middle burn dual cranks

ukalipt

ukalipt

Likes Dirt
for quiet a while i have consider the granny ring luggage. i don't use
it much - well if it wasn't there i could live without it. it is extra weight :rolleyes:
so i have been thinking seriously about getting some middleburn duo cranks.

i have a few questions about them - sorry i have less than
no idea about them. i am looking at the RS7 and i solely ride XC
not an AM guy at all.

it will be running on a scott scale 30 using the e-type mount from
around the BB.

so:
are they any good?
i gather i will need isis?
will i need new a new shifter and derailleur?
is this all possible or just to difficult?
 
Slowman

Slowman

Likes Dirt
ukalipt said:
for quiet a while i have consider the granny ring luggage. i don't use
it much - well if it wasn't there i could live without it. it is extra weight :rolleyes:
so i have been thinking seriously about getting some middleburn duo cranks.

i have a few questions about them - sorry i have less than
no idea about them. i am looking at the RS7 and i solely ride XC
not an AM guy at all.

it will be running on a scott scale 30 using the e-type mount from
around the BB.

so:
are they any good?
i gather i will need isis?
will i need new a new shifter and derailleur?
is this all possible or just to difficult?
Click to expand...
Got no idea about the cranks but the current FD should be fine you will just need to adjust the H and L limit screws,...which you could actually do now and take the granny ring off. That would be the simplest; adjust the L limit screw so you can't change down to the granny ring. Then just take it off but you'll probably want to change the 44 and 32 rings out for something like a 40/28.
 
alchemist

alchemist

Manly Warringah MTB Club
so:
are they any good? Yes
i gather i will need isis? If you choose the Isis cranks then yes, if you get the square taper cranks then an Isis BB is probably not a good idea.
will i need new a new shifter and derailleur? Nope
is this all possible or just to difficult? Very possible
 
Jason B

Jason B

Likes Bikes
If you want something different they should be great.

Not sure of there cost but being UK they will be expensive, dont know if thye would be any better than top end shimano really?

But they will be different.

ukalipt said:
for quiet a while i have consider the granny ring luggage. i don't use
it much - well if it wasn't there i could live without it. it is extra weight :rolleyes:
so i have been thinking seriously about getting some middleburn duo cranks.

i have a few questions about them - sorry i have less than
no idea about them. i am looking at the RS7 and i solely ride XC
not an AM guy at all.

it will be running on a scott scale 30 using the e-type mount from
around the BB.

so:
are they any good?
i gather i will need isis?
will i need new a new shifter and derailleur?
is this all possible or just to difficult?
Click to expand...
 
T

tjb

Likes Dirt
The main advantage of 2x9 isn't really weight .... but chainline.

You could even achieve a similar thing to a Middleburn Duo possibly by getting a granny ring around 28 or 30 teeth and fit a 42 or so middle ring.

You drop some weight and get a better chainline to boot .... with your current crankset.

And in the middleburn the RS8 is the lighter version of the RS7 btw.

Middleburn are cool as they have removable spiders, you can fit duo rings, the uno SS ring, or 94 or 104 mm BCD spiders.
 
G

gixer7

Likes Dirt
Jason B said:
Not sure of there cost but being UK they will be expensive, dont know if thye would be any better than top end shimano really?
Click to expand...

Not really. Buy from CRC and the RS7 & RS8 are around $300 w/o BB depending on what you spec them with.

As TJB mentions chainline is the main advantage. Some riders using a 2x9 setup use a Dura Ace front mech converted to a top pull with the use of a Speen adaptor (which I think comes from Germany). This saves more weight over using a mtb front mech.

If you want more info check out www.mtbr.com and the weight weenies forum. Plenty of guys in there using a similar setup and you should find answers to most of your questions.
 
M

Markymark188

Likes Dirt
Rotor Q -rings 2 x 9

Why not go the whole hog. 2 x 9 Rotor Qrings. ?

I mean - If they're good enough for Carlos Sastre and co..

Aussie distributor - Unlimitedbicycles.com.au

Write up in issue 11 Enduro Mag
 
A

Australia says no

Likes Bikes
Markymark188 said:
Why not go the whole hog. 2 x 9 Rotor Qrings. ?

I mean - If they're good enough for Carlos Sastre and co..

Aussie distributor - Unlimitedbicycles.com.au

Write up in issue 11 Enduro Mag
Click to expand...
I second that opinion; I’ve had mine 6 months and can run a 12-27 (1-1) cluster for flatter tracks (close gearing is awesome). Or just run 11-32 for the Mountains to Beach I did the other week and have a bail out gear just in case, not that it was used that much but good to have.

The chain line is ridiculous I can use the whole stack in the big ring (40t) without the chain line getting to bad it’s only a little crossed in the biggest at the back
 
ukalipt

ukalipt

Likes Dirt
weight wasn't really the main reason, i just don't use the granny gear so yes chain line would be a more appropriate advantage. i was more thinking why
run a triple when only really needing a duo.

as for the Rotor Qring'ss [biopace] i have just spent a crap load of time getting
my pedal stroke correct. not that it can't be adjusted but... there is a learning
curve for the Qring's

i actually like the concept of being able to use multiple muscles when pedalling
helping with fatigue, imho i think the Qring's would make this a little more
difficult.

thanks all
 
cha_cha_

cha_cha_

Likes Dirt
I recently got a set of duos. 44/29 on a square taper bb. really happy with them. it took a little getting used to, like everything, but i've got my shifting sorted out now so it's all good.

only thing i can add that hasn't already been said: CRC don't let you order their "comprises of" crankset with a hardcote inner. if you want to buy separately then you can order from bikedock.co.uk.

also, i have a spare set of rings for sale here: http://forums.farkin.net/showthread.php?p=1772152#post1772152
 
Ryderman

Ryderman

Likes Bikes
In Foromtb.com an spanish mountainbike forum some months ago was a sooo long post about 2x9 cranks, i'll try to give you all the intetresting things I've stracted.

2x9 triple plate cranks:

Cons: The same Q-Factor (the Q factor is the separation of your legs pedalling), and a bad chainline.

Pros: The cheaper option.

Strongligth Oxale Two


Pros: cheap, ligthweigth, good chainline.
Cons: Not integrated BB.

http://www.bikeonline.it/catalog/product_info.php?manufacturers_id=108&products_id=1797

Just for 215€ a full crankset under 700grams.

Middleburn Duo
Pros: good chainline, wonderful appearence.
Cons: Not integrated BB, not so good Q factor.

FRM CU92
Pros: good chainline, good appearance, weigth, integrated BB.
Cons: expensive.

Rotor 2x9
Pros: good chainline, good appearance, weigth, integrated BB, the lowest Q Factor, and of course they're made in Spain:D.
Cons: Expensive.

FSA K-Force
Pros: good chainline, good appearance, integrated BB.
Cons: Expensive, too heavy plates.

Road cranks converted to 2x9
Pros: good chainline, weigth.
Cons: is not so easy to do it

Cannondale SLI addapeted for a normal BB
Pros: good chainline, weigth, soooo exclusive.
Cons: it's so hard and you need a person able to work in mechanised.

There's other options like cook bros, old Coda tarantula, Specilites Ta Vega.

Now I use an 12-27 cassette with triple and I'm plannig to come back to a 32 or 34 cassette with just a couple of plates, now I preffer to wait for the new Sram XX.
 
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