Brand New Cannondale Topstone

[Eziemnaik]

Wonky or not the truth is the new FD from Shimano seem to have more problems with trimming and rubbing than some of the old ones

 

[KT004]

Big /Big and Small/ small (physical size of rings/sprockets) you might expect it to rub a tiny bit and you shouldn't use these (and immediately adjacent) ratio's anyway as it is "cross chaining" too much, but it should not rub at all in any other ratio if the FD is set up properly and you are using the Trim positions correctly.

As for them bending the FD cage to try to alleviate the problem (if that's what they were doing), I'd be wanting a replacement FD and be using a difference shop / mechanic to get it set up properly. All that will do it make the shifting poor as the cage internal width will be too much to shift both up and down crisply.

Hi tomo
I made them replace FD and went out on bike today. It seems from some of the posts that I should expect some rubbing on the FD in certain gears and to clarify from this mornings ride i got rubbing in the small front ring while in small ring at back and when in the big front ring I got rubbing in the smallest ring at back (which I believe is top gear) and then the bottom three i.e. the three at the other end. I'm getting used to the trims but the fella in the shop told me the trim will only work when I'm in the top ring at front. To cap it all off the saddle feels like it clicks on something. I love the bike and just feel let down by the shop which indecently is Evans cycles so a big chain store. From your text above you feel it should only really have small rub in the gears you've specified and everything else should be relatively smooth?

 

[KT004]

When you say "big big" do you mean big ring and sprocket or big gear big gear?
If its the latter ie big front ring and smal rear sprocket (therefore big gear) then that would create too much cross over and would certainly cause rubbing.
Bending the derailleur? don,t go back there.

Hi it does rub in big ring sprocket and small sprocket at back (top gear). are you saying this is not a gear to ride in and you would expect chain rub here. (I mean its a hard gear so would probably only be in it downhill)

 

[KT004]

Agreed that the chain is irrelevant.
Forgive me if this is obvious to you but it is the case with everything that I have ridden that on occasions when riding you need to "trim" the front shifter with a nudge (in the opposite direction) following a change on the back to stop this happening.
However, I would doubt the shops expertise on this from what you have said.

ive only just discovered what the trim mechanism does, and the fella in the shop did not seem to know and said it would only work when I was in the big ring at the front. I love the bike and just want to be confident its set up right. ive contacted one of there other stores a bit further away and will take it to the mechanics there to hopefully get it done, just to clarify chain rub in certain gears to be expected if chain crossed but should be minimal

 

[Teamfixed]

Hi, that's good, the trim should work for any position. Yes chain rub is always very likely if there is too much chain cross. With a 2x10 for example you would typically have a maximum of 18 usable positions of front and back chain ring and rear sprocket.

 

[T4tomo]

expect some rub on red positions (which you shouldn't use)

if you are getting rub on big front ring and small rear sprockets, it could be as simple as setting the upper limit screw out quarter / half a turn - look at a youtube video on front derailleur set up if in doubt. - this will / should move the FD cage out slightly to stop rub, but not let he chain slip right off the big ring outwards, but still shift back down to little ring when you change down

 

[Ajax Bay]

When in the large chainring and the smallest sprocket, your chain should NOT touch the outer cage plate of the FD. The gap should be at least 0.5mm. Same when you're in small chainring and the largest sprocket (your lowest gear): gap of 0.5mm to the inner cage plate of the FD.
The LBS will know this and adjust the FD so both these requirements are met. The talk you heard about 'shouldn't use gears' is the cross-chaining which @T4tomo has illustrated.

 

[Chislenko]

Hi tomo
I made them replace FD and went out on bike today. It seems from some of the posts that I should expect some rubbing on the FD in certain gears and to clarify from this mornings ride i got rubbing in the small front ring while in small ring at back and when in the big front ring I got rubbing in the smallest ring at back (which I believe is top gear) and then the bottom three i.e. the three at the other end. I'm getting used to the trims but the fella in the shop told me the trim will only work when I'm in the top ring at front. To cap it all off the saddle feels like it clicks on something. I love the bike and just feel let down by the shop which indecently is Evans cycles so a big chain store. From your text above you feel it should only really have small rub in the gears you've specified and everything else should be relatively smooth?

Hi tomo


just feel let down by the shop which indecently is Evans cycles so a big chain store.

That's probably why they had to take a link out as they are a "big chain" store!!

 

[T4tomo]

Hi tomo
..... and just feel let down by the shop which indecently is Evans cycles ....

absofarkinglutely indecent of them. perfect incorrect autocorrect

 

[KT004]

yep autocorrects done me there and the big chain gag,,,, that's a cracker

thanks for all your help guys appreciate it

 

[itboffin]

So i've just taken delivery of a carbon topstone 5 and have the same issue, not cross chain rub or bad indexing (which it came with) but rubbing when i'm in the large chainring and smallest sprocket 11T when pushing down hard on the pedals i.e. climbing or sprinting, as its a solid carbon frame i can only imagine this is down to flex in the crankarms and or bottom bracket, both Cannondale.

Further to this i have a CAAD12 which i've upgraded to Ultegra R8000 groupset but not the BB or cranks (again Cannondale) and that has the same problem, i'm a pretty experienced home mechanic even so its been to two LBS neither were able to fix the out of saddle rubbing.

My next step is replace the BB & cranks with Shimano so its a complete matching groupset if that fails both will be changed to 1x SRAM AXS, 100% no chance of rubbing or internal cable rattles.

 

[Smokin Joe]

So i've just taken delivery of a carbon topstone 5 and have the same issue, not cross chain rub or bad indexing (which it came with) but rubbing when i'm in the large chainring and smallest sprocket 11T when pushing down hard on the pedals i.e. climbing or sprinting, as its a solid carbon frame i can only imagine this is down to flex in the crankarms and or bottom bracket, both Cannondale.

It probably needs the high limit screw let out a fraction. When you press hard on the pedal the chainring will flex slightly outwards hence the chain rubbing at that point.