Need a new bottombracket.

Daniel S

Need to replace a bottom bracket, this will be my first time doing it. I don't know which one to get, thats the problem. It will (hopefully) be done on this bike:
http://www.eurocycles.ie/Mens_Mountain_Bike/Raleigh_AT10/647_p.aspx

The cranks are square tapered.

Are bottom brackets a standard size? Say will all Shimano BBs fit most bikes?

Also, what tools will I need to remove it, would this do the trick? http://www.chainreactioncycles.com/Models.aspx?ModelID=14914

lennymc

you will need a tool like this: http://www.chainreactioncycles.com/Models.aspx?ModelID=10181 for removing your crank arms.
depending on what type of bb you have the tool you listed might not work.

As far as I know (but i could be wrong) the size of the bb refers to the wditch of the width of the frame. There are also european and italian threads.

I may be wrong on the terminology above, but have changed a few BBs in my time.

HTH!
Lenny

Daniel S

Since its a Raleigh bike, it'd be safe to assume it's a British thread?

lennymc

mtb_kng wrote: »

it's a British thread?

yeah, thats what i meant!

Daniel S

I mesured the width and its about 68mm.

I was thinking this: http://www.chainreactioncycles.com/Models.aspx?ModelID=17473

There's a second measurment that varies between 107 and 127mm, it that the width of the BB itself? Don't know how I'll mesure that.

Daniel S

If I was to change it from square tapered to hollowtech, what exactly would I need to buy?

Single Malt

New cranks and BB

btw, the length of the bb axle on square taper is critical. Shimano bb's are available in 107, 110, 113, 115, 118, 122, 127 mm lengths, and only one will give a correct chainline for correct front derailleur set up

Daniel S

So would I be better off getting this BB out of the bike by whatever means nessesary, to find out the right size and then order another?

Single Malt

no, as the bike will be unusable while bb is out. "whatever means necessary" screams not knowing what you are doing. If you haven't dones so, then educate yourself as to the steps required when changing BB. Youtube, park tool website, sheldon brown and shimano tech docs are all invaluable resources when it comes to bike maintenance. Use your LBS, as the parts are cheap anyway, and if you accidentally go with wrong length, returns are easy. Also the LBS can advise you what bb should fit, and that alone is worth the extra few €'s the LBS charges over CRC

Daniel S

Single Malt wrote: »

no, as the bike will be unusable while bb is out. "whatever means necessary" screams not knowing what you are doing. If you haven't dones so, then educate yourself as to the steps required when changing BB. Youtube, park tool website, sheldon brown and shimano tech docs are all invaluable resources when it comes to bike maintenance. Use your LBS, as the parts are cheap anyway, and if you accidentally go with wrong length, returns are easy. Also the LBS can advise you what bb should fit, and that alone is worth the extra few €'s the LBS charges over CRC

I won't need the bike until after the holidays. The reason I said "by whatever means necessary" is because I won't be using that bb again, but I could get the size from it. My local bike shop are completely useless, can't go to them.

I'm just going to order the BB removal tool, remove the BB and order again.

Single Malt

They must be pretty bad if they cannot advise you re crank puller and BB suitable for your bike.

OK then, you need this http://www.chainreactioncycles.com/Models.aspx?ModelID=38068 before you start to remove cranks, and this http://www.chainreactioncycles.com/Models.aspx?ModelID=689 to remove BB from frame. Loosen LH cup 1st, and then the RH. RH is a left thread.

Daniel S

Single Malt wrote: »

They must be pretty bad if they cannot advise you re crank puller and BB suitable for your bike.

OK then, you need this http://www.chainreactioncycles.com/Models.aspx?ModelID=38068 before you start to remove cranks, and this http://www.chainreactioncycles.com/Models.aspx?ModelID=689 to remove BB from frame. Loosen LH cup 1st, and then the RH. RH is a left thread.

The cranks are already off (they're cheap so I used a tea towel and wooden mallet). That shimano tool is more expensive than the xtools one, is it worth it?

Paul Kiernan

The X-Tools versions of those tools are a fair bit cheaper

http://www.chainreactioncycles.com/Models.aspx?ModelID=10181
http://www.chainreactioncycles.com/Models.aspx?ModelID=14914

Might be worth getting a complete toolkit while you're at it, you won't get a better excuse:pac:. Shop around, though, that CRC is quite dear. I got a very good deal at PBK (£36) but they're out of them at the moment.

Edit: I see Halfords have a comprehensive toolkit for €38.99.

Single Malt

OP, I just linked the 1st tools that hit the search:D. Not to say you need those exact ones. I am a little concerned that the cranks came off with a mallet, as the taper should be super tight. If the taper was loose the cranks may need replacing. Did you need to re tighten crank bolts regularly before removing the cranks? Were the arms marked on removal with mallet?

Daniel S

Paul Kiernan wrote: »

The X-Tools versions of those tools are a fair bit cheaper

http://www.chainreactioncycles.com/Models.aspx?ModelID=10181
http://www.chainreactioncycles.com/Models.aspx?ModelID=14914

Might be worth getting a complete toolkit while you're at it, you won't get a better excuse:pac:. Shop around, though, that CRC is quite dear. I got a very good deal at PBK (£36) but they're out of them at the moment.

Edit: I see Halfords have a comprehensive toolkit for €38.99.

Got the Halfords one today, and I got that SOAB off :P

[IMG]http://mtb_kng.webs.com/100_0200.JPG[/IMG]

So I think I need a 68mm English tread, but how will I find out the length?

Also thinking of getting a full new set of cranks as I've comepletely fecked mine getting them off (Threads were ruined, so couldn't use crank puller), would getting a Hollowtech II setup be a good idea? Could someone suggest a BB and crankset for my bike, cheap as possible but still decent?

Do the "cranksets" on CRC all come with a BB, some say they do, but surely one size doesn't fit all?

Paul Kiernan

According to Sheldon http://sheldonbrown.com/bbsize.html the length is the total width so just try and measure your old one.

I don't know whether a Hollowtech will be compatible with your frame. Hollowtech seem to be a standard size and AFAIK are cross-compatible (you can use any BB with any cranks).

I would be inclined to stick with square-taper. I recently built up a couple of hybrid bikes (second bike here) using these but only because they were cheap. For an extra few quid this gets a good review on bikeradar. I used this crankset, it's cheap and is widely used by lots of manufacturers.

Daniel S

Paul Kiernan wrote: »

According to Sheldon http://sheldonbrown.com/bbsize.html the length is the total width so just try and measure your old one.

I don't know whether a Hollowtech will be compatible with your frame. Hollowtech seem to be a standard size and AFAIK are cross-compatible (you can use any BB with any cranks).

I would be inclined to stick with square-taper. I recently built up a couple of hybrid bikes (second bike here) using these but only because they were cheap. For an extra few quid this gets a good review on bikeradar. I used this crankset, it's cheap and is widely used by lots of manufacturers.

Okay, so square taper seems to be the simplist and that BB looks grand with good reviews :P I'll go downstairs and nag my dad to let me get these also http://www.chainreactioncycles.com/Models.aspx?ModelID=46025

Paul Kiernan

Those cranks look nice, all right. Just make sure you order the same size as your old cranks (e.g. 22-32-42) unless you specifically want to change. If you do want to change make sure your derailleurs and chain can cope:p.

Daniel S

Thanks for all the help Paul and all the others. S'pose I might aswell get a new chain while I'm at it. Would this be okay? (I have a chain tool to remove links incase)

http://www.chainreactioncycles.com/Models.aspx?ModelID=25653

Going to mesure the BB now (From tip to tip right?) and order, got dad's visa off him

Paul Kiernan

I'm not sure if that chain will work but I'm pretty certain this one will.

Yes, the measurement appears to be (from Sheldons diagram:o) tip to tip.

While you have your Dad's credit card you might like to look at this.

Daniel S

I'm sort of confused again. If I order new cranks, will I need a different size BB or do the cranks not make any difference.

I measured it again, and again, and again and it seems to be 118mm.

I think the broken BB is "Neco B920AL".
http://www.necoparts.com/Products.aspx?page=&cate=32&pid=120

Paul Kiernan

mtb_kng wrote: »

I'm sort of confused again. If I order new cranks, will I need a different size BB or do the cranks not make any difference.

Yeah, I think you're right to be confused, I know I am. The combination of the cranks and BB decide the chainline, which should be 47.5 (ideally) or 50 if space needed due to fat seattube on a typical MTB. You need to check the Shimano website for the Alivio M410 cranks and you'll probably find that a 110 BB gives a 47.5 and a 113 BB gives a 50 chainline. Basically as long as your front derailleur can shift from the inner to the outer you'll be fine!

Daniel S

http://techdocs.shimano.com/media/techdocs/content/cycle/SI/SI_0094A/SI-0094A-001-ENG_v1_m56577569830667768.PDF

:eek:

Paul Kiernan wrote: »

Basically as long as your front derailleur can shift from the inner to the outer you'll be fine!

An excuse for more new parts

Sure it'll work or it won't :rolleyes:

Time to get on adverts.ie looking for a decent fork.


Thanks again everyone!

Paul Kiernan

mtb_kng wrote: »

http://techdocs.shimano.com/media/techdocs/content/cycle/SI/SI_0094A/SI-0094A-001-ENG_v1_m56577569830667768.PDF

:eek:

You'll be grand. The M410 needs a 113 BB for a 50 chainline and a 110 for a 47.5. Safest bet is to go for the 113 and you should be laughing:D. It's also in-stock and cheaper than most of the other sizes.

Daniel S

Paul Kiernan wrote: »

You'll be grand. The M410 needs a 113 BB for a 50 chainline and a 110 for a 47.5. Safest bet is to go for the 113 and you should be laughing:D. It's also in-stock and cheaper than most of the other sizes.

But the one I ordered was 118mm... is there any way to change that?

Ah nevermind, if I have to, I'll use spacers to bring it back in or return it.

Paul Kiernan

mtb_kng wrote: »

But the one I ordered was 118mm... is there any way to change that?

Ah nevermind, if I have to, I'll use spacers to bring it back in or return it.

Yikes. If you can't change it online then ring them ASAP. If too late to change, I wouldn't worry. 118mm is only 2.5mm wider each side than 113mm. It's negligible and is unlikely to make any difference.

If you do feel happier changing it it'll only cost a quid or two to return it and you'll make that back on the price difference:).

Daniel S

Paul Kiernan wrote: »

Yikes. If you can't change it online then ring them ASAP. If too late to change, I wouldn't worry. 118mm is only 2.5mm wider each side than 113mm. It's negligible and is unlikely to make any difference.

If you do feel happier changing it it'll only cost a quid or two to return it and you'll make that back on the price difference:).

Okay, the order is cancelled (but I'm still getting new gear cables so that will give me something to do ).

For the Alivio BB and Crankset, which is low to mid range
Square taper = €47
Octalink = €43

For €71.66, I could get a Deore Hollowtech II BB and Crankset. I'm starting to think it would be silly to miss out on this when I have a perfect oppertunity to do so, but I think there's something I'm supposed to do to the frame to make sure its flat.

http://www.chainreactioncycles.com/Models.aspx?ModelID=40496

I could just go completely cheap and get this::D
http://www.chainreactioncycles.com/Models.aspx?ModelID=41902
+
http://www.chainreactioncycles.com/Models.aspx?ModelID=17473

Paul Kiernan

The Deore has a 50mm chainline so it should work OK. I don't think you'd have any issues with the frame if you bang the BB on good and tight but other people may not agree with me (ideally you smooth down, or "face", the painted side to give a perfectly smooth surface where frame sits against BB cup).

However £60 is not cheap and it's doubtful whether you'd notice any difference compared with the cheap option at £23. Suntour website doesn't have full CW8 spec but both CW7 and CW9 http://www.srsuntour-cycling.com/dstore/products/Chainwheels/2981/XCC/CW9-XCC-T208-PB.html show a 122mm BB giving a 48mm chainline which should work (you could use a 127mm for a 50mm chainline but that'll cost you a fiver more!). Do you know what size your seatpost is or what size the bracket on your front derailleur is? If seatpost is greater than 30mm or FD is 34.9 you might need the 50mm clearance!

Icyseanfitz

i suggest just getting this after all its not your credit card and it will all work properly (or would fecking want to anyway hahaha)
oh wait BB not included :eek: for that price you should get a complimentary trip to the moon ffs

Daniel S

Paul Kiernan wrote: »

However £60 is not cheap and it's doubtful whether you'd notice any difference compared with the cheap option at £23. Suntour website doesn't have full CW8 spec but both CW7 and CW9 http://www.srsuntour-cycling.com/dstore/products/Chainwheels/2981/XCC/CW9-XCC-T208-PB.html show a 122mm BB giving a 48mm chainline which should work (you could use a 127mm for a 50mm chainline but that'll cost you a fiver more!). Do you know what size your seatpost is or what size the bracket on your front derailleur is? If seatpost is greater than 30mm or FD is 34.9 you might need the 50mm clearance!

Measured the diameter of the frame where the seatpost drops into, and thats 32mm. I'm starting to think that its too expensive for my bike also (The Deore Hollowtech), but I don't want to go square taper as they always seem to go all dodgey on me. Octalink looks better to me, its cheaper and the Alivio cranks look better than the sr suntours. It's so complicated, all I want to do is replace and upgrade

Will the Alivio's and a 113mm BB do the trick?

Paul Kiernan

mtb_kng wrote: »

Measured the diameter of the frame where the seatpost drops into, and thats 32mm.

Is that the inner or outer diameter?

If you look at that Bikerader review of the UN54 BB you'll see most comments are singing the praises of square taper. But at the end of the day you pays your money and you takes your choice ............