• Achtung, achtung!  :)

    During July 27th 2024 (or 28th, depending on your time zone), hosting server maintenance is planned and the forum will not work normally (we'll set it to read-only mode at best, though it will be completely offline for a while). Hopefully, it will all go well and we will be back on line within less than 8 hours.

    Thank you in advance for your patience.

    Note, this has nothing to do with the planned forum upgrade to version 2.3, which will most probably happen at a later date (probably in Autumn).

    Relja

46 - 30 subcompact crankset compatability with FB

marcus81

Cadence Cadet
Hi,
I am running a 46/30 10 speed setup. My shifters are 10 speed 105s.
My problem is that the standard 5700 front derailleur hits the chainstay when the chain is on the inner ring.
Off course i can move the FD higher, but that leads to shifting problems 'cause the FD is too high.

do you have any experience with this issue?

thanks.
 
Solution
Hi,
I am running a 46/30 10 speed setup. My shifters are 10 speed 105s.
My problem is that the standard 5700 front derailleur hits the chainstay when the chain is on the inner ring.
Off course i can move the FD higher, but that leads to shifting problems 'cause the FD is too high.

do you have any experience with this issue?

thanks.

Hi Marcus,

Hopefully, by the start of 2024, the software running this forum will allow for adding the quick-jump (i.e. anchor) links (I'm avoiding any custom-coding, as that could break upon the software update, so it is how it is for now).
Until then, I suppose you'll have to manually scroll to the "Short(er) answer" section. :)

1. Explaining the problem​

Yes, I have the exact same...
Hi,
I am running a 46/30 10 speed setup. My shifters are 10 speed 105s.
My problem is that the standard 5700 front derailleur hits the chainstay when the chain is on the inner ring.
Off course i can move the FD higher, but that leads to shifting problems 'cause the FD is too high.

do you have any experience with this issue?

thanks.

Hi Marcus,

Hopefully, by the start of 2024, the software running this forum will allow for adding the quick-jump (i.e. anchor) links (I'm avoiding any custom-coding, as that could break upon the software update, so it is how it is for now).
Until then, I suppose you'll have to manually scroll to the "Short(er) answer" section. :)

1. Explaining the problem​

Yes, I have the exact same problem with my commuter-haul-kids-and-groceries-trailer bicycle (42-32-22 cranks, friction shifters, trekking bike frame). :)

Even with friction shifters, the front shifting is less than ideal, because my FD is placed abut 1 cm higher than optimal, in order to avoid hitting the chainstay.

To fix the problem, I would have to use some 48-38-28 cranks, but that is not low enough for the steep climbs when hauling heavy luggage (not past 40 years of age at least :) ).

As far as I know, there is no really good solution to that problem, apart from using larger chainrings, putting up with poor shifting and occassional chain drops when riding fast over bumpy terrain, or using the good old triple cranks. :)

Similarly to that, my gravel bike has its water-bottle cage mount set so that I can't get the FD low enough for the 46-30 cranks (with 50-34 cranks, I could put some spacers and mount both the bottle cage and the FD clamp).

For that bike, a solution for lower gearing would be to use some triple cranks. The problem with triple cranks is that most shifter manufacturers have decided to not make mid or high-end shifters for triples.

Shimano Claris still does the triple brifters (3x8).

I run friction shifters on all my bikes (commuter, and "gravel" or "a decent road bike that can take a few bumps and some luggage" as I prefer to call it :) ). Quality, durability and robustness of modern brifters is appaling in my opinion, while the pricing is exorbitant (again, from my point of view).

2. Short(er) answer :)

Having said that, I am fully aware that most normal people very much prefer the ergonomics and click shifting of modern brifters, as well as mid to high end groupsets (as opposed to "settling" for Shimano Claris).

2.1. Solution 1​

With that in mind, I would mention the Gevenalle bomb-proof “brifters” as perhaps an acceptable compromise in terms of ergonomics.

That should allow for running triple cranks.

2.2. Solution 2​

Another option would be going with a larger cassette (an MTB one), and adding a RD hanger extension - see my video Pairing Shimano 11speed MTB cassette with a road groupset.

That should allow for some lower gearing (thanks to larger cassette sprockets), even with 50-34 cranks.

I hope this helps.

Relja BrevityIsNotMyVirtue Novović
🙃
 
Solution
I have a similar problem wanting to use fd ultegra 6700 levers with 46-34 chainrings. I don't know if it would be possible to use the 9-speed fd Sora 3000: as the chain is wider, the cage is wider, as seen on https://bike.bikegremlin.com/1297/bicycle-front-derailleur-compatibility/#7.

The extra cage width of the 9-speed Sora should not be a problem.
Other things can be a problem: FD mounting angle, its cage shape (should match the largest chainring's curve) etc.

The details explaining what should be matched (what to pay attention to) are in the front derailleur compatibility article.

Relja
 

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