Compact Crank -- 53 on the big ring?

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

Quoted message said:

Going through the different posts on this site re compact cranks,
nobody ever talks about running a 53 on the big ring. Is this
possible? I've got a hilly commute with a couple serious downhills
where its helpful to maintain the pace of traffic. Also, if I switch
to a compact (from my current 53-39) can I continue to run 8-speed
campy? I've got an investment in rear wheels and hubs I hate to give
up to switch to 9 or 10 speed.

You can. I have seen up to 54t big rings for 110mm BCD cranks.

The biggest issue is why? There's only so many teeth differential that the
front derailleur can handle. If yer going up to 52/53/54t big rings, you need
to stick to 38/39t small rings.

Remember, a 50t big ring is one cog different in the back than a 53t ring. ie:
a 50/12 combo is going to feel about the same as a 53/13 combo. If yer spinning
out on the downhills, its time to coast anyway. IIRC studies have shown you go
10% faster spinning down a hill vs. coasting. If energy expenditure is your
goal, go for it. If saving energy to sprint later is yer goal, stop pedaling
asap.

Yes, you can keep the gears in the back.

I've got an XTR crankset with an adaptor that I usually change cross rings for
road rings come springtime. I go from 34/46 to 39/53 and all's well.

M

Peter Rowe said:

Going through the different posts on this site re compact cranks, nobody
ever talks about running a 53 on the big ring. Is this possible?

What, you want a 53/34? It is possible, but I'd recommend a chain watcher
for that large a jump. You'd also need either a tight cassette,
nearly a corncob, or a large-capacity derailleur. Short-cage Campy
derailleurs are rated to either 27 or 28 teeth, and you'd be 3o or over
unless you have a 12-19 or 12-21.

110/53 can be found. There isn't a significant difference between a 53/12
and a 52/12, anyway, and most hills you could do just as well with a 50/12.

Quoted message said:

Also, if I switch to a compact (from my
current 53-39) can I continue to run 8-speed campy?

Sure.

--

David L. Johnson

__o | You will say Christ saith this and the apostles say this; but
_`\(,_ | what canst thou say? -- George Fox.
(_)/ (_) |

Quoted message said:

Going through the different posts on this site re compact cranks,
nobody ever talks about running a 53 on the big ring. Is this
possible? I've got a hilly commute with a couple serious downhills
where its helpful to maintain the pace of traffic. Also, if I switch
to a compact (from my current 53-39) can I continue to run 8-speed
campy? I've got an investment in rear wheels and hubs I hate to give
up to switch to 9 or 10 speed.

Peter: How fast is the traffic moving? A 50/12 is still a mighty-high gear;
higher even than the 52/13 that I raced with many years ago. For serious
downhills, you'll find you can usually go faster if you tuck in rather than
pedal, once your speed gets much above 40mph. However, I have little trouble
getting my 50/12 up to 44mph (downhill, of course!), which is about the same
speed I topped out at with my older 53/12.

If you do go to a 53 on the large with a 34 on the small, you're going to
have a lot more chainring clipping than you'd get with the 50t. In fact,
it's likely that you could lose the two smaller cogs in the back (when in
the small front chainring) due to the chain clipping on the 53. You'd also
want to use a chain watcher, as someone else suggested, to keep the chain
from dropping off on the inside.

The derailleur isn't rated for that much difference in chainring size
either, so it's possible that the chain might ride across the bottom of the
derailleur cage when in the small chainring and one of the smaller rear
cogs.

No problem running your 8-speed setup though.

50/34 is wonderful (assuming you have the terrain to need lower gears). I
should have gone to that a long time ago! It takes maybe a couple weeks to
really get used to, but once you do, there's no going back.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
IMBA, BikesBelong, NBDA member

Peter Rowe said:

Going through the different posts on this site re compact cranks,
nobody ever talks about running a 53 on the big ring. Is this
possible? I've got a hilly commute with a couple serious downhills
where its helpful to maintain the pace of traffic. Also, if I switch
to a compact (from my current 53-39) can I continue to run 8-speed
campy? I've got an investment in rear wheels and hubs I hate to give
up to switch to 9 or 10 speed.

Yes.

Sheldon "Succinct" Brown
+------------------------------------------+
| I’ll be voting for John Kerry Tomorrow |
| I hope you will too. |
+------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Peter Rowe said:

Going through the different posts on this site re compact cranks,
nobody ever talks about running a 53 on the big ring. Is this
possible?

Yes, but it's nightmarish with front indexing unless you want to increase
the size of the small ring (and then why not run a 130mm BCD anyway).

I have a 52/34 (vs. 13/34 in the rear) but then I use bar-end shifters, so
the front is unindexed.
--
David Damerell <[email hidden]> flcl?

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In article <b6Ahd.91317$cJ3.3424@fed1read06>,

SDMike said:

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

Quoted message said:

Going through the different posts on this site re compact cranks,
nobody ever talks about running a 53 on the big ring. Is this
possible? I've got a hilly commute with a couple serious downhills
where its helpful to maintain the pace of traffic. Also, if I switch
to a compact (from my current 53-39) can I continue to run 8-speed
campy? I've got an investment in rear wheels and hubs I hate to give
up to switch to 9 or 10 speed.

You can. I have seen up to 54t big rings for 110mm BCD cranks.

The biggest issue is why? There's only so many teeth differential that the
front derailleur can handle. If yer going up to 52/53/54t big rings, you need
to stick to 38/39t small rings.

_ 53/36 works pretty well. You need to be a bit cautious on the
down shift, but IMHO if 52/34 makes sense for where you ride,
then it's not an unreasonable compromise, especially if you
add a chain watcher.

_ Booker C. Bense

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[email hidden] (Peter Rowe) wrote in message news:<[email hidden]>...

Quoted message said:

Going through the different posts on this site re compact cranks,
nobody ever talks about running a 53 on the big ring. Is this
possible? I've got a hilly commute with a couple serious downhills
where its helpful to maintain the pace of traffic. Also, if I switch
to a compact (from my current 53-39) can I continue to run 8-speed
campy? I've got an investment in rear wheels and hubs I hate to give
up to switch to 9 or 10 speed.

Going from a 39 inner ring to a 34 inner ring with the compact
crankset will allow you to get 1 gear lower. About 4.5 gear inches.
From a 23 to a 26 large rear cog. A 39x26 is identical to a 34x23.
Is 1 gear lower going to matter enough to get you up the hills? At a
cost of $250? Assuming you are getting one of the new FSA or Ritchey
aluminum compact cranksets and its corresponding ISIS bottom bracket.
Much more expensive if you go with one of the carbon compact cranksets
for over $300 and its corresponding titanium bottom bracket for $100.

Now you want to replace the 50 tooth ring on the compact crankset with
a 53. Another $30 minimum.

Dang. $280 for 1 lower gear by going to a compact crankset. Makes my
Centaur triple crankset, bottom bracket, rear derailleur, and front
derailleur look positively cheap when I bought it for $175 total from
Nashbar last year.

I think your best solution would be to buy an extra cassette with a
large rear cog and add it to your current cassette. QBP made/makes a
8 and 9 speed 28 tooth cog for loose cog Campagnolo cassettes. Just
replace the last cog with the QBP 28 tooth cog and you have lower
gears. I replaced the 26 cog on my 9 speed loose cassette with the 28
cog and run a 13-28 cassette. I bought my QBP cog from Harris
Cyclery.

David Damerell said:

Peter Rowe said:

Going through the different posts on this site re compact cranks, nobody
ever talks about running a 53 on the big ring. Is this possible?

Yes, but it's nightmarish with front indexing unless you want to increase
the size of the small ring (and then why not run a 130mm BCD anyway).

He has Campy shifters so the front is not indexed, anyway. I've never had
trouble shifting set-ups like this.

--

David L. Johnson

__o | If all economists were laid end to end, they would not reach a
_`\(,_ | conclusion. -- George Bernard Shaw
(_)/ (_) |

"SDMike" <[email hidden]> wrote in message news:<b6Ahd.91317$cJ3.3424@fed1read06>...

Quoted message said:

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

Quoted message said:

Going through the different posts on this site re compact cranks,
nobody ever talks about running a 53 on the big ring. Is this
possible? I've got a hilly commute with a couple serious downhills
where its helpful to maintain the pace of traffic. Also, if I switch
to a compact (from my current 53-39) can I continue to run 8-speed
campy? I've got an investment in rear wheels and hubs I hate to give
up to switch to 9 or 10 speed.

You can. I have seen up to 54t big rings for 110mm BCD cranks.

The biggest issue is why? There's only so many teeth differential that the
front derailleur can handle. If yer going up to 52/53/54t big rings, you need
to stick to 38/39t small rings.

Remember, a 50t big ring is one cog different in the back than a 53t ring. ie:
a 50/12 combo is going to feel about the same as a 53/13 combo. If yer spinning
out on the downhills, its time to coast anyway. IIRC studies have shown you go
10% faster spinning down a hill vs. coasting. If energy expenditure is your
goal, go for it. If saving energy to sprint later is yer goal, stop pedaling
asap.

Yes, you can keep the gears in the back.

I've got an XTR crankset with an adaptor that I usually change cross rings for
road rings come springtime. I go from 34/46 to 39/53 and all's well.

M

If I stick with the 50t big ring and continue to run the 8-speed cogs
in the back, can I stick with a short-cage rear derailleur or do I
need to go long?

pcr

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In article <[email hidden]>,

Peter Rowe said:

If I stick with the 50t big ring and continue to run the 8-speed cogs
in the back, can I stick with a short-cage rear derailleur or do I
need to go long?

_ Add the difference in the front to the difference in the back
and see if it exceeds the rated capacity of your derailler.
See this for more details.

http://www.sheldonbrown.com/harris/derailers-rear.html

_ If you were running 53/39 then I suspect switching to
50/34 should be okay. It's only 2 more links.

_ Booker C. Bense

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Peter Rowe said:

Going through the different posts on this site re compact cranks,

BTW: USENet isn't quite a site, it's a worldwide network that you
might read on some site.

Quoted message said:

nobody ever talks about running a 53 on the big ring. Is this
possible?

Sure, I'm running 53/36 sometimes. That said you'll need to use
cranks with a BCD where 53t is available...

--
MfG/Best regards
helmut springer

Peter Rowe said:

If I stick with the 50t big ring and continue to run the 8-speed cogs in
the back, can I stick with a short-cage rear derailleur or do I need to go
long?

You should be OK with short. 15 teeth difference in the front, so you can
use just about any cassette made for your 8-speed Campy -- the widest
being 12/26 IIRC.

--

David L. Johnson

__o | "A foolish consistency is the hobgoblin of little minds, adored
_`\(,_ | by little statesmen and philosophers and divines." --Ralph Waldo
(_)/ (_) | Emerson

With Campagnolo shifters, no problem...53/34. We have done it a couple of
times.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

David L. Johnson said:

Peter Rowe said:

Going through the different posts on this site re compact cranks, nobody
ever talks about running a 53 on the big ring. Is this possible?

What, you want a 53/34? It is possible, but I'd recommend a chain watcher
for that large a jump.

I run a 53-33, and don't drop the chain. The trick is to add an extra 1 mm
spacer (5 ea) between the little ring and the crank.

Quoted message said:

You'd also need either a tight cassette,
nearly a corncob, ....

Actually it is the opposite if he doesn't want a hole in increments or be
required to fully cross the chain to avoid the gearing gap.

Quoted message said:

... or a large-capacity derailleur.

True.

Quoted message said:

Short-cage Campy
derailleurs are rated to either 27 or 28 teeth, and you'd be 3o or over
unless you have a 12-19 or 12-21.

110/53 can be found. There isn't a significant difference between a 53/12
and a 52/12, anyway, and most hills you could do just as well with a 50/12.

Quoted message said:

Also, if I switch to a compact (from my
current 53-39) can I continue to run 8-speed campy?

Sure.

--

David L. Johnson

__o | You will say Christ saith this and the apostles say this; but
_`\(,_ | what canst thou say? -- George Fox.
(_)/ (_) |