Q's about swapping front chainring

C.J.Patten said:

Howdy!

I'm planning to install a larger front chainring and would like to know what
issues I need to consider.

The bike appears to use a tapered-square type BB.
Current front crank is an FSA Alpha drive 2-ring set (32/44), 170mm arms.
This setup has a 4-bolt pattern.
Derailleur is a Shimano Deore. FWIW, in back there's an 8-speed cassette.

*** *** ***

I'd like to install a 50-tooth large front ring.

Is this as easy as walking into a well equipped bike shop, buying a new ring
with a 4 bolt pattern and substituting it where the 44 was?

Perhaps the front derailleur would need to be moved up to accomodate the new
ring?

Will I likely need a new chain?

Thanks,
Chris

Chris
Your Alpha drive will be a 104mm bolt circle diameter. I believe the only way you can go to a larger chain ring is to swap crank sets. I am pretty sure 44 is tops for that one.
Dan

C.J.Patten said:

I'd like to install a 50-tooth large front ring.

Is this as easy as walking into a well equipped bike shop, buying a new ring
with a 4 bolt pattern and substituting it where the 44 was?

Perhaps the front derailleur would need to be moved up to accomodate the new
ring?

Will I likely need a new chain?

Yes to all. I think the hardest part, though, will be finding a 50
tooth 104mm BCD ring. The largest I could find is a 48 tooth:
http://harriscyclery.net/site/page.cfm?PageID=49&SKU=CR3661

A 50 tooth may exist, but I couldn't find it quickly.

Jeff

Dan Burkhart said:

Chris
Your Alpha drive will be a 104mm bolt circle diameter. I believe the only way you can go to a larger chain ring is to swap crank sets. I am pretty sure 44 is tops for that one.
Dan

Oops. I just checked one of my catalogues, and I find I was not correct in my assertion. Turns out there is a 46 tooth ring for a 104mm BCD.
Dan.

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

Quoted message said:

Yes to all. I think the hardest part, though, will be finding a 50
tooth 104mm BCD ring. The largest I could find is a 48 tooth:
http://harriscyclery.net/site/page.cfm?PageID=49&SKU=CR3661

A 50 tooth may exist, but I couldn't find it quickly.

Jeff

That's really above and beyond the call of duty Jeff - thanks for doing the
research.
I'll keep looking but you may be right. Perhaps I'll have to replace the
whole front drivetrain with a 5-bolt.

Any brand suggestions? It's being used on a 20" wheel folding bicycle for
touring.

Thanks again Jeff.

Regards,
Chris

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

Quoted message said:

Dan Burkhart said:

Chris
Your Alpha drive will be a 104mm bolt circle diameter. I believe the
only way you can go to a larger chain ring is to swap crank sets. I am
pretty sure 44 is tops for that one.
Dan

Oops. I just checked one of my catalogues, and I find I was not
correct in my assertion. Turns out there is a 46 tooth ring for a 104mm
BCD.
Dan.

Thanks Dan. Even if it went up to 48, I'm looking at 50+ teeth so it looks
like a crank swap. 🙂

Recommendations welcome. I understand steel lasts longer so I'm not adverse
to that. Can't really afford DuraAce, nor am I that concerned about weight.

Cheers,
Chris

Dan Burkhart said:

Chris
Your Alpha drive will be a 104mm bolt circle diameter. I believe the
only way you can go to a larger chain ring is to swap crank sets. I am
pretty sure 44 is tops for that one.
Dan

Salsa makes a 46 and a 48 in a 104BCD

http://www.salsacycles.com/comps_chainrings.html

-n

Per C.J.Patten:

Quoted message said:

Is this as easy as walking into a well equipped bike shop, buying a new ring
with a 4 bolt pattern and substituting it where the 44 was?

Others who know more can probably fill in the details, but my experience has
been "maybe, but probably not". One thing is the number of teeth difference
your der can handle - smallest chainring vs the new large one. If 44 has you at
the limit....

I'd bet on a new chain - or another quick link and some extra links in the
existing one. Personally, I'd opt for the new chain.
--
PeteCresswell

"C.J.Patten" <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

Recommendations welcome. I understand steel lasts longer so I'm not
adverse to that. Can't really afford DuraAce, nor am I that concerned
about weight.

Cheers,
Chris

Once again, let me wave the flag for the Sugino XD300 as the best crank
deal in the universe. Gorgeous finish, steel rings that look like aluminum,
and it can be had for under $50. It comes stock as a 46/36/26 triple, but
110mm BCD compact road rings in the mid-50s can be had easily. My Veloce
triple FD didn't like a 50/36/26, but only on the 36->26 shift with the FD
clamped that high. If you ditch the granny (which would be fine if you have
20-inch wheels), you shouldn't have any problems with any FD that can
handle 14 teeth, and most doubles can do 15.

Have a look:

http://store.airbomb.com/ItemDesc.asp?IC=CR1032

-Hank

I'll look it up! Thanks! 🙂

Chris

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

Quoted message said:

"C.J.Patten" <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

Recommendations welcome. I understand steel lasts longer so I'm not
adverse to that. Can't really afford DuraAce, nor am I that concerned
about weight.

Cheers,
Chris

Once again, let me wave the flag for the Sugino XD300 as the best crank
deal in the universe. Gorgeous finish, steel rings that look like
aluminum,
and it can be had for under $50. It comes stock as a 46/36/26 triple, but
110mm BCD compact road rings in the mid-50s can be had easily. My Veloce
triple FD didn't like a 50/36/26, but only on the 36->26 shift with the FD
clamped that high. If you ditch the granny (which would be fine if you
have
20-inch wheels), you shouldn't have any problems with any FD that can
handle 14 teeth, and most doubles can do 15.

Have a look:

http://store.airbomb.com/ItemDesc.asp?IC=CR1032

-Hank

C.J.Patten said:

That's really above and beyond the call of duty Jeff - thanks for doing the
research.

What research? I just know where to look things up. 8-)

Quoted message said:

I'll keep looking but you may be right. Perhaps I'll have to replace the
whole front drivetrain with a 5-bolt.

Any brand suggestions? It's being used on a 20" wheel folding bicycle for
touring.

You've been pointed to the Sugino XD300- that looks like a screaming
deal. Finding a 50 tooth ring shouldn't be too tough, considering this
is the new "standard" for "compact" cranks.

Most of my bikes are 110mm bolt pattern, so I've got a variety of
chainrings for this. Track down an old-time bike shop (one that's been
in business for 20 or more years) and see if they've got an assortment
of rings. I'm lucky to have a couple shops like that nearby (Portland,
OR).

Jeff