Friday, September 18, 2015

Bad Product Reviews - Shimano XTR 9000 drivetrain

Where do I start....  

when I mean "Bad Product Review" what I really mean is that my review of the product is bad.  How's that.

So, this past January, I was trying to help Andy get ready for Nat's out at the BOD.  I was riding the mtb and after who knows how many miles, the chain finally had enough and a link gave.  I slowly removed the bad link and resumed moving.  It's worth noting here that I (like many) run my chain tight but also allow for cross-chaining.  I know it's bad practice but sometimes say late in a race it might happen and I don't want to drag my derailleur into my wheel.  Well that's precisely what happened after removing a link that not really cold January day.

So I started looking around for replacements and noticed that the xtr 9000 (11speed) derailleurs were only a bit more than the 10sp versions.  The shifters were pretty cheap too (relatively speaking).  Where the pain point was is the cassette but in a second or two, you'll see why.

A bit more searching and I found a relatively local guy who'd removed his brand spanking new XTR 9000 drivetrain in favor of one from SRAM.  So I pounced on that and ended up with a nearly new Rear Derailleur, rear shifter, chain and a cassette.

Now this is where it gets neat, I gain an additional cog (a big cog @40T) and it weighs less than the 10speed...???

10 Speed xtr 980 cassette 11-36
11 Speed xtr 9000 cassette 11-40
why yes that's true.  I borrowed the pictures below but you can see that the spiders are made of the coveted carbonium (or something similar) 

I wanted to have these line up side by side but you probably get the idea.  Neat stuff.  Also note that there are four clusters of two cogs and the last three only are separate.  Check out all the scarring after a season of racing (note that this is an aluminium freehup from a DT 350).  How freaking awesome is that!

Note the distinct lack of cuts/indentations
save for the end near the lockring
where the cogs are NOT paired

Now you'll likely note that most "race" items don't wear well and that is true.  I changed out my "race" hub around 700miles.  It was still usable but the bigger cogs are aluminum and tend to wear pretty fast.  It's now a "spare".  In it's place I procured something else that should wear a lot longer...
the XT 8000 cassettes only recently became available but since the cogs are all steel, they should be good for most of next season's training.  As you can see, there is a small weight penalty (~80g) but at roughly 40% the cost of an xtr cassette...  yeah.  this is the way to go.  The downside is that there are only one or two paired cogs so there will be more scarring on the hub.

For reference,
an 11speed xt 8000 cassette, 11-40

So how did it work?  

well, it worked just fine.  These fit on a standard shimano freewheel and while they lack the "range" of the SRAM product, I didn't really like the big jumps between the cogs or the cost/hassle of buying xd drivers for my mtb wheels ( I have 3 sets I can use but really only use 2).  The shifters have a noticably lighter action than the XT 780.  Early on I wished they had a firmer feel but quickly moved past that.  

I did find that the rear derailleur was occasionally reluctant to upshift out of the big cog when conditions were dirty.  not 100% sure if that was because of the large amount of chain (I'd usually run 112 (or is it 114?) links with 39/26 chainrings) - OR - does the derailleur need a more resilient return spring?

By and large this drivetrain was flawless throughout the season.  When I'd have trouble shifting, I'd usually just tap the front derailleur to get some additional chain tension and things would go back to normal.  Because the XTR cassettes use of aluminum cogs, it is imperative to keep this drivetrain clean else you'll quickly be blowing through ~$250 pretty quickly.  I'm sure you can purchase individual spiders but haven't really looked into it.

Due to the cost, it's not for everyone but if you're looking for a sweet shifting and wide range without klugeing together expensive bits from different manufacturers give this (or the XT 8000) a good look.

that's all I have, let me know if you have any questions.

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