire change. Same worry I had with my first stem valve removal and install. Riding and checking the new part(s) often has proven that I did the job properly; well, that the result of my work was proper anyway. If the tire hasn’t fallen off its rim in 3,000 miles, I think it’s safe to assume that “I used enough rim glue”. If the tire pressure hasn’t dropped in over a week after switching to angled aluminum racing valves, it’s definitely got the air of a proper install about it.
I also calculated my own gearing and decided on the final drive ratio I am going to run at the Nashville Superspeedway. I relied solely on what I had learned from Ed Bargy at his racing school and used a gearing calculator to see how the change would affect things, at least in theory.
I better get a pair of angled pliers so I can get that blasted pinion nut safety washer off and back on in less than 30 minutes. Further, whereas the rear axle nut has a tightening torque of 100Nm, the pinion nut has a tightening torque of 125Nm. Which means, I’m in the market for yet another tool: A slightly more robust torque wrench, since mine only goes up to 102.8Nm. So, for now the proper torquing procedure is as follows: Tighten the fastener until you hear a click and then give it a little extra after. I also noticed I have lost my 18mm hex socket or never had one. I have a 17mm and a 19mm, but no 18? Have to score one of those bad boys before I leave for Nashville on Friday, so I can properly torque down my rear sprocket nuts before the race.
I geared up for a test ride. I was a somewhat anxious. I didn’t know what to expect. Well, I did know what to expect in theory. Real world application is usually a little different, however; and the interpretation thereof is highly subjective. I knew that I would be seeing higher RPMs for any given speed than I was used to. I assumed that my speedo would be even more inaccurate than it already was due to running a 190/50 rear tire instead of the stock size of 190/55.
On a side note: The stock 2010 BMW S1000RR does not have the high inaccuracy percentages in speedometer readings that plague all the Japanese bikes; for example my 2009 Suzuki Hayabusa was reading fast by over 9%. The difference between the Pirate in stock form and my GPS was about 1%.
I also knew that I had traded top end speed for some low end grunt and that the midrange would probably be torquier, too.
I decided to go ahead and do some preliminary road testing of my new throat mic and the universal Finger Grip RAM mount for my Droid X, since I needed a GPS to verify my actual road speed anyway. But that is for another post at another time. As it turned out, the speedo reading wasn’t affected at all, at least not where I could tell the difference. This observation leads me to venture a guess and assume that the ABS’s rear wheel speed sensor is used to calculate road speed and mileage. That the only reason why my speedo is off by about 5 miles or so at cruising speeds is that by using a differently sized tire I changed a constant in the formula and that this constant can be reprogrammed to actually match a differently sized tire. I had thought about asking my BMW dealer about this before. But why bother? I only have one Hayabusa-sized rear tire left, and I’ll burn that one up in one race weekend. Then the problem will take care of itself. =D
As I dropped down the curb and turned out of my driveway into the street, I realized when I came to the stop sign, that I had already forgotten the main reason I was going for a ride: the gearing change. Oops… I just peeled out of there like I usually do. Controllable, then; I’d say. Looks like I won’t have any worries after all.
After I turn onto the main road I verify that the DTC is in ‘Race’ mode, as it should be, and then I lay into the throttle a little. She’s definitely more ferocious sounding! Of course, that’s to be expected, the poor girl is now screaming along at higher RPMs than what she’s been asked to do before. I know I’m going to pay for this shift toward badassery in the Pirate’s attitude with plenty o’ Rum. I have a feeling she’s going to be a lot thirstier than she used to be. She’s a loudmouth now, too. Also a definite side effect of the higher RPMs required.
I like the way the new race chain transfers power. The feedback transmitted through the frame seems slightly different. Smoother. Less pronounced, maybe? Seems that shifting is even a little easier. But maybe I’m just in my groove tonight.
I had also decided in favor of the 520 conversion. From the factory, the S1000RR sports a size 525 118-link o-ring chain that runs on a 17-tooth countershaft sprocket and a 44-tooth rear sprocket. My bike’s stock chain was made by Regina. I don’t know if this is true for all 2010 S bikes, but if it is like the OEM tires, then there might be different brand chains, too.
Another superfluous side note: There are at least two different pairs of shoes that an S1000RR could be wearing on the showroom floor, at least to my personal knowledge. I lucked out and mine came with a set of Metzelers RaceTec Interact K3. I liked those tires, but I just can’t afford them. The other option that I spotted were Conti Attacks, but I can’t remember the exact model nor the compound.
I never liked the stock chain. The first time it rained, it rusted and after trying a few things to polish the oxidation back out, I finally gave up. It also stretched way too much, way too soon. I constantly had to adjust the tension. This behavior eventually dropped off to infrequent, though. The chain also feels jerky and loose in the upper adjustment range (around 40mm), it definitely seems to perform better on the tight end of the scale (around 30mm). I still don’t like it. I already like the RK chain tons better, and I adjusted it to about 39mm, which is looser than I would normally prefer.
Maybe the 520 conversion has something to do with the different feedback I’m getting from “down below”? The 520’s links are not as wide and the rear sprocket is aluminum, so I know the entire setup is lighter than the stock components, but I couldn’t tell you how significant the weight reduction is. I’ll weigh the stuff when I revert back to my street setup, just for curiosity’s sake.
My persistent worry of changing my bike into an uncontrollable rear-tire-smoking wheelie-machine was also grossly unfounded. I managed to ride her just fine, it looks as though I have learned a little throttle control along the way after all. I couldn’t bring myself to do a full-throttle run, though. It was dark and, although pretty late for a Monday, there was still too much traffic on the road for me. I do know that acceleration is much more aggressive with the new setup. Whereas before she blew your socks off, now you better hang the fugg on!
I think I’m going to like the setup I chose for the Nashville Superspeedway. It will make the track easier to run, that’s for sure. It may even help with my lap times. I did a few corner-entry exercises while I was out there on my 12-mile test ride from about a ton or so down to 50. This will work in my favor, definitely. I think this will also help me to stay in the proper RPM range, it feels better “up there” now. For whatever reason, I’m also not as nervous about downshifting… sometimes, for fear I won’t be able to complete my downshift before I have to turn-in, I just say screw it and don’t and then end up lugging through my silly ass through the turn, because now I definitely don’t want to downshift. LOL I know that this is related to my tendency of starting my corner-entry way too early and then taking my sweet time to slow down, so that I can shift and throw it over. Maybe it’s because I want to do one thing at a time. Maybe it is a holdover kink I had acquired when momentarily losing the rear on that blasted CBR600RR during a badly executed downshift with no slipper-clutch to save me from myself. Up until that point I didn’t even know what a slipper clutch was supposed to prevent. *moan*
I don’t know. I’m working on it, am slowly getting better at it. I will get this under control, but it’ll take a few more baby steps before I’m happy with my corner entry. I practiced doing all of it a little quicker and a little less sequential, if you will, because for some odd reason the new gearing makes me more confident… I really don’t get it. Oh well, why question it? It’s good. So it shall be until the next kink has to be worked out. This has got to be worth a second or two at least. 🙂 We’ll see later this year at JenningsGP. I want to get below 1:30. That’s five seconds. Can I do it???
After wrestling for over a week with the question of what to do about my final drive ratio and what sprockets and chain to get, I have finally made a decision and pulled the trigger. I’m glad this is over. I’m always stressing over price/value and which way to go. Should I go cheap or should I go for quality? It is true what they say about getting what one is paying for, but trying to strike a balance between going all out and keeping it reasonable and less painful on the bank is what creates an elevated risk for an embolism in the grey matter.
First, there was the gearing to consider. I’ve never been to the Nashville Superspeedway. I couldn’t find a decent track map online and the scarce info that can be gleaned off of message boards and various web sites is suspect at best; at least to me. Then there is the slight hangup I have about owning my solution and a tendency of not listening to people whose credibility cannot be verified. Not to mention that there is a bunch of contradicting info out there. And I’d rather mess up of my own volition than play the victim without a clue to somebody else’s BS. In short, I can deal with my own mistakes and their consequences. Nobody to blame but myself. That’s the way it should be. Since I don’t know jack about gearing and cannot yet distinguish the utter crap from the useful information, I have to be very selective about my sources.
I’ve learned this much in racing school:
- Gearing is track specific.
- The vast majority of stock street bikes are geared wrong. It is very rare for stock gearing to be correct for the race track.
- Navigate the race track using the top half of the gearbox, meaning gears four through six; the gears are closer together there and hence RPM variances are less, making it easier to find the correct gear for any given corner.
- You should be able to hit red line in sixth gear somewhere on the track, usually at the end of the longest straight.
- Gear your bike to always be in the optimum power band.
With that said, I know I am missing essential information. How long is the longest straight at Nashville Superspeedway? Or at least what is the average top speed attained on a liter bike? I suppose I could leave well enough alone and go there with my stock setup. But I don’t work this way. Now that I have learned about this neat little morsel of racing info, I have to try and apply it. I’ve been doing fairly well lugging through some corners or screaming around in others or on the straights. Yes, I’m lazy. My shift light rapidly blinks to inform me it’s time and all I can think of? “I’m almost there… almost… I can make it… I don’t want to upshift just now, because ah… right here I would have had to downshift.” Most of the time, I street shift anyway… I am nowhere near the power band… I tool around the track in fuel saving mode. That tendency has to stop. No wonder I suck at going fast in a straight line. By the time I get the Pirate into her sweet spot where she pulls hard, it’s time to get on the binders again and stuff her into the next corner, where I –yet again– get to go around all those people who just passed me in the straights. I would like to get to a point in my riding where I only pass people ONCE. Less work that way. Unless I’m lapping them… then twice would be good. 😉
And why am I always catching up with them in the corners? Seems to me that I shouldn’t be… but that is a different blog post altogether.
I have finally decided to just wing it and go with theoretical values and bring my top speed down to my personal best, which somewhat coincides with values flung around online.
Now, where exactly would my shift points be on the S1000RR? That’s determined by the power band. To be scientific about it, I would have to get the bike on a dyno and see where she’s got what. I don’t have the money for that, nor do I know where to find one of those around here. Lastly, I just don’t feel up to finding out at the moment. My bike is stock, properly broken in, and dyno figures are a look at estimated real-world performance. Dyno figures do not translate directly. Not that simple. I just make it easy on myself and look at a few stock dyno charts. 9.5 – 13K. Good, that kind of meshes with my subjective experience and perception. The red line is at 14.5K and the front wants to come up around 11K. Further, BMW suggests to bring the revs up to 9K for a proper race start. Good enough. Now, I have a range.
I plug in some values into an online tool called the Gearing Commander and am torn between running 16/46 or 16/47, which would be -1/+2 and -1/+3 from stock respectively. I don’t like even/even distribution on teeth, so I opt for the 16/47 choice which seems better on overall wear and gets me a theoretical 4 MPH closer to that red-line moment I’m supposed to have at some point.
But it isn’t over quite yet. Should I stick with the stock 525 setup or go with a 520 conversion? 520 is obviously lighter since it isn’t as wide. The first number denotes pitch, which is the distance between two pins; the second number is the width of the chain. After sitting on the fence for another day, not being able to make up my mind one way or the other, the deciding factor came in the form of my LSR meet at the Maxton Mile in May. Weight matters there, never mind that I’m not going to be running these sprockets, but I want to keep everything the same size, so I can swap stuff at the track if I really need to. Another monetary consideration, definitely.
I’m not fast enough yet to even consider tweaks such as weight reduction to the point of measuring my fuel, ripping unnecessary parts off my bike, or to be concerned about the minute differences in chain acceleration, tension, and sprocket sizes. I’ll get to that when it is necessary. Right now I have other concerns. 520 it is. Cheaper also, less materials involved. And most of the good price/value ratios can be found in that size, too.
After checking that I have the necessary adjustment room on the rear axle and hoping that I have the clearance required to actually run a 47-tooth rear, it is time to order two sprockets and a chain. Two more days are spent wrestling with compromise between price and value and I finally decide on the following and pull the trigger before I can change my mind three more times:
- Vortex Racing 520 16T countershaft sprocket
- Vortex Racing 520 47T rear sprocket
- RK 520 GXW XW-Ring chain (118 links, I will need to cut one)
This will give me a final drive ratio of 2.94 as supposed to the stock ratio of 2.59.
The theoretical top speed would be 159 MPH as opposed to 181 MPH with stock gearing.
Theoretical shifting speeds at 9,500 RPM: 56, 70, 85, 98, 108, 117 through the six gears.
Yeah, I’m going to have to wear a diaper to stay in the top three gears. =D But it should be an improvement over the stock gearing. Now, wish me luck so I don’t wad that shit.
My work here is done. Come what may. I will own it.
I’ve never given much thought to proper gearing. I’ve heard about it, but the most I really knew about the final drive ratio was that it was just another of many a brilliant way to screw up a perfectly good ride. I knew that changing sprockets could be used to manipulate the power delivery characteristics of the engine, add top speed to the detriment of low-end torque or sacrifice some off the top for more of that awesome arm-stretching pull down low. Want your bike to sound like an Osterizer going down the road but don’t have a 250? Bring that final gear ratio down for more of that “I’m so much faster and exponentially cooler than you” engine sound. Really gives that new $600 rip-roaring loud slip-on a ton of street cred. You’re wound up tight but get there quicker. You’re also shifting quite a bit more, because the gears are closer together at the top of the box. But be aware that you now only sound fast. Your engine is working harder and your bike’s maximum speed just took a nose dive below the need of that TRE you just bought off eBay.
Note: A Timing Retard Eliminator aka de-restrictor is a device designed to remove or circumvent the artificial top speed restriction to 186 mph imposed on Japanese-made sport bikes capable of going faster. This practice is known as the “Gentlemen’s Agreement” between the USA government and the four major Japanese manufacturers: Suzuki, Kawasaki, Yamaha, and Honda.
Want to pop those wheelies on your ‘Busa, but having a hard time getting it up? Drop a few teeth in the front and be ready for that Viagra moment!
It didn’t dawn on me when Ed Bargy addressed the issue and said that most stock sport bikes are not geared properly for the track. They are geared way too tall. You should be hitting red line in top gear somewhere on the track, usually that means the end of the longest straight. You should be using the upper three gears negotiating the track, since the gear ratios of the top gears are closer together, not as tall. This will enable you to stay in the optimal power band more easily and gear selection for any given corner is simplified since you run less of a chance of getting stuck between the choices of “lug ‘n bog” or “scream and bounce (off the rev limiter)” because your gears are too tall, meaning they are too far apart in the RPM range. Acceleration is also much better when you’re in the “sweet spot”, too. The sweet spot is the point in your engine’s power band where horsepower and torque are at their peak.
Blah… blah… blah… I listened, in that store-for-analysis-later semi-disinterested way, made a mental note of “each track usually has its own unique setup requirements for your bike”. I muse that this final drive ratio bit falls into the same category with dialing in proper suspension settings and tire selection. Who has the money for that? Not that this matters at my level. I’m still 16 seconds away from having to worry about stuff like this, or so is my conviction. For an anal retentive and recovering borderline-pathological perfectionist, I can be pretty blasé about some things. OK, I promise I’ll worry about it in 10 seconds.
I’ve forgotten all about gearing until I watched my onboard track videos. Good grief! The stuff you never knew you did wrong! Blaringly obvious! I shifted like I was tooling around on the back roads, stuck behind a gaggle of cruisers and worrying about my fuel economy! I short-shifted…. No, you can’t even call it that. I shifted so early, I had to pre-register the request with my transmission. No wonder I lost several runs on the straights, even when I didn’t forget to get on the gas coming out of a turn! I felt like I was going backwards in time when I was waiting for the bike to accelerate, it took so long for the engine “to kick in”. Shifting too soon in the RPM range and not being at full throttle are only two of reasons.
The third, it had finally sunk in, is my gearing. The words of Mr. Bargy came rushing back to me. All that information I didn’t think I needed just yet suddenly seemed a lot more important. And my bike wasn’t all that happy in the lower gears. Like I always have said, she doesn’t like to be in too tall a gear. Not that the S1000RR lugs, she just feels vibey and discontent. I can definitely feel when she is in “her range”. The buzz in the bars lessens; the bike seems to settle and is more responsive, like a cat readying herself to pounce, if that makes sense. She feels like she is on rails when you’re up in the RPM range and giving it throttle in the turns… not so much when you’re “coasting” through the corners at 5,000 RPM at quarter throttle singing la-dee-da-dee-da… it’s a beautiful day… whistling and thinking happy thoughts. Yup, I caught myself riding it like a girl out on a Sunday drive, not a care in the world and feeling fi-iiine. Gawd! I’m less of a Miss Daisy on the street. At least it seemed that way. Holy hell. I guess I was having so much fun, I forgot I was there for roadracing training, not for a stroll down the track in the beginner group.
I did watch the novice group and it was almost like they were going in slow motion. I saw one control rider going around the fast part of the track in standard street pose. You know, upright, kind of cockeyed on the bike, clutch hand resting on the upper thigh. Poor guy probably drew the short straw at that morning’s staff meeting. Bummer! And to think I almost signed up for the novice group because I thought I wouldn’t be able to keep a constructive pace in the intermediate group.
I also watched the expert group for a while. I mentioned to Mr. Slow how freaking fast they look. He nodded and said it was fun to watch these guys duke it out in the corners. I asked him that we must be crawling compared to them. He nodded in agreement: “Those guys look at you like you look at the novice group.” Wow! That’s kind of neat when you think about it. My first ever track day w/o instructors and class room sessions and I’m mid-pack in the mid-pack. That is freaking cool beans. For some reason I didn’t think I was “that fast” already.
Speed is a strange critter. Well, not speed… the perception of speed. When you are on the track you seem pretty fast to yourself. Of course you do, because you’re riding at the upper third of your skill range, or at least should be when you’re learning and concentrating on technique and being smooth, but still pushing boundaries and feeling for the limits. When you watch the POV video from that same session, you’re so embarrassingly slow, you only watch it alone, in the dark, behind a closed door. When you watch others go by who are riding at about the same speeds with comparable skill you think you’re out of your mind and can’t believe you’re actually out there doing the same. Yeah, baby!
What does this mean to me? I am at work studying the fine art of gearing selection with the help of Ed Bargy’s book “Introduction To Motorcycle Roadracing” and this handy little online tool called “Gearing Commander”. Stay tuned… this subject has the smell of walkthrough about it. I engage my brain this much while studying a subject matter, I have to put it in concise and organized form to remember it all and make sure that I have actually grasped the concept. For now, I better stick my nose back into the books and figure this thing out. I’m not going to Nashville to hit the Superspeedway just so I can do a little street riding around 6,000 RPM. I’m going to have this sorted. I already have to change my tires after every track weekend, and put the bike back into street trim. What’s adding two more sprockets to the task going hurt?
I really need a dedicated race bike… Nah! I’m the girl who wears knee pucks on the drag strip. I’m also the girl who rides her S1000RR 285 miles in full race gear just to hit the track. I wrestle drag bikes through the twisties and abuse supersports on the drag strip. Did I mention I am the first person in the world to do the entire BRP (Blue Ridge Parkway) end-to-end on a BMW S1000RR in second gear, observing the speed limit (more or less)? Why start and be normal now? =D