Will Shimano compact cranks (FC-R700) fit Dura-Ace 7800 BB

[Brad Ford]

Or any other compact cranks for that matter? I'd like to infrequently
swap out Dura-Ace double cranks for a compact. I'd prefer not to have
to swap the BB as well if there are compact cranks out there that will
fit it.

Thanks.
-B.

 

[Qui si parla Campagnolo]

Brad Ford wrote:
> Or any other compact cranks for that matter? I'd like to infrequently
> swap out Dura-Ace double cranks for a compact. I'd prefer not to have
> to swap the BB as well if there are compact cranks out there that will
> fit it.
>
> Thanks.
> -B.

Same BB for all road shimano outboard bearing BBs....Same cups for the
MTB ones as well...just a different center plastic thingy...

 

[Qui si parla Campagnolo]

Brad Ford wrote:
> Or any other compact cranks for that matter? I'd like to infrequently
> swap out Dura-Ace double cranks for a compact. I'd prefer not to have
> to swap the BB as well if there are compact cranks out there that will
> fit it.
>
> Thanks.
> -B.

Just a side note...with a compact-50-34, and a 11-23 cogsest, you will
have a higher high gear and a lower low gear than a 12-25 and a
53/39....

 

[[email protected]]

Qui si parla Campagnolo wrote:
> Brad Ford wrote:
> > Or any other compact cranks for that matter? I'd like to infrequently
> > swap out Dura-Ace double cranks for a compact. I'd prefer not to have
> > to swap the BB as well if there are compact cranks out there that will
> > fit it.
> >
> > Thanks.
> > -B.
>
> Just a side note...with a compact-50-34, and a 11-23 cogsest, you will
> have a higher high gear and a lower low gear than a 12-25 and a
> 53/39....

But not a much lower gear, and that is my big beef against the current
fad of 110mm bcd cranksets. Instead of wasting lots of money on new
cranksets and usually new bottom brackets, just put the next size up
cassette on the bike. With the currently sold bike parts, the only way
to get low gears with a double crankset is to get the compact crankset
AND a bigger cassette. Bigger meaning bigger cogs in back. Lot of
money.

Assume Campagnolo 10 speed cassettes since I'm familiar with Campagnolo
cassettes, not those other brands.

50-34 11-23 has 120" high, 39" low.
50-34 12-25 has 110" high, 36" low.
50-34 13-26 has 102" high, 35" low.
50-34 13-29 has 102" high, 31" low.

53-39 11-23 has 128" high, 45" low.
53-39 12-25 has 117" high, 41" low.
53-39 13-26 has 108" high, 40" low.
53-39 13-29 has 108" high, 36" low.

Starting with a normal 53-39 crankset, changing the cassette from 11-23
to 12-25 gets you about the same as changing the crankset to 50-34.
Easier and cheaper to change the cassette.

Or changing from a 12-25 cassette on a 53-39 to a 13-29 cassette gets
you the same as changing the crankset to 50-34. Easier and cheaper to
change the cassette.

The only way to get fairly low gears, not as low as a triple crankset,
is to change the cassette to a 13-29 AND change the crankset to 50-34.
Probably easier and cheaper and much more effective to just get a
triple crankset and have even lower gears than is possible with a
compact crankset.

 

[Werehatrack]

On 27 Apr 2006 08:40:23 -0700, [email protected] wrote:

>The only way to get fairly low gears, not as low as a triple crankset,
>is to change the cassette to a 13-29 AND change the crankset to 50-34.
>Probably easier and cheaper and much more effective to just get a
>triple crankset and have even lower gears than is possible with a
>compact crankset.

Or build an 11-29 cassette, perhaps? I haven't dealt with 10s Campy
yet, but isn't it possible to dismantle them and create what you want?
I would expect that to be cheaper than swapping out the cranks.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

 

[[email protected]]

Werehatrack wrote:
> On 27 Apr 2006 08:40:23 -0700, [email protected] wrote:
>
> >The only way to get fairly low gears, not as low as a triple crankset,
> >is to change the cassette to a 13-29 AND change the crankset to 50-34.
> >Probably easier and cheaper and much more effective to just get a
> >triple crankset and have even lower gears than is possible with a
> >compact crankset.
>
> Or build an 11-29 cassette, perhaps? I haven't dealt with 10s Campy
> yet, but isn't it possible to dismantle them and create what you want?
> I would expect that to be cheaper than swapping out the cranks.

Campagnolo is similar to Shimano in that the higher up the line you go,
the more cogs are bolted together and can only be used as a complete
spider/module. Veloce and Mirage, like the lower 105 or such models,
are all loose cogs so you can mix and match anything. Centaur has only
the last 2 or 3 cogs bolted together and the rest are loose. Record
and Chorus have a couple 2-3 or 3-4 modules with a couple loose cogs
that could be mixed and matched. Due to cost I am not sure you would
want to buy two Record or Chorus cassettes and make one cassette. Even
gets kind of expensive buying two Veloce 10 speed cassettes and making
one cassette. 9 speed Campagnolo cogs are the same thickness as 10
speed cogs so you could get cheaper Veloce or Mirage 9 speed cassettes
and use them to build up a custom cassette.

I've tried the mixing of cogs on a Campagnolo cassette and noticed the
incorrectly lined up cog ramps. So I would not do much or any mixing
of cogs except at either the low or high ends.

Shimano does have the advantage in this area. They make lots of really
dirt cheap individual cog cassettes in 9 speed in all sizes so mxing up
custom cassettes is really cheap. But with 10 speed Shimano 27 is the
biggest cog. IRD makes a 28 tooth 10 speed cog. Campagnolo 10 speed
goes to 29 teeth. And Marchisio and/or Miche makes a 30 I heard for
Campagnolo 10 speed.

 

[Qui si parla Campagnolo]

[email protected] wrote:
> Qui si parla Campagnolo wrote:
> > Brad Ford wrote:
> > > Or any other compact cranks for that matter? I'd like to infrequently
> > > swap out Dura-Ace double cranks for a compact. I'd prefer not to have
> > > to swap the BB as well if there are compact cranks out there that will
> > > fit it.
> > >
> > > Thanks.
> > > -B.
> >
> > Just a side note...with a compact-50-34, and a 11-23 cogsest, you will
> > have a higher high gear and a lower low gear than a 12-25 and a
> > 53/39....
>
> But not a much lower gear, and that is my big beef against the current
> fad of 110mm bcd cranksets. Instead of wasting lots of money on new
> cranksets and usually new bottom brackets, just put the next size up
> cassette on the bike. With the currently sold bike parts, the only way
> to get low gears with a double crankset is to get the compact crankset
> AND a bigger cassette. Bigger meaning bigger cogs in back. Lot of
> money.
>
> Assume Campagnolo 10 speed cassettes since I'm familiar with Campagnolo
> cassettes, not those other brands.
>
> 50-34 11-23 has 120" high, 39" low.
> 50-34 12-25 has 110" high, 36" low.
> 50-34 13-26 has 102" high, 35" low.
> 50-34 13-29 has 102" high, 31" low.
>
> 53-39 11-23 has 128" high, 45" low.
> 53-39 12-25 has 117" high, 41" low.
> 53-39 13-26 has 108" high, 40" low.
> 53-39 13-29 has 108" high, 36" low.
>
> Starting with a normal 53-39 crankset, changing the cassette from 11-23
> to 12-25 gets you about the same as changing the crankset to 50-34.
> Easier and cheaper to change the cassette.
>
> Or changing from a 12-25 cassette on a 53-39 to a 13-29 cassette gets
> you the same as changing the crankset to 50-34. Easier and cheaper to
> change the cassette.
>
> The only way to get fairly low gears, not as low as a triple crankset,
> is to change the cassette to a 13-29 AND change the crankset to 50-34.
> Probably easier and cheaper and much more effective to just get a
> triple crankset and have even lower gears than is possible with a
> compact crankset.

I agree...just have double rings, with a third 30t ring....a triple. If
the bike starts out as a frame, no real penalty for going to a triple,
particularly with Campag(shimano being much more finicky) but many want
lower gears and a cheaper way to get them. Many already have a
13-29-53/39 and want lower but for reasons of $ or what others will say
about their wimpy-ness, they choose a compact.

 

[Qui si parla Campagnolo]

Werehatrack wrote:
> On 27 Apr 2006 08:40:23 -0700, [email protected] wrote:
>
> >The only way to get fairly low gears, not as low as a triple crankset,
> >is to change the cassette to a 13-29 AND change the crankset to 50-34.
> >Probably easier and cheaper and much more effective to just get a
> >triple crankset and have even lower gears than is possible with a
> >compact crankset.
>
> Or build an 11-29 cassette, perhaps? I haven't dealt with 10s Campy
> yet, but isn't it possible to dismantle them and create what you want?
> I would expect that to be cheaper than swapping out the cranks.

Well if you use 2 cogsets..Centaur(lowest with a 11-23) and a
Veloce-that can be the cost of a Veloce or Centaur aluminum compact
crank...buying a 13-29, and then a 11t and lockring-that is about
$50...and the 11-13 shift won't be a clean one.