A Cycling & bikes forum. CycleBanter.com

Go Back   Home » CycleBanter.com forum » rec.bicycles » Techniques
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Sram i-Motion 3 Speed Coaster Review



 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
  #1  
Old November 25th 09, 11:35 PM posted to rec.bicycles.tech
pdxrandonneur
external usenet poster
 
Posts: 36
Default 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
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
FS: DUOMATIC 2 Speed Coaster Brake Hub Peter Schwar Marketplace 3 December 3rd 09 04:12 PM
Nexus 7 speed coaster brake questions [email protected] Techniques 2 June 6th 07 07:59 AM
WTB: 3 speed coaster brake hub 28H [email protected] Marketplace 3 October 7th 06 03:00 AM
SRAM 5-speed internal gear coaster brake hub Bruce Lange Marketplace 0 May 28th 06 08:08 PM
9 speed sram shifter with 8 speed sram derailleur brent Techniques 1 October 30th 03 03:12 AM


All times are GMT +1. The time now is 10:07 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 CycleBanter.com.
The comments are property of their posters.