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Sram i-Motion 3 Speed Coaster Review
Gear hub fans have never had it so good. With the formidable
maturity and reasonable prices of the Shimano 8 speeds, the renaissance going on over at Sturmey-Archer and radical new (or very old) designs like the Nuvinci, it is easy to overlook SRAM’s new three speed. For three speed lovers, that would be a major mistake. This is one of the best, if not THE best, ever made. I have ridden many three speeds over the years, and loved them all (except for that 333 hub), but I have never had as much fun as I am having on the SRAM. Two caveats: #1-This is the common complaint about gearhubs, but the grip**** is God Awful. The mechanism is so rough that I though it was broken when I first installed it. After some lubrication and riding in it has improved somewhat, but it still feels like you are breaking something when you shift. The barrel adjuster set up is even more annoying than the ones on nexus shifters. The grip part has come off in my hand twice already (it is mounted on drop bars). I don’t expect the shifter to last two years. I confess that I loathe grip**** in every form, but SRAM has made much nicer ones than this. The hub deserves better. The only good things that can be said about it are that it works and is very simple to set up (credit for this belongs with the hub itself). As impressed as I am with IM3, there is *NO WAY* I would pay $400 for an IM9 and have to deal with a shifter this poor on a nine speed, and I wonder if the complaints about that hub being loud and grindy aren’t caused by the crap cheap shifter failing to pull cable correctly. A trigger shifter has been sighted in a photo of a cannondale prototype, but there is no evidence of that shifter being available aftermarket. The good news is that the cable pull is about 6mm, less than a Sturmey, so with due care and some fiddling it should be possible to adapt one of Sturmey’s new bar end shifters. All that said, it is a three speed and just about any shifter will do just fine on such. #2-Imotion distribution runs from bad to terrible in the states, even more so for small parts. I almost had to cancel my wheel build when the shop couldn’t find a shifter. After calling seven bike shops here in _bicycle_crazy_ Portland, Oregon I managed to find one that had a distributor with a shifter in stock. Shops that could not get the shifter included two that specialize in gear hub bikes and three that stock the Imotion equipped Swobos. SRAM’s “just in time” distribution system means that when parts are out of stock it can be just a really loooong time before they come in again. This problem is worse with the IM9 as it needs its own special cogs. All that said, SRAM has actually brought their product to market (I’m looking at you Sturmey-Archer) and they didn’t try to charge me extra for a bunch of small parts that should come with the hub to begin with. If the Alfine is the Death Star of gearhubs, this is the Millennium Falcon. She may not look like much, but she's got it where it counts. (I guess this makes the S3X the X-wing: you better be a Jedi knight to be an early adopter, and you will probably have to use the force to actually buy one.) Under the discrete steel shell is a three speed mechanism perfected and purged of every bug and flaw, fully matured, tough as a panzer and solid as a single cog. Shifting is perfect, and after a week of trying to foul the hub I managed to induce a single pawl skip during a shift under heavy load, and was unable to induce it again. No waiting for the hub to engage, no pedaling through a grindy zone, no neutral, just an instant shift. The shift cable linkage is a huge improvement over the click box, cassette joint, and bell crank, with better protection than an axle chain. A cable comes out of the hub and connects to your shift cable, making tire changes no more difficult than on any other bolt on hub. As the hub does not use A/R washers, you can position the shift arm in any direction you like (anyone know why this hub doesn’t need them?). The unity gear feels like a single cog and I find the efficiency hit in 1st & 3rd to be unnoticeable. SRAM’s T3 was the most efficient hub of its generation, and as this hub seems to be an all around improvement it is a safe bet that this is the most efficient gear hub available. Due to the problem of small cog inefficiency, the top gear in this hub may actually be more efficient than the top gear on a modern derailleur set up. With a Sugino chain ring and Izumi chain I had no problem setting up a fixie- tight chain line, with no drag or binding. The coaster brake has more power than the roller brake it replaced, without the dreaded fade effect. It creaked once or twice the first day and has been silent since. It has enough play to be ridden over trails, dropped off of curbs and even down stairs with engaging unintentionally, and enough power to throw my 1.5 inch Schwalbe marathon into a skid under all conditions. While Sturmey-Archer is the hands down winner for style and variety, and the Shimano hubs are far more available, this is the hub to buy for hard use, be it sprinting of off-roading, and I really recommend this hub to fixie riders. Let the hipsters find out the hard way if the S3X has teething issues. The mechanism is perfect and the coaster will make your brakeless track bike street legal and at least slightly less kamikaze to ride in traffic. -Rando |
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