Team BKool CycleChat

[Brendan Parker]

I used to run 11-25 but have moved to 11-28 and 11-32 on different bikes, without changing the derailleur.

I've not had any problems. I run compact cranks, both 50/34 and 52/36.

The bigger the cassette, the more you 'stretch' the chain and pull the derailleur forward in the extreme position of biggest front crank and biggest rear cassette, but that's not really a sensible combination to select anyway.

Thanks @Del C mines a 52/36 aswell understand the cross chain, think ill put a new chain on aswell maybe an extra link?

 

[Brendan Parker]

Looks like splashing out on this BKOOL was the most idiotic thing I have done this year! Nothing but problems ffs

bloody nightmare at the moment, my subscription is up next month so we ll see what happens in the next month, really enjoy Handicap and CG but if we cant even do that!

 

[peterob]

morning everyone

seeing as there is nothing to talk about last nights CG can anyone help,
I have on my road bike Ultegra Di2 with a 11 - 25 cassette on, I would like to up to a 11 - 30, I'm reading lots of different advice as to if I have to change the derailleur aswell, seen some vids saying its ok and some advising against it. anyone done similar?

I'm looking to do the same thing myself and have just bought a 11-30 cassette. I assume, like me, you have the short cage rear derailleur. There's two initial things to consider...
1) What does the spec say is the maximum cassette the RD will support? On mine (Shimano 6800 SS) it says 11-28
2) What is the maximum total tooth capacity? The spec says 33T. I'll be running 52/36 front with the 11-30, so this will be 35T ((52-36 + (30-11))

So according to the specs it isn't supported. But then it seems loads of people have had no issues running 11-30 and there is plenty of length in the b-screw to facilitate it, so I'll be giving it a go. Ideally I'd like a 32T at the back, but that'll be pushing it too far on the short-cage and I'm not going to fork out for a new RD (or cage?).

I may be making the change this weekend and will report back if I do

 

[CXRAndy]

morning everyone

seeing as there is nothing to talk about last nights CG can anyone help,
I have on my road bike Ultegra Di2 with a 11 - 25 cassette on, I would like to up to a 11 - 30, I'm reading lots of different advice as to if I have to change the derailleur aswell, seen some vids saying its ok and some advising against it. anyone done similar?

I've done loads of modification to gearing, even run 11-40 with a Di2 road setup, i digress.

Ideally you need a GS cage in the rear derailleur. I usually buy a 114 link KMC chain, fit without taking links. I then put bike in small ring front and small gear in cassette. If the chain sags, I remove one link(actually it's two, but they make one pair) .Refit and test again. If the derailleur is now giving enough tension, job done. Sometimes the 'B' screw needs adjusting to get over the large gear on the cassette.

If you have Synchro shift you can program the bike to not cross chain either big-big or small-small. Di2 is wonderful

 

[bridgy]

Only just catching up on problems- again - from last night (I am out of action with a bad back).

Has anyone emailed bkool about this or questioned them on Facebook? I am doing so now but the more the merrier ....

 

[Brendan Parker]

I'm looking to do the same thing myself and have just bought a 11-30 cassette. I assume, like me, you have the short cage rear derailleur. There's two initial things to consider...
1) What does the spec say is the maximum cassette the RD will support? On mine (Shimano 6800 SS) it says 11-28
2) What is the maximum total tooth capacity? The spec says 33T. I'll be running 52/36 front with the 11-30, so this will be 35T ((52-36 + (30-11))

So according to the specs it isn't supported. But then it seems loads of people have had no issues running 11-30 and there is plenty of length in the b-screw to facilitate it, so I'll be giving it a go. Ideally I'd like a 32T at the back, but that'll be pushing it too far on the short-cage and I'm not going to fork out for a new RD (or cage?).

I may be making the change this weekend and will report back if I do

Same set up as you I believe 52/36, much appreciated if you could let me know I was going to do myself this weekend but will be in dublin for the rugby so will instead be drinking Guinness

cheers for letting

 

[CXRAndy]

@bert1971

I assume you have 6870 rear derailleur?

you need to choose the GS version
http://www.wiggle.co.uk/shimano-ultegra-6870-di2-11-speed-rear-derailleur/
and
http://www.wiggle.co.uk/kmc-x11-93-11-speed-chain-with-114-links/

 

[berty bassett]

I'm looking to do the same thing myself and have just bought a 11-30 cassette. I assume, like me, you have the short cage rear derailleur. There's two initial things to consider...
1) What does the spec say is the maximum cassette the RD will support? On mine (Shimano 6800 SS) it says 11-28
2) What is the maximum total tooth capacity? The spec says 33T. I'll be running 52/36 front with the 11-30, so this will be 35T ((52-36 + (30-11))

So according to the specs it isn't supported. But then it seems loads of people have had no issues running 11-30 and there is plenty of length in the b-screw to facilitate it, so I'll be giving it a go. Ideally I'd like a 32T at the back, but that'll be pushing it too far on the short-cage and I'm not going to fork out for a new RD (or cage?).

I may be making the change this weekend and will report back if I do

i am sure there is a small bit of kit you can add between the gear hanger and the rear deraileur that enables you to use larger rear gears but i forget what its called now

 

[CXRAndy]

i am sure there is a small bit of kit you can add between the gear hanger and the rear deraileur that enables you to use larger rear gears but i forget what its called now

you can, and they do work. sometimes the chain wrap isn't sufficient for crisp reliable gear changes.

wolf tooth
https://www.sigmasports.com/item/Wo...eXCOpjIBxBqXvlhV8FRoC_MsQAvD_BwE&gclsrc=aw.ds

 

[peterob]

you can, and they do work. sometimes the chain wrap isn't sufficient for crisp reliable gear changes.

wolf tooth
https://www.sigmasports.com/item/Wo...eXCOpjIBxBqXvlhV8FRoC_MsQAvD_BwE&gclsrc=aw.ds

I thought that only works with the GS RDs. Do you know if it also works with the SS Andy?

 

[AAAC 76C]

I thought that only works with the GS RDs. Do you know if it also works with the SS Andy?

Your all speaking in code.
It's worse than FLA in meetings at work.

 

[Whorty]

Your all speaking in code.
It's worse than FLA in meetings at work.

Not just me thinking that then

 

[rob01792]

@bert1971 i run a 32 with ss rd and have done since DD last year with no problems at all but i do have syn shift enabled so never goes big to big

 

[Brendan Parker]

I've done loads of modification to gearing, even run 11-40 with a Di2 road setup, i digress.

Ideally you need a GS cage in the rear derailleur. I usually buy a 114 link KMC chain, fit without taking links. I then put bike in small ring front and small gear in cassette. If the chain sags, I remove one link(actually it's two, but they make one pair) .Refit and test again. If the derailleur is now giving enough tension, job done. Sometimes the 'B' screw needs adjusting to get over the large gear on the cassette.

If you have Synchro shift you can program the bike to not cross chain either big-big or small-small. Di2 is wonderful

Andy

how the hell do you programme di2 not to cross chain?

 

[Brendan Parker]

@bert1971 i run a 32 with ss rd and have done since DD last year with no problems at all but i do have syn shift enabled so never goes big to big

Cheers Rob