Questions about cranks, which are the pieces of metal the pedals are attached to and then, in turn, rotate the bottom bracket and chainring.

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26
votes
12answers
24k views

Triple vs Double chainring?

I'm bike shopping for my first road bike, and I've asked for a lot of advice from my father who was a serious cyclist once upon a time. After showing him one prospective bike, he dismissed it with a ...
22
votes
13answers
59k views

Creaking from cranks/spindle. How to fix?

Recently the cranks on my bike started to creak. I checked with my usual "bike-bible" Park Tool. They recommended dis-assemble, lubricate, re-assemble. So I did that. Remove cranks. Remove spindle. ...
21
votes
7answers
2k views

Are Z-shaped cranks a good idea?

I've stumbled across this kickstarter project, which promotes an original shape for cranks: They claim a wider arc of useful push during rotation. While their main point is rendered moot by ...
19
votes
1answer
367 views

Selecting the right crank length

What is the best way to determine the correct crank length for my height and more specifically my leg length?
11
votes
4answers
5k views

Differences between Biopace and Rotor cranks

On mountain bikes of a certain age, "Biopace" chainrings are ubiquitous. These chainrings are (purposely) not circular. It seems that most people today agree that Biopace rings didn't live up to the ...
10
votes
4answers
334 views

Why use multiple materials on chainrings?

Why is it that on a typical mid-level road triple crankset, the outer rings (larger rings) will be aluminum, while the inner ring (small ring) is chro-mo? It seems to me that if aluminium was good ...
9
votes
7answers
15k views

How to remove a crank arm with stripped threads?

A friend called me up yesterday after a mis-adventure during his attempt at a bottom bracket overhaul. He stripped out the threads on the (left) crank arm while using a Park crank puller. In a pinch, ...
8
votes
2answers
209 views

Why such a tiny difference in crankarm length?

Why are there only 170 and 175mm lengths for the crank arms of MTBs? I would have guessed that touring bikes would benefit from far longer crank arms than those, suitable for mountain riding.
7
votes
4answers
5k views

What should a big guy look for when buying a road bike?

I'm 6ft 4" (1.8m) and 22st (139kg). I do a fair bit of cycling, mainly spinning and mountain biking. I would like to get into road riding so I'm looking to buy a road bike. I want to spend between ...
7
votes
1answer
622 views

The pros and cons of crank self-extractors

I'd like to know more about the reliability of self-extracting crank bolts, but haven't found much information on how they perform (or how they don't). My interest stems from touring and ...
6
votes
3answers
1k views

Solutions for pedals screwed in the wrong sides?

I have a Focale44 fixie with a single speed on the other side of the gear (this is called a flip-flop I think?) and I LOVE it so far! I've ridden it for about six months and haven't had to fix ...
6
votes
8answers
13k views

Why does my bike make a noise when I pedal hard?

When I pedal forcing a little with my right leg, the bike makes a noise that I don't know how to describe. I'll try to do it. It's like: a short "ting" a tiny bell if a small rock hits the down tube ...
5
votes
2answers
1k views

Can I run a dual crankset with a chain guide tensioner?

We recently got a new mountain bike for my son via craigslist, it is a couple year old Transition Bottle Rocket and came with a E-Thirteen SS+ chain guide/tensioner. He would like a lower gear for ...
5
votes
2answers
975 views

Swapping cranks, but the new crank is wider, how do I compensate for this?

I was swapping the cranks and bottom bracket on my karate monkey from a Truvative stylo crankset (Mountain Double, GXP bottom bracket) to a Race Face Evolution DH (Mountain Triple, Race Face bottom ...
5
votes
2answers
515 views

How to get enough leverage to remove pedals when their cranks are not attached to a bike?

I'm trying to troubleshoot a weird barely-felt click on my cruiser. The nest step of the process is to swap out the pedals and see if the problem goes away (if not, the problem is likely the bottom ...
5
votes
2answers
492 views

Which Phil Wood bottom brackets are compatible with Shimano XT cranks?

As far as I can tell just the Outboard BB is.
5
votes
2answers
196 views

Carbon cranks care?

I have carbon cranks (SRAM S-2200) on a new bike. The side is quite protected but the bottom part, where the pedals are fitted, is not. Hitting rocks on the bumpy road is sometimes inevitable. How ...
4
votes
3answers
661 views

Crank arms are not parallel to each other. What could have caused this?

It is a cottered crank. Crank arms themselves don't seem to be bent. It is a non-cartridge style spindle. Any ideas as to why they are not lining up?
4
votes
2answers
245 views

What is the effect of changing length of crank arms?

There are some length options for the crank arms - like 170mm, 175mm. What is the difference for the rider? In which way does it effect the commute? Tried looking at Selecting the right crank ...
4
votes
4answers
725 views

Cruiser bottom bracket is clicking and grinding

My Trek Pure Deluxe 3-speed cruiser has been making a clicking noise when riding for some time. The problem is faint, and is more felt than heard. However, it's been getting worse; it now makes a ...
4
votes
3answers
1k views

How do I remove these crank bolt plugs

I have an old 10-speed bike (presumably 80's vintage). I'm trying to remove the bottom bracket and cranks but have struck a problem. The crank bolts have a plastic cap over the top of them and I'm ...
4
votes
1answer
430 views

What MTB 10 speed double cranksets exist with 180mm cranks?

I am looking for a a 10 speed dual crankset that has 180mm cranks. I see the SRAM cranksets only come in 170 and 175mm.
3
votes
4answers
329 views

Trick or tool to help line up 48 splined crank arms

Besides eyeballing it and comparing the line to the seat tube, are there any tricks to getting 48 splined crank arms perfectly aligned? I must have spent a solid 15 minutes looking at them from every ...
3
votes
4answers
3k views

My crank fell off, how do I re-attach it?

I was out riding on my mountain bike when my crank unexpectedly fell off (video). How do I reattach the crank? There's a torque range specified (25-30 Ft-Lbs): how critical is this? I don't own a ...
3
votes
4answers
3k views

Replacing Crankset. Do I need to replace chain? Then do I need to replace cassette?

Over the past year, my road bike's crankset has gotten pretty bent up and out of wack. Not due to abuse, just wear and tear I guess. It's pretty bent and has a nice wobble that I can see as I look ...
3
votes
3answers
482 views

BMX gearing - for road / commuting

I have a 2010 Haro Pro Race, which I bought for commuting and general tomfoolery. I commute on it 2 miles a day, and I want to be able to go faster by changing the current single-speed gearing ...
3
votes
3answers
347 views

Single Chainset

just wondering if there is much point in having a tripple chainset on my MTB, I very rarely change gear on the crank and I feel like having a single cog would make the bike lighter and also tidier as ...
3
votes
4answers
2k views

What cassete do I need to run with a compact crankset (50/36), to equal the same gearing as running a standard crankset (53/39) with a 11-28 cassete?

Every new bike in my price range comes with a compact crankset, which I want for climbing, but I race and I need to keep the same top speed that I've had for sprinting and descending (I live in the ...
3
votes
3answers
1k views

Shimano Hollowtech left crank arm getting loose

After 2 years of good use, left crank arm on my FC M542 crank set has started to get loose quite often (cca 500 km). It is usually indicated first by few now an then click-clanks somewhere in the ...
3
votes
1answer
478 views

Can't remove crank arm on older Mercier

I'm rebuilding an older Mercier and have decided to tackle the bottom bracket. I've read a few articles and watched a few videos on how to remove the crank but none of them look anything like what ...
3
votes
2answers
145 views

Crank arm snapped: what could have caused it?

Recently, on my single-speed bike, the right crank arm just snapped. Was slowly going up a hill, and all of a sudden it broke in two pieces. I have now exchanged the entire crank & chain set ...
3
votes
1answer
117 views

Should I grease pins when re-installing them on cottered cranks?

I'm restoring a vintage Peugeot with cottered cranks. When reattaching the cranks to the bottom bracket spindle, should I grease the pins or put them in dry?
3
votes
1answer
178 views

Help me to attach inner ring

I have cranks with 4 holes for outer and middle rings attachment. There are no holed for inner ring attachment. On my other bikes crankset middlering has 8 holes 4 for cranks and 4 for inner ring. I ...
3
votes
1answer
335 views

Short cage derailleur: how to find out maximum sprocket differences?

I'm building a kind of new bike and would like to put a triple or compact crankset on it. I've still got this NOS huret derailleur set (front, rear and shifters) laying around which would match the ...
3
votes
2answers
315 views

How can you tell how far apart your chainrings are?

I just replaced my cassette and my crank with one from the LBS that the guy said would work. I've had no problems with the cassette, but the crank is too wide so that my front derailleur does not ...
2
votes
1answer
908 views

Why does my non-drive side crank arm come loose?

I tighten the bolt super hard. Ride for a while. Then it comes loose again. I don't know if its my BB or the bolts. How can this be fixed??
2
votes
1answer
489 views

How do I re-attach a crank that has fallen off?

I have already read My crank fell off, how do I re-attach it?, but it did not answer my question. I was biking up a hill in first gear, and I felt my left crank was a bit loose. Never having had ...
2
votes
1answer
40 views

What is the crank length on a Shimano Deore XT?

I have this bike: http://www.trekbikes.com/int/en/bikes/mountain/cross_country/superfly/superfly_9_8/ Frame Size is 17.5 Crank is: Shimano Deore XT, 38/24 I purchased a garmin edge. It asks for ...
2
votes
1answer
242 views

Problems with gears after re-attaching front chainring

I had to remove the pedal crank arm together with the front chain set when fixing a bottom bracket problem, but now that I've re-attached it, gear changes in my front derailleur are completely off. ...
2
votes
1answer
462 views

Older road bike: squeaky crank?

I have an old Free Spirit road bike. It's in good shape and runs fine, but I started noticing that when I'm going uphill or pedaling in a high gear there is a squeaky sound coming from what seems to ...
2
votes
1answer
243 views

What types of BB-axle to crankarms interfaces are there?

On the lowest end, we have the taper/square interface. I believe it is standard i.e. there are no variations in the sizes. image property of VP Components USA Then there is the octalink. Actually ...
2
votes
1answer
170 views

Size of Pedal Threading on old German Glockenlager?

I removed the pedals of a Göricke bike from 1934 or 1935 (according to the bike number). It has a Glockenlager (What is that in English? Bell shaped bottom bracket?) as seen in the picture. The crank ...
2
votes
1answer
396 views

What crankset should I buy to suit an 8 Speed Campy freehub?

I've just bought a pair of campagnolo/mavic wheels without a freewheel. I'm finding it very hard to understand what will fit on the rear hub. It's English thread, does this mean that any 8 speed ...
1
vote
4answers
205 views

Do I need to replace cranks after newly installed pedals torqued out along with some threads in my crank?

I must have crossed threads like an idiot when I installed pedals for my new SPD cleats. After several miles of riding (~100-200 m), I suddenly got this inexplicable rolly, bumpy motion in my foot. ...
1
vote
3answers
520 views

Are there research graphs for the Rotor Q Ring system?

I was looking into Rotor Q Ring system that supposedly increases power by 4% which is rather significant especially when climbing. It should shave off quite some time off your resulting time due to ...
1
vote
2answers
2k views

How to fix a stripped pedal crank

The threads on my bike's pedal crank just became fully stripped and the pedal fell off, though the pedal itself is fine. Is there any way I can fix this without fully replacing the pedal crank?
1
vote
3answers
795 views

Noise from crankshaft spindle and then the pedal falls off

In the last 6 months I have been getting really bad noises, creaks, clunks, etc coming from somewhere around the spindle connecting to the crankshaft. Every time I put pressure down on the left hand ...
1
vote
2answers
2k views

Does anyone have experience with Bottom Bracket Tap/Facing sets?

I'm interested in recommending my boss get the workshop in which I work a bottom bracket tap and facing set. As it's quite an investment it's important to me to know what you're getting for your ...
1
vote
2answers
2k views

Will 10 speed cranks work with an 8 speed freewheel?

I'm looking at building a road-bike, and I've just purchased some wheels with campagnolo hubs, with an 8 speed freewheel on the back. Can I use Campagnolo Daytona / Veloce cranks on the front? I ...
1
vote
1answer
165 views

Using a Sram 22 group with 10 speed crank

I have a SRAM Red 22 group set that has a standard crank (53/39), and I also own a SRAM Red 10 speed crank with compact chainrings. I'll be doing some climbing soon and would like to use the compact ...