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2x9: Middleburn RS8 ISIS Duo = 522g (no BB)

19265 Views 46 Replies 18 Participants Last post by conrad, Jan 8, 2011

Cheers!

Discussion Starter · Dec 17, 2008 (Edited)

8

Here is my 2x9 choice.

Middleburn Duo RS8 ISIS. Purchased from https://chainreactioncycles.com

Hardcoat 42T and 29T rings.
175mm length
Bottom Bracket choice not made yet. Probably 108mm Token TK872CT or KCNC Scandium ISIS.

Choice were between:
-Extralite E-Bones 68mm BB, 30T + 44T
(lightest, most expensive, some hate the bearings, some say too flexy... in the end it was the price that turned me off to try them)

-Rotor Agilis 2x9
(kinda heavy, and from an engineer's point of view the DTT thing is stupid)

-Raceface Next LP w/ Phil Wood BB
(I couldn't find a nice example of Compact 5 arm on ebay, I didn't have the phil wood BB, so the price was not goign to be cheap)

-XTR M952 NOS w/ 94 BCD spider used for Single speed guys
(found several nice examples on ebay for good price, I also found a compact spider for it, but the weight was going to be 700+g heavy)

-TA Specialities Carmina crank
(ok price, heaviest choice, hard to find... https://weightweenies.starbike.com/forum/viewtopic.php?t=27852&highlight=carmina)

Here are the pics. Enjoy.

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BruceBrown

· #2 · Dec 17, 2008 (Edited)

Cheers! said:
Here is my 2x9 choice.

Middleburn Duo RS8 ISIS. Purchased from http://chainreactioncycles.com

Hardcoat 42T and 29T rings. Bottom Bracket choice not made yet. Probably 108mm Token TK872CT or KCNC Scandium ISIS.

Congrats!! Nice choice. I've got the heavier Middleburn 2x9 (RS7 180mm custom black anodized arms with the hardcoat 29/42T rings). Add in the Crank Brothers ISIS 113mm spindle BB and it all works out to a decent set.

I should list my Next LP cranks (I've got shred red square taper and black ISIS - both in 175mm) on eBay and or here in the classifieds at some point since I don't use them any more. I moved to 180's a while back and have a lot of 175mm stuff sitting around in the parts bin. All the Race Face cranks can be refurbished either with a polish or a sandblast and powdercoat to take on a "new life".

My new JET 9 will be sporting refurbished color Race Face Turbine 180mms(425g) with a Taperlock Ti 110mm bottom bracket (166g) and the Rotor 2 x 9 Q rings (95g). That set up should end up with a decent weight depending on the final weight of crank bolts and chainring bolts. I've raced the Middleburn 29/42 with a 11/34 cassette on my 29"er for the past two seasons. I made every climb, but was on the teather a few times on the steepest stuff. I'm hoping the 27T up front will help my climbing with the big wheels on the steepest stuff of XC racing and will be a nice combination.

Middleburn used to have the Duo in 27/40 combo back during the RS1 days. I wish they would bring that combination of Duo rings back - especially so one could run a lighter cassette in the rear or for the big wheel crowd, allow 29"er's to enjoy a more appropriate 2x9 combination than the 29/42 affords. Join me in emailing them if you agree....;-)

BB

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Cheers!

Discussion Starter · #3 · Dec 17, 2008

BruceBrown said:
Nice choice. I've got the heavier Middleburn 2x9 (RS7 180mm custom black anodized arms with the hardcoat 29/42T rings) that comes in around 560g for everything. Add in the Crank Brothers ISIS 113mm spindle BB and it all works out to a decent set.

I should list my Next LP cranks (I've got shred red taper and black ISIS - both in 175mm) on eBay and or here in the classifieds at some point since I don't use them any more. I moved to 180's a while back and have a lot of 175mm stuff sitting around in the parts bin.

My new JET 9 will be sporting Race Face Turbine 180mms(425g) with a Taperlock Ti 110mm bottom bracket (166g) and the Rotor 2 x 9 Q rings (95g). That set up should total 740 or so grams depending on the final weight of crank bolts and chainring bolts. I've raced the Middleburn 29/42 with a 11/34 cassette on my 29"er for the past two seasons. I made every climb, but was on the teather a few times on the steepest stuff. I'm hoping the 27T up front will help my climbing with the big wheels on the steepest stuff of XC racing.

Middleburn used to have the Duo in 27/40 combo back during the RS1. I wish they would bring that combination of Duo rings back. Join me in emailing them if you agree....;-)

BB

Thanks! I thought about getting my anodized too. But looking at the finish I think I'll wait till they are banged up a bit then get them anodized. I hope I didn't make a mistake going for ISIS... (fingers crossed)

BruceBrown

· #4 · Dec 17, 2008

Cheers! said:
Thanks! I thought about getting my anodized too. But looking at the finish I think I'll wait till they are banged up a bit then get them anodized. I hope I didn't make a mistake going for ISIS... (fingers crossed)

You didn't make a mistake. If you want to talk about a solid ISIS bb, the Crank Brothers (with 5 year warranty) has been a champ the past 2 years. The Ti version weighs 180 which might be more weight than you want to go, but it's a work horse. The chromo is 220 and equally good.

I've got the RS7 in ISIS and using a 113 spindle on my Dos Niner - the shifting is perfect!! I can use every gear on both rings (I use the X.0 twist to trim the front derailleur). At least on my Dos Niner with the 68mm bb shell, I don't see any way I could use a shorter spindle on the drive side, so 113mm is dandy. On the left, there looks to be a pair of mm's to play with by bringing the crank arm in towards the frame for Q factor.

As far as anodizing....it would rub off anyway. My black arms have shoe rub marks. It looks nice when new, but unless your shoes don't rub it's probably not worth it. If you do ever anodize - it's nothing a sharpie can't take care of up to a certain point....

Enjoy your new 2 x 9.

BB

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BruceBrown

· #5 · Dec 17, 2008

Cheers! said:
Thanks! I thought about getting my anodized too. But looking at the finish I think I'll wait till they are banged up a bit then get them anodized. I hope I didn't make a mistake going for ISIS... (fingers crossed)

Dang. I forgot to ask. Is this new 2 x 9 for the Kona or another project?

BB

Kris

· #6 · Dec 17, 2008

Sweet, I love my RS7 Duo, something about the setup screams "hammer me"! I got mine from CRC a couple of years back, they mounted the spider ring before shipping which made me happy as I didn't have the tool. I wonder why they stopped doing this?

BruceBrown

· #7 · Dec 17, 2008

Kris said:
Sweet, I love my RS7 Duo, something about the setup screams "hammer me"! I got mine from CRC a couple of years back, they mounted the spider ring before shipping which made me happy as I didn't have the tool. I wonder why they stopped doing this?

The Shimano Spider lockring tool is not a bad thing to own as it's nice to have around to tighten things up if need be. I think they run about $10 - 15 and can be picked up at your LBS (or ordered). I bought one and have used it several times on my Middleburn. You never know if you might have to take your rings off and true them after a log hit or cleaning or replacing, etc... .

I didn't know they used to mount the spider with the lockring before they shipped. Is it easier to pack and ship things unmounted? Who knows?

BB

Cheers!

Discussion Starter · #8 · Dec 17, 2008

BruceBrown said:
Dang. I forgot to ask. Is this new 2 x 9 for the Kona or another project?

BB

Something else... It will be even lighter.

What can I say... The chase is better than the catch.

chpfly

· #9 · Dec 17, 2008

Cheers -

Why did you not look at the FSA 2 x 9 set up?

And what is the DTT on the Rotor that you don't like. I am looking at the FSA or Rotor for a 29er I am building.

Cheers!

Discussion Starter · #10 · Dec 17, 2008 (Edited)

chpfly said:
Cheers -

Why did you not look at the FSA 2 x 9 set up?

And what is the DTT on the Rotor that you don't like. I am looking at the FSA or Rotor for a 29er I am building.

FSA one is too heavy... And someone posted a picture of a failed FSA crankarm over on the weight weenie forums (the other forum). Also the fact that the BCD is not a standard one and you are forced to run FSA rings.

DTT is a double threaded bolt.

http://weightweenies.starbike.com/forum/viewtopic.php?t=37845&highlight=fsa*

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limba

· #11 · Mar 28, 2009

Have you tried these cranks yet? I know you had clearance problems and trouble with your front derailleur. Have you used the bike yet? How's the shifting compared to Shimano or Race Face?
Can you feel any flex?

Cheers!

Discussion Starter · #12 · Mar 28, 2009

limba said:
Have you tried these cranks yet? I know you had clearance problems and trouble with your front derailleur. Have you used the bike yet? How's the shifting compared to Shimano or Race Face?
Can you feel any flex?

I have ridden the bike on pavement only. The trails are off limits for spring melt.

Can you define clearance problems? If you are asking if I can make the front derailleur shift the chain from the 29T to the 42T and back to the 29T the answer is yes. I can also ride 42T front chainring and 32T cog in the back. I can also ride 29T front chainring and 11T cog in the rear without any rubbing. This is true of both the Dura-Ace 7800 FD w/ The speen.de top pull converter. It is however not a very good setup as the force required by your thumb to shift the Dura-Ace derailluer is extremely high. I have since installed a XTR FD-M970 derailleur on the bike. The force required by my thumb is 10X less.

Shifting is fine. It is not as smooth or seemless as Shimano Chainrings, but then again Shimano chain rings shift the best out of all chain rings on the market. I'm also use a 10 speed chain. KMC X10SL chain to be exact.

I do not feel any flex. Mind you my whole bike isn't exactly the stiffest bike out there. Titanium spoked wheels on ultra light weight rims. Titanium frame, flexy light weight stem... everything on the bike flexes a bit. It is not a Cannondale or Klein aluminum hardtail from the 90s, nor is it a modern carbon fibre ultra stiff frame.

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limba

· #13 · Mar 28, 2009

The clearance problems I brought up were your chainrings. I remember your chainrings were too close to your frame. What bottom bracket did you end up using?

Cheers!

Discussion Starter · #14 · Mar 28, 2009

THe original BB I tried was a 108x68mm road bottom bracket. Everything fit, but everything was too close for comfort. I ended up with a 113x68mm American Classic Bottom Bracket.

743power

· #15 · Mar 28, 2009

no luck with that 952 on ebay cheers?

The more I research 2x9, the more it looks like the middleburn is the way to go.

Cheers!

Discussion Starter · #16 · Mar 28, 2009

743power said:
no luck with that 952 on ebay cheers?

The more I research 2x9, the more it looks like the middleburn is the way to go.

None. I bidded on one, but when I talked to the seller I asked if it was top pull. The box in the picture he/she had said it top pull, but his reply was bottom pull. The picture of the FD hinted it was bottom pull but I couldn't tell because of hte fuzzy image. I decided not to re-bid when someone beat my bid.

I'm still on the hunt though... I see a lot of M950 derailleurs but the 952 TP, 34.9mm clamp is rare.

JaLove

· #17 · Mar 29, 2009

May be a silly question but are the chainring bolts standard (double) size bolts as they seem to be from the pictures, or are they shorter than normal bolts--as in BMX or single-speed size?

Cheers!

Discussion Starter · #18 · Mar 31, 2009

2

JaLove said:
May be a silly question but are the chainring bolts standard (double) size bolts as they seem to be from the pictures, or are they shorter than normal bolts--as in BMX or single-speed size?

To be honest. I don't know. I have not really had to play around with cranksets and chainrings much. This was actually the first time I put a crankset together. Prior to that the XTs and XTRs all came pre assembled in a box and I just installed it onto the bike.

I did follow the Middleburn instructions and added Loctite 222 to the alloy chain ring bolts and torqued them to 80 inch-lbs.

Here are the bolts that were supplied with the Middleburn DUOs

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JaLove

· #19 · Mar 31, 2009

Cheers! said:
To be honest. I don't know. I have not really had to play around with cranksets and chainrings much. This was actually the first time I put a crankset together. Prior to that the XTs and XTRs all came pre assembled in a box and I just installed it onto the bike.

I did follow the Middleburn instructions and added Loctite 222 to the alloy chain ring bolts and torqued them to 80 inch-lbs.

Here are the bolts that were supplied with the Middleburn DUOs

I appreciate you taking the time to measure! I'm still on the fence between these and a set of Race Face Deus with King BB and TA rings. I'm wondering how much different the 42-28 combo will be from a 42-27 combo.

Cheers!

Discussion Starter · #20 · Mar 31, 2009

I'm not a fan of the RaceFace Deus crankset where it has the so called "X type" bottom bracket setup. The chainline is adjustable via plastic washers and such. It's not an easy system to setup correctly. A lot of people fail to setup the spindle and bottom correctly and as a result the crank arm gets loose and the threads and splines of the axle/spindle get damaged and the crankset is junk.

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