BB Problem / Advice Please

Clippy said:

Current set up - Orange Evo 4 (2004 model) with Race Face Evolve XC
crank and bottom bracket.

Was originally looking to upgrade to something stronger as there is a
bit of flex in it (I'm probably heftier than most!) something along the
lines of the Atlas crank and the new X-type BB?? Comments?

The Atlas crank is all of 30g heavier than the Evolve, and is made of
similar materials in a similar form. You will not notice any increased
stiffness there.

If you want more stiffness, you'll need either a heavier crank or a
crank of hollow construction. If you want a stronger crank, just going
to a hollow section probably won't make much difference, if the overall
weight is similar.

Note that steel is 3 times stiffer than aluminum for a given cross
section.

Something like the FSA Gamma Drive MegaExo crank would provide a
meaningful increase in stiffness and strength, a very modest weight
increase, and a relatively low cost.

http://fullspeedahead.com/fly.aspx?layout=product&taxid=52&pid=219

Something like the FSA X-drive or Pounder crank, or the Suntour X-Off
crank, would provide a dramatic increase in stiffness and strength and
a significant increase in weight.

http://fullspeedahead.com/fly.aspx?layout=product&taxid=52&pid=217
http://fullspeedahead.com/fly.aspx?layout=product&taxid=52&pid=197
http://www.srsuntour-cycling.com/standard.xml?vpID=179

Chalo Colina

Chalo said:

Clippy said:

Current set up - Orange Evo 4 (2004 model) with Race Face Evolve XC
crank and bottom bracket.

Was originally looking to upgrade to something stronger as there is a
bit of flex in it (I'm probably heftier than most!) something along the
lines of the Atlas crank and the new X-type BB?? Comments?

The Atlas crank is all of 30g heavier than the Evolve, and is made of
similar materials in a similar form. You will not notice any increased
stiffness there.

If you want more stiffness, you'll need either a heavier crank or a
crank of hollow construction. If you want a stronger crank, just going
to a hollow section probably won't make much difference, if the overall
weight is similar.

Note that steel is 3 times stiffer than aluminum for a given cross
section.

Something like the FSA Gamma Drive MegaExo crank would provide a
meaningful increase in stiffness and strength, a very modest weight
increase, and a relatively low cost.

http://fullspeedahead.com/fly.aspx?layout=product&taxid=52&pid=219

Something like the FSA X-drive or Pounder crank, or the Suntour X-Off
crank, would provide a dramatic increase in stiffness and strength and
a significant increase in weight.

http://fullspeedahead.com/fly.aspx?layout=product&taxid=52&pid=217
http://fullspeedahead.com/fly.aspx?layout=product&taxid=52&pid=197
http://www.srsuntour-cycling.com/standard.xml?vpID=179

Chalo Colina

Thanks very much for the info. I'm not really after a downhill crank
but the MegaExo may fit the bill. Has anybody seen any on-line reviews
of this? Tried searching but came up with nothing except odd one line
comments like cheap and basic? Not always bad things but is it really
that good for my needs?

On another note what's the opinion on the current state of my BB? Is it
likely just to be the BB gone that gives the impression of play between
outside edge of BB the frame shell itself? will give it check over on
the weekend.

Clippy

--
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"Cheese - Milk's leap toward immortality"
- Clifton Fadiman

Clippy said:

I'm not really after a downhill crank
but the MegaExo may fit the bill. Has anybody seen any on-line reviews
of this? Tried searching but came up with nothing except odd one line
comments like cheap and basic? Not always bad things but is it really
that good for my needs?

I did a little research on the alloys employed in these cranks, and
based on what I found, I'll have to retract the suggestion that FSA
Gamma Drive cranks would be any stronger than the Race Face Evolve
cranks you have now. While Gamma Drive cranks are heavier, they are
cast from 356 aluminum, which has a yield strength of 22 ksi. The
6066-T6 alloy used in the Evolve crank has a yield strength of 52 ksi,
while for example the 7050 alloy used in the Truvative Holzfeller crank
has a yield strength of 68 ksi.

For comparison, 6061-T6 aluminum (as close to a "typical" structural
alloy as you are likely to find) has a yield strength of 40 ksi.

When the materials used vary as widely in strength as these do, there
can be no certain correlation between the weight and stiffness of a
crank and its strength.

For strength, your current crank seems like a pretty safe bet. If you
want something significantly stiffer, you'll probably have to live with
something significantly heavier.

Chalo Colina

Chalo said:

Clippy said:

I'm not really after a downhill crank
but the MegaExo may fit the bill. Has anybody seen any on-line reviews
of this? Tried searching but came up with nothing except odd one line
comments like cheap and basic? Not always bad things but is it really
that good for my needs?

I did a little research on the alloys employed in these cranks, and
based on what I found, I'll have to retract the suggestion that FSA
Gamma Drive cranks would be any stronger than the Race Face Evolve
cranks you have now. While Gamma Drive cranks are heavier, they are
cast from 356 aluminum, which has a yield strength of 22 ksi. The
6066-T6 alloy used in the Evolve crank has a yield strength of 52 ksi,
while for example the 7050 alloy used in the Truvative Holzfeller crank
has a yield strength of 68 ksi.

For comparison, 6061-T6 aluminum (as close to a "typical" structural
alloy as you are likely to find) has a yield strength of 40 ksi.

When the materials used vary as widely in strength as these do, there
can be no certain correlation between the weight and stiffness of a
crank and its strength.

For strength, your current crank seems like a pretty safe bet. If you
want something significantly stiffer, you'll probably have to live with
something significantly heavier.

Chalo Colina

Thanks very much for all the effort you've put in! I'll have a think
and do some further research before making any more decisions.

Cheers

Clippy

--
MSN Messenger: [email hidden]
Yahoo / Steam: crymealiver

"Cheese - Milk's leap toward immortality"
- Clifton Fadiman

"Chalo" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Clippy said:

Current set up - Orange Evo 4 (2004 model) with Race Face Evolve XC
crank and bottom bracket.

Was originally looking to upgrade to something stronger as there is a
bit of flex in it (I'm probably heftier than most!) something along the
lines of the Atlas crank and the new X-type BB?? Comments?

The Atlas crank is all of 30g heavier than the Evolve, and is made of
similar materials in a similar form. You will not notice any increased
stiffness there.

Chalo, I believe that the Evolve XC crank/BB combo that the user currently
has is the regular ISIS type.

--
Phil, Squid-in-Training

Phil said:

"Chalo" <[email hidden]> wrote in message

news:[email hidden]...

Quoted message said:

Quoted message said:

Clippy said:

Current set up - Orange Evo 4 (2004 model) with Race Face Evolve XC
crank and bottom bracket.

Was originally looking to upgrade to something stronger as there is a
bit of flex in it (I'm probably heftier than most!) something along the
lines of the Atlas crank and the new X-type BB?? Comments?

The Atlas crank is all of 30g heavier than the Evolve, and is made of
similar materials in a similar form. You will not notice any increased
stiffness there.

Chalo, I believe that the Evolve XC crank/BB combo that the user

currently has is the regular ISIS type.

Quoted message said:

Yeah I am running the older ISIS Evolve setup. Was under the impression
that the new Atlas X-type with the 'built in' BB would be a lot more
stiffer than my current setup. Any ideas?

--
MSN Messenger: [email hidden]
Yahoo / Steam: crymealiver

"Cheese - Milk's leap toward immortality"
- Clifton Fadiman

"Clippy" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Phil said:

"Chalo" <[email hidden]> wrote in message

news:[email hidden]...

Quoted message said:

Quoted message said:

Clippy wrote:

> Current set up - Orange Evo 4 (2004 model) with Race Face Evolve XC
> crank and bottom bracket.
>
> Was originally looking to upgrade to something stronger as there is a
> bit of flex in it (I'm probably heftier than most!) something along
> the
> lines of the Atlas crank and the new X-type BB?? Comments?

The Atlas crank is all of 30g heavier than the Evolve, and is made of
similar materials in a similar form. You will not notice any increased
stiffness there.

Chalo, I believe that the Evolve XC crank/BB combo that the user

currently has is the regular ISIS type.

Quoted message said:

Yeah I am running the older ISIS Evolve setup. Was under the impression
that the new Atlas X-type with the 'built in' BB would be a lot more
stiffer than my current setup. Any ideas?

I think that upgrading would increase your crank stiffness measurably. I
personally don't ever notice stiffness increases on our newly-built 2-piece
crank-equipped bikes since I'm all of 135lbs.

--
Phil, Squid-in-Training

Clippy said:

Yeah I am running the older ISIS Evolve setup. Was under the impression
that the new Atlas X-type with the 'built in' BB would be a lot more
stiffer than my current setup. Any ideas?

If there is a significant difference in stiffness (and there proabably
is), then it would be mostly attributable to stiffer bearings spaced
closer to the crankarms. The outside diameters and wall thicknesses of
an ISIS spindle and an outboard-bearing type spindle are almost
identical.

Chalo Colina