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You mean the crankset itself? Well, you could simply stop using the granny ring.

If you mean changing your crank to a double, you will need a new crank (obviously) and a new front derailleur. You can use the current (triple) Ultegra shifter.
 
Discussion starter · #3 ·
I read this somewhere months ago and I was wondering if it was this simple. I use 105 shifters.

Dear Jim: I'm wondering if there's a way to cheaply convert
an Ultegra triple crankset to a double, because I never use
the small chainring. The bike is a LeMond Arrivee. A triple
was all they had in stock when I bought it. -- Craig J.

Jim Langley Replies: Sure, Craig, it isn't too hard or
expensive, especially if you have the tools and know-how to
do the work yourself.

Your left STI brake/shift lever is designed to work with
triple or double chainrings. That's the key to this being an
affordable conversion.

To do it, remove the 30-tooth granny ring, leaving you with
the 42 and 52. Replace your triple bottom bracket with the
narrower Ultegra double model, part No.BB6500 (118.5 mm
vs.109.5 mm). Then readjust your front derailleur to shift
correctly with your new chain line.

You'll only be out the cost of the bottom bracket (plus
labor if the shop does the work). And if you save the old
parts, you'll be able to switch your LeMond back to a triple
should you decide to go touring or move where it's hillier.
 
Jim Langley's instructions are good, but English-threaded Ultegra BB-6500 bottom brackets are very hard to find. You could use the 105 BB-5500 double (109.5 mm) instead. Then again, why even bother changing the bottom bracket unless the wider tread of the triple bothers you?

A triple front derailleur will shift a double, no need to replace it.

Another option is to get a new Ultegra FC-6500 double from Nashbar for $80 while they last (only 170 mm / 53-39 left) and that 105 BB. Excellent crank for the money.
 
wim said:
A triple front derailleur will shift a double, no need to replace it..
but not vice versa right?:idea:
 
Discussion starter · #8 ·
wim said:
Jim Langley's instructions are good, but English-threaded Ultegra BB-6500 bottom brackets are very hard to find. You could use the 105 BB-5500 double (109.5 mm) instead. Then again, why even bother changing the bottom bracket unless the wider tread of the triple bothers you?

A triple front derailleur will shift a double, no need to replace it.

Another option is to get a new Ultegra FC-6500 double from Nashbar for $80 while they last (only 170 mm / 53-39 left) and that 105 BB. Excellent crank for the money.
I don't like my chainline so I was hoping to resolve this issue by removing the small ring.
 
IIRC, you will need to make changes to the FD shifter so that it uses the 'lower' two shifting positions (at least if you still want to have the trim available). Just removing the granny ring won't fix that.
 
If you are talking about the the shifters, that is easy.

1) just shift your left shifter to the smallest chain ring.
2) remove the granny gear on your crank or install your double/compact crank.
3) adjust your front derailure to that of your 39 or 42 tooth gear.
4) adjust your front derailure to that of your 53 tooth gear,

Thats it ! if your adjustments are correct it will shift to the 39/42
and the 53 tooth just like any double shifter would. You wont be able to
shift to a third gear now because the front deraillure wont let it.The key is
making sure that at the start of the deraillure adjustment your left
shifter is set to your granny gear position.

I have two bike setup like this and you would not know that my left
shifters were triples unless I told you. Hope this helps !
 
AJL said:
slyjackson, do you still have the trim positions available (slight tap up from smaller CR, slight tap down from larger CR)?

TIA!
yes I do.:thumbsup: nothing has changed except I elimanated one gear shift capability. The front deraillure controls this. there is tons of info on the internet on how to do this too.
 
Where are you guys getting that he has an older Ultegra crank/ BB? If it's an external bearing setup and he wants a narrower chainline, he'll need a new crank. Otherwise, the advice received is great.
 
Discussion starter · #16 ·
wim said:
Don't know about others, but post # 3 indicated to me that the OP's desired modification is identical to the one Craig J. asked Jim Langley about.
This is true. All I want to do is remove my small ring and straighten my chainline. I never use the small ring and I would like a straighter chainline. To achieve this goal it is my understanding that I needed a double bb. I don't care if it's Ultegra or 105. It doesn't really make a difference to me.

m_s said:
Where are you guys getting that he has an older Ultegra crank/ BB? If it's an external bearing setup and he wants a narrower chainline, he'll need a new crank. Otherwise, the advice received is great.
My bike is only 2-3 years old so it can't be an "old" Ultegra crank and bb. It's an 06 or 07 Trek 1500 SLR. If you need any pictures let me know.
 
Alkazeer said:
My bike is only 2-3 years old so it can't be an "old" Ultegra crank and bb. It's an 06 or 07 Trek 1500 SLR. If you need any pictures let me know.
No need for pictures. Post #3 mislead me severely. Post #13 by m_s is right on the money.

You have a Shimano external bearing ("Hollowtech II") crank. These cranks all take the same bottom bracket—there is no double or triple version of that bottom bracket. You need an external bearing ("Hollowtech II") double crank if you want the perfect chainline.
 
Ok so to do the opposite of this i.e. convert a double groupset to a tripple all you need to do is change the crankset? (hollowtech II) and maybe the front derailleur?
I heard somewhere that the brifters are double OR tripple, and they are even sold seperately!
what am I missing here :confused:
 
muscleendurance said:
Ok so to do the opposite of this i.e. convert a double groupset to a tripple all you need to do is change the crankset? (hollowtech II) and maybe the front derailleur?
I heard somewhere that the brifters are double OR tripple, and they are even sold seperately!
what am I missing here :confused:
Yes, you change the crankset—no need to change the bottom bracket. Before you slide on the left crank, you install a 3 mm spacer (should come with the triple crank), which the double crank doesn't need. Front derailleur should be a triple derailleur for reliable and quick shifts. Rear derailleur needs to be the long-cage version ("GS"). Short-cage version ("SS") won't work. Chain length may have to be changed.

105 front brifter is double or triple. I don't know if you can buy the front and rear shifters separately on-line.
 
Discussion starter · #20 ·
wim said:
No need for pictures. Post #3 mislead me severely. Post #13 by m_s is right on the money.

You have a Shimano external bearing ("Hollowtech II") crank. These cranks all take the same bottom bracket—there is no double or triple version of that bottom bracket. You need an external bearing ("Hollowtech II") double crank if you want the perfect chainline.
Sorry about misleading you. I found that information online and wasn't even sure if it was relevant so that's what led me to ask it here. I should have put that disclaimer on the post. Alright I'll start saving up for a double crank and sell my triple. Thanks for all of the advice. It's very much appreciated.
 
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