I’ve not used Middleburn cranks before but have been toying with the idea of using Middleburn Duo cranks in a 2×10 setup; I’m still a fan of old style cartridge bottom brackets and so was thinking square taper or ISIS (there are still some about).

However, after looking into things it appears that square taper Duo cranksets have 3 arm spiders and that the spider for the inner ring is built into the first ring; presumably this would mean that I’d be limited to Middleburn Duo specific chainrings and I’d quite like to have the option to use standard 104bcd chainrings. I notice that the X-type Duos are moving to a 4 arm spider but I’m not sure whether this would still require the use of a Middleburn Duo specific chainring with built in spider.

I was wondering whether there are any Duo spider options available (or planned) that would allow the use of standard 10 speed chainrings in a Duo setup.

The x-type cranks are set up to use any other 10 speed rings like shimano’s. great cranks and come highly recommended

I’m sure you can buy the RS7 or 8 arms with a 104 BCD spider and fit whatever rings you like, Middleburns or others (someone correct me if I’m wrong)…

Edit:

linky and other linky

I think that spiders for 3 ring set ups are standard 4 arm pieces, but my understanding of Duo’s (hopefully I’m wrong) is that they have 3 arm spiders built into the rings. I’m trying to find out whether there’s a 2 ring, 4 arm spider for square taper/ISIS cranks. I’ve tried emailing Middleburn but haven’t had a reply.

From the Middleburn website spiders page:

There is a wide choice of spiders to fit pretty much any type of chainring on the market.

Uno and Duo users will find their spiders incorporated into the chainrings.[/i]

Middleburn are pretty slow to respond to email IME. They will reply but probably not until next week some time.

The Sq/ISIS Duo isn’t a specific chainset as such is it…
Middleburn only make 2 basic models of crank arm now – RS7 (Sq or ISIS) or RS8 X-Tyre (external BB) They’ve apparently discontinued the RS8 Sq/ISIS as the weight saving was no longer significant enough…

The “Duo” is simply an RS7 spider option, that special ring/spider attaches via the same splined interface any of their other spiders would.

I was suggesting you could just fit the standard “3 ring” 4 arm (104/64-BCD) spider with inner and middle position rings, and simply omit the outer position ring with shorter bolts (that’s what a lot of people have done in the past on various other 4 and 5 arm cranks) thus you’ve got your 2 x N chanset…

But obviously duo does look much neater and saves weight, I don’t think there’s a 4 bolt version of the duo ring/spider, the 3 bolt thing was partly about weight saving and partly about forcing compatibility, so Duo users only ever replace old middleburn rings with new middleburn rings (or get a different spider).

Duo rings

The thing is once you have bought the arms you can fit whatever combination of rings / spiders you fancy (within reason), just because you bought it as a Duo doesn’t mean it has to stay as one should you choose to go to single or triple rings in the future, if you buy an SLX or XT thought then you can only ever fit 104/64 BCD rings, for that reason alone the RS7 is a far more versatile option…

As an aside, if Middleburn were to do a Thick/Thin Uno ring, that would be a winner IMO…

Middleburn 2X spider
They do a 2 ring spider for both X type & square taper types but the offset is different so you can end up with an unusable chainline on certain combos.
I’m selling a complete crank with one as I’m fitting X01 – email in profile.

Phone them. Always best policy with these smaller English setups such as Hope etc.

+1 for phone them. Last time I did I was put through to the MD. My Email was never answered.

Thanks for the thoughts. Those 4 arm Duo spiders are X-Type only I think so presumably won’t fit the square taper cranks.