The part of your bike that contains the axis the cranks arms spin 'round. (The crank arms are where the pedals attach.)

learn more… | top users | synonyms

27
votes
13answers
115k 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. ...
1
vote
1answer
81 views

What is an attached bottom bracket?

Reading the specifications of a Merida Reacto 500 (2015) I noticed that at the bottom bracket is Attached, I only ever read about brackets threaded in the frame or press fit brackets.
4
votes
2answers
61 views

What direction are the threads on Ultra Torque bearing cups?

I need to remove the bottom bracket bearing cups from my 2010 Athena groupset. Do they both unscrew anti-clockwise, or is one side different (and which one)?
3
votes
1answer
96 views
1
vote
1answer
77 views

Bottom Bracket issues

So I took the old bottom bracket out of my hybrid frame, FSA Platinum ISIS Bottom Bracket 68 x 118mm. I then replaced with a Shimano BBUN55 Square Taper 68 x 11.8cm. Then realised that this was a ...
0
votes
3answers
3k views

What are my options for replacing a Shimano Hollowtech II BB?

I have had a 'Deore' equipped mountain bike for 3-4 months now. However, there is grinding noise from the area of the cranks and I suspect the bottom bracket. On a local MTB forum I heard that Deore ...
0
votes
0answers
57 views

Purefix Kieren Pro

TL;DR FRAME: Kieren Pro (68mm BB) Which BB is suitable for this frame? (want to use SRAM s100 crank) If BB must be Truativ 108 or 113mm, how do adjust chainline? Thanks for your time and efforts ...
5
votes
2answers
1k views

Pros and cons of gears in bottom bracket vs. rear hub? [duplicate]

Since 6 years, I am the happy user of a bicycle with a Rohloff internal hub gear. German quality squeezing 14 gears and a 526% gear range into the rear hub. Less known is the newer and equally ...
0
votes
3answers
102 views

Bottom bracket creaking only when pedaling hard.

When pedaling with a decent amount of force a very loud creaking sound can be heard coming from the bottom bracket area (it is very loud when standing on the pedals). It makes a creaking noise on each ...
3
votes
2answers
396 views

Bottom Bracket Lube?

Lately, after my normal wash & lube routine, I've been squirting a little Teflon lube into the bottom bracket hub. I do so without dissembling by inserting the lube straw into the hub crevice. Is ...
5
votes
1answer
807 views

Do Miche bottom brackets require a special tool, or is this one damaged?

I just bought a Miche Primato bottom bracket and tried installing it using Park's BBT-5 (the same tool I used to remove the previous bottom bracket, also Miche, but from 2008). The BBT-5 fit into the ...
3
votes
2answers
140 views

What should I do with my crank/bottom bracket?

I just got this mountain bike almost 3 weeks ago. I took it for a long ride(120km back and forth). We encountered heavy rain during our ride, we were riding on a highway back then, there's flood water ...
2
votes
1answer
73 views

Stuck Bottom Bracket

I have an 80's Fuji bike and It's definitely well past time to replace the bottom bracket. The adjusting cup came off fine, but the crank side cup is super stuck. I've tried stacking lockring washers ...
8
votes
4answers
2k views

Creaking bottom bracket

I have a Trek 3900 Mountain bike that had a serious creaking problem whenever I would pedal. I found that the ring that holds the Shimano sealed bearing was really loose. I tightened it up and it ...
0
votes
1answer
1k views

How to fit BB bearings to install Ultegra Crank on road bike Wilier Cento 1

I've bought a used Wilier Cento 1 carbon road bike frame (not the new Cento1SR, but the previous model). Now I would like to transfer all Ultegra 6700 groupset components from my existing bike to it. ...
12
votes
3answers
15k views

What are the benefits of external bottom brackets?

Pretty soon, I plan to replace the bottom bracket on my early 90's Sakae Litage road bike. It takes a standard, English-threaded bottom bracket. Right now I think it contains loose bearings--I was ...
0
votes
1answer
175 views

What bottom bracket do I need for a decathlon rockrider 5.0

The bottom bracket on my Rockrider 5.0 has a little too much play in it so I figured it best to change it before I get a failure whilst I'm commuting. Does anyone know which bottom bracket I would ...
4
votes
1answer
241 views

Claud Butler Tandem - add a front derailleur?

I'm in the process of stripping a SWB Claud Butler tandem so I can get it repainted. There are a couple of things I need help with.... a) Can you fit a front mech to the bike, and if so, are there ...
2
votes
1answer
103 views

What is the purpose of greasing BB threads?

As is known for Shimano sealed bottom bracket cartages (e.g. page 16 here), if the BB cup is made out of metal, grease should be applied to the frame-cup thread. If the cup is plastic, grease should ...
1
vote
1answer
579 views

Giant Defy 2 Bottom Bracket

I'm considering upgrading to an Ultegra groupset, found a very good price online, but I do not know what bottom bracket is in my bike. I have a 2015 Giant Defy 2, aluminum frame, and to me, this looks ...
2
votes
1answer
102 views

Crank sliding horizontally through the bottom bracket

Was out biking today when I noticed the pedals were moving side to side, with the pedal arm almost coming off the left side. As I was investigating the washer with "LH fsa AL" actually came off in my ...
4
votes
3answers
2k views

Expected chainline from 103 mm bottom bracket to 107 mm bottom bracket?

Frame Windsor - The Hour Hub Width - 120mm Stock Bottom Bracket Sizing - 68 x 103 mm Miche Bottom Bracket Sizing - 68 x 107 mm Miche Crank Set Requirements - 68 x 107 mm bottom bracket ...
3
votes
2answers
1k views

Attaching crank arm with Shimano SLX M660

Firstly, apologies if this question has tones of frustration, my new crank set and bottom bracket has never been installed correctly, so I am going to do it myself. Should the drive spline on the ...
2
votes
1answer
94 views

Orienting Shimano Cup and Cone square-taper bottom bracket spindle

Let's say you were servicing a Shimano adjustable bottom bracket and forgot which way the spindle was originally oriented. You also forgot your ruler. How would one correctly orient the spindle (so ...
3
votes
4answers
567 views

Identify my Motobécane racing bike

I bought a Motobécane last year (pics below), and now that the bottom bracket is broken, I really need to know the model of the bike, to help me change that piece. It would also be helpful if someone ...
4
votes
1answer
348 views

I can remove crank arms without a crank puller, is this a problem? I'm worried the crankarms might be loose

Currently, I'm little bit worried about the compatibility of my crankset and the bottom bracket. The crankset is Truvativ Isoflow, the BB is BB-UN55 (Square taper). Yesterday, after the bike hit +1400 ...
5
votes
1answer
1k views

Are Shimano Hollowtech II bottom bracket spacers unique?

I'm moving my Shimano Hollowtech II XT crankset and bottom bracket over from a bike with 73mm bottom bracket to a 68mm bike. The only problem is that I only have 1 spacer and now I need 3 bottom ...
2
votes
2answers
413 views

How many spacers I can put on a Shimano hollowtec 2 BB for a 68 mm BB shell

My bottom bracket shell is 68 mm English thread. I put a 1 mm spacer on the drive side BB to move the chain rings further away from the frame, so to prevent the chain rub against the inside of the ...
0
votes
2answers
206 views

How does pedaling power transfer to the bearings in Hollowtech II bottom bracket?

I just installed a Shimano Hollowtech II crank and bottom bracket on my bike, and I'm wondering how they work together. My understanding is that the bearings are located in little cups that screw ...
0
votes
1answer
274 views

Help me understand bottom brackets and cranks

I have a Norco Threshold cyclocross bike (http://www.norco.com/bikes/road/cyclocross/threshold-carbon/threshold-sl-ultegra/) . It has a PF30 bottom bracket and an FSA Energy Cross PF30 46/36T crank. ...
0
votes
2answers
140 views

What kind of bottom bracket fixing is this?

Dismantled my bike to try and take a look at the crank bearing, as I fear it may be getting dry. Unfortunately at the stage pictured I could go no further. The outer and inner rings appear to be ...
0
votes
2answers
75 views

Replacing my bottom bracket. I need help IDing a replacement

So I have owned a Swhinn Network 3.0 (21-speed. Square tapered BB. All aluminum) for almost 5 months, and at about month 3 the bottom bracket started giving me some noise. I work in a bike shop on my ...
1
vote
1answer
343 views

Praxis Bottom Bracket Performance on BB30 Frame

I'm looking at upgrading the crank (stock FSA to Force 22) and getting a Praxis BB for my Cannondale CAAD10 BB30 frame. http://www.praxiscycles.com/product/conv-bb-sramgxp-isis-2/ It seems like ...
0
votes
1answer
664 views

Shimano Hollowtech II bottom bracket: milling the frame necessary?

In a bike shop I recently asked for bottom brackets. The seller said, when choosing a Hollowtech II bottom bracket (like SM-BB70), compared to Octalink/square taper bottom brackets the outer (lateral) ...
0
votes
1answer
155 views

Bottom Bracket Press fit to a square taper

I like to use my old Campagnolo crank on a new road bike frame. The frame has already a Pressfit BB71-41A installed. The crank needs a sqaure tape. Is it possible to use the crank with a adapter or do ...
1
vote
3answers
2k views

Removing bottom bracket from 79 peugeot frame

I would like to remove the bottom bracket from an old french peugeot race frame. I believe the frame was built in 79 judging by the decals and stamp on the bb. The bottom bracket and spindle at the ...
1
vote
1answer
208 views

Is anyone aware of specific problems with Vanmoof cranks/bottom brackets?

I have a 2013 Vanmoof 5.1. I had it serviced recently by Vanmoof in Amsterdam and when I got it back, it was riding wonderfully—everything felt smooth and "free", like every little bit of power I was ...
0
votes
1answer
54 views

Campagnolo 1973 strata cranks(BMX) help

I am installing them on a very rare BMX frame.the bottom bracket shell measures 66mm.I believe I'm looking for a spindle length of approximately 110mm.it also has to have English threads.my question ...
0
votes
3answers
375 views

Trouble Removing bottom bracket. Is it my Tool?

I'm having trouble removing my bottom bracket. I'm using quite a bit of force as far as I can tell. But neither side is budging. The bike is a 2011, and I've never removed the bottom bracket, but ...
0
votes
1answer
816 views

Technical documentation for Shimano FC-M510

I'm having a hard time finding the technical documentation (equivalent of https://www.dropbox.com/s/yx5hq4cezpdz641/alivio-crankset-service.pdf?dl=0) for the Shimano Deore Hollowtech 1 crankset, ...
-1
votes
1answer
162 views

Frame not faced for BB. Strip the paint or leave as-is? [duplicate]

So I just got my new frame from the LBS. They were supposed to face the frame, but only faced the head tube (hopefully, can't check it since the headset is already installed.). Sadly, they didn't ...
0
votes
1answer
276 views

Over-tightening a BB

I just installed an external bottom bracket (Hollowtech II type) on my steel bike. The manufacturer (Sugino) prescribes a 40-50Nm torque. I own no torque wrench, so I just wrenched it on pretty tight. ...
1
vote
1answer
74 views

A gap in the hole when inserting JIS square BB to a Truvativ Crank

I push the BB inside a crank hole without any tool but I expect a few milimeters gap. The Truvativ crank definitely uses JIS interface, but the question is: DOES the gap make any problem? or is it ...
0
votes
2answers
1k views

Do I need to chase a thread before installing a bottom bracket on a new frame?

Currently I'm building a new Surly Cross Check, and it needs a 68mm BB (english threaded). Furthermore, I plan to use a cheap $15 shimano BB with JIS square tapered interface, nothing special. Do I ...
1
vote
2answers
247 views

How much assembly is required when an LBS orders a bike?

I'm looking to order a Marin Lombard Elite from my LBS but I want to replace the FSA BB and crankset with Shimano or SRAM parts, and change to a 52/36. When my LBS orders it, does all of that come ...
0
votes
1answer
1k views

Which bottom bracket do I need to replace crank on a Trek FX 7.1?

I have a Trek FX 7.1 that I've rode for several years now and replaced parts as they've worn out. Now I'd like to upgrade the whole drive train with Tiagra 2x10 flat bar shifters, derailleurs, crank, ...
3
votes
2answers
173 views

Converting from square spline to external bearings, what do I need to know?

I need to replace the entire drivetrain on my circa 2000 MTB commuter. Quality groupsets all seem to use external bearings these days. Replacing my current cartridge bottom bracket for a modern ...
3
votes
2answers
2k views

how many spacers do I need for a 83mm bottom bracket and a 142x10 hub?

I have a Zee crankset on a 83mm bottom bracket (downhill bike). The Shimano manual says to use two 2.5mm spacers on the drive side, and one 2.5mm spacer on the non-drive side. However, this presumes ...
1
vote
1answer
213 views

Q-factor of external bearing BBs

Seems to me that the Q-factor for an external bearing bottom bracket will be greater than that of an equal size (say, 68mm road bike BB) cartridge bearing. Is that the case?
1
vote
2answers
454 views

How do I know what is the right bottom bracket for my old road bike?

I've got an old road bike. I'm not exactly sure what the frame is as it was repainted. I've reason to believe the that bottom bracket is wrong because the crankset ring is too close to the chainstay. ...