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FSA Pro Compact 50T chainring vs Shimano 105 FC5750

by mikebounds
Tue, Jun 20, 2017 21:59
9

Does anyone know how FSA Pro Compact 50T chainring compares to Shimano 105 FC5750.

I have an mainly Ultegra 6700 drivetrain  (at least shifters and derailuers and Ultegra) and the chainring is worn so I am looking at the following:

Shimano 105 FC5750 10 Speed Compact    £27.00
FSA Super Pro Compact N11     £30.00
FSA Pro Road Compact     £36.00
Shimano Ultegra FC6650 Compact    £60.00

£60 sounds a lot unless Ultegra shifts considerally better than 105, so was thinking of going for Shimano 105, but was wandering if anyone knew what FSA was like?

Thanks

Mike

 

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9 comments

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mikebounds | 7 years ago
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I don't really know what the "FSA copy" was as there was no brand on it at all, so I suspect it was "Driveline" as this is the only one I can find that doesn't always put its brand on and looked very similar and you can get these for about £25, so I don't know what you can expect from these, but the 105 chainring, visably, has much clearer profiling on the teeth

The bike shop did try adjusting the chainring and it changed gear fine on the rack, but not under load when I cycled, but I agree that you would think even a bottom range chainring should change quicker than 20-30 seconds,  but I really have no idea of what you should expect from a chainring ranging from £20 to £60:

For my old Tiagra chainring it would take 1-3 seconds to change up to 50T, but this did not bother me as I only use 34T on steep long hills  (above 8%) and even on tough 100km + event, you only get about 4 hills this steep, so I am only changing back up to 50T 4 times for the whole event after gettting to top of hills and for all other hills less than 8% I stay on the 50T.

For my new 105 chainring, most of the time it changes up sub 1 second, almost as smoothly as cassette gear changes and occassionly the 50T may not catch and it takes a second or 2.

Mike

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Dnnnnnn replied to mikebounds | 7 years ago
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mikebounds wrote:

most of the time it changes up sub 1 second, almost as smoothly as cassette gear changes and occassionly the 50T may not catch and it takes a second or 2.

I would say that's about the acceptable range for properly set-up kit - a good change is almost instant and imperceptible (apart from you being in a different gear!) and a not very good change feels a bit clunky, and noticeably (but not much) slower under load, but still only taking a second or two.

Cheap new rings mightn't achieve the top end of the acceptable range - but they should manage  the lower end. I suspect the rings used by pros a few decades back were pretty primitive compared to even today's modest things but I'm sure they they still shifted pretty smartly!

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mikebounds | 7 years ago
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The Shimano 105 FC5750 50T chainring has now been fitted and shifts a lot better than the briefly fitted "FSA copy" and shifts better than my old Tiagra chainring, but this maybe more to do with the fact that the Tiagra chainring was worn, rather than 105 is one step up from Tiagra.

Mike

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mikebounds | 7 years ago
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Thanks for all the replies - my local bike shop have just put on an "FSA copy" and this didn't shift very well so I have ordered the Shimano 105 FC5750, so hoping this will shift as least as well as the Tiagra 50T that was taken off (seem everything is Ultegra apart from chainrings and crank).

I'd rather it shift well than save a few grams or it last a little longer - I never thought about shifting with my old (very worn) Tiagra chain ring - it always shifted from 34T to 50T first time, but the "FSA copy" my bike shop put on rattled round for up to 20-30 seconds sometimes before it went in.

Mike

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Dnnnnnn replied to mikebounds | 7 years ago
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mikebounds wrote:

the "FSA copy" my bike shop put on rattled round for up to 20-30 seconds sometimes before it went in.

Surely that would be just a slight adjustment thing? I could understand a slight difference in shifting speed and accuracy, especially under load, due to minor profiling, ramps, pins, etc. but failing to complete a change for such a long period suggests that the "FSA copy" just needed a slight adjustment. Black mark for your LBS.

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BehindTheBikesheds | 7 years ago
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Not the same shape/design but Stronglight Zicral, Miche or TA Alize, very hard wearing and plenty stiff enough.

I actually sent off a 50T/110 steel ring to a missionary chap in Maylasia earlier this year that was from an 80s Sugino compact chainset. These do 20,000 miles easily but very hard to find.

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turnerjohn | 7 years ago
1 like

FSA Super Pro seem to last forever ! They last far longer than Shimano but as above posts say don't shift quite as well. Personally I'd go for the FSA ones every time 

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Carton | 7 years ago
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The Super is actually a bit more premium than the Pro. It actually looks a bit more like the Ultegra one than the 105, IMHO.

FSA probably a bit lighter, Shimano probably shifts better, but YMMV. I have an FSA crankset and it does the job. 

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TypeVertigo | 7 years ago
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My bike came stock with an FSA Omega 46/36 crank. As far as I can tell, Omega is the bottom tier for their two-piece cranksets. Worked fine for the most part, but I did have a couple instances of chain suck shifting from big to small ring. Just those couple instances though. I think it went away after I swapped chains.

Eventually traded it for the 105 FC-5750 because I wanted the wider gear range - and it so happened to match the rest of the bike which ran 105 5700 everything else. Also, my Omega crank has a strange 19 mm spindle that is tough to find bottom bracket bearings for (Shimano's is 24 mm).

I don't think you'll be disappointed with FSA chainrings. I was surprised even the BB86 bottom bracket bearings were in good condition after lots of riding in the wet for a year or so.

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