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vorpalchortle 04-03-16 12:17 PM

Shimano STI conversion options

I'm looking for some shifter compatibility advice.
I really do not care for the drop bars with integrated STI brake-shifters that originally came with one of my bikes and am looking into configuration options.
I currently use Velo Orange portuer bars on a Satori stem riser with inverse brake levers which I enjoy quite a bit since it allows a more upright position for commuting and is easier on my neck.
The shifters are the problem though and are presently on my top tube since the brazons on the down tube are bit of a further reach and I cannot fit what parts I have on the stem. Not my ideal set-up to say the least, but luckily I do not shift often in my relatively flat area.
The bike, an All City Space Horse, has a Shimano Tiagra 10-speed set-up (4600, I believe) which I am fine with, I just need to resolve a comfortable and compatible shifting solution.
Bar end shifters are not an option since I use inverse brake levers and some trigger/quick shift options look bulky and seem to be designed for a brake lever to go along with them or may not be compatible with the Tiagra 2x10 (I-Spec?), although I would consider these if I knew they could work.
So I'm thinking thumb shifters and wondering if there are compatibility issues that I should look out for.
Would Microshift or IRD flat bar thumb shifters work? They seem to be nicely minimal and I hope they would fit around the curves of the portuer bars. Or perhaps the Microshift XCD triggers, which are very affordable and not so bulky.
Would a Microshift mountain bike product play nicely with Shimano road bike gearing?

Thank so much!

GeoKrpan 04-03-16 12:26 PM

Microshift 10 speed flat bar trigger shifters would work perfectly. They are much cheaper than the Tiagra flat bar shifters but they do not look or feel cheap. I'm using 9 speed Microshift flat bar trigger shifters on an upside down northroad bar. For brakes I'm am using hydraulic MTB discs.

Darth Lefty 04-03-16 03:22 PM

Whatever shifters you get you need to make sure it matches your derailleurs. They need to match Shimano 10 speed road on the rear and Shimano road double on the front. MTB and road lost their rear compatibility they had up til 9-speed. First the MTB changed at 10 speed and then the road changed at 11 speed so the newer ones are neither compatible with each other or anything old. The fronts were never compatible.

So far as I know the Tiagra 4600 flat bar set is the only one from Shimano itself. There was a Dura Ace 2x10 road flat bar set but it was a long time ago now and not common so good luck to find one.

If you want thumbies, microSHIFT -The best control system seems like the right one.

Raiden 04-03-16 06:32 PM

Edit: ^^^There is a very narrow generation of 10 speed non-dynasys (ie road-compatible) Shimano mountain bike parts that are still available. I don't have the time to research it right now; just sayin' :) Second Edit: You can always hack a triple shifter into working on a double crank/derailer, the problem is when you're trying to use incompatible triple shifters and triple crank/derailers.


How about standard brake levers, and short grips (or a short amount of bar tape, perhaps JUST long enough to fit in your hand) with bar-end shifters?

Or twist shifters. I've read that people make aftermarket Shimano-compatible 10 speed twist shifters but have never seen one in person. You could always downgrade your cassette. I realize this is a silly suggestion but....

vorpalchortle 04-06-16 05:46 PM

Thanks so much for the replies.

I think I may try out the MicroShift Thumbies, those seem like a good option for me, classic and minimal.
Glad to confirm that these will be compatible.

And to answer, I'm a big fan of the inverse brake levers so bar end shifters are not an option, and I just don't care for twist shifters, but thank you for the suggestion.

TomPalmer 04-07-16 05:35 AM

I have some VO Porteur bars and they are the same diameter as road bars. I tried to use some MTB thumb shifters and they would not go onto the bars. Check your bars before you buy any new parts.
Good luck in your search.
Tom Palmer
Twin Lake, MI

vorpalchortle 04-07-16 09:50 AM

Thanks for the input, Tom.
So would these MTB shifters not go over the end of the bars at all? Or just not around the curve of your potruer bars?
The ones I'm looking at are described as Road with a 22.2mm dia which hopefully has some give and flex to accommodate curves.

TomPalmer 04-07-16 02:35 PM

The bars come in 2 diameters- 22.2mm for mtb brakes and shifters and 23.8 mm for road brakes. Mine are 23.8 and I bought some special brake levers that are for upright riding, like a mountain bike, but with clamps that were for road bike diameter bars. Confusing isn't it? if you have 23.8 bars, the MTB levers will not go on at all.
Have a great day,

vorpalchortle 04-07-16 04:40 PM

Thanks for the clarification, and reminder for me to recheck my bar size!
I was mistaken. I need 23.8 shifters and cannot confirm that those Microshift thumbs will fit.
Whats's more confusing is that the Microshift website does not clarify the diameter of the "city" shifters (there are separate categories for Road and Mountain and City) and Amazon has two versions available, a MTB and an unspecified.
Need to search for that answer or look into other options.
Thanks again.

Darth Lefty 04-07-16 05:50 PM

Well, shoot. The "city" shifters are almost certainly also 22.2. It's the flat bar standard. Some other solutions...
  • You could probably wedge them open enough to work.
  • Paul Thumbies come in 31.8 size, and then you could use a shim from Problem Solvers.
  • You could go looking for handlebars the right diameter. Gator Handlebar | SOMA Fabrications

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