Lightest crank bottom bracket combination for Roubaix comp ?

Discuss light weight issues concerning road bikes & parts.
burlguy
Posts: 32
Joined: Thu Apr 07, 2005 4:30 am
Location: Fort Bragg California

by burlguy

I have got my Roubaix down to under 15 3/4, right around 7042 grams if Iam not mistaken . I have a triple Fsa carbon Slk with outboard bottom bracket bearings , which weighs in at a Supposed 830 grams, but I suspect more. I see that could go with a 550g Stella Azura or a Team Fsa and Light weight 110 gram bottom bracket and save 170 grams . I dont know what the spindle length is going to need to be to keep the same chain line. The spindle length is not listed with the Fsa integrated crank spindle combo. Bottom line is anyone have any suggestions as to what crank and bottom bracket combo to use ? I have no problem going to a double and the lighter the better . I am at 170 pounds right now without my camel back . I really like to get out of the saddle and tweak on the cranks and I dont want to shear one off . Any ideas ?

by Weenie


Greyhound
Posts: 109
Joined: Tue Jun 22, 2004 9:56 am
Location: Germany

by Greyhound

I would go for a Stronglight pulsion compact or a FSA K-Force compact with CT Rings from Stronglight. Weight is around 410 and 440 gram.

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CaptainWilier
Posts: 1913
Joined: Thu Feb 24, 2005 5:14 am
Location: Georgia

by CaptainWilier

I have the Stronglight Pulsions with the FSA platinum TI BB and the set up weighs about 630 grams. I am 180 lbs and love to sprint and so far have not felt any flex with these.
The FSA SLK mega's are quite heavy, @ 800 grams. Check their website for chain line info and Q.....etc...fullspeedahead.com. Good luck :D

burlguy
Posts: 32
Joined: Thu Apr 07, 2005 4:30 am
Location: Fort Bragg California

by burlguy

I was hoping to find somone who already has swapped there crank and bottom bracket combination out . Fsa mentions q factor but that does not tell me needed spindle length on a conventional bottom bracket . I dont want to mess the chain line up as it shifts verry nice. I just need to find out if I need a 108 or a 114 , ect . I like the idea of the stronglight chainrings . I would really like to get the crank weight and bottom bracket down under 600g that would be a verry good savings


I dont want a compact , I tend to spin out as it is around 35 with my 53- 12 combo and I would like to be able to push 40 . I deffinetly dont want to get a smaller chainrings.

I guess I will get in touch with fsa and find out what there equivilent spindle length would be . Anyone out there know?

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Superlite
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Joined: Fri Aug 29, 2003 9:01 pm

by Superlite

Just to let you know I have weighed SLK's in a 172.5, they weighed almost 900g complete. K force weighs in at ~760g at the same length.

burlguy
Posts: 32
Joined: Thu Apr 07, 2005 4:30 am
Location: Fort Bragg California

by burlguy

.....Ditch this boat anchor of a crank. Help anyone , I just need to find the equivalent bottom bracket and keep the same chain line. I have an Slk integrated crank and spindle weighing in at a whopping 900 grams. Help please , I cant sleep at night with this torturous crank making my frame sag in the middle ... well maybe not that bad. I need lighter.. What spindle length and how to measure the existing Fsa?

bobalou
Posts: 1013
Joined: Mon Dec 15, 2003 6:05 am

by bobalou

burlguy wrote:.....Ditch this boat anchor of a crank. Help anyone , I just need to find the equivalent bottom bracket and keep the same chain line. I have an Slk integrated crank and spindle weighing in at a whopping 900 grams. Help please , I cant sleep at night with this torturous crank making my frame sag in the middle ... well maybe not that bad. I need lighter.. What spindle length and how to measure the existing Fsa?


I'd contact FSA to make sure but, you can probably just buy the k-force crankarms w/o BB and slide it in place. I don't think any other spindle/crankarms are going to fit that FSA BB. There's been threads on this before so :search: here on WW's to check. Integrated BB's are not all compatible unfortunately.

bobalou
Posts: 1013
Joined: Mon Dec 15, 2003 6:05 am

by bobalou

Just my .02 cents on crank weight.. I know people talk about rotational weight being worth twice the other components but I think this is less true for cranks. Most of the crank mass is in a very small diameter. It's not like wheel mass. In fact, I think wheels are where rotational mass definitely makes a difference. Put a light set of wheels on your bike - you will notice immediately faster accelleration.

Not true for cranks. Just my opinion but it's stiffness I notice in the cranks. In fact, I think pedal weight and cleat mass is more important then crank weight. The pedals and cleats are at the most outer circumference of the cranks and will be more noticeable then losing 100g in your crank arms or BB.

burlguy
Posts: 32
Joined: Thu Apr 07, 2005 4:30 am
Location: Fort Bragg California

by burlguy

I want to ditch the Fsa crank setup all together. I dont want to keep the bottom bracket . From all the post I have looked at I am planning on going with extralite ebones wrc or stronglight pulsion ct2. I just need to know what spindle length I need in order to keep a good chainline on my Specialized Roubaix.

I Already have Am classic 350 and Easton ec90 bar and seatpost , Dura ace derailleur, Fsa stem , Dura Ace pedals , Hollow pin chain, Dura ace cassette. The brake pods and front derailleur are Ultegra, till I go up to 10 speed. Carbon seat ,ti quick releases, Conti Supersonic tires . This bottom bracket and crank need to go to a new home.

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Superlite
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by Superlite

Why not DA cranks? They rock.

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cadence90
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Joined: Sun Dec 14, 2003 1:52 am

by cadence90

Yep. You got almost all DA, just get the DA crankset.
"Gimondi è un eroe umano, che viene sconfitto ma che continua la sua corsa fino a tornare a vincere." - Enrico Ruggeri

burlguy
Posts: 32
Joined: Thu Apr 07, 2005 4:30 am
Location: Fort Bragg California

by burlguy

Hmmm I am in the weight weenies Forum . Oh yeah I should get Dura Ace when there are crank sets 200 grams lighter . No that is not what I want to do . Iam sure they are an excellent product but I dont want them . I listed some components not to brag but to show where I have gone with the bike and why Iam continuing to get the weight down . Yeah I dont have millions at my disposal and have to shop around ... Hence I want to buy the right product the first time . I came here looking for advice... So I will assume Dura Ace is the best advice . Thanks , I will have to call Shimano and get the recomended spindle length to get the right chain line .

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ultimobici
in the industry
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Location: London, UK
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by ultimobici

cadence90 wrote:Yep. You got almost all DA, just get the DA crankset.
EXTRALITE E-Bones WR. Sub 500g without rings so 620g including rings should be possible.

jozuph
Posts: 354
Joined: Thu Sep 02, 2004 10:19 am
Location: Germany

by jozuph

get propellers, stif and mad light :]]]

by Weenie


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spoke n words
Posts: 222
Joined: Wed Jan 26, 2005 5:59 am
Location: USA-CT

by spoke n words

If you end up going with a double crankset then choose a 108 spindle length for BB. If you choose a BB other than the FSA Isis then the spindle length may vary by a millimeter or so. No big deal unless it gets above 110.

Anyway, FSA Plat Pro Ti in 68x108 with a Pulsion Compact Isis crank seems like a light and intelligent set up.

But then again, I ride Dura Ace. :D

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