Do front "flat bar shifters" have STi internals?

Manc33

I read somewhere, if you use "flat bar" road shifters (for example Claris R243 or Ultegra R780), these have to be used with a road front mech. On a MTB front mech the swingarm is too long and the STi shifter would not pull enough cable. Conversely on a road front mech, the swingarm is shorter and a MTB shifter would pull too much cable.

This sounds reasonable, since anyone using those shifters shouldn't be expected to replace their front mech - plus those flat bar ones are after all sold as "road bike equipment".

I have also read that all Shimano trigger shifters are MTB based, even ones called "flat bar". :evil:

They can't both be right!

Does the left shifter on so-called "flat bar" versions have STi internals, or not?

I tried some XTR shifters with a Sora front mech and the MTB shifters pulled too much on the front mech. That's when I got the coveted R443 front mech, a supposed compromise where it works with MTB shifters but allows for road chainrings.

I never tried the flat bar shifters I had with the Sora front mech though. Its just that people seem to say the shifter is a road flat bar shifter implying it has an STi cable pull, then others say you can't use a road mech with them.

nicklouse

Yes no and maybe.

It depends.

Mechs for two rings can be ok. The mech cage shape is more of an issue due to ring sizes.

So really it depends on what you are really wanting to do.

Note most road based shifters have a trim ability that MTB shifters don't.

Manc33

Thats why I ditched those Claris R243. Four clicks / five positions on a front triple shifter!

I hated that trim thing. For some reason on STi brake shifters it was a lot more tolerable/usable, in fact I preferred it to have it.

I have always thought Shimano road equipment is better quality than MTB equipment at the same price. Also what kids ride around on serious road bikes? Very few. Every kid has a MTB. I think this comes out in the products at times.

I mean those Claris R243 shifted gears better than Altus EF51 MTB shifters did and they are both around the same price. The Altus seemed like cheap junk in comparison.

desweller

The cable pull-per-ratchet-click is detemined by the diameter of the pulley that the cable runs round in the shifter. So it's pretty easy for Shimano or whoever to reuse the same MTB escape mechanism and just change the pulley for one with a different diameter for the road product.

Manc33

DesWeller wrote:

The cable pull-per-ratchet-click is detemined by the diameter of the pulley that the cable runs round in the shifter. So it's pretty easy for Shimano or whoever to reuse the same MTB escape mechanism and just change the pulley for one with a different diameter for the road product.

Yep. No one actually knows though.

Someone once said "all" trigger shifters use MTB internals but why would he know any better than anyone else lol.

All you can do is put the equipment on and see.

There was even talk of "what if the flat bar shifters aren't MTB or road pull" but OMG don't even say that...

I did get my XTR shifters to work with my Sora FD anyway, on a triple. Yeah I probably had to really slacken off the cable, but it did work, its just that I always knew the swingarm was short and the lever was really stiff so I swapped to the R443. Now I have another problem causing the cable to need to be slack for it to function right - chainrings too close to the frame.

The few short rides I have done on that new chainset though... it is perfect for the gear ratios. 8) I can finally get a lot more use out of my big chainring. When I had a 50T on I literally never used it except downhill, it was pretty redundant.

I think I must have the legs of a 90 year old women.

arlowood

Have just got to the shifter fitting stage of my build on a bike for my grandson.

After some research I bought the Ultegra R780's because I could not get the Tiagra ones in black. These I've combined with 105 5700 front and rear mechs (medium cage rear). Not finished the set up yet (chain not installed yet) but the left shifter seems to be working well with the 105 FD and is moving the cage to an appropriate position over the front chainrings. (Shimano CX50 - 46/36)

Also the right shifter seems to be moving the RD over the rear cassette sprockets with each index "click".

So far all looks to be on track to work harmoniously. Will update once chain is attached and indexing fine tuned.

Manc33

arlowood wrote:

Have just got to the shifter fitting stage of my build on a bike for my grandson.

After some research I bought the Ultegra R780's because I could not get the Tiagra ones in black. These I've combined with 105 5700 front and rear mechs (medium cage rear). Not finished the set up yet (chain not installed yet) but the left shifter seems to be working well with the 105 FD and is moving the cage to an appropriate position over the front chainrings. (Shimano CX50 - 46/36)

Also the right shifter seems to be moving the RD over the rear cassette sprockets with each index "click".

So far all looks to be on track to work harmoniously. Will update once chain is attached and indexing fine tuned.

The back won't matter, I mean any 10sp shifter will work, whether it is "flat bar" like you have got, or STi shifters. With actual MTB shifters I can't say because the rear mech does differ for MTB and you can't use a MTB 10sp rear mech on a road setup as far as I know.

What you say seems right, a road front mech and the R780's working together, this means the flat bar shifters must have STi internals. But then you did say its not all fully setup yet. Also you're on a double which I think makes it more likely to work with potentially mismatched stuff.

Mine is the reverse, I have "actual" MTB shifters and the R443 front mech (aka Tiagra) not knowing if the R443 needs a STi pull or a MTB pull and this is the problem - people say flat bar shifters are STi (which makes sense) and the R443 must be used with them. Then others say the R443 is for use with "MTB type" shifters. Well, flat bar shifters look like MTB shifters and are referred to all the time as "MTB type" trigger shifters etc. It can get ludicrously confusing.

From CRC about the Tiagra front mech:

"Part of Shimano's component groupset designed for road bikes featuring flat handlebars."

How come my XTR shifter from 1998 works with the R443 then?

I even don't fully know it does until I get that BB with a wider axle.

I can't upgrade to flat bar shifters though without an entire upgrade from 8sp to 10sp. Which is why I got those Claris R243. They are the only available 8sp flat bar specific shifters you can buy new and its entry level stuff. You can't have it all lol. If I did upgrade to 10sp I am then stuck trying to find a road mech that can take a 32T sprocket on the cassette, because a 10sp MTB mech has a different cable pull to a 10sp road mech apparently. I need the low gears.

arlowood

Manc33 wrote:

If I did upgrade to 10sp I am then stuck trying to find a road mech that can take a 32T sprocket on the cassette, because a 10sp MTB mech has a different cable pull to a 10sp road mech apparently. I need the low gears.

Watch this space

---

. I have fitted a Shimano SLX HG81-10 cassette (11-32) on the build for my grandson's bike. This is mated with the 105 5700 GS (medium cage) RD which is rated to take a max 32 tooth sprocket with a double chainset.

I guess if you're running a triple chainset then the GS might/would struggle

arlowood

arlowood wrote:

Have just got to the shifter fitting stage of my build on a bike for my grandson.

After some research I bought the Ultegra R780's because I could not get the Tiagra ones in black. These I've combined with 105 5700 front and rear mechs (medium cage rear). Not finished the set up yet (chain not installed yet) but the left shifter seems to be working well with the 105 FD and is moving the cage to an appropriate position over the front chainrings. (Shimano CX50 - 46/36)

Also the right shifter seems to be moving the RD over the rear cassette sprockets with each index "click".

So far all looks to be on track to work harmoniously. Will update once chain is attached and indexing fine tuned.

Just fitted the chain this afternoon and checked out the function of the front and rear derailleurs.

After a bit of tweaking with the outer limit screw and the cable tension I have the FD working smoothly. The rear derailleur is also operating efficiently after a few small adjustments to the inner limit screw and the cable tension. Indexing is fine tho' the changing is slightly more "clunky" than I'm used to with the current 105 5700 FD and RD on my road bike. This could be a combination of the shifters themselves and the fact that I'm using a wide range MTB 11-32 cassette. The RD is coping well with the 32 cog and looking at the relationship between the top jockey wheel and the largest sprocket I reckon I could probably get away with a 34 lowest cog but that's another story.

Just out of interest, I may try out an oldish Tiagra 12-30 road cassette just for comparison

Anyway - so far so good. Just waiting on the brake cables to arrive so that I can do a proper test ride

Manc33

Mines pretty much out of action until I get this BB with a longer spindle.

It works but middle > 11T rubs a lot (outer plate of the FD).

Granny > 32T also rubs a lot, because the FD won't even change down to the granny if I so much as look at the limiter screw. Thing is, the back of the FD hits the chainstay that way.

I solved the outer plate of the FD cage being so near to the crank arm but thats why now, the FD is hitting the chainstay again. :roll:

I could ride it as it is, but I would have to not use the granny ring at all (because I don't want the FD whacking the chainstay, its carbon!) and use only the biggest 4 sprockets of the cassette on the middle ring, then use the big chainring and the smallest 4 sprockets. Funnily enough the middle chainring and biggest sprocket (34F/32R) is such a low gear as it is you wouldn't need a granny ring.

That granny ring is for when I go over Snake Pass and all the way down the 9 mile side then want to get home again. It basically has MTB gearing now.

None of anything I have said has anything to do with the topic by the way. :oops:

Well it sort of is because if my front changing is still not right with a longer BB spindle, it might be that the MTB shifters won't run well with the FD-R443. Yep, that again. No one really knows, again. The fact that it does work now says it should work, because the cable pull isn't wrong, its just that my FD is all tucked in too much due to the BB spindle being too short and the chainrings too far in. Also I don't have the FD as close to the big chainring as it should be and the shifting is alright. It does take a big shove to get from granny to middle, then a normal shove to get to large. That is the nature of triples, its a way bigger shove from granny to middle but on my setup it is exaggerated where the cable is very loose on the granny ring. The thing is, the FD is right "in" (inner limit screw takes the FD as far in as it will go, hitting the chainstay) so that means the whole angle of the mech is wrong and no wonder it needs so much cable to make it change, I mean part of what the cable would be holding is being held instead by the limiter screw. The mech actually needs to go even further in, but can't.

I am not Shimano buff but I would think, on a triple FD, with your chainrings exactly in the right place, you'd probably have both limiter screws screwed in an equal amount. On mine this isn't the case, the inner screw is about 4 threads out compared to the outer screw.

If the 122.5mm doesn't cut it I will have to go to the 127mm and if that doesn't cut it, wow, I don't even want to think about it.

desweller

Manc33 I'd love to see your bike someday. This front derailleur saga has been going on for yonks.

Wheelspinner

For a while I had Shimano SL-R770 shifters in use, which were a 10 speed flat bar model made for road bike use. Ran them with Dura Ace 7800 front and rear mechs and they worked perfectly, on a 2*10 speed setup. Think they've discontinued them which is a shame as they were excellent. They were STi specific, not for MTB.

If you can find a set somewhere snap them up.

FransJacques

it's a lot simpler than people are making out.

All Shimano 9s and 10s front mechs are compatible with flat bar shifters. I've used road front mechs with both 9sp and 10sp thumb shifters and it's fine. I use a road mech b/c I run a 2x10 on a Cannondale F4000. On my flat bar commuter I have all road cranks, brakes and derailleurs but run 9sp thumb shifters and it's fine.

If your front shifters are for a triple but you only have 2 rings, you just need to set the limit screws on the front mech carefully and decide which of the 2 clicks you're going to use on the shifter. I prefer the middle to big click when doing a 2x drivetrain. I tried the granny to middle click but it was less positive.