Convert 105 11 speed disc brake to TT setup

Is there an easy way to do this? I have a trek domane and want to use it as a long tt bike. It has 11 speed 105 on it and disk brakes. I’m thinking something like the tririg bar Alpha One Carbon Bar/Stem Combo System – TriRig

But shifters and brakes? 11 speed bar end shifters are one thing but I’m having trouble with brakes. Any easy ideas? Thanks :slight_smile:

9160 bar end shifters should plug right in with a junction. If you want shifting on the base bar I think there may be an Ultegra but I’m sure there’s a 9160 disc out there.

E: 9180

I see, go from mechanical 105 to Di2 with dura ace levers and whatever derailleurs.

However, if there was a brake lever that fits the base bar and shimano disk brakes I could keep my mechanical derailleurs.

Actually…there looks like there might be a way. Swap brakes to sram for $280

Put bar ends for 11 speed shifting for $115

$400 plus the bars and maybe some incidentals might be the cheapest way to get there. 'Course that gets me to $2K with the tririg bars…$2300 with the fancy forearm pads.

This is whole thing is for a team triathlon race. 60 miles and some short but steep hills. My TT bike is made for a max of 55 minutes and has 1X 58 X 11-25 gearing (no front derailleur). But my other options are ride the domane with clip ons (already set up that way) or get a smaller ring and bigger cog for the TTbike, raise the pads and try to get into some semblance of comfort. Or maybe buy a small ring and just reach down and move the chain over when I hit the hilly parts. Or do the expensive stuff above and move to 2x AXS drivetrain if we really wanted to bust open the piggy bank.

Maybe the smartest thing would be to do some runs between the domane and TT bike, just to see how much of a penalty I’m paying if I ride the bike as-is. Also could drive out to the course and see if there is any possible way to heave my 200 pounds up the hills with my current TT gearing (probably not). Once I have that info then re-evaluate.

I’ve done repeats on Sugarloaf in training on my mtb in prep for a mountainous race…it comes in at the 48 mile mark. It only says 7% but it felt a lot steeper. 'Course I’m used to super flat so maybe it was only 7%.

Thanks for listening guys :slight_smile:

My bad, youre on mechanical. I thought you were on di2

I have some ultegra mechanical brakes and TT shifters I’d sell for cheap

I’d be all over it but have hydro brakes. Thanks though :slight_smile:

I have some bad news for you my friend… that course is HARD… its non stop short punchy hills… There is almost no flat sections on this race. People talk about sugarloaf like is some kind of monster. There are hills on that route that kicked my ass WAY harder than sugarloaf did.

If you are only doing the bike portion (you said you will do the race as part of the team), do NOT go and spend 2k+ on some fancy TT setup. No real reason other than wanting to spend some money. IF you want to spend your hard earn money I would suggest you get a new di2 setup instead and ride as a road bike. The course will be way better on a di2 gears.

Clip ons will get you most of the aero benefits of a proper TT cockpit (assuming you can get in a similar body position). Only significant downside is having to move hands to shift (add that to your justification list for upgrading to electronic shifting).

I’d also look again at your TT bike since you already have one. Unless it just doesn’t fit, you should be able to adjust it to get comfortable for a ~2.5 hour TT. That 58t gearing seems crazy, but I guess living in florida means lots of pan flat courses. Still doesn’t make sense to me unless you are rocking a 400+ watt FTP or just prefer a really low cadence. A 58-11 will do over 40mph at 100rpm. Not sure you can make a 1x setup work with that course if you are used to flat, but maybe a 50 or 52 chainring. A 50 would still give you 36mph at 100rpm.

Good to hear. Well … not really…but sugarloaf kicked my ass LOL. I can see I need to ride the course so thank you for that :slight_smile:

Well when you say it like that my scheming sounds ridiculous! I’ve been to plenty of races where what I thought was important turned out to be completely different from what really was important. This may be one of those times!


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I don’t have a picture of my road bike…but it’s not nearly as good as my TT bike. Lots more comfy though!

I’m in the 26-27mph average on 270-280 watts for 8-25 miles and the 58 gives a nice straight chainline to the 14 and 13. I never get into the 11…in fact…I don’t really want to go that fast! But depending on how sharp the climbs are, I agree…maybe a smaller ring and 11X28 cogs would do it. Looks like 44X11 at 100rpm is 31mph…plenty fast. And 44X28 at 40rpm (really grinding up the steep bit) is about 5mph. Not sure if it’s slow enough but maybe…it just might work!


I would absolutely rock that bike / position and not even screw around with a road bike.

Not even a question.

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IN this instance… position is less important…
Yes aero is important for long races, but I dont think you want to go all out and modify your road bike for this… setting your TT bike would be a better choice IMO, if you want to keep the position.

He will have problems with some climbs… they are not horrible but he will need his small gear

I did IMWI twice on a Shiv TT with a similar position…way more climbing on longer and steeper climbs. Zero issues. Just get on the bullhorns and spin up 'em. I think I had a 34x27 as my smallest gear?

And there is 20 miles of flats in between the hills on that course…gobs of time to be made up there.

I wouldn’t even hesitate to use my TT bike…especially with the position he has.

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I would use the TT bike… 0 questions.

The problem is that flat landers might have issues climbing. If you are used to it sure…if not… Painful

Any reason not to go even wider on the cassette range so you’re not stuck at 40rpm?
Bigger gaps between gears but sounds like a potentially acceptable compromise given the course.

Tt bike is running ultegra di2 11 speed….I think 28 is the max but not sure? But I could live with bigger gaps for this definitely.


30t max for short cage (SS) SHIMANO ULTEGRA Short Cage DI2 Rear Derailleur 11-speed | SHIMANO BIKE-EU
GS (medium cage) should be 34t max and even though it’s expensive it’s probably still cheaper and easier than going 2x. Might even be able to borrow a medium cage off someone for the event (trade rear mechs for a week and then swap back)

Shimano is also known for being conservative with derailleur capacity - should be able to get a 32 in the SS or a 36 in the gs (and possibly even bigger), particularly if you’re running 1x and there’s less total difference in max/min teeth for the pulley to take care of. The ‘total capacity’ spec on the Shimano website is the difference in teeth between big-big and small-small, so if there’s only 1 chainring you’re asking less of it. Will all be down to whether you can dial your b-limit screw out far enough to make the guide pulley clear the biggest cog on the cassette.

In a pinch could also get a mech hanger extender like a wolftooth road link to get the extra clearance. Might slow your shifting down a bit but they’re like $30-50 so you’d be in the game for the cost of the cassette, a longer chain, and the part and that’s it. Smaller chainring would probably still be helpful too.

11-32 has a chunk with more Road-like spacing at the small end of the cassette. 11-34 has consistently bigger gaps the whole way up. That might influence what size you decide to aim for as well.

Even more extreme version of this thought: SHIMANO GRX DI2 Rear Derailleur 11-speed (42T max low sprocket) | SHIMANO BIKE-EU
GRX 1x rear mech is directly compatible with R8050 so it’s a straight swap and then you could fit an 11-40 or 11-42. You’d effectively have MTB gaps in your gearing though which is probably excessive even for someone with a relatively wide range of comfortable cadence. Your setup would certainly get you noticed though!

If feeling particularly adventurous you could even take that a step further and start mixing and matching cogs from different cassettes to give yourself a functional 2x5 drivetrain where you’ve got road spacing at the tight end of the block, then one big awkward jump up to the climbing end of the cassette which then preserves the MTB spacing. The shift with the big jump will be slow and a bit unpleasant going up, but probably no worse than having to switch chainrings up front.

Before the era of discs I converted my Bianchi 928 to a TT set up. IIRC the main changes were a TT cockpit, a disc cover and fastforward ahead seat post.

When I bought a TT bike the next season its pb was only 16s faster.

I think that would do it…which leaves only positioning as an issue…which, if I put all of the riser blocks under the bars could probably be just fine. I like it! Thanks!