Shimano UN55 Square Taper Bottom Bracket
Shimano UN55 Square Taper Bottom Bracket

NOW$19.99

RRP$29.99
|
SAVE33%

Select Colour

Select Option

English Thread

Italian Thread

Select Size

73 x 110mm

73 x 113mm

73 x 118mm

73 x 122.5mm

70 x 107mm

70 x 110mm

70 x 113mm

70 x 115mm

68 x 113mm

68 x 110mm

68 x 118mm

68 x 115mm

68 x 127mm

68 x 122.5mm

73 x 107mm

68 x 107mm

IN STOCK(5+)

ADD TO WISH LIST

> VIEW ALL OPTIONS AS A LIST

This item ships to United States of America
Shipping amount : $9.99
365 DAYS to return or exchange
Pay by Bank Transfer or PayPal or Card

DESCRIPTION
SPECS

Shimano UN55 Bottom Bracket

Shimano Road UN55 model has super-accurate bearings for smooth operation and improved durability

Features:

Durable, hard-wearing sealed cartridge bottom bracket.
Maintenance-free sealed cartridge bearing assembly keeps out dirt, mud and water for long bearing life
Fast and easy installation without adjustment
Hollow Axle

Buy Shimano UN55 Bottom Bracket at Chain Reaction Cycles, the world's largest online cycling store.

Colour: Silver
Size: 73 x 110mm, 73 x 113mm, 73 x 118mm, 73 x 122.5mm, 70 x 107mm, 70 x 110mm, 70 x 113mm, 70 x 115mm, 68 x 113mm, 68 x 110mm, 68 x 118mm, 68 x 115mm, 68 x 127mm, 68 x 122.5mm, 73 x 107mm, 68 x 107mm
Option: English Thread, Italian Thread

REVIEWS
QUESTIONS

Rated 4.6 out of 5 by 37 reviewers.

Rated 4 out of 5 by Tibbo Easy to fit and works well A solidly performing bit of kit from a reliable company, its made my bike good as new. 17 July 2014

Rated 4 out of 5 by Marts25 Solid and durable bb A quality replacement part. Needs a little breaking in to start with. 13 June 2014

Rated 5 out of 5 by LizardRider Update your bike with this I acquired an old Raleigh Trail for free (1980s or thereabouts). The bottom bracket was completely wrecked, but I persisted in riding it. Eventually it got so bad, that I was going to call it a day. The local repair guy pointed out the excellent 501 frame and the excellent wheels. A bit of research on the web and I found out you could replace the old ball-bearing setup with this sealed unit. Replacing the old set-up myself would have proved very difficult and costly with several special tools needed. The bike guy showed me how to measure the old spindle etc and I bought this (English thread for Raleigh). He did it for £20. My bike works like new now - for a total cost of under £35. I was planning to buy a new bike but with this my old bike works like new again. I've just saved £500. Very pleased with website, product and speed of delivery. 04 June 2014

Rated 4 out of 5 by LondonCommuter88 Does what it's meant to Ordered as a cheap but good quality replacement for an old loose ball bearing bottom bracket (BB). I've used these BBs on my main commuting bike for years without issue. Arrived in the post very quickly and fits perfectly. As far as I know, this is the cheapest shimano BB with an aluminium non-drive cup, as opposed to plastic. 21 May 2014

Rated 4 out of 5 by Santi1973 Buen producto y Buen precio Buenas prestaciones del producto, no obstante el eje que tenía antes era el UN26 y tenía las mismas prestaciones de fluidez de giro del eje. No merece la pena gastarse el doble de precio por el UN55, por el hecho de que algunas piezas de cierre, en vez de plástico sean metálicas. Con el antiguo eje no he tenido problemas con las piezas de plástico. 04 May 2014

Rated 5 out of 5 by karibojegs It's cheap and it works!! Can't fault this bottom bracket so far. Replaced a completely trashed original part and it has put up with everything from being immersed in flood water too being thrashed along dirt tracks! Runs smoothly enough for me and at the price I really can't find a negative! 30 April 2014

Rated 5 out of 5 Bullet proof Great value strong bottom bracket. For the money you can't go wrong. 26 April 2014

Rated 5 out of 5 by Scheele Bomproof classic These are the weapon of choice for MTB tourers for a reason, they are solid, bombproof and pretty much fit and forget. I switched all my external bottom brackets to these this year as I find externals aren;t all they are cracked up to be. The thing i like most is these spin round and round for ages with no resistance, like your bike did as a kid! and how often did you change the bottom bracket on your old street bike? never?..... exactly.... I've heard of these being replaced at 80,000 on world tours! good enough for me! 25 April 2014

2 next>>

26 Questions : 40 Answers

Product Q&A

Ask your questions. Share your answers.

Q&A Home

« Back

Search Q&A

All

Has staff answer

3 answers

Does this come with crank bolts?

Age: 18 to 24

Gender: Male

Attitude: Just for Fun

6 months ago

FourPalad

Answer this question

0points

0out of 0found this question helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

1I have this question too

Answer:

Crank bolts are not included with this bottom bracket; the suggested bolts below are compatible.

Attitude: On the up

Products related to my answer

Brand-X Self Extracting Square Taper Crank Bolts

(24)

6 months ago

CRCAndyC

+2points

2out of 2found this answer helpful.

Was this helpful?helpful2unhelpful0

Report inappropriate content

Answer:

Yes comes with plain hex head steel ones

Gender: Male

4 months, 3 weeks ago

Akira

Reading,GB

-1point

0out of 1found this answer helpful.

Was this helpful?helpful0unhelpful1

Report inappropriate content

Social Answering Subscriber
Just for Fun

Answer:

No, no crank bolts comprised.

Age: 35 to 44

Gender: Male

Attitude: Just for Fun

4 months, 3 weeks ago

Carletto74

+1point

1out of 1found this answer helpful.

Was this helpful?helpful1unhelpful0

Report inappropriate content

2 answers

Sizing

I have a Specialized Allez that I need to replace the bottom bracket on. The size is 68x113mm, but you only do that size in the Italian thread, will that fit my bike as I purchased it in the UK?

Age: 35 to 44

Gender: Male

Attitude: Passionate and Obsessive

1 month, 3 weeks ago

Matt16

Rosliston,GB

Answer this question

0points

0out of 0found this question helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

1I have this question too

Answers

Social Answering Subscriber
On the up

Answer:

I bought this this and a week later the sealed bearings were knackered n thats with the right size. so i would get another mate

Age: 18 to 24

Gender: Male

Attitude: On the up

1 month, 3 weeks ago

Fase12

0points

0out of 0found this answer helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

Social Answering Subscriber
Passionate and Obsessive

Answer:

'Italian' is not in regards to the origin of your bike- it is a thread descriptor- it is very unlikely that your bike frame needs an Italian threaded bottom bracket- double check with your bike maker but I'd suggest it will need a British (ISO) bottom bracket- 99.9% sure.

Age: 25 to 34

Gender: Male

Attitude: Passionate and Obsessive

1 month, 2 weeks ago

tworldsmine

0points

0out of 0found this answer helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

Has staff answer

2 answers

Will this fit my 2013 GT Karakoram 3?

I have 2013 GT Karakoram 3 and it has a sealed unit that looks like this. Do you know whether this would be suitable and what size would be required? Thanks

Age: 35 to 44

Gender: Male

Attitude: Just for Fun

Products related to my question

Shimano UN55 Square Taper Bottom Bracket

(37)

2 months, 3 weeks ago

YorkshiremanWarcry

Rugby,GB

Answer this question

0points

0out of 0found this question helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

1I have this question too

Answers

Social Answering Subscriber
Passionate and Obsessive

Answer:

It will fit your frame but what you need to establish is the length of your axle- take your pedals off and measure it or remove the bb and simply read the axle length from the bracket itself.

Age: 25 to 34

Gender: Male

Attitude: Passionate and Obsessive

1 month, 3 weeks ago

tworldsmine

0points

0out of 0found this answer helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

Staff
On the up

Answer:

Yes this bottom bracket will fit the frame; however the exact cartridge size and spindle length are not measurements we can advise on as there are many variations.

Simply measure the current bottom bracket width's in relation to the diagram here - http://i.imgur.com/hfNhAM9.jpg

The 68mm, 70mm, 73mm are in relation to the cartridge width and the frames bottom bracket shell (http://i.imgur.com/qfhqzHT.jpg) and the other measurments of 107mm, 113mm, 118mm etc. are in relation to the spindle length.

Attitude: On the up

2 months, 3 weeks ago

CRCAndyC

0points

0out of 0found this answer helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

Has staff answer

2 answers

Could you recommend a tool for fitting this bottom bracket

Age: 25 to 34

Gender: Male

Attitude: Just for Fun

6 months ago

Sverrir

Answer this question

0points

0out of 0found this question helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

1I have this question too

Answers

Social Answering Subscriber
Just for Fun

Answer:

This is perfect:
http://www.chainreactioncycles.com/it/it/weldtite-shimano-bottom-bracket-cartridge-tool/rp-prod86711

Age: 35 to 44

Gender: Male

Attitude: Just for Fun

4 months, 3 weeks ago

Carletto74

0points

0out of 0found this answer helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

Staff
On the up

Answer:

The suggested square taper tool suggested below is required for fitting this bottom bracket. For future reference; the crank puller will likely be required to dissemble it again.

Attitude: On the up

Products related to my answer

X-Tools BB Tool Octalink-Square

(22)

Park Tool Cotterless Crank Puller CCP22

(7)

6 months ago

CRCAndyC

+1point

1out of 1found this answer helpful.

Was this helpful?helpful1unhelpful0

Report inappropriate content

Has staff answer

2 answers

Shimano un55 bottom bracket

Hi i need a replacement bottom bracket for my Trek 7.2 FX the old one is a un55 but the label says 68 but on the length it as the letters D-NL not numbers. Can you tell me which bb i need.

Thank you

Age: 45 to 54

Gender: Male

Attitude: Just for Fun

1 month, 2 weeks ago

Ricardo66

Answer this question

0points

0out of 0found this question helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

1I have this question too

Answers

Social Answering Subscriber
Passionate and Obsessive

Answer:

You can simply measure the bb yourself my friend- use the ruler or callipers and buy the relevant axle length. The 68 is teh BB shell compatibility- you can buy 73 and use a spacer when needed too.

Age: 25 to 34

Gender: Male

Attitude: Passionate and Obsessive

3 weeks, 6 days ago

tworldsmine

+1point

1out of 1found this answer helpful.

Was this helpful?helpful1unhelpful0

Report inappropriate content

Staff
Best answer
Just for Fun

Answer:

The 68 refers to the shell width, but you can double check the required length by measuring the end to end of the existing bracket (image below).

Age: 25 to 34

Gender: Male

Attitude: Just for Fun

1 month, 2 weeks ago

CRCHops

+1point

1out of 1found this answer helpful.

Was this helpful?helpful1unhelpful0

Report inappropriate content

Has staff answer

2 answers

What Spindle Interface Type on italian thread? JIS or ISO?

Age: 25 to 34

Gender: Male

Attitude: Passionate and Obsessive

3 months, 2 weeks ago

stalech

Kostroma,RU

Answer this question

0points

0out of 0found this question helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

1I have this question too

Answers

Staff

Answer:

Это JIS Taper.

3 months, 1 week ago

CRCIna

0points

0out of 0found this answer helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

Social Answering Subscriber
Passionate and Obsessive

Answer:

Из того, что я помню, 99% Shimano квадратного конуса является JIS (единственным исключением является Dura-Ace).

Так что я ма на 99% уверен, что это JIS.

Age: 25 to 34

Gender: Male

Attitude: Passionate and Obsessive

3 months, 1 week ago

tworldsmine

0points

0out of 0found this answer helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

Has staff answer

2 answers

I have a Gaint Revel what type of thread will I need?

Age: 17 or under

Gender: Male

Attitude: Just for Fun

2 months, 1 week ago

Thingy

Hemel Hempstead,GB

Answer this question

0points

0out of 0found this question helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

1I have this question too

Answers

Staff
Just for Fun

Answer:

You can determine the width you need by either measuring your existing bracket, or across the shell on the frame (68 or 73mm is English thread, 70mm is Italian).

Axle length is determined by the chainset you intend to use; check with the manufacturer of your cranks to confirm what axle length you should be using. If re-using your original cranks, simply check the axle width on the previous bracket (image below)

Age: 25 to 34

Gender: Male

Attitude: Just for Fun

2 months, 1 week ago

CRCHops

0points

0out of 0found this answer helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

Social Answering Subscriber
Passionate and Obsessive

Answer:

British (ISO) thread will do you good.

Age: 25 to 34

Gender: Male

Attitude: Passionate and Obsessive

1 month, 3 weeks ago

tworldsmine

0points

0out of 0found this answer helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

2 answers

Is the UN55 a compatible replacement for a UN54?

I’ve been using UN54’s (68 x 122mm British Thread) for a number of years, they now appear to be either discontinued or out of stock. Is a UN55 (68 x 122.5mm British Thread) a compatible replacement? If so what actually is the difference as they appear to be identical

Thank you

Age: 45 to 54

Gender: Male

4 months, 1 week ago

Porridge

Answer this question

+2points

2out of 2found this question helpful.

Was this helpful?helpful2unhelpful0

Report inappropriate content

1I have this question too

Answers

Best answer
Social Answering Subscriber
Just for Fun

Answer:

The UN55 is perfectly compatible as a replacement for the UN54 - forget about the 0.5mm numeric difference! I think the UN55's left cup washer was slightly redesigned (different shape and, I think, different material) to eliminate some creaking that the UN54 could suffer from.
HTH

Age: 45 to 54

Gender: Male

Attitude: Just for Fun

4 months, 1 week ago

Neezurt

+2points

2out of 2found this answer helpful.

Was this helpful?helpful2unhelpful0

Report inappropriate content

Social Answering Subscriber
Passionate and Obsessive

Answer:

The difference is the axle length and bearings. The axle will be ok with only 5 mm difference. The bearings- you will never notice the difference.

Age: 25 to 34

Gender: Male

Attitude: Passionate and Obsessive

4 months ago

tworldsmine

+1point

1out of 1found this answer helpful.

Was this helpful?helpful1unhelpful0

Report inappropriate content

2 answers

Which size should I choose?

My current Japanese vintage bike's BB is signed 1.37x68. Which size should I choose for this BB to replace it well?
Many thanks.

3 weeks, 5 days ago

Anonymous

Answer this question

0points

0out of 0found this question helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

1I have this question too

Answers

Social Answering Subscriber

Answer:

Your required axle length will depend on which cranks you intend to use. Try searching the web with your crank's brand and model number to find the right length.

Gender: Male

3 weeks, 4 days ago

Marts25

0points

0out of 0found this answer helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

Social Answering Subscriber
Passionate and Obsessive

Answer:

You'll need a standard (aka British aka ISO) bottom bracket. 68mm will fit directly in. If you get 73mm bottom bracket make sure you get the spacer.

You will also need to measure the axle length (sometimes written on the bracket itself) to make sure that your chainline remains unchanged.

Age: 25 to 34

Gender: Male

Attitude: Passionate and Obsessive

5 days ago

tworldsmine

0points

0out of 0found this answer helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

Has staff answer

2 answers

Can I replace old UN25 with UN55?

Looking at the ticket on the side of the old unit it states 68 BC1.37x24 MM110 however on the UN55 the only option English thread is for 70 BC1.37x24 MM110. The only option that seems to match (68x110) states that it is Italian thread.

Which of these do I need?

Age: 55 to 64

Gender: Male

Attitude: Just for Fun

3 weeks, 3 days ago

FatGroover

Kidderminster,GB

Answer this question

0points

0out of 0found this question helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

1I have this question too

Answers

Staff
Just for Fun

Answer:

Our sku271953 is the 68x110mm English Thread bracket. This should be fine to replace your UN25.

FYI, 68/73mm is English Thread, 70mm is Italian Thread.

Age: 25 to 34

Gender: Male

Attitude: Just for Fun

3 weeks, 1 day ago

CRCHops

-1point

0out of 1found this answer helpful.

Was this helpful?helpful0unhelpful1

Report inappropriate content

Social Answering Subscriber
Passionate and Obsessive

Answer:

Get a 73mm version and get a spacer for the bottom bracket (the bracket itself does not come with the spacer sometimes)- ask your LBS for the spacers and you'll be sorted. When getting 68mm you're limited to 68mm only. When getting 73 you can get it into the 68 shell with spacers or directly into the 73 shell.

Age: 25 to 34

Gender: Male

Attitude: Passionate and Obsessive

5 days ago

tworldsmine

0points

0out of 0found this answer helpful.

Was this helpful?helpful0unhelpful0

Report inappropriate content

2 next>>

Policies & Guidelines

Ask a new question