Installing square taper bottom bracket, cranks, and pedals

How to install a cartridge square taper bicycle bottom bracket, cranks, and pedals.
Table of CONTENTS:
00:00 Introduction - chainline, standards
01:24 Thread preparation
03:55 BB installing and tightening
06:53 To grease, or not to grease?
10:16 Tightening torque
14:05 Mounting the left crank
15:21 Installing the pedals
Useful LINKS:
If you have any questions, please use the BikeGremlin forum (I try to respond to every comment, but KZbin sucks at notifications, especially when it comes to any follow-up questions):
www.bikegremlin.net/
Article about how to install square taper cranks:
bike.bikegremlin.com/17055/ho...
Bicycle chainline explained:
bike.bikegremlin.com/1755/
Threaded bottom bracket standards:
bike.bikegremlin.com/1634/
Right and left hand(ed) threads:
bike.bikegremlin.com/3965/
Anti seize and mounting pastes explained:
bike.bikegremlin.com/7172/
The best bicycle bearing grease:
bike.bikegremlin.com/20/
What length square taper axle do I need:
• What length square tap...
TOOLS:
SHIMANO Tool bottom bracket TL-UN74S (Amazon affiliate link):
amzn.to/3usf2kl
List of all the BikeGremlin videos, sorted by categories:
bike.bikegremlin.com/youtube/
id: 1063

[@BikeGremlinUS]

If you have any questions, please use the BikeGremlin forum (I try to respond to every comment, but KZbin sucks at notifications, especially when it comes to any follow-up questions): www.bikegremlin.net/ Relja

[@jonahwhale9047]

How do you feel about drilling a hole in the bottom of the frame while you have the bottom bracket out to allow any water out? It may be more of a thing on steel frames with cable holes in them, than alloy ... I don't know. There's always a load of rust collected there in old steel frame bikes.

[@paulomarques1795]

I recently changed the BB on my mountain bike. I didn't realize how much the old BB was cooked until I went riding with the new one in. New BB makes up for a very pleasant ride!

[@iainmacleod4007]

I am about to replace the bottom bracket on my classic British touring bike. Although I have done this before watching this video was still very useful. Your command of the English language is exceptional.

[@dhons1]

you explain everything very nicely and calm. better then a lot of other videos, like it! thx!

[@IronHorsey3]

Was changing my Trek 5200 bottom bracket and used your efforts here for a good reference. Thank you for your detailed illustration and your added commentary through the process. Learned a lot and everything came out well. Thanks again BikeGremlin!

[@BikeGremlinUS]

Awesome. Glad to hear that. :)

[@johnrbnsn]

Thanks for doing this video, great explanation, looking forward to more!

[@petercostello3196]

Best video I've seen on this subject thank you.

[@glacialdrumlin]

thank you for your in-depth explanation on why you grease the spindles!

[@BikeGremlinUS]

Sure. In this article, I explained that in even more detail, with some sketches: bike.bikegremlin.com/17055/how-to-install-square-taper-cranks/ Relja

[@Toretto16]

Very well explaines. Thanks a lot!

[@iankosky6211]

Wish I had found your video before I installed a replacement bb. Best video by far and I have looked at a few today - many thanks

[@BikeGremlinUS]

Glad it helped. :) If it helps, here is the list of my bike-related articles: bike.bikegremlin.com/post-list-by-category/ And a list of my videos: bike.bikegremlin.com/youtube/ It's sorted by categories (since KZbin search is often poor). Relja

[@hesgone6699]

Nice clear instructions, thanks. Your English is really good

[@mark7362]

Thanks for the video! I'm going to try to put a 100mm BB in a 73mm BB bike using spacers on the threads in hopes of getting .25" more pedal width on both sides to be able to fit a larger chainring, 32T to 48T so that I can go a lot faster on flat ground. 100-73=27mm, or .50"

[@BikeGremlinUS]

Very little thread engagement - I'm not sure how robust it will be on an aluminium frame (steel may be fine). :( Is it not possible to mount a double (or a triple) crank (with a matching FD and a shifter)?

[@mark7362]

@@BikeGremlinUS yea that part worries me a little but I think that enough of the threads will be there, going to give it a shot. I would but that would be more expensive & I'd prefer to just stick with my current 1x setup

[@BikeGremlinUS]

At the cost of stating the obvious: Stripped threads might end up being more costly. :( Unless you often ride in very muddy conditions, or ride very technical trails that require a frequent de/activation of the dropper seatpost, 2x and 3x systems are a beautiful thing, often superior to 1x. Tastes and aesthetics aside - that's very subjective and no arguing that.

[@mark7362]

@@BikeGremlinUS good point, that would ruin the bike... I usually get a 3x bike but I liked the looks and price of this one too much to pass it up

[@mark7362]

@@BikeGremlinUS thank you very much for your reply/advice

[@sherwinligon4841]

Can I know the details of the bb tool adapter you have used for thightening the bb? So I can upgrade mine or just repack if can. It seems I cannot find it here in my area since I do not know the name or size or model due to they do not use that kind of bb here. Details would be a big help! Advance Thank you.

[@BikeGremlinUS]

If you mean the BB tightening/loosening tool, it's listed in the video description.

[@nmatthew7469]

Like that you use anti seize on everything, saving the next guy a lot of headaches. "Ghost ride". Haha, when we were kids as a mean trick we'd give other kids bike a ghost ride down the hill.

[@Gledii]

hi there, thanks for sharing. look, ive read that such square taper crankset can woble a little from side to side when pedaling hard. im noticing this on mine. if i pedal right, the chain touches the right side of the front derraileiur and the oposite side when i pedall left. do you know any way to avoid this? thanks a lot

[@BikeGremlinUS]

Hi, Please use the BikeGremlin forum for technical questions: www.bikegremlin.net/ Relja

[@mjk302]

I recently received a brand new mtb, and I noticed the crack when the bike upside down spins at n angle when you compare it to the frame.. you see it slight get closer as it spins, which makes it impossible to align gears Is there anything I can do so it spins right in the bottom bracket ?

[@BikeGremlinUS]

I'm not sure I understand the question. Regardless of that, I would recommend you use the BikeGremlin forum for any technical questions: www.bikegremlin.net/ Relja

[@B_COOPER]

When you said “holding the frame to prevent it from taking too much torque” at 4:55. What exactly do you mean by that?

[@BikeGremlinUS]

If the frame is held by the seatpost (or the seat tube), then it takes all the torque (while keeping the frame from turning as I apply force). Relja

[@jhoanmiguelescobararboleda8547]

Sorry I am not native speaker, what is the name of the white like glue that you add inside of the whole?

[@BikeGremlinUS]

It is called "mounting" or "anti-seize" paste (the model is Famol PT). I wrote here about that in more details: bike.bikegremlin.com/7172/anti-seize/ Relja

[@user-si6pz3qb1d]

How do they tighten while riding? The spindle moves in the unscrew direction when pedalling.

[@BikeGremlinUS]

Good question. The answer: Bearing balls in between the spindle and cups, and the mechanical precession phenomena. en.m.wikipedia.org/wiki/Precession_(mechanical) Relja

[@user-si6pz3qb1d]

Perfect answer, thanks! @@BikeGremlinUS

[@namdarbolour9890]

I think it would help to explain what exactly you are tightening against when installing the left hand nut on the bottom bracket. Also, I don't understand how the tightness of this nut can affect bearing smoothness. Doesn't it slide over the cartridge? Thanks for the video, just the same!

[@BikeGremlinUS]

Good questions. The left cup is tightened against the cartridge. It does create some bearing preload thus affecting the "ease of axle spinning." The silvery part on the cartridge on the opposite side from the right cup is the bearing. It slides inside the left cup, i.e. the left cup is tightened against it. If the left cup is not tightened nearly enough, the whole axle can rattle, but if it is just a bit under-tightened, the axle will spin just a tad more freely than when it's all properly torqued. Cup tightening torque is what matters most, that can be checked (I go by feel, no torque wrenches used), but the spinning test is an extra check I use to confirm it all is seated and mounted properly.

[@namdarbolour9890]

Thank you for your reply. I guess what I'm really trying to understand is its theory of operation. I am a home bike mechanic, amateur, and I like to understand how anything works before servicing it. I have a couple of Nishiki bikes with this type of BB that I will be renewing because they are over 20 years old and stiff. I just wanted to confirm my understanding now: 1) So the left cup slides over the cartridge but has a shoulder inside that tightens down on the outer race of the bearing, correct? 2) The left cup is not a press fit AROUND the BB, so there is room for minute radial play, but this play is stopped by the left cup pressing laterally, as it is tightened, onto the outer race of the bearing, correct? 3) Another thing I was curious about, is the spindle press-fitted at the factory to the inner races on each side? No rush on any answers. By the way, your English is very good, not Tarzan (ha ha) and you use all the correct bike and scientific terminology.

[@BikeGremlinUS]

All yes answers. :) Some left cups have a pronounced lip that can hit against the frame, but if it doesn't hit against the cartridge (bearing) first, and create enough preload, it's not good (68 mm BB shell cartridges can have this problem with frames that have a 73 mm wide BB shell). Edit: Any radial play is noticed and happens when pedalling, when it's loaded. Because of the elastic deformation of all the parts (that's fixed with a proper preload).

[@namdarbolour9890]

Thanks again.

[@clonkex]

"a moderate amount of fun" lol

[@interceptor7905]

Je li to Unior stalak za bicikle?

[@BikeGremlinUS]

Unior je stalak za centriranje, a stalak za servis je "uradi-sam": bike.bikegremlin.com/9838/bicycle-repair-stand-diy/

[@interceptor7905]

@@BikeGremlinUS Dobro izgleda

[@behzadehdaie7866]

👍👍👍👍👍🙏

[@alexstatham1499]

brate stavio si botom bracket za 73 il 70 na solju rama od 68 jel moguce da nevidis koliko ti viri iz rama

[@BikeGremlinUS]

kzbin.info/www/bejne/l4WcfaBqjp1rbM0

[@TheKawasakiManiac]

why didn’t you take advantage of the situation and improve the drive?

[@jonahwhale9047]

And that, children, is why you never use a bottom bracket with plastic cups. Something doesn't seem right about that left hand side, it should fit in easier and deeper. Perhaps there was too much anti-seize?

[@BikeGremlinUS]

Anti seize doesn't prevent it - it helps. Some hubs are designed to work with both 68 and 73 mm BB shells (others are designed for either 68 or 73 mm). Such hubs can have their left-hand side cup stay a bit further out - but there is enough thread to engage properly (it's still working). Plastic cups are not bad in and of themselves. I haven't noticed them affect engagement or durability (cartridge BBs are mounted once, and removed when they are worn). The upside is that with plastic cups there is not galvanic corrosion. Relja

[@fernandoperezc.7036]

I would’ve washed and degreased everything before installing anything.

[@juansaladzar]

Too many ads 👎

[@BikeGremlinUS]

Ending animations aside, adverts are the brightest points of my videos! :)

[@juansaladzar]

@@BikeGremlinUS You set your vid to monetize trying to get rich & sh_t brah

[@BikeGremlinUS]

Yes, got it all perfectly set up - but Google keeps interrupting the ads with my videos. No way to get rich if they keep doin' that! :) On a more serious note - sure, the videos are getting monetized. That's enabled me to save for a phone with a decent camera over the past few years, and this year it's also enabled me to buy a decent wireless microphone - finally. Which makes recording videos a lot easier. I don't think this hobby is commercial enough to make any kind of real profit, but as long as it pays for itself at least, it's cool. If you hate ads, you can pay the KZbin subscription, or watch my videos for free on Odysee, without any ads: odysee.com/@bikegremlin:c

[@juansaladzar]

Doood! ads 👎

[@scottwalden1]

If he didn't take 20 mins to do a 5 minute job, we wouldn't have to sit through 3 ad breaks...

[@juansaladzar]

@@scottwalden1 true story brah 😐