I was wondering if anyone has had any experience installing the THM crankset to the Dogma? I have a new Dogma 2 EPS and it seems that the Q factor isn't wide enough for the crank to support the shifting. I have seen dogma's with the THM crankset installed just wondering how they did it? The issue i have is when the chain is in the largest ring in the front and i shift to the top 3 largest cogs in the rear cassette, there is chain rub on the front derailleur cage. The bike is with the dealer in Florida and they are trying to figure it out as well. Didn't know if there needed to be a spacer involved in the bottom bracket or not.

They have tried the 30 different adjustments on the new EPS system to get it to work, but there still seems to be some rub on the front cage. IF this crankset works for the cable system not sure why it's not workng for the EPS?

Any thoughts? or any help would be greatly appreciated!

Setup, is a THM Standard Crankset w/ 53/39 Chainrings, and Praxis Classic rings.

This doesn't address your technical issue - but why would you even want to be in the big ring in front, and top 3 gears in the rear? That chainline is sure to be terrible no matter what your derailleur rub situation is. Shift to the low ring in front when you are at a point that you need to be using the upper 1/3 of your cassette when in the big ring.

you have a point, but on the cable system I was able to be in the upper three rings with in the big chain-ring in the front. My old set up was a Zipp Vuma quad w/ Super record Ti. just because i go electric doesn't mean it should limit my options. I think if you look at the campy eps videos you will see that you can be in the large chain ring and shift through all gears w/o any rub. not sure what's going on.

Yes, I completely agree. Its frustrating that it *should* work, and doesn't. I'm just saying, on the good side, its probably one of those things that would make you a more efficient biker if you didn't do.. or so I'm told.. Anyway, you need someone with actual experience on those pieces of equipment to weigh in.. and sadly, I do not (I would sure like to though!).

my first guess is that it is a front derailleur cage alignment issue.
what chainrings are you using? -edit- reread your post and noticed you mentioned the Praxis rings.
can you take pics of your front derailleur setup, mainly from directly above, and from the side in profile?
thanks.

and just as an fyi, "q-factor" is the left-right distance of the pedal mounting faces of the crank arms, nothing more, so it does not pertain to the chainrings. you may have meant "chainline", although im not sure how that would apply either.

You definitely don't need to add a spacer to increase Q-factor as you will be making the chainline from big ring to large sprockets worse.

The clavicula already has a wide q factor, from memory, I think it's about 5mm wider than Campag ultra torque.

We are talking about the chain on the big ring at all times here, right?

I don't see how this could have to do anything with the crank, unless it's way out there from the norm, which it's not.

I know like nothing about EPS, but if the FD cage is wide enough to really allow all eleven sprockets in the rear without trimming, then it's just a matter of putting it into the right position.

I don't see why Campagnolo would design the cage like that though, when they apparantly use an auto trim function. Sounds to me like that doesn't work "right", for whatever reason. Maybe Campagnolo wanted the chain to rub, so that you knew you were cross chaining?

_________________
"Nothing compares to the simple pleasures of a bike ride," said John F. Kennedy, a man who had the pleasure of Marilyn Monroe.

On mechanical 11 speed Campy I don't need to trim the front der position when going from sprocket 1 thru 11. Electric shouldn't have to compensate if mechanical doesn't either.

With regards to other prior posts re: staying out of the top 3 gears - while maybe top 2 should be generally be avoided, in race/aggressive situtions you do what you need to do for a short time - and that can mean a temporary time in big-big. My mech Campy does it fine without harping at me. Not idea but real life.

Tommasni,

Thank you! finally, yes i had the SR 11 TI cable system with no issue finally some one who realizes my pain! The dealer I am working with is very supportive. It seems like maybe campy doesn't want you using a third party crank. Spoke to my dealer this morning. the THM Crank is wider than the Campy crank system, so what they are looking into is a way to set the auto trim function. His concern (which is valid) is that the chain is rubbing on the outer plate which is carbon. I think we are all (dealer/ members on this forum) in agreement that the front der. is the issue.

Again, when in the largest chain ring, the top three gears in the rear cassette rub on the outer plate not the inner portion. it seems like the auto trim is the issue, a bit dissappointing as there doesn't seem to be a solution. to add to the problem that there isn't many groupset's on the market and the only eps system with a 3rd party crank was a Dogma 2 with a Rotor Crankset done by Wrench Science, but it seems you can adjust for the der. issues with the 3D crank system.

Another poster asked for pictures of the chain line, I don't have the bike with me it's in florida with the dealer as they work to assemble it. The poster who asked for the pics, thats for the definition of Q-factor, all this time i thought it was the gap between the outer left crank arm and the right side (drive train side) of the crank. learn something new every day.

Thanks again everyone for the feed back, open to more ideas.

so the chain rubs on the OUTER cage plate when in the largest, easiest cogs, when in the big ring. i'm assuming that when in the hardest cogs (11 or 12t) there is no rub, correct? so the auto trim is overcompensating...
i will look at the eps bike (happens to be a dogma2) in the shop tomorrow, and see what the adjustments there look like.

Thanks, you are correct. I appreciate the help

They don't have to, but a narrower cage shifts better and with the auto trim option of EPS they don't have to make this compromise.

_________________
"Nothing compares to the simple pleasures of a bike ride," said John F. Kennedy, a man who had the pleasure of Marilyn Monroe.

So i took a look at the bike in the shop.
Id try this:
Shift the bike into the big/big.
Hold the MODE button until the control box light turns purple.
Press the large paddle on the left shifter until the derailleur inner cage plate does not rub the chain.
Tap the MODE button.
Check shifting overall. I believe the chain will have plenty of clearance overall, including more than usual in the large ring/small cog. I think this extra clearance in the hardest gear is why your bike was adjusted how it was.
Greg

Greg, thanks again, i think that's the conclusion they came to as well since the got it solved!!!! i can't wait. will post pics soon.. what shop are you with?

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