Gravel Bikes with Shimano Cranks

[guru]

Have a Focus Paralane with Shimano 6800 group. Find that I have to constantly trim the front derailleur on mixed terrain rides. Front derailleur is set up spot on. LBS told me that upgrading to a 8000 crank and derailleur might help because of the 8000 cranks has been modified to deal with the 142mm disc spacing Another LBS believes that its because of the frame geometry and can't be changed with the new crankset

[oldpotatoe]

Originally Posted by guru

Have a Focus Paralane with Shimano 6800 group. Find that I have to constantly trim the front derailleur on mixed terrain rides. Front derailleur is set up spot on. LBS told me that upgrading to a 8000 crank and derailleur might help because of the 8000 cranks has been modified to deal with the 142mm disc spacing Another LBS believes that its because of the frame geometry and can't be changed with the new crankset

From RoadBikeReview forum in June, 2017.

The only difference is that the crank has moved the small ring inboard by .4mm and kept the large ring in the original position. The front derailleur has been profiled to allow it to move closer to the seat tube before it contacts and stops moving. Most bikes will have no issue here, but a handful may find their older derailleur may not be capable of moving far enough inboard to stop chain rub in the climbing gears. Not may bikes will have this issue, but a few will.

I'm thinking that a new rear der(8000) 'may' result in less need to trim but I kinda doubt it.

[merlinmurph]

FWIW, I have a Seven Evergreen bought in '16 with 6800 disc and no issues like yours. Lots of gravel riding in the small ring, especially where we are outside Asheville NC right now. I'm kinda curious how you resolve this.

[boomforeal]

Originally Posted by oldpotatoe

From RoadBikeReview forum in June, 2017.

i'm reading the OP's dilemna not as his "derailleur may not be capable of moving far enough inboard to stop chain rub in the climbing gears", but as he's having to trim while in the climbing gears in order to stop chain rub

Originally Posted by oldpotatoe

I'm thinking that a new rear der(8000) 'may' result in less need to trim but I kinda doubt it.

i can't see how a new rear derailleur could address front shifting issues - can you elaborate?

Originally Posted by guru

Have a Focus Paralane with Shimano 6800 group. Find that I have to constantly trim the front derailleur on mixed terrain rides. Front derailleur is set up spot on. LBS told me that upgrading to a 8000 crank and derailleur might help because of the 8000 cranks has been modified to deal with the 142mm disc spacing Another LBS believes that its because of the frame geometry and can't be changed with the new crankset

1x ftw

[oldpotatoe]

Originally Posted by boomforeal

i'm reading the OP's dilemna not as his "derailleur may not be capable of moving far enough inboard to stop chain rub in the climbing gears", but as he's having to trim while in the climbing gears in order to stop chain rub



i can't see how a new rear derailleur could address front shifting issues - can you elaborate?



1x ftw

I saw that but was commenting on the one LBS saying the 8000 crank was optimized for 135/142mm rear triangles..moving the small ring inboard would do that, since a 135/142mm cogset is a bit further inboard but only .4mm....

Mis-typed..meant new 8000 FRONT der..

[mattsurf]

Just done a Gravel bike build with Shimano R8020 groupset, and can confirm that both front and rear derailleurs work much better than 6800, with no rub on the front derrailleur whatever gear is selected on the rear.

[Clean39T]

I find R8000 FD shifting and setup to be awful with a Parlee FD clamp. I've been unable to get it perfect once after attempting on three different bikes, regardless the chainrings on the R8000 (compact, mid, standard).

Zero issues w Campy 10 of course. Works first time, every time.

Sent from my Pixel 2 XL using Tapatalk

[zennmotion]

Originally Posted by guru

Have a Focus Paralane with Shimano 6800 group. Find that I have to constantly trim the front derailleur on mixed terrain rides. Front derailleur is set up spot on. LBS told me that upgrading to a 8000 crank and derailleur might help because of the 8000 cranks has been modified to deal with the 142mm disc spacing Another LBS believes that its because of the frame geometry and can't be changed with the new crankset

My 6800 gravel bike works great with a CX70 front derailleur once set. My issue was the long arm running into the rear tire, but the cage is also wider than 6800. Try something with a wider cage, even an older 9speed model might work fine.

[93KgBike]

FWIW, I am finding that 7400 works great with a 7800 crank on CX bike. Keep fiddling.

[cachagua]

I don't know this equipment very well, is there indexing in the front shifter? Can you switch it to a friction mode? When you have to trim, it's because the index positions aren't putting the derailleur where you want it.

With a double crank, the only positions the derailleur properly needs to be in are the limits of derailleur travel.

(The shop that says the cure for this problem is to buy a new parts group... that's not a shop I'd go to again. Come to think, a shop that says the problem's due to frame geometry is essentially saying the solution is to buy a new frame, or bike. Don't guess I'd go back there either.)

[macaroon]

The Focus looks like it's got short stays (415mm), the stays on most gravel bikes will be 20 to 40mm longer which'll no doubt help the derailleur/chain positions. I think Another LBS are talking sense.

[bigbill]

My gravel bike has a 9100 Dura Ace front derailleur. I wanted an 8000 but they were on back order at the time. I use it with a 6800 crankset 36/46. It was kind of a hassle to set up, but I haven't touched it in a year and around 4000 miles. IMO, the 8000/9100 front derailleurs are some of the best products to come from Shimano since the Antares low profile baitcasting reel.

[oldpotatoe]

Originally Posted by bigbill

My gravel bike has a 9100 Dura Ace front derailleur. I wanted an 8000 but they were on back order at the time. I use it with a 6800 crankset 36/46. It was kind of a hassle to set up, but I haven't touched it in a year and around 4000 miles. IMO, the 8000/9100 front derailleurs are some of the best products to come from Shimano since the Antares low profile baitcasting reel.

I'll add 5801 front der..Too bad shimano 'beta tested' 5800/6800/9000 first.

[Gummee]

Originally Posted by zennmotion

My 6800 gravel bike works great with a CX70 front derailleur once set. My issue was the long arm running into the rear tire, but the cage is also wider than 6800. Try something with a wider cage, even an older 9speed model might work fine.

That's my setup on the CX bike. Works great.

Haven't tried an older derailleur 'cause I've got a spare CX70 for the next build(s)

M

[Big Dan]

I like my 5800 FD over my 8000 any day of the week.
Actually have an extra one for the next build.