# 07' Xtr Crank/ring Weights!!!



## Mr. RMB (Sep 7, 2005)

Just took apart my 2007 XTR crankset.

Rings:
22T: 22 grams
32T: 44 grams (carbon/ti)
76T: 76 grams (carbon/ti)
Bolts: 14 grams

Rings & Bolts
156 grams

Bottom Bracket:
85 grams

Crank arms (no rings)
511 grams

Crank Arm Bolt
9 grams

TOTAL: 761 grams


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## Hardtailforever (Feb 11, 2004)

76t big ring?! You must have some HUGE quads, eh?

Anyway, I just got mine and it weighs in at 768 on my scale, so that sounds about right. Not the lightest thing in the world, but like I've said before, the thing shifts like nothing I've ever used before.


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## Mr. RMB (Sep 7, 2005)

Ya i found the stock 44 tooth too small so I upgraded...lol....


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## akashra (Dec 30, 2006)

Don't you find there's a massive jump there? I mean, you wouldn't be able to use anywhere near the same gears you use on the rear chainring due to the massive size of a 76T front chainring - crossover would be a huge problem.


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## Mr. RMB (Sep 7, 2005)

I was kidding....I accidentally wrote 76 tooth because thats how much it weighs.

The large ring is only a few grams heavier than an FRM 44t ring.


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## Jesseg (Aug 27, 2005)

*BB weight*

That's interesting about the BB weight being significantly lighter than my raceface deus BB at, I think, 110 grams and I think FSA ones being about 130. I wonder who has got the lightest BB cups. Maybe keeping your external crank and changing to an XTR or perhaps even lighter cups might be an easy and economical way for some people to shave weight, particularly when bearings go anyway. If anyone else can measure their BB cups with and without the sleeve that some people won't want to run, that might be useful. If RMB could tell me how much of the 85 was the sleeve, I'd like to know. My frame has an "insulated" BB shell anyway, so I don't use that. It also seems like if water can get in at the spindle, the sleeve will keep it next to your bearings unnecesarily.


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## Mr. RMB (Sep 7, 2005)

*they are light!!!!!*

My XTR FC M970 bottom bracket cups weigh 79. The "sleeve" weighs around 5. I don't see the point in the sleeve.

I'll start a new thread to get other peoples attension.


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## dot (Jan 14, 2004)

What's the point using carbon/ti rings without saving ANY weight at all? They weigh like LX stuff.


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## Mr. RMB (Sep 7, 2005)

They are supposed to last twice as long.....and who says they don't save weight?

You'd have to compare them to 2006 XTR rings....but since the entire crankest is lighter I'd say the rings contribute to a little of that.


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## akashra (Dec 30, 2006)

Yeah, I'd imagine there would have to be some other benefits - I noticed the same thing with my cranks - they're 100g lighter than XTR cranks! (and about 1/5th the cost).


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## sergio_pt (Jan 29, 2007)

akashra said:


> Yeah, I'd imagine there would have to be some other benefits - I noticed the same thing with my cranks - they're 100g lighter than XTR cranks! (and about 1/5th the cost).


what crankset do you have?


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## akashra (Dec 30, 2006)

It's actually just a standard Deore set.
However, after talking this over with a mate, we discovered why it weighted this way - the XTR includes the bottom bracket. The Deore crankset doesn't, and required a separate octalink bracket - adding about 280g. So the XTR in the end works out lighter.


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## evilgeek (Jun 12, 2006)

so it's heavy as well as ugly.


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## SBK (Oct 18, 2006)

Mr. RMB said:


> They are supposed to last twice as long.....and who says they don't save weight?
> 
> You'd have to compare them to 2006 XTR rings....but since the entire crankest is lighter I'd say the rings contribute to a little of that.


Actually, the '06 XTR M960 rings are in fact lighter than the numbers you've posted. Here's how the '06 rings measured on my scale:

22t - 22g
32t - 40g
44t - 69g

The BB cups are apparently lighter on the new XTR crankset, as my '06s are 96g including the center tube. Between the heavier rings and lighter BB cups, it looks like a wash. The savings in the '07 must be in the arms. Makes sense that the '07 big ring is heavier, since it has to have "legs" to reach to the smaller chainring bolt circle, vs. the '06 which relied on longer integrated spider arms and an essentially round chainring.


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## dan0 (Oct 12, 2005)

Mr. RMB said:


> Just took apart my 2007 XTR crankset.
> 
> Rings:
> 22T: 22 grams
> ...


hate to tell you but the big ring is aluminum, only the middle ring is carbon/ti


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## Tracerboy (Oct 13, 2002)

*not fair!*

Hey, not fair! My XTR M970 weighs 790g all in, including spacer, crank fixing bolt (8g) with 175mm arms.

How did you get yours down to 768g?!

While I'm here, I'm not sure I understand the function of the little ring on the non-drive side arm. The instruciton say to rotate it after installation of the arm to 'take up play', so I assume you screw it up to the bearing, then tighten the little allen bolt. 
What does this bit do? Apllies a load against the bearing? Helps seal the bearing? Can I toss it in the bin??!!


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## macd (Feb 2, 2007)

Mine was also 790g. Because the left side crank arm presses on you need that adjuster to tension the arm against the bearing. Shimano redesigned the left crank arm interface from 06 because there was trouble with bearing play. Also don't use the al bolt to fix the left crank arm back on. Use the steel press piece that comes with the crankset.


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## Tracerboy (Oct 13, 2002)

*thanks...*

..useful info, but this piece is not tensioning the arm against the bearing. The arm is on the axle, end of story. It does not connect with the bearing in any way. I tightened mine on up to 45Nm (with an accurate torque wrench) as per Shimano's instructions. It felt like it hit a stop at about 40 Nm, so it's on OK. But there is still about 10mm of gap between arm and bearing, with this little ring thing taking up about 5 of those 10mm. So I tightened the ring up by hand (using the little spanner they give you) so that it contacts the bearing and applies very slight pressure against it. Then tighten the allen bolt to hold in place.

I can only think that this gives the bearing extra lateral support....?

By the way, I did use the alloy bolt to tighten the arm on - it was fine up to 45Nm, no probs.

Because I am a dufus sometimes I also tried out the removal tool, as I forgot to put the 1 spacer in on the drive side!!! And I am happy to report that it works pretty well, if unconventionally......don't lose it!


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## nino (Jan 13, 2004)

*798g here...*

i just read into this thread and it's interesting to see so many different weights. i weighed the 07 
XTRs at 782g


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## Tracerboy (Oct 13, 2002)

yeah, looks like I got reamed with my 790g set.....oh well!

Lets hope this chainset shifts well - I ditched my Extralite Ebones cos I was fed up with ISIS, so hopefully these bearings will last more than 3 months.

As for the 200 or so grams I just gained, I have managed to almost win them back with a KCNC seatpost (i/o Thomson), (-50g) XTR 07 rear mech (-20g) (i/o XTR06), and Syntace F99 stem planned (i/o FSA) -40g.

So the faithful old Sugar 1 is still at 9.55kg!

So Nino, u have an opinion on this preload ring thing? The instructions really don't explain at all what it's for.......


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## Mr. RMB (Sep 7, 2005)

The preload ring takes up side to side play in your crank arms. Last year you had to use spacers to take up this play (and had to remove the crank arms to do this). This new tension ring takes up play without the hassle of having to remove the cranks and gives more precise adjustment. I guess you could remove this lockring and replace it with plastic spacers but it is so handy.

Last years cranks seemed to fir perfectly on my Rocky but i guess shimano had to rely on frame manufacturers to make their bottom brackets the exact same size...Now they have 5mm to play around with.

Do you get it bernithebiker?


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## Mtc (Jun 9, 2004)

bernithebiker said:


> While I'm here, I'm not sure I understand the function of the little ring on the non-drive side arm. The instruciton say to rotate it after installation of the arm to 'take up play', so I assume you screw it up to the bearing, then tighten the little allen bolt.
> What does this bit do? Apllies a load against the bearing? Helps seal the bearing? Can I toss it in the bin??!!


 That spacer is supposed to reduce drag and tension on the BB bearings. All the other external BB's you just crank down on the crank bolt to tighten the crank(up against the BB). With that ring you take the gap out of the spindal without wrenching the crank arm up against the bearing. Its "supposed' to make for a free spinning and long lasting BB.
So don't throw it away.


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## Axis II (May 10, 2004)

evilgeek said:


> so it's heavy as well as ugly.


WORD. And let's not forget UBER expensive.:nono:


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## cogswell23 (Apr 24, 2006)

*Steel tool is a crankarm puller . . .*



macd said:


> Also don't use the al bolt to fix the left crank arm back on. Use the steel press piece that comes with the crankset.


This is dead wrong.

The steel press piece that comes with the crankset is not a "press piece". It is for the removal of the left crankarm. Use the bolt to put the crankarm back on, but do watch your torque.

How would you use the steel removal tool to install the crankarm? Makes no sense.

FWIW, my crankset, with three spacers, bb cups, bb sleeve, and crankbolt weigh in at 770g on the nose. Where does all the variation in weight come from? Must be the arms, no?


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## Mr. RMB (Sep 7, 2005)

*A little heavier....*

I got my digital scale in the mail today and reweighed my XTR crankset. It came out at 784 grams.

I guess my analog scale with 10 gram increments doesn't cut it for weighing bike parts!


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## macd (Feb 2, 2007)

cogswell23 said:


> This is dead wrong.
> 
> The steel press piece that comes with the crankset is not a "press piece". It is for the removal of the left crankarm. Use the bolt to put the crankarm back on, but do watch your torque.
> 
> ...


You are right I am "dead wrong". It doesn't make sense to use the press piece to install.


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## slcpunk (Feb 4, 2004)

Another one weighing in at 796...I wonder what the difference is. Anyone know? can we check serial numbers or something?


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## Irrenarzt (Apr 19, 2006)

I'm guessing crankarm lengths as well as variance from balance to balance are what is causing this spread of masses.


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## slcpunk (Feb 4, 2004)

yeah, I should have mentioned, 175mm crank arms. -- oh and all 3 spacers


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## 245044 (Jun 8, 2004)

Mine was right on 770 grams.


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## Dream Bikes (Oct 1, 2005)

Mine comes at 788 g (22-32-44 175 mm)



After a little tuning :


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## 4212darren (Nov 15, 2005)

How do those rings shift? How much $? They look cool.


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## Irrenarzt (Apr 19, 2006)

That's hot as fukk


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## Wiksa_na_Maxa (Oct 3, 2006)

Heh, that's of mine 785g with no spacers










:thumbsup:


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## Irrenarzt (Apr 19, 2006)

What length chainring bolts are needed and where do you get the orange ones like that? Me likey.


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## meph (Sep 18, 2003)

*So my 960's aren't boat anchors . . .*

I was thinking about trading up to the 970's but it looks like my 960's with a Boone Ti middle ring (that ring lasts forever) is right about the same weight (~785 grams when new). My cranks are probably even lighter because I scraped off at least 5-10 grams of the finish on the first couple of rides. Too bad they look like crap now. How does the finish last on the 970s?


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## Dream Bikes (Oct 1, 2005)

4212darren said:


> How do those rings shift? How much $? They look cool.


They're Extralite Octaramps, I remember only euro prices : 22T (24 euro) 16 g (stock 23 g) - 32T (39 euro) 34 g (stock 44g) - 44T (49 euro) 64 g (stock 84 g)

They're very light, they shift well (with CNC ramps) and they're quite durable. They aren't stiff as Shimano stock ones, but they're surely a good solution!:thumbsup:


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## Dream Bikes (Oct 1, 2005)

Irrenarzt said:


> What length chainring bolts are needed and where do you get the orange ones like that? Me likey.


For outer/central rings standard chainrings bolts, the inner ring needs longer bolts (+ 2.5 mm)

Mine are special custom made for Dream Bikes only (don't ask it to Extralite). They comes in a cool orange color for males and females too. They introduce some tech improvement too, like hex wrench key insert and antispin grain together on females.


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## hollerbachMTB (Jul 17, 2005)

\those rings are absolutely gorgeous. the carbon and ti is beyond sexy, but couple it with some awesomely orange bolts? damn


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## Asahi (Jan 30, 2004)

cogswell23 said:


> ... Where does all the variation in weight come from? Must be the arms, no?


Could be the scales. . .


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## Dream Bikes (Oct 1, 2005)

I love orange anodized!!!


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## Batas (Jan 16, 2004)

Did you replace the bolts just for the looks? Because the oem bolts are aluminium already...

By the way, mine is 787gr. (175mm no spacers)


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## Dream Bikes (Oct 1, 2005)

Batas said:


> Did you replace the bolts just for the looks? Because the oem bolts are aluminium already...


Yes, principally for the look, but Extrabolts are a little lighter too...


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## Irrenarzt (Apr 19, 2006)

I would like to purchase 2 cranks worth of these Extra bolts in orange. Can you PM me to tell me where to get these Dream Bikes? Thanks.


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