Mixing components with friction TT shifters

[grellboy]

Happy New Year!
Currently ordering (but not yet fitting) some components for a TT build. I had ordered a 5800 105 front mech and now on lookout for a chainset. Been offered the new 105 (r7000) but apparently due to new configuration of the rings, they are now spaced 4mm further from each other than on 5800 chainset. This would render old mech incompatible with new chainset. However, due to it being a TT build, the front shifter works on friction I believe; therefore - and I may well be completely wrong here - as a friction shifter, would this overcome the spacing issue and render it irrelevant - whereas if it were a standard road bike set up with indexed front shifting it would be an issue?

 

[robgul]

From experience with lots of bikes if you run friction shifters you can get away with almost anything in the way of components - you just "trim" the lever to make it work as you change gear.
Doubtless someone will come along and say I'm wrong ... but it's worked for me in the past 20+ years and about 15 different bikes, most of which have been "ASP" (the old expression in cycling : All Spare Parts!)

Rob

 

[Smokin Joe]

It will be no problem with friction shifters, anything will work with anything else.

 

[Ajax Bay]

. . . a 5800 105 front mech . . the new 105 (r7000) [chainset] but apparently due to new configuration of the rings, they are now spaced 4mm further from each other than on 5800 chainset.

I read this and thought "blimey". With an extra 4mm a chain would fit between the rings (not healthy). A quick search suggests the additional distance between the rings is 0.4mm. But this is (apparently) enough to make the FD-5800 not work with the R7000 chainset accurately. Leaving aside the 'friction' TT lever aspect, have to say I'm surprised that 0.2mm both ways with STIs cannot be sorted by cable tension adjustment to provide a satisfactory (if not 'perfect') outcome.
https://accidentalrandonneur.wordpr...tal-musings-shimano-105-r7000-and-ultegra-rx/

 

[12boy]

That is not always so. I have had friction shifters designed for a 5 speed cassette not shift all the way through an 8 speed. However by filing down the detent that limits the shift lever movement it works fine for 8 speeds. On the front, you are on the money.