Tiagra 4700 crank 50-34 vs 52-36 compatiblity
06-26-23, 06:51 AM
#1
Junior Member
Thread Starter
Join Date: Jul 2014
Posts: 176
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 126 Post(s)
Likes: 0
Liked 11 Times
in
9 Posts
Tiagra 4700 crank 50-34 vs 52-36 compatiblity
I currently have 50-34 on my gravel bike. Soon it will be time to replace chainrings.
I want to leave 34 at the bottom (because I climb a lot), but can I put 52 chainring on the top (for more top speed), will it be compatible when it becomes 52-34? Or it can only go as 50-34 or 52-36 combinations ?
I want to leave 34 at the bottom (because I climb a lot), but can I put 52 chainring on the top (for more top speed), will it be compatible when it becomes 52-34? Or it can only go as 50-34 or 52-36 combinations ?
06-26-23, 08:09 AM
#2
Senior Member
Join Date: Jun 2002
Location: Montreal, Quebec
Posts: 5,946
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1829 Post(s)
Liked 1,706 Times
in
982 Posts
The extra 2 tooth gap between the chainrings may create problems shifting from ring to ring. However I am surprised that your 50 tooth ring has worn out sooner than the 34 tooth ring
06-26-23, 08:27 AM
#3
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 2026 Post(s)
Likes: 0
Liked 1,096 Times
in
742 Posts
Shimano specifies their chainrings in matching pairs for optimum shifting so going to a 52T chainring from a 50T may compromise shifting slightly but it will certainly work. Now a couple of unsolicited comments/questions:
Are you sure your 50T chainring is really worn out? The shaped teeth Shimano uses as shifting aids can look like worn teeth but they are intentional. It takes a lot to wear out chainrings unless you ride in dreadfully abrasive conditions a lot.
Also, do you really spin-out in the 50T chainring and your smallest rear cog? A larger chainring won't let you ride any faster unless you are strong enough to take advantage of it.
Are you sure your 50T chainring is really worn out? The shaped teeth Shimano uses as shifting aids can look like worn teeth but they are intentional. It takes a lot to wear out chainrings unless you ride in dreadfully abrasive conditions a lot.
Also, do you really spin-out in the 50T chainring and your smallest rear cog? A larger chainring won't let you ride any faster unless you are strong enough to take advantage of it.
06-26-23, 11:46 AM
#4
working on my sandal tan
Join Date: Aug 2011
Location: CID
Posts: 22,630
Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers), All-City Space Horse (hers)
Mentioned: 98 Post(s)
Tagged: 0 Thread(s)
Quoted: 3871 Post(s)
Liked 2,571 Times
in
1,579 Posts
06-26-23, 09:27 PM
#5
Senior Member
Join Date: Jul 2005
Location: Boulder County, CO
Posts: 4,404
Bikes: '80 Masi Gran Criterium, '12 Trek Madone, early '60s Frejus track
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 517 Post(s)
Liked 452 Times
in
339 Posts
It's not optimal, since Shimano front derailleurs are designed for a maximum jump of 16t, and the rings are designed as pairs in 50-34 or 52-36. Personally, I've only spun out a 50/11 at speeds over 39 mph, so my first thought is learn to turn the cranks faster.
06-27-23, 02:30 AM
#6
Mostly harmless ™
Join Date: Nov 2010
Location: Novi Sad
Posts: 4,430
Bikes: Heavy, with friction shifters
Mentioned: 22 Post(s)
Tagged: 0 Thread(s)
Quoted: 1107 Post(s)
Liked 216 Times
in
130 Posts
I would expect it to negatively affect shifting.
Jumping from 50 to 52 teeth, with an 11-tooth rear sprocket, on a road bike, with a 90 rpm cadence, should let you ride some 2 km/h faster (from about 52 km/h to about 54 km/h).
Sounds like a silly idea to me, but it's your bike, your choice, and if you think it is cool, the only price would be a bit slower front shifting, most probably.
Relja
Jumping from 50 to 52 teeth, with an 11-tooth rear sprocket, on a road bike, with a 90 rpm cadence, should let you ride some 2 km/h faster (from about 52 km/h to about 54 km/h).
Sounds like a silly idea to me, but it's your bike, your choice, and if you think it is cool, the only price would be a bit slower front shifting, most probably.
Relja
06-27-23, 04:35 AM
#7
Junior Member
Thread Starter
Join Date: Jul 2014
Posts: 176
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 126 Post(s)
Likes: 0
Liked 11 Times
in
9 Posts
I see that 52 chainring is more available in the stores while 50 is often sod out, thats why I was thinking could I go with 52 next.
After reading comments about possible shiftinig problems, I will stay on 50 when the time comes.
And yes, I do spin out on 50 on descents, but I guess thats normal.
