Need some new cranks for Katie’s Rohloff equipped bike which means it’s for single ring use and we don’t actually need any chainrings (but if they’re standard we can use them on another bike).

Ideally –
– 170mm or shorter
– standard BB (Hope ceramic already fitted)
– lightweight
– not silly expensive.

Suggestions please…

Define “standard BB”

If you’ve a Hope Ceramic fitted already, I assume you mean HT2?

Anyway, plenty of choice. XTR would be the obvious, though expensive choice. Middleburn now do HT2 compatible cranks. Raceface Deus cheap from Merlin with rings you could sell.

Personally though, I’d just buy SLX with rings for £78 from Merlin. Sell the chainrings and you’ve got a bargain. They’re only a few grams heavier than XT, only about 50 grams more than XTR or Middleburn, and the money you save can be spent elsewhere on more important things.

Middleburn with your choice of spiderless chainrings from Homebrewed 8)

http://www.homebrewedcomponents.com/store.php/categories/spiderless-rings-for-middleburn-cranks

Or track down a secondhand XTR M960 to Jones – or a secondhand M970.

I have some very low mileage xt cranks for sale m770 but 175mm arms…

I’d just look at one of the Campag UT carbon chainsets. External bearings, nice carbon and light – also with 170mm cranks…..

So to clarify – by ‘standard’ I mean HT2. It’s got XT 175’s on at the moment so needs to be-

170mm
Lighter than XT

Length is the primary reason to change but shaving any amount of weight (even 10’s of grams) is worthwhile – very few other places to lose weight on this bike now.

Is there anywhere that lists ‘ringless’ weights? Weightweenies seems to have little info from the last 6 years.

🙂

I’m sure SRAM do a version of the Stylo specifically for a single ring. It comes with a natty bashguard too.

very few other places to lose weight on this bike now

How much does it currently weigh? I love my Rohloff but one day would like to build it into a light option as it’s currently a long way from that even though it’s rigid. And have you thought about a belt drive or is that not an option with the current frame?

very few other places to lose weight on this bike now

Except the hulking great rear hub?

Truvativ cranks aren’t light. What about KCNC or Extralite?

Except the hulking great rear hub?

🙂 That’s not negotiable.

And have you thought about a belt drive or is that not an option with the current frame?

Not an option on the full sus.

KCNC cranks are an option but need their own BB. Extralite I’ve not looked at yet. Tune might be an option as well but again needs it’s own BB.

Don’t get Fast Foots, they’re horrible, and the 6 pack BB isn’t great. A friend bent both of his cranks, I’d avoid!

One of the local wieght weenies here raves about Cannondale Coda cranks. may need a BB30 bottom bracket though.

Clavicula?

not silly expensive.

That rules out THM Carbones then…

Cannondale cranks are BB30, and cant be retrofitted to a normal frame.

Cannondale cranks are BB30, and cant be retrofitted to a normal frame.

They can, but don’t ask me how. I would imagine it is a proper bodge!
It would be hard to find anything better than XTR, although getting a suitable chainring would be the problem.

Hard to beat an XTR M970. Sell the rings and fit a Renthal.

Just looked on CRC… M970 are more expensive than the new M980/M985… WTF ❓

FSA EXO MEGALIGHT. There is an ad on here for CRC

I still run XTR M970’s with Middleburn rings, as light and strong as pretty much anything – though if buying new now I’d go Middleburn.

Cannondale cranks are BB30, and cant be retrofitted to a normal frame.

They can, but don’t ask me how. I would imagine it is a proper bodge!

http://www.cannondale-parts.de/epages/61764971.sf/en_US/?ObjectPath=/Shops/61764971/Products/KP094

middleburn RS8 – 406g
Royce ti BB – 183g
= 589g

means you can get a perfect 54mm chainline for the rohloff too. 113mm axle needed for normal 47.5mm chainline with RS8s, 126mm gives you 54mm and royce can fabricate up to 135mm.

XTR 970 whole chainset incl BB and rings = 786g
XTR 970 chainrings 23, 43, 83 = 149g
= 637g

(EDIT Hope BB = 110g so add it to the M980 weight below and you get 636g)

sixc?

xtr m980

the 88mm bcd can be had with custom single rings

here

(i have a HBC 28t and 30t 88mm BCD chainring for sale poss)

How does the weight for Middleburn X-type cranks compare to XTR M970?

They can, but don’t ask me how. I would imagine it is a proper bodge!
It would be hard to find anything better than XTR, although getting a suitable chainring would be the problem.

Ah yes, I forgot the Cannondales use a separate axle, I was thinking that even if you could get the bearings the axle would be too short, as with other BB30 cranks.

I got a custom 36t chainring from Mattias Helore for my XTR double cranks, €40 for a ti chainring, lasting well too. Agree that XTR are the sensible option, you know they’ll just work! If you get the triple cranks then you can run any ring you want, and can probably sell the original rings for a reasonable sum of money.

i had the hollowgrams, bought used, creaked with every pedal stroke, bought xtr, like above, they just work, dont have to worry about some propriety nonsense failing

very light though

I have a friend who might be willing to sell his RS8 x-type Middleburns which would drop straight on. You could then fit an Uno if you wanted or run a single ring on the outer fixing of the spider, also pretty much spot on for a Rohloff (I used to run this combo)

Let me know if interested. Not sure what he might want tho..let me know if you’d like me to ask.

So we’re starting with the current, and obvious, choice

So no saving over this from Middleburn (and they’re pricier).

So it’s looking like –

Current setup – XT + Hope – 715g. A complete XT crankset with rings can be picked up for c£130 and the rings must be worth £50+. Bargain.

RS8 +Royce Ti – 589 (does that include the spider?). Not priced up BUT I currently run this on my Argon hardtail. Creaks like a bastard sometimes (seems to depend on the weather – fine right now) and doesn’t clear the front chainguide so doesn’t work on a full sus Rohloff bike.

MBurn X type (+Hope Ceramic) – 712 (No lighter than XT, more expensive)

XTR + Hope 635g

XTR looking like the best option. Tell me more –

XTR970 is the old 9 speed, XTR980 the new 10. They’re both online for about £300 or so.

Merlin want £85 for a ‘960’ big ring alone so the complete set must be worth twice that? So maybe crank arms alone final cost c £150.

Merlin also seem to claim that the XTR chainset has a standard 104 BCD (I thought it was a custom size) so the nice new blue ano ring she’s got would swap straight over.

What am i missing (and who wants a set of unused XTR chainrings? 🙂 )

Only xtr 960 use 102mm bcd (104 is ‘standard’).New original 960 rings are like rocking horse poo….only more expensive.

What price 970/980 rings?

970 chainset is more standard BCD, but you need spacers if you go away from the right fitment on the inner chainring. It is easy and possible though.

980 uses a new BCD standard and there are much fewer options at the moment. It is a really lovely chainset though 🙂

Rotor Agilis come in at 548g and Rotor 3D come in at 543 (steel axle) or 506 (ti axle). And all MTB cranks are 20% off at the moment!

5 arm spider on the rotors 😐 .Got some coming for my new road bike,unsure about the wobbly rings though.

Do ‘normal’ rings fit those rotor agilis?

Shimano XTR Hollowtech II M960 532g
Titanium bolts (2 of) 5g
Shimano pre-set 5g
Middleburn rings 44/32/22 145g
Titanium ring bolts (2 sets) 22g
Hope Ceramic BB 107g

So 816g all in

Merlin also seem to claim that the XTR chainset has a standard 104 BCD [

M970 has standard 4 arm bolt pattern
M980 has standard 4 arm bolt pattern
M985 has 88mm BCD

5 arm spider on the rotors .Got some coming for my new road bike,unsure about the wobbly rings though.

Both the 3D and Agilis come in either 5 (double) or 4 (triple) arm versions.

Do ‘normal’ rings fit those rotor Agilis?

They do, normal 104/64 BCD on the triples, and 110/74BCD on the doubles. The 5 arm rings aren’t as prolific as 4 arm, but TA Specialites do them.

980 uses a new BCD standard and there are much fewer options at the moment. It is a really lovely chainset though

The new XTR triple is standard BCD, I have one with a Chromag 34t ring on it, no problems at all.