Replace inner chainring on 10 speed Shimano 105 Triple with smaller one



S

Steve Gravrock

Guest
On 2007-07-27, [email protected] <[email protected]> wrote:

[ Wanting to run a 50-39-24 triple ]

One other thing to consider: A smaller granny ring is by far the
cheapest way to get lower gears. If it doesn't work well enough, you're
only out $20 or so. I say give it a try.
 
J

Johnny Sunset aka Tom Sherman

Guest
Ozark Bicycle wrote:
> W.S. Armstrong wrote:
>
> > I am about to order a new road bike that comes with a 10-speed
> > Shimano 105 drive train components: 50-39-30T chainrings, 12-27T
> > cassette, front derailleur, rear derailleur with long cage, and STI
> > shift levers.
> > I would like to replace the 30T inner chainring with a smaller
> > one, preferably a 24T. Is this a compatible modification? I
> > recognize that it may not shift up to the middle chainring as smoothly
> > as stock, but as long as it gets the job done I would be satisfied.
> > To me, this is a deal breaker -- if I can't get a 24 inch low gear, I
> > will have to select a different bike.

>
> The 24 to 39 and 39 to 24 shift is "iffy" with an STI front shifter,
> IME.
>
> OTOH, 105 RD will clear a 30T cog, that and a 28T inner will give you
> a "25 inch" gear.
>
> Another alternative is using a friction shifter for the front (barend,
> DT, 'traditional' Campy Ergo). Then, you can do as you wish....


I have ridden a bike with 54/44/24 chainrings and 8-speed chain, and
shifting was acceptable using a bar-end shifter.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful
 
O

Ozark Bicycle

Guest
On Jul 27, 12:53 am, Johnny Sunset aka Tom Sherman
<[email protected]> wrote:
> Ozark Bicycle wrote:
> > W.S. Armstrong wrote:

>
> > > I am about to order a new road bike that comes with a 10-speed
> > > Shimano 105 drive train components: 50-39-30T chainrings, 12-27T
> > > cassette, front derailleur, rear derailleur with long cage, and STI
> > > shift levers.
> > > I would like to replace the 30T inner chainring with a smaller
> > > one, preferably a 24T. Is this a compatible modification? I
> > > recognize that it may not shift up to the middle chainring as smoothly
> > > as stock, but as long as it gets the job done I would be satisfied.
> > > To me, this is a deal breaker -- if I can't get a 24 inch low gear, I
> > > will have to select a different bike.

>
> > The 24 to 39 and 39 to 24 shift is "iffy" with an STI front shifter,
> > IME.

>
> > OTOH, 105 RD will clear a 30T cog, that and a 28T inner will give you
> > a "25 inch" gear.

>
> > Another alternative is using a friction shifter for the front (barend,
> > DT, 'traditional' Campy Ergo). Then, you can do as you wish....

>
> I have ridden a bike with 54/44/24 chainrings and 8-speed chain, and
> shifting was acceptable using a bar-end shifter.
>


Yep. "Old fashioned" friction front shifting solves the problems
created by "new" indexed front shifting.
 
On Jul 26, 5:52 pm, NeauDL <[email protected]> wrote:
> An easy way to get the low gear that you want is simply to use an
> 11-34 cassette with the standard triple chainrings (30-39-53). You
> would need a long cage mountain rear derailleur and a slightly longer
> chain. IRD makes 10 speed cassettes in 11-34. You could keep the
> standard cassette when you don't need super low gears and just put on
> the 11-34 cassette when you're going to need very low gears. You can
> check out these cassettes at interlocracing.com. I think any bike
> shop could get them for you, probably at a price competitive with
> Ultegra.


Competitive with Ultegra if you add $100 to the Ultegra 10 speed
cassette price to get it near the IRD 10 speed 11-34 cassette..

$169.99 for 10 speed IRD Shimano spaced 11-34 cassette. Before 20%
off today.
http://www.nashbar.com/profile.cfm?...estoreid=&pagename=Shop by Subcat: Freewheels

$65.99 for Ultegra 10 speed cassette. Not showing the 12-27 now but
they have it sometimes. Price before 20% off coupon today.
http://www.nashbar.com/profile.cfm?...estoreid=&pagename=Shop by Subcat: Freewheels

$59.45 for the Shimano 105 10 speed cassette in 12-27. Before 20% off
coupon today.
http://www.nashbar.com/profile.cfm?...estoreid=&pagename=Shop by Subcat: Freewheels



>
> I use this approach for riding in the mountains, but on Shimano 9
> speed.


About the only good thing about Shimano. 9 speed cassettes range from
11-21 to 12-34 and work with any and all shifters. Cheap cassettes
too. Less than $20 to whatever you want to pay at the other end.
Fairly easy to put on a cheap Shimano long cage rear derailleur,
$15.99 at Nashbar for a Deore before 20% off coupon, and the big
cassette and have pretty low gears.


>
> L:. D. Lide
 
S

Sheldon Brown

Guest
A shy person wrote:
> I am about to order a new road bike that comes with a 10-speed
> Shimano 105 drive train components: 50-39-30T chainrings, 12-27T
> cassette, front derailleur, rear derailleur with long cage, and STI
> shift levers.
> I would like to replace the 30T inner chainring with a smaller
> one, preferably a 24T. Is this a compatible modification?


Yes, we do this all the time.

See: http://harriscyclery.com/74

>I recognize that it may not shift up to the middle chainring as smoothly
> as stock, but as long as it gets the job done I would be satisfied.
> To me, this is a deal breaker -- if I can't get a 24 inch low gear, I
> will have to select a different bike.
> Are the inner chainrings for 10-speed triples different than
> those made for (1991) 7-speed triples? I have an old 28T and and old
> 24T chainring, each with the required 74 mm bolt diameter, I could try
> out.


That should work fine. When you go as small as 24, the use of a chain
deflector is almost always indicated, as explained at the link above.

Sheldon "Limbo" Brown
+-----------------------------------------------------------------------
+
| Science is the belief in the ignorance of experts. -Richard
Feynman |
+-----------------------------------------------------------------------
+
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
 
E

Espressopithecus (Java Man)

Guest
In article <[email protected]>,
[email protected] says...

I'm running a 9-speed 105 brifter with a 12-27 and a triple 50-40-26.
Occasionally, it dumps the chain off when downshifting to the 26, but it
can be brought back with the FDR if you don't delay shifting until the
last second. Overall, I am satisfied with the shifting.

I have another bike with a 12-27 and triple 50-40-30. The 26F does help
on long, steep grades, but there's not a lot of difference between it
and the 30F. If a 24 tooth granny ring doesn't work for you, I'm sure a
26 will shift well enough and still give you a stump-puller low gear.

Java
 
T

ttoshi

Guest
I ran a 52-42-26 with 105 FD (9-spd) and 11-34 Deore in the rear with
Ultegra STI shifters with no problems at all.

I didn't like the spacing between the 26 and 42, so I thought I would
get a 38 middle ring and try a Dura-Ace 9spd FD, since it uses 53-39,
I thought I would try 52-38 and 24. I couldn't get the Dura-Ace to
work, but got the 105 to work with
52-38-24. I do use a chain watcher, and for the 24, I need to do a
half-click with my Ultegra STI shifters to shim the FD so I don't get
chain rub as I shift the RD into higher gears while in the granny
ring, but otherwise I am extremely happy.

I know it would work much better with the 48-38-24, but I actually
like the 52 ring. I need the low gears when I tow my son in the hills,
but like the high gears for riding on my own. Yes, I do pedal on
downhills 30+ mph when the occasion allows.

The other thing I didn't see mentioned is that you can get a stock
Sugino XD crank which allows a 48-38-24 (I think you can get from
Rivendell bicycles) and a square taper BB as another option.

Toshi