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Checking out the "darkside"




      If you have done any internet Valkyrie boards surfing at all, you've seen the ubiquitous posts and promotions of the "darkside" - that is, putting a car tire on the rear of a motorcycle.  There are tons of claims of the benefits of doing so, and virtually no reports on any downside to the darkside.  It's obvious the folks promoting the idea are passionate about their pet, while those who have tried and rejected it are pretty much mum about it - rather than get into any heated discussions with said passionate posters - and there are a lot of them, apparently. Count "Lamonster" among those who have tried it and said "not for me". (I can't quote the exact post he put up, just recall he posted years ago that he tried it, then put a bike tire back on and said he would not do that again.)  I'll say right here, at the top of this article, that I gave it a fair try, and my conclusion is, it's not for me.  I am reporting my findings here - what I found both positive and negative.  Depending on your riding style, and where you ride, the "darkside" may be for you - it is for lots of people.  If you are like me, than probably not.   Frankly I don't care what you put on your bike - if you install a car tire, and you like it and are competent riding with it, and you don't kill someone else or even yourself from the resulting handling, I say more power to you, I'm glad you're happy and get the resulting savings on some of your tire costs.

      I have seen lots of reports that say things like "I couldn't tell the difference from a bike tire"  and "there are no degrees of bad, just different degrees of good" and "the tire is just providing feedback of what the road is doing - you don't have to accept it" and "there is no downside".  While also saying "traction is greatly improved"  and "much more reliable and durable"  and "much better in the rain" and "much lower cost" and so on.  Here are a couple of the more prominent sites on the subject: 

      Note, if you know about the darkside dedicated site "", it's been shut down, I think they were going to archive it somewhere but I don't recall where.

      Here's a couple of forums with "darkside" sections - in both cases scroll down to the "darkside" sub-topic:

      And of course you can find lots of posts on the subject on the VRCC boards - both tech and general, just use the search function for "darkside":

      I found no impartial reports on the "darkside" - everything was of the tone, it's the best idea since peanut butter.  Frankly I didn't believe them - especially the claims of "I couldn't tell the difference."  I set out to find out for myself if all the ballyhoo I was reading was true.

      So this article is to provide an unbiased report for those who haven't tried it, and they could thus try the idea if they want to, with prior info on what to expect - or even decide without trying, if their circumstances are like mine.

    UPDATE - Edited 07/13/12

    Note - My web page editor has been End-Of-Lifed, and it's broke. These pages exist in that ap's format - so until I replace it, edits are a PITA - I really need to manually translate this whole website to a supported format. But don't have time right now. So meanwhile I am editing this in notepad, directly in the html. Don't expect fancy stuff.

    Dogg on the VRCC reported the DS tire he had chosen, didn't have much of the bad behaviors DS tires exhibit, and I reported on below. Probably because the tire has rounded shoulders, more so than other car tires - but not as rounded as bike tires. So I tried his tire a few months and 2150 miles ago. He was right - and I'm still running that tire. It's a Yokohama Advan A048 in 205/55-16. This is a high-performance - even for racing - car tire, with shallow tread depth, no siping, and a tread pattern that looks like a bike tire. It does have some of the car tire advantages, and much-reduced disadvantages. Pluses - better traction than bike tire, cushy ride, long life, more stable on the straights. Minuses - more countersteer required - but much less than the GYTT; less clearance in corners; much harder to mount than a bike tire - I had to have it mounted, couldn't do it myself with my tire mounter and levers. The tire is still steered by grade seperations and ruts, but much less than the GYTT. I can live with that, as I don't ride rutted roads other than my driveway. Parking lot handling is much better than the GYTT - I can do full lock turns while dragging the pegs again - and I have experienced no bump steer with the Advan. This tire is not cheap - cost is similar to a bike tire. I don't know about it's longevity yet - but if it lasts 20k I'll get another one. I like the look, the extra stick and cushy ride, and the handling is acceptable.

    So I'm running a specific DS tire now - though I still support my earlier comments below with the addition that IT MATTERS WHAT TIRE YOU CHOOSE - which will affect the degree of the bad behaviors described below, that you will experience. I am sure I can ride tight twisties faster on a Cobra than this tire - for one reason, now the bike is lower and the pegs drag sooner. But if I really want to hit the twisties fast - I have other bikes more suited to twisties anyway.

    UPDATE - Edited 09/08/12

    I am pleased with the handling. Bad behaviors are minimal, in fact I can drag pegs full lock in the parking lot doing Jerry Paladino's exercises. Almost none of the bad behaviors I experienced and reported on the GYTT, on my page at I ran the tire with 34lbs and ride-on installed. Ride is very smooth and cushy, grip is outstanding.

    I have 3814 miles on the tire now and it's nearly shot. Left side of the tire, tread is gone. Worst mileage I've ever heard of on tires put on a Valk. This is like sport bike mileage. OK, I can accept that as an experiment. At least I proved to my own satisfaction that the darkside can work if you are picky about handling and find the right tire.

    I am going to try the Yokohana Advan Neova AD08 next. It's tread depth is 9/32 rather than 6/32, and it's not a racing tire but high performance (v rated) so the compound should be a little harder for more life. Profile looks about the same as the A048, and tread still looks something like a bike tire. Price is $76 cheaper at $157. I'll report here sometime later when I have some results.

    UPDATE - Edited 11/04/12

    I like to get my money's worth out of my tires, so when they get thin I inspect with each ride and keep the rides pretty short. Cord is visible on the Yokohama Advan A048 racing tire. So it's time to retire. Changed it out today with the Advan Neova AD08, also high performance but not racing. I believe the compound to be a bit harder, while there's more siping and the tread is twice as thick. It has pretty much the same profile. I was really pleased with the performance & handling of the first one, but of course not the durability or price. The old tire lasted exactly 5050 miles from new to cord showing. I expect the replacement to go 15-20k.

    The handling was good enough to sell me on the darkside when I was dead set against it from experience. I ran the tire at 34#'s for it's entire life. Note the wear pattern - I think I got it about right as the cord is about to show in the center, while it is showing on the left side and also in one spot on the right side. Pretty even wear. I had 13oz Ride-On installed for the entire time. I rarely ride fast (80+) but do ride aggressively - not easy on the throttle and drag the pegs a lot - when I'm riding alone. The S.O. on her Magna rides much slower so when together I go at her pace. Except some of the corners or accelerating. OK, I slow down the cruising speed with her...

    BTW this tire was not easy to mount. But I persisted and got it on. Went slow and used a hunk of pipe to increase leverage, and used lots of silicon spray. And several large tire irons. Both of these tires are 205/55-16. I had given up trying to mount the first one and had my dealer do it.

    My report as posted on the VRCC on 06/23/08

        First off, no offense if the darkside is your baby. This is my honest, impartial report. If you like the darkside, I'm happy for you. However, I would admonish you (if I was king of the world) not to mislead others when seeking new members to your flock. I shouldn't say I was misled - but I will say, after seeing reports of "no difference" - which I was skeptical of - I said, I'm going to find out for myself. So I did.


        Yeah I watched the video.
        He wonders why the tire wears in the middle. Because he mostly rides on the flats / slab. He brags he bought it on ebay for $20. Doesn't mention the last guy got rid of it.

        I saw all - OK most of the posts praising the virtues of the darkside. Here on the VRCC, and on Lamont's other boards, and on the VOA. Saw many posts of riders claiming they "couldn't tell the difference between the darkside and a MC tire". That was suspicious to me, because I can sure tell if a worn bike tire has a 2" wide flat spot in the middle - nevermind a 7" wide flat spot.

        So I said, OK I'm going to see for myself, and keep an open mind. Bought the most popular tire - Goodyear Triple Tred in 205/60/16. Ran it for 1381 miles with all pressures in 2lb increments between 20 and 40. I had seen posts saying, there are definitely differences in handling with different pressures. "Not bad, just different degrees of good". I ride all kinds of roads, and even non-roads, from trails that should be for dual sports only, through tight twisties in the mountians, to fast sweepers, to the slab. I have almost a quarter million miles of experience over the last decade on large cruisers and tourers.

        My conclusion? The bike is back on a MC tire. A Cobra 200/60-16. And now a Dunlop K491 rear, on the front. And the bike handles like a bike again. And I am SO happy to have good handling again. The "darkside" is outta here.

        Darkside benefits?
        1) The ride is soft, really cushy - of course this varies with the pressure.

        2) Rear braking is much more effective - so is traction in non-dry non-clean road conditions.

        3) Cost benefit - tire lasts several times longer and costs less to begin with.

        4) Attracts comments, conversation, criticism, maybe respect as you truly are a Maverick - not another Harley lemming.

        1) VERY poor handling. Extreme countersteer pressure required to turn and to maintain the bike in a lean. I didn't measure it, and now I can't, but I guesstimate countersteer pressure gets up to 20 lbs. The bike does NOT want to turn. Ever have a back tire go flat slowly? When the pressure gets down to about 7 lbs - that's what this tire feels like. Only worse. If you ride only on the slab and so don't like turning - this tire is for you.

        2) Bump steer. The bike got crossed up from this several times. If I hadn't been expecting it, I might have gone down.

        3) Unstable when starting a turn sometimes. Bike swerves unexpectedly - I experienced this several times but it would take more time and use for me to nail down where this is coming from. That's not gonna happen because the other factors were sufficient for me to get a unanimous (me, myself & I) verdict on the tire. Most upsetting when first initiating a turn after riding straight.

        4) The bike wants to follow every road anomoly it hits. Grade seperations, ruts, everything. More pronounced at low speeds, but happens at high speed too. Be careful entering slanted driveways, try to avoid rutted roads. Stay the hell off bad dirt roads and trails.

        5) Don't look away from the road - you might go in the ditch. The bike needs constant steering corrections. Does not track accurately. Stay away from close formation riding you might take out the unsuspecting rider next to you.

        6) Fitment issues - though this is minor for me, for some it may matter more.

        I kept an open mind. Yet I wanted this to work, I'd love to save money, have a (more) cushy ride, better traction in the slop. But I also turn the bike. Especially in the twisties. And I EXPECT my bike to have neutral handling, and not bad handling idiosyncracies that I have to compensate for. Just like flying an airplane, I don't fly with the aircraft out of trim and have to hold yoke pressure constantly. Turning the darkside is analogous to flying a fixed wing aircraft out of trim.

        I saw lots of reports from folks praising the darkside, I'm referring now to the ones who reported "no difference". I have an opinion about them, but I'll tone it down here. Take such reports with a "grain of salt". They were partly the reason I tried this myself. THEY ARE WRONG. There is MOST DEFINITELY A DIFFERENCE. I would characterize those who post such reports as either 1. having an agenda, "spin-doctoring" their report accordingly, or 2. Inexperienced riders, or 3. Ride the tire almost exclusively on the flat and turn so infrequently and rarely get on grade seperations or ruts, so as to forgive the bad side, or 4. Maybe the darkside tire they chose behaves completely different from my Triple Tread 205/60-16 or 5)Liars. Take your pick - 1-4 is more charitable but 5 is possible.

        If you ride connected twisties - like the Dragon, like Deer Creek Canyon SW. of Denver, and you like your bike to handle with neutral handling - you will HATE the darkside.

        If you ride mostly the slab, never care if your bike handles badly, especially in turns and uneven surfaces, and want to save money - the darkside may be your tire.

    My Follow-up Post to the above:

        The darkside isn't a theology, though some seem to proselytize like it is. I just posted here as devil's advocate, because I just got done checking it out, and I was thorough, and YES I DID HAVE AN OPEN MIND, MY COMMENTS ARE NOT ONE SIDED - if anything I was generous pointing out pluses I found. No it's not for everyone, and yes I think those posting that they can't tell the difference are doing a disservice to those who haven't tried it.

        As for choice of tire - well I'm not gonna try them all. Of any single tire, I saw the most raving posts about the GY TT. If I had picked another, no doubt some would say that was the wrong one too. Sorry. Only gonna try this once. If I picked the wrong one, oh well. Not gonna get suckered into that argument.

        For those who want to tout that it's as good as a motorcycle tire - bring your Valk here to Denver, I'll take you over to Deer Creek Canyon and the High Grade - and plenty of other tight twisty roads on the Front Range - you ride your darkside, I'll ride my Cobra against a stopwatch.

        Nah, that's not scientific, doesn't allow for other differences. And I don't want you killing yourself to try to back your baby. Somebody like Yellow Wolf could no doubt compensate for the differences with skill and giant balls. Any unbiased, scientific test with enough numbers to not be anecdotal, I'll wager Deerslayer that the result would be, the darkside is a solution only for a limited set of circumstances - which you may fit in your style. Doesn't fit me or mine, except in a small percentage of my riding. I almost left the tire on Deerslayer, and then dedicated it to the flats only. And use BlewbyU (GL1800) for fun riding in the mountains. But that wouldn't save me money because I also use BlewByU for everything I would otherwise use a car for - it gets LOTS of miles, so where's the savings? Deerslayer is for stylin. Gets less miles because I want it to last. I might be buried with her.

    2nd Follow-up:

        I didn't measure the countersteer effort. And it changed a lot, depending on the speed, radius of the turn, resulting lean, and especially pressure in the tire. Probably affected by crown of the road too. Lots of variables. I know it was much more pressure than what I want to use. I want my bike to be set into a turn, and then be very close to neutral in steering inputs. Especially when dragging iron, downhill in the twisties, at the apex of the turn there's a bicyclist going my way, near the centerline and leaning hard, but 10mph slower than me. He thinks the road is his, not expecting to be passed as the cages poke at 25 tops - but I'm doing 50. I want the best handling I can have at that point, not have to deal with bad handling while not hitting the peddler.

        Instability when intitiating some turns - that was scary. It's like WHAT THE F IS THAT? Like some invisible giant just grabbed the front wheel and yanked it hard back & forth. That was a seperate behavior from bump steer - another new problem I don't want to deal with. Maybe there is more - like I said, that was the last straw - I decided then it's off the bike, without further explorations to identify if that's caused by something other than the tire. I need good overall handling, not just in some circumstances - and I enjoy the foothills so much, that would just wreck my ride to not have the handling I crave.

    3rd Follow-up:

        Yeah I tried it - for about 1400 miles. 205/60-16 Triple Tred - One of the most popular choices. I tried all pressures in 2 lb increments from 18 to 36 and even tried 40. I had a Venom on the front (I think this was before I went to the E2 bias rear on the front) I wanted it to work. I ride the twisties a lot. But more than that, I wanted traction on my dirt/clay/sand road when it's wet.

        What I found was, pretty much what you've heard on the average - not counting the "flyers" who claim they can't tell the difference.

        Pros -

        1 - much better braking traction.
        2 - May stick a bit better in the wet - though I don't push traction then so I didn't really test  it.
        3 - very stable on the slab. In fact the bike doesn't want to turn. I think you could ride for hundreds of miles without touching the bars except occasionally if you have cruise. I'm talking about flat, concrete slab here, not asphalt lanes heavily rutted by trucks.
        4 - ride is very cushy at lower pressures - if this is a plus for you. Absorbs sharp bump edges like nothing else I've seen.
        5 - much lower cost per mile, with longer life and lower cost.
        6 - higher weight capacity - if this matters to you. Doesn't to me and I'm not skinny.
        7 - Probably has better traction in mud. I didn't test this, I just expected it.

        Cons -

        1 - Bike doesn't want to turn - once again, talking about unrutted road. Requires excessive countersteer pressure to force the bike to turn. I didn't measure it, but I'd say with my tire combination, loading, and air pressure, it was as bad as 20 lbs continuous pressure on the handlebar. That effect changes significantly with changes in air pressure. I don't know about the effect changing with other car tires, or other weight riders.
        2 - Bump steer. This is unsettling. Hit a bump mid curve in a sweeper and the line changes. You might be able to get used to it but I am unwilling to compensate for bad handling.
        3 - Sudden wobble sometimes in turns. Again very unsettling. This could be something else with my bike, like head bearing wear, I don't know. But it doesn't happen without the car tire.
        4 - Follows ruts BADLY. This will scare you even when you know it's coming. Sure, I could have got used to it. But once again, not gonna compensate for bad handling.
        5 - I hated the handling in the twisties. I don't want to have to hold excessive pressure most of the time. Yeah I could have got used to it. Why should I? I ride for the enjoyment. I require neutral handling - or close to it. Not 20 lbs of countersteer pressure.

        I need every bit of cooperation I can get from my ride. I already have to do the driving for all the idiots in cages - don't need to add these "darkside" challenges right when I'm dealing with a bimbo yakking on a cell cutting me off. It's been my experience, that "accidents" in most venues are the result of the accumulation of multiple factors. I can give many examples I experienced myself and witnessed of others experience, or read the post mortem analysis (aviation), several in hang gliding, general aviation, road incidents, and construction accidents. Without taking the time to do that, I think y'all know what I mean. In this case, I choose to not stack the deck against me, with known bad handling properties already extant on the bike, then I have to handle a couple other error factors.

        I would add to the above paragraph, this:  I'm intrigued by folks who play on the tracks, as it were.  Sky divers.  BASE jumpers.  Hang Glider pilots (used to do this myself).  Linemen who ride on the outside of helicopters, and their pilots.  Cave Divers.  Firemen. Racers, car and bike. And so on.  Sooner or later, every one of these risk takers is going to have something go wrong, and he will have to handle it.  Statistically, no matter how careful, no matter how prepared, no matter how expert they are, sooner or later it will happen.  Problem is, the consequences of a misjudgement, or an equipment failure, or a wind gust at the wrong moment, can be severe. Now what if ANOTHER anamoly happens at the same time?  e.g., The cage idiot just turned in front of you and now there's sand on the road. How close are you to the edge of the envelope? How much, if any, margin are you working with?  If the athelete is winning, at the top of his game, he is probably operating with razor thin margins - on the brink of disaster constantly. What if he is slightly off his edge?  All atheletes have bad days they can't really account for.  That's why some are superstitious.  e.g. pro baseball players.  They can have a bad day, a bad week, and can't attribute that to any cause-effect rational explanation so they look to explanations in the realm of karma, the occult,  the paranormal.  If I detect my edge is off while  riding I will take a break.  If I can't take a break, I increase my margins a LOT.  SLOW DOWN. And take extra care I don't make a mistake.  Normally I ride fast, make no assumptions of trusting others, expect them to be stupid, but still go around them like they are complete rookies, inept and idiots, and don't belong in my world.  I'm operating in a different time zone, whereas they can't handle driving with no challenges, nevermind an obstacle in the road - and this while thinking they have extra competence so they talk on the phone thus dividing what meager brain power they have to their call - I on the otherhand expect them to make stupid choices, long before they are even aware there's a choice coming up.  Yeah I'm sure there are some drivers out there that are as aware and quick as me, and some even more skilled - but I haven't met many.  Probably would if I hung with sport clubs.  Sometimes you'll see an old guy with battered leathers and no chickenstrips on a sport bike or even a Gold Wing who just amazes - I had a guy pass me on the freeway in a Ferrari when I was in my cage, obviously operating at a very intense level - I was doing 70-some, he was into triple digits - missed me by less than a foot as he passed on the right and cut in front of me - I was surprised, but not so much pissed off as impressed. That Ferrari had not a ding on it, and it was well into a 6-figure price tag.  (I was the "old guy on a Wing" a couple years ago when I blew past a Harley rider in Deer Creek Canyon, going twice his speed and throwing sparks.  I stopped at the end and waited for my party to catch up - the Harley pulled up, the guy obviously impressed and his girl said, "man you can really ride that thing.") No doubt racers operate beyond my level and are incredibly competent.  I remember riding with friends years ago, up in the Flaming Gorge area of Utah-Idaho, and had trouble staying with a rider who had many more miles under his belt than I.  I mentioned to my friend - an old racer - that night, that I thought he was risky, took too many chances.  He said something that's stuck with me - "Don't judge him with your skills."  I became aware that was what I was doing - and further, what others do to me.  Ever make a completely safe pass, yeah it's on double yellow, but you are nowhere near your margins - and have the passee panic, blow the horn, slam on the brakes, swerve?  Now I tone it down a little, wait instead of passing though I know it's safe for me - the oncoming cage or the passee might panic and make a bad move.  Unless I'm REALLY in a hurry, medical emergency or something serious.

        I've learned over the years that I've managed to survive to this point that it is unwise to tempt fate repeatedly.  My living through my youth was more luck or fate than skill. Yeah it's a rush to take your life in your hands, pull it off, and walk away with an adrenaline buzz.  Make a habit of it, and sooner or later, it's a certainty that playing on the tracks will get you run over by a train.  Though I believe it's no big deal to operate within your comfort level - that is, leaving more than enough margin to allow for contingencies, even if that's nothing like what is mandated by law - as long as you don't cause the less skilled to do something stupid and crash.  Assuming your comfort level doesn't include assumptions of the drivers around you not doing the unexpected.

        BTW I quit hang gliding because I learned there were some factors I couldn't control or predict, and I was trusting to fate.  Clear air turbulence, especially close to the ground, for one.  I had friends who were better, more skilled and higher rated than me, that were killed by CAT flying my favorite sites.  It was just a matter of time, if I continued playing on the tracks, what the outcome was going to be.  I sold the glider and got back into motorcycles.

        The tire is off my bike. I couldn't wait to get rid of it. Though I wanted it to work, I am just not willing to accept the compromises. It's also possible that other car tires don't have properties as bad as the GY TT (but I doubt it). If that's the case, I'll never know it, because I gave it the best try I'm willing to do - not gonna say, "Oh it's my tire choice" and waste more time and money and risk to my neck looking for the right car tire. It might be different for you. Especially if you ride concrete slab a lot.  But I have a problem with these riders who claim they "can't tell the difference". That's a crock. You can't ride a Valkyrie and be inept, so that claim doesn't come from a lack of skill. Such claims are pure "spin doctoring" - and the claimants should work for the media or the DNC. IMHO. And I have adequate riding experience, approaching a quarter million miles mostly in Colorado.

        I presently have a Cobra 200 on the back and LOVE the handling. Though I don't have a solution to my original problem, traction in mud.


    Epilog - Should I do it?

      Of course that's your call.  I'm not saying you should go to the "darkside", far from it.  I agree with, and quote Lamonster:

        A car tire is not recommended by anyone other than those who have chosen to ignore the manufactures recommendations. If you choose to run a car tire on your motorcycle you do so at your own risk.

      If you ride the slab a lot, especially in wet conditions, don't do a lot of turns especially aggressive turning, don't have to deal with rutted roads much, and/or want a really cushy ride,  "darkside" behavior may fit.   No doubt you would like to save money, we all do. 

      If you ride the twisties a lot, have to deal with ruts, and/or require your bike to have neutral handling (little or no countersteer pressure required DURING turns)  then the "darkside" doesn't fit so well.


      Here's the REAL tire I replaced the "darkside" with - the EXCELLENT performing Avon Cobra, still brand new.

Goodyear TripleTred 205 & Cobra 200

Cobra 200 & Dunlop K491

All technical mods described here are merely reports of what I've done.  You may attempt to replicate them at your own discretion and risk if you choose.  Horseapple Ranch, LLC and Mark Tobias will in no way be responsible for the results of your attempting to perform these mods on any motorcycle, regardless of the outcome.

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