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Front Derailleur Rubbing (Shimano 105 R7000)

by steve_s1
Mon, Aug 02, 2021 17:49
8

I recently bought a Specialized Tarmac SL6 with 105. Very happy apart from one annoyance; the 105 R7000 front derailleur rubs on the chain.

I own 2 other road bikes with older 105 and both allow me to ride with the big front chainring and get the complete range of the cassette with no rubbing, but with the new R7000 it seems I can adjust the cage so that with big front chainring I get no rubbing on the 2 largest cassette rings or the 2 smallest cassette rings but not rub-free at both ends at the same time. The cassette is 11-30, and the rear derailleur is long cage version.

I know when I'm in the big cassette and big chainring I'm cross-chaining, but that doesn't seem to be a problem on my other bikes and I'm used to riding this way on short / shallow hills, where I prefer not to keep shifting to the small chainring.

I'm tempted to bend the cage out slightly to eliminate the rub, but that's probably not recommended!

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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8 comments

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PRSboy | 3 years ago
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I'd always laboured under the misapprehension typically put about by youtube videos that you index a Shimano front mech in the big ring position.  It was only when I read the Shimano manual for my Ultegra 6800 that I discovered that the cable tension is set in the trim position below the big ring.  This then means the trim position works properly, giving more scope for 'extreme' gear combinations.

From a look at the R7000 manual, you still do this, but it looks different as you use indicators to set the cable tension... see P18.

https://si.shimano.com/pdfs/dm/DM-RAFD001-05-ENG.pdf

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IanEdward | 3 years ago
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I've got to admit, as a 2x drivetrain die hard ("how hard can it be to set up a front mech"?) I find Shimano's new front mechs really challenging, the trim feature on a GRX 812 front mech and existing 105 R7000 front mech basically stopped working fairly quickly.

In fact, in 20 years spannering I don't think I've ever struggled as much with front mechs as I have with most recent generation Shimano.

Would suggest making sure all cables are new, clean, routed as smoothly as possible and ideally highest quality, I think this is the only thing that has really worked for me, and even then the 'least rubby' set up is also the 'only grudgingly shifts into big ring' set up 

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kil0ran | 3 years ago
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The alignment method for R7000 is very different to conventional front mechs, have a read of the dealer manual and watch a few videos on it. It's tricky to get right.

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mike the bike replied to kil0ran | 3 years ago
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kil0ran wrote:

The alignment method for R7000 is very different to conventional front mechs, have a read of the dealer manual and watch a few videos on it. It's tricky to get right.

Aah, but so worth it; my R7000 gears are the sweetest I've ever owned.  In fact I'll probably not bother with Ultegra again, the difference in performance is negligible but the difference in price is considerable.

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kil0ran replied to mike the bike | 3 years ago
1 like

Agreed, I put the revised FD-5800 on both my bikes which were running Tiagra 4700 to get the improved front shifting. Also improved clearance on the gravel/tourer for mudguards and big tyres. First one took 2 hours to get right, second one about 10 mins. 

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james.bowman | 3 years ago
1 like

See if you can find the Shimano manual for the R7000 online in PDF form. Most modern Shimano front derailleurs have a trim setting to allow you to move the cage over slightly to accommodate the opposite extremes of the cassette when in the small and large chain rings.

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steve_s1 replied to james.bowman | 3 years ago
1 like

Thanks for the suggestion. I think you are right, I should be able to use the trim. It doesn't seem to work currently and after some research I think this could be due to the cable tension not being high enough. There are some marker lines that should line up but they don't. I'll tinker some more.

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Judge dreadful replied to steve_s1 | 3 years ago
2 likes

If you look at the R7000 front mech, it's quite different to that found on earlier versions of the 105 groupset. The cable routing is a bit 'odd' compared to earlier versions, and It's got a kind of little trap door thing on the top of it. When I upgraded a Sora equipped bike to R7000, a few years ago, the front cage did rub the chain at extremes of chain line, and the trim wasn't doing the job. I checked the cable routing, which I had managed to get slightly wrong, corrected it, and then the trim worked, and it solved the problem.

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