Shimano 7800 compatibility questions

[hoonjr]

Hi, I'm building up a new bike. I'm planning to swap over my 7800 group from my old bike to my new bike. Would a 6700 ultegra chain and cassette work? Or should I stay with 6600 stuff?

Also will any of the new shimano compatible brake/shift cables work with the 7800 group?

Thanks!

[echelon_john]

yes and yes.

[54ny77]

everything is interchangeable between 7800, 6700 and 6600. i have some iteration of those combos on 3 different bikes.


Hi, I'm building up a new bike. I'm planning to swap over my 7800 group from my old bike to my new bike. Would a 6700 ultegra chain and cassette work? Or should I stay with 6600 stuff?

Also will any of the new shimano compatible brake/shift cables work with the 7800 group?

Thanks!

[hoonjr]

Thanks all! Off to shop.

[LegendRider]

I have 7800 on both of my road bikes and typically buy Ultegra chains and cassettes to keep costs down. No issues whatsoever.

[54ny77]

p.s. PM forum member Dave Thompson on this topic--he's an authority on it. Was very helpful when I had similar questions.

[BYKE-RIDER]

the only parts that should not be mismatched are the brake calipers/ shifters

the newer caliper has a slightly different leverage ratio and the new shifters match that.

chain and cassette- go 4 it

[dave thompson]

the only parts that should not be mismatched are the brake calipers/ shifters

the newer caliper has a slightly different leverage ratio and the new shifters match that.

chain and cassette- go 4 it

Not entirely true. As you point out there are slight differences, that in my real-world experiences don't make enough to be concerned about. Newer brakes work quite nicely with the older shifters.

[BYKE-RIDER]

I must admit that I have not tried the new caliper with previous shifters.

My negative experience was one with the new shifters and both previos shimano brakes aswell as non shimano caliper.

In my experience there is no loss of power, but there is a loss of modulation and general lever feel.

It is similar to the feeling of a linear pull lever attached to a non -linear pull brake (mtn. lever rd. caliper). Only not near as pronounced

[oldpotatoe]

Hi, I'm building up a new bike. I'm planning to swap over my 7800 group from my old bike to my new bike. Would a 6700 ultegra chain and cassette work? Or should I stay with 6600 stuff?

Also will any of the new shimano compatible brake/shift cables work with the 7800 group?

Thanks!

Yep, as would a 5700 cogset and chain. By 'new' do you mean the 9000 stuff? Yes, however, it is recommended that you get new shimano brake fixing bolts and plates for the 9000 brake cables cuz they are really slick.
As mentioned up there and brakes, no issue with other calipers and shifters with the only real exception being 7900 calipers and 9000 calipers. Previous models, no issue or problem mixing and matching shimano calipers.

[54ny77]

fyi i have a mix & match across 4 bikes: 6700 levers w/7800 calipers, 7800 levers w/velo orange grand cru calipers, 6700 levers w/6600 calipers, and 6700 levers w/6700 calipers. all brakes have black dura ace rubber pads. cables/housing used are a mix of shimano oem and jagwire.

i have absolutely no issues with stopping or feel on any combo, in all manner of weather conditions and speeds/terrain.

as to the optimized lever pull ratios folks sometimes talk about, honestly, if you can feel the difference to the point that it's meaningful, then you must be one of those rare souls who can detect a 0.003mph southeasterly wind direction change while driving in a car. shimano marketing folks will love you.

in other words, mix & match 6600, 6700 & 7800 with confidence.

;)

[BYKE-RIDER]

You dont have to be a dick. Well maybe that comes with being a senior member on this forum?

I was just sharing my opinion. Which FYI was also Shimano's opinion when the 7900 parts were released.

Though they have since ceased printing it in the tech info, probably because large OEM sales might be lost if they were steadfast about enforcing it. i.e. brands using tectro/ fsa calipers to save a buck.

[dave thompson]

I don't think there was any 'dickness' intended by either me or 54. We both related some extensive real-world experiences that counter oft regurgitated 3rd hand info.

Stick around here and you'll a) appreciate our humor and b) get some terrific and sound information.

[54ny77]

whoa easy there, no obnoxiousness intended. i was simply trying to be helpful, in case you were looking to run lever/caliper combos based on the pull ratio guidance from shimano (i.e., taking their marketing or tech guidance as gospel). i was simply trying to say that you can save money and not have to buy the newest stuff as a set. apologies if you took my words any other way.

as dave said, we're both trying to help. i asked almost identical questions here a year or two ago when i was putting together various builds using combos of 6600, 6700 and 7800.

p.s. i'm no senior! i'm in my 40's! ;)

You dont have to be a dick. Well maybe that comes with being a senior member on this forum?

I was just sharing my opinion. Which FYI was also Shimano's opinion when the 7900 parts were released.

Though they have since ceased printing it in the tech info, probably because large OEM sales might be lost if they were steadfast about enforcing it. i.e. brands using tectro/ fsa calipers to save a buck.

[roydyates]

fyi i have a mix & match across 4 bikes: 6700 levers w/7800 calipers, 7800 levers w/velo orange grand cru calipers, 6700 levers w/6600 calipers, and 6700 levers w/6700 calipers. all brakes have black dura ace rubber pads. cables/housing used are a mix of shimano oem and jagwire.

i have absolutely no issues with stopping or feel on any combo, in all manner of weather conditions and speeds/terrain.

as to the optimized lever pull ratios folks sometimes talk about, honestly, if you can feel the difference to the point that it's meaningful, then you must be one of those rare souls who can detect a 0.003mph southeasterly wind direction change while driving in a car. shimano marketing folks will love you.

in other words, mix & match 6600, 6700 & 7800 with confidence.

;)
+1 I also use 6700 levers with 6600 calipers. The feel is different (the squeeze is a little harder) but it seems well within the range of normal. Perhaps if you have very weak hands, then this cross combo should be avoided.