New chainset - bb length?

Page may contain affiliate links. Please see terms for details.

lulubel

Über Member
Location
Malaga, Spain
Now that I'm replacing practically everything else on my bike, I've been looking at chainsets and found this Sora triple 3403 for a really good price.

According to Shimano's compatibility chart, I'd need this ES25 bb to go with it.

I've just spent 2 hours trying to figure out what length I'd need, and I can't find any definite answer. There's a choice of 118 or 126, so if I had to guess, I'd go for 126 (assuming the 118 is for the double chainset), but it seems quite long, and I'd like to be certain rather than end up ordering another wrong bb.
 

Smokin Joe

Legendary Member
Lulubel, that's a Hollowtech chainset which does not need a seperate bottom bracket. All you need is a set of Shimano outboard bearings.
 
OP
OP
lulubel

lulubel

Über Member
Location
Malaga, Spain
Lulubel, that's a Hollowtech chainset which does not need a seperate bottom bracket. All you need is a set of Shimano outboard bearings.

Okay ......

So, why does the Shimano document specify a compatible bb, and the listing at CRC states "bottom bracket not included"?

(I'm confused rather than trying to start an argument about it :smile: )
 

PaulSecteur

No longer a Specialized fanboy
The way I read it, the FC3403 chainset needs a FC4500 bottom bracket, which is the hollowtech type.

I think you were looking at the bottom of the left hand column where it says "ST3400", but thats the column for tghe levers, not the chainset.

But I could be wrong!

FC4500 bottom bracket looks like this...
10878.jpg


fc3403.jpg
 

biggs682

Touch it up and ride it
Location
Northamptonshire
true hence why tandem came out for first time in months
 

RecordAceFromNew

Swinging Member
Location
West London
The way I read it, the FC3403 chainset needs a FC4500 bottom bracket, which is the hollowtech type.

I think you were looking at the bottom of the left hand column where it says "ST3400", but thats the column for tghe levers, not the chainset.

But I could be wrong!

Paul I am willing to bet money you are right.

I am however unsure if the outboard BB is not included in Ribble's deal - it doesn't say it is excluded?

Lulubel why are you abandoning your existing chainset? They don't wear out easily. You might need different tools to what you have for HT2. By the end of this you will be able to open your own shop in sunny Spain and give your LBSs a run for their money! :thumbsup:
 
OP
OP
lulubel

lulubel

Über Member
Location
Malaga, Spain
The way I read it, the FC3403 chainset needs a FC4500 bottom bracket, which is the hollowtech type.

Got it! I understand now.

Thanks, Paul.

I was assuming that any of the 4 options linked to from the big box were fine (I'm sure that's how flow charts worked when we did them in school, but it was a long time ago!)

Lulubel why are you abandoning your existing chainset? They don't wear out easily. You might need different tools to what you have for HT2. By the end of this you will be able to open your own shop in sunny Spain and give your LBSs a run for their money! :thumbsup:

Because I want a shiny new one :biggrin:

Seriously, my original plan was to replace everything eventually, so I figure I might as well do it now when I've found a chainset at that price. My old bike was also running an 8-sp triple chainset with a 9-sp cassette and chain. I don't know if that was the cause of all the setup problems - only one lbs out of 3 I tried ever got it running smoothly, and I've spent hours tweaking it myself and not managed to get the indexing spot on - so I'd like to see what it's like having components that match. (For comparison, I found my MTB very easy to index.)

All the bits off the old bike that aren't broken are going to be cleaned up and put in the spares box, so nothing will go to waste.
 
OP
OP
lulubel

lulubel

Über Member
Location
Malaga, Spain
I would doubt its included, When I brought a tiagra chainset it wasnt.

It should be less than £15, and a tool to fit and remove it is about £10...But you may also need a tool to remove the old bb too.

Does it matter which one I get? ie tiagra, 105, ultegra? Will any of them work with the chainset?

Oh, and I also have a choice of English or Italian, which I take it is the thread type, and I need English. My frame manufacturer also specifies 68mm wide, but I haven't seen a width measurement anywhere. Is 68mm the standard width?
 

RecordAceFromNew

Swinging Member
Location
West London
Does it matter which one I get? ie tiagra, 105, ultegra? Will any of them work with the chainset?

Oh, and I also have a choice of English or Italian, which I take it is the thread type, and I need English. My frame manufacturer also specifies 68mm wide, but I haven't seen a width measurement anywhere. Is 68mm the standard width?

You can use any of those BBs, from Sora to DuraAce. You need English thread. 68mm is standard road BB shell width.
 
Top Bottom