Rotor R-Hawk Cranks - Review

May 3, 2018 at 9:10
by Paul Aston  
Starling Murmur Review Rotor Hawk cranks

Rotor Bike has been in the cycling industry for over twenty years. Based in Madrid, Spain, they have been looking for a solution to better connect human legs designed for running to perfectly round pedaling circles. After a whole host of weird and wonderful systems, they have settled on pushing oval chainrings. They also make a range of cranksets, power meters, and more recently complete road bike groupsets, all made at their own engineering plant in Spain. The R-Hawk is their take on an enduro/downhill crankset, the modular system can be pick-and-mixed from the ground up including different axle widths and weights, direct mount chainrings, arm length and silicone protectors in various colors.

A crankset including chainring and axle comes in at $345 USD or €345.



Starling Murmur Review Rotor Hawk crank
R-Hawk Crankset Details

• Arm length: 165/170/175mm
• Axle: 30mm
• Q-Factor: 164 mm / 170mm boost / 179mm DH
• Chainline: 49,5mm / 52,5mm boost
• Material: 7055 aluminum, 100% CNC-machined
• Compatibility: BBRight / BB30 / PressFit30 / BSA 68mm, 73mm and 83mm
• Silcone protectors in seven colors
• Made in Spain
• Weight: 798 grams (165mm arms, protectors, 32t ring, Boost axle and BSA BB)
• Price: $345 USD / €345 (exc. BB)
rotorbike.com



Construction

Being a small brand, Rotor wanted to create a system that could adapt to ever-changing industry standards, which is why they went with a modular system that allows any Rotor axle, bottom bracket, crank arm and chainring to work together. This also means that if you manage to bend a crank arm, or change bikes and need a new bottom bracket or axle width, you should be able to buy the necessary parts individually.

The cranks start life as an extruded lump of 7055 alloy, which Rotor says has the same mechanical properties as the more common 7075 series, but with better fatigue properties. Each extrusion goes through an ultrasonic check by the supplier to discover and eliminate any defects found in the raw material. The crank arms are deeper than most and have three holes bored through their full length to save weight. This also means they could shorten the overall length of the crank arm by removing material on the terra-firma side of the pedal axle, which should be great news for those who suffer rock strikes.

The R-Hawk cranks appear to be ready to withstand anything, but for safety, there is added silicone protection to ward off shoe rub and rock strikes for today's low bottom bracket society. And, for the color-coding crowd, there are seven shades to choose from.


Starling Murmur Review Rotor Hawk crank and Q-ring
I used the Q-Ring with success in the standard mounting position, but riders can adjust the ring via the OCP system to suit their style.


Installation

Fitting the R-Hawk cranks was a doddle. Using the included wrench to thread in the BSA threaded bottom bracket, install the 30mm axle (Rotor say their axles are machined within a 29.99-30.0001mm tolerance) with the correct spacers, then attach both of the arms. The chainring simply slots on to the splined OCP system and the parts are laser etched to make sure you have everything the right place. Finally, the bottom bracket preload can be adjusted using the non-drive side collar and locked in place with a 2.5mm Allen key. Removing the cranks is easy, as both sides are installed with self-extracting bolts.

Starling Murmur Review Rotor Hawk BB
The preload ring can be adjusted by hand then locked with a 2.5mm hex key.
Rotor Hawk Cranks
The chainring uses Rotor's own tool- and lockring-free spline interface. Simply put the chainring on in the desired position then bolt on the crank arm.


Performance

I set the Q-Ring in the standard position and got on with it well from day one, barely noticing the need for a different pedaling technique. As I mentioned in my Starling Murmur review, it did seem to mess with the anti-squat of the bike, but this will vary between bike and setup. For me, pedaling the oval Q-Ring is definitely more comfortable, smoother, and provided better grip and power transfer on loose terrain than a round ring. I tried to adjust the Q-Ring slightly either way but ended up back at the standard position. If you are not a fan of oval rings, Rotor makes a standard round ring to fit the OCP system with a narrow-wide design.


Rotor R-Hawk crankset Review
The complete crankset including 32t chainring, Boost axle, BSA 73mm bottom bracket, spacers, 165mm arms and silicone protectors weigh in at 798 grams.

Views: 3,461    Faves: 1    Comments: 0



Underfoot, the cranks feel solid. After months of abuse and rock smashes they are still in one piece and straight. The lack of material on the outside of the pedal threads help with a few more millimeters of clearance and the silicone protectors dampen alloy vs. rock striking noises.

Looking down on the crank arms they are quite straight compared to others that have more of an 'S shape' shape to give ankle clearance, and although I didn't have any problems knocking my ankle bones the anodizing has started to wear. The drive side bottom bracket bearing has started to feel a little rough as well, but still spin freely after more than 400 kilometers of riding in winter conditions.



Pinkbike's Take:
bigquotesThe R-Hawk cranks are a fit and forget crankset. The chunky and solid aluminum design and protective guards will appeal to many riders who frequent rocky terrain. Paul Aston



58 Comments

  • 68 1
 "Fitting the R-Hawk cranks was a doddle." - Can someone translate this into 'merican? Top Gear hasn't taught me this one yet... Can't tell if it means easy or difficult.
  • 15 0
 It means easy.
  • 21 0
 @Captain1Eye: Thanks. It would have been a doddle to look it up on google, but I knew I could rely on fellow PB commenters to enlighten me.
  • 48 3
 400km? That's less than a month of riding (for me). If the bearings are feeling rough there's something wrong. Even a Raceface BB lasts a at least another 10km.
  • 20 87
flag Jimmy0 (May 10, 2018 at 0:26) (Below Threshold)
 Good for you
  • 13 0
 If it's wearing after 400km it's not worth the time of day. Shimano BB's last me 1.5-2 full seasons of bike park riding. 400kms and it should be just breaking in lol
  • 59 22
 @Jimmy0: Thanks f*ckface. My point wasn't to brag about how much I ride (which I suspect isn't much more than the average rider) but to illustrate the point that a BB should last more than a month.
  • 10 0
 He said that after 400 km in winter conditions they spin freely and he has them for months so he probably did a lot more than that.
  • 24 0
 They already smashed that chainring real bad, looks like an egg......
  • 15 8
 @Powderface: i wasnt being sarcastic. I dont ride that much and genuinely meant "good for you". Jesus yall need to chill
-f*ckface
  • 4 2
 Your race face bb last you 410km wow you are lucky... hahaha
  • 2 0
 mine lasted me a full year, well over 1k miles. I mean it’s creaky and rough as hell but it works
  • 1 0
 @Chingus-Dude: I was sarcastic mine last a full season usually but winter on van isle doesn't help
  • 1 0
 I run the rotor ceramic BSA bb with sixc cranks and it is significantly smoother than the stock raceface one. Never used their cranks but that bb is excellent.
  • 3 0
 errrr... My raceface bb has had about 7 years of twice a week rides all year round, mud, snow, commuting, you name it. And I'm just starting to think it's starting to get a bit rough.
  • 2 0
 Read the context. The reviewer is referring to the finish on the outside surface of the bearing and how it holds up to rock strikes. The piece is literally rough to the touch, not 'rough' or unsmooth to pedal. "...the anodizing has started to wear. The drive side bottom bracket bearing has started to feel a little rough as well..."

The reviewer notes that they "still spin freely" which means they are not wearing out by any means.
  • 23 3
 *aluminium.
  • 11 1
 Very nice and well made, but it’ hard to pick these over cheaper and lighter xt cranks
  • 2 1
 I used to think like this until I bent my XT cranks. So in my experience, Shimano's construction isn't as impact resistant as one piece forged and CNC'd cranks...
  • 8 0
 Yeah when my 5 year old XT's finally gives up maybe I'll look at something different. Doubtful though, I'll probably just get some more XT's
  • 1 1
 @jzPV: per the article, "The cranks start life as an extruded lump of 7055 alloy..."
Not forged, but extruded and machined. The XT cranks are a two piece forging and then bonded. So while the XT cranks are forged, they are also bonded and hollow, which makes them stiff and light, but also very thin, which hurts their impact resistance.
  • 5 0
 If you like oval rings, this is the way to go. Being able to adapt the ring clocking to your riding style and position is the point of oval rings. Otherwise it is like running fixed handlebar or saddle that you can not tilt.
  • 4 1
 Having survived square taper, octalink, isis and profile splines, I'm not sure i trust anything without pinch bolts, I've accidentally rode my saints and slx cranks loose for an embarrassingly long period of time, a tweak on the allen bolts and they're as good as new.
  • 3 0
 I would agree with you on the square taper, octalink, isis and profile splines but the RHawk cranks hold up very well. I have been running them for a year now with no issues coming loose. I am on the same bearings as well, but I do very little riding in poor conditions on the bike I run these cranks on.
  • 1 0
 Profile 48 spline spindles are still used on almost every modern high performance bmx crankset. I have some on my bmx, they’re still around.
  • 2 0
 @R-trailking-S: All the splined 3pc cranks ive had and everyone i know ended up with them going sloppy and wobbling badly, swapped to powerbites with pinch bolts and they've lasted 7-8yrs. Ps, fun tip, if your splined cranks go baggy, smash the axle with a hammer it mushes up the splines and creates a tighter interference with the crank arm... works quite well, probably wont see that in a park tools guide though.
  • 7 1
 A better way to connect the human leg bla bla . Give us a break from this bs
  • 3 0
 Wasn't the whole point of Boost increase the chain line as much as possible without having to increase Q factor? Seems disappointing that the change the chain line by increasing the axle width, rather than changing the chain ring offset...
  • 2 0
 There are quite a few boost bikes that will not clear a 164 q factor crankset, including mine.
  • 2 0
 @R-trailking-S: @R-trailking-S: that's his point. If you had to increase q factor, then you might as well just used 157mm rear which was already an option. The point of boost was supposed to give you a wider hub and maintain the narrow Q factor- that went right out the window.

I had a 157mm bike and the Q factor bothered my knees, when they announced boost I was all for it because a narrow Q factor is be for me. Well that claim ended up being BS.
  • 1 0
 @TheOriginalTwoTone: Standard q factor used to be 175 mm. 164 used to be reserved for xc race bikes. Only recently have I seen most cranks only available in 168 ish, and now ultra narrow 156 are available for xc.

Boost spacing hasn’t changed so much from standard, but the expectation to fit 164 mm q-factor cranks on everything is new.
  • 1 0
 @R-trailking-S: oh dang. That explains it...I should have looked up standard Q.
  • 1 0
 I'm a bad bike owner. I don't even know what q factor is.
  • 2 0
 Why would you want a silicone protector on the arm of the crank? Doesn't that just add friction between your shoe and crank arm. I'd imagine grippy silicone would wear out a shoe faster than smooth aluminum or carbon. Is it all for looks? Personally, I like the look of a crank arm that's worn smooth and shiny!
  • 1 0
 I have them and appreciate the ability to fine tune the clocking of the oval ring. Now I did experience (painful) ankle clearance issues. Not only are the crank arms pretty straight, but they are pretty edgy. It was no problem on flats but clipped in was the problem as I couldn't move my foot further outboards.
  • 4 1
 Who the heck needs an oval ring for DH? Even at Blue Mountain an oval ring would be pointless. Nobody is exactly going for a KOM across the top.
  • 5 1
 I am glad the ditched its pre-production name, the Mike-Hawk
  • 1 0
 @paulaston: Are you running the Catalyst pedals?

I'm curious on whether it is purely for testing purposes or for performances?
  • 1 0
 Ditto, a review would be nice.
  • 4 0
 @fartymarty: I actually own those pedals and have ridden them for quite some time now. You don't see them very often, hence my question.

If you want some feedback about those, then here are my two cents:

The catalysts are the first pedals I feel at home with. Lots and lots of platform real estate (I like it a lot as I tend to constantly move and adjust my feet position depending on the terrain). I was interested in the rationale behind the design; the ability to support both ends of the arch of you foot feels weird at first but you quickly feel the massive plus in grip, support and overall stability over technical terrain.

I just love them, very nice product IMO, they may not be for everybody but definitely a well thought out and solid product design.

In addition, they are easily serviceable and very robust.
  • 2 0
 @Barkit: same opinions this guy. Been using them on both my mountain and fat bike. Also bought a set for my dad with leg/ankle issues and he loves them.
  • 1 0
 @ratedgg13: Yeah, I definitely see the point of using them in order to alleviate ankle issues as they put much less stress on this area of the body.
  • 3 0
 @fartymarty - fully agree with @Barkit . I've been using them for a couple years now. I wish they were a bit wider or available in a wider model (I have very wide feet), but the length is what gives the amazing support. The pedal itself is a standard-issue, well constructed flat pedal - solid product, nothing spectacular. Grub screws for pins is a bit annoying to me (as they require a bit of effort to get out if they've been mangled by a rock strike, unlike the hex bolts screwed through from the other side in something like Saints or even RF Chesters), but that also seems to keep the profile relatively low, so it's a reasonable trade-off. Internals are solid and easily maintained (take apart, clean, grease, reassemble) - and they will gladly ship you a very reasonably priced rebuild kit if you need one. They'll also sell you reasonably priced spindles if you bend one in a crash (don't ask how I know...)

Seems like these are a to-each-their-own sort of thing. I have a second pair, and have loaned them out to friends; the reaction was about evenly split between people who loved them as much as I did vs others who didn't see the point. So if you're even remotely unhappy with regular flats (feel unsupported, cramping arches after long descents), give them a try (I believe they have a money-back thing if you end up not liking them).
  • 1 0
 @g-42: @Barkit: @ratedgg13: thanks for the comments. I read thru James Wilson's Flat Pedal Manifesto and it all seemed to make good scientific sense. The pedals also make sense and I may give them a go when my Straitlines die.
  • 1 0
 @fartymarty: Yeah, that's quite the manifesto... Wink Hype aside, the longer pedals work for me, and a lot of people I know. They also don't do anything for a bunch of other people. So I'd say this is one of those to each their own sort of things.
  • 1 0
 @fartymarty:
Pretty clear you were always gonna be a James Wilson believer to me bud.
  • 1 0
 @hilfskonstruktion: cheers, will have a read
  • 4 1
 nice but quite heavy for that price
  • 1 0
 Well, I ride a Race Face Respond crankset + an Absolute Black 32T narrow wide ring for months on my enduro bike and its great... and 3 times cheaper than this.
  • 1 0
 The B.B./pivot/yoke area of that bike you’ve bolted those cranks to looks like a total jalopy.
  • 1 0
 What? No puns? Oh well,...
  • 1 0
 how are these better than RF Turbine?
  • 1 0
 Heavy, ugly and expensive... im confused.
  • 4 3
 These don’t look good.
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