Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Converting a MTB drivetrain to drop bars and STI shifters, recommended derailleur?

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Converting a MTB drivetrain to drop bars and STI shifters, recommended derailleur?

Old 01-22-13, 04:06 PM
  #1  
bobotech
Senior Member
Thread Starter
 
Join Date: Jan 2012
Location: Spokane, WA
Posts: 2,255

Bikes: Specialized Sequoia Elite/Motobecane Fantom Cross Team Ti/'85 Trek 520

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Converting a MTB drivetrain to drop bars and STI shifters, recommended derailleur?

I have a mid 2000s Specialized Hard Rock that has normal flat bars. I rode it for the first time in almost 9 months this past week. I am riding it again because I my road bike doesn't have good 700c tires for bad weather. I now remember why I hated riding my MTB. My hands hurt like hell and were numb after only a 2 mile ride.

And I just didn't like being forced on the flat bars. So I want to convert it to drop bars. I have a nice set of STI Ultegra triple shifters and a decent enough rear derailleur. I would prefer to just keep the factory crankset but if I have to, I will put a different one on.

I'm just not sure what would be the best choice for a front derailleur. The seattube is a bigger one, I think its the 31.8 size so I can't use my nicer triple Ultegra that is only for 28.8 sized tubes.

What would be a good choice for a front 44t or 48t triple using STI shifters?

Something cheap if possible. I am no weight weenie!
bobotech is offline  
Old 01-22-13, 04:46 PM
  #2  
striknein
Goes to 11.
 
striknein's Avatar
 
Join Date: Oct 2010
Location: Wichita, KS, USA
Posts: 2,547

Bikes: 2015 Soma Double Cross

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Tiagra for triple is affordable and works well with smaller MTB chainrings.
striknein is offline  
Old 01-22-13, 05:38 PM
  #3  
surreal
Senior Member
 
surreal's Avatar
 
Join Date: Mar 2002
Location: NJ
Posts: 3,084
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
Originally Posted by striknein View Post
Tiagra for triple is affordable and works well with smaller MTB chainrings.
I agree, if your cables are routed along the downtube. Mid-2000s Spesh HR, they're probably along the toptube.

Actually, I agree regardless, but you might need to install a pully on the seat-tube.
surreal is offline  
Old 01-22-13, 05:57 PM
  #4  
xenologer
Senior Member
 
Join Date: Aug 2008
Posts: 2,589
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 238 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Well, I was about to suggest that if you're keeping the stock crankset; then the stock derailer should be fine.

but a quick google search suggests that road and mtb shifters nowadays use different cable pull?
when did that happen and what's the ratio difference?
wierd; the issue never came up for me.... campy ergopower driving mtb alivio fd works fine on my bike....



Also; if you're main motivation is that the flat bars hurt your hands; drop bars arent the only option
a swept back or 'alt' bar may be comfortable; and allow you to keep your existing mtb controls.
examples; on-one mary, origin8 space-off (mary clone), soma sparrow, north roads, surly open bar, trekking bars

Last edited by xenologer; 01-22-13 at 06:03 PM.
xenologer is offline  
Old 01-22-13, 06:00 PM
  #5  
Retro Grouch 
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 29,964

Bikes: Catrike 559 I own some others but they don't get ridden very much.

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 1466 Post(s)
Liked 392 Times in 235 Posts
My general philosophy is that, if I'm buying parts, I'll hold out for stuff that matches. If I already own parts, I'll try it and see if I can make it work.

You are in the perfect situation to test my theory. I know that lots of folks are going to say the road shifters won't work with a mountain front derailleur and they might be right. One other thing that I know for sure is that in the 1990's it was common for tandems and some hybrids to come from the factory with mountain shifters and road front derailleurs so the opposite has been done.

If it was my bike I'd bolt up the Ultegra STI's that you already own and see if I could make them work with the existing front derailleur. The worst that could happen is you won't be able to get them to work to your satisfaction and you'll be exactly where you are now.
Retro Grouch is offline  
Old 01-22-13, 07:35 PM
  #6  
bargainguy
Senior Member
 
bargainguy's Avatar
 
Join Date: Sep 2012
Location: Trekland
Posts: 1,917
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 379 Post(s)
Liked 71 Times in 47 Posts
I have a suggestion that would certainly be cheaper than what you suggest, and perhaps a lot less hassle.

I hate flat bars too. One way around this is to get a set of bars that offer multiple hand positions without replacing your drivetrain.

I'm particularly fond of the Nitto Trekking bars, first two (silver or black) at the top here: https://sheldonbrown.com/harris/handlebars/index.html

The usual disclaimers: YMMV, ask your doctor or pharmacist, etc.
bargainguy is offline  
Old 01-22-13, 07:43 PM
  #7  
bobotech
Senior Member
Thread Starter
 
Join Date: Jan 2012
Location: Spokane, WA
Posts: 2,255

Bikes: Specialized Sequoia Elite/Motobecane Fantom Cross Team Ti/'85 Trek 520

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
The trekking bars would be an interesting idea but I kind of want to get this bike done for the big FBC ride this sat night. I called around and a bike shop near me has a used Ultegra triple road front derailleur braze-on style which is perfect because I have a braze-on adapter for the 1 3/8" tube that my bike has. it is only 20 bux and then I can put the bike together. I have pretty much everything else I need except for the handlebar tape.
bobotech is offline  
Old 01-22-13, 07:49 PM
  #8  
pierce
S'Cruzer
 
pierce's Avatar
 
Join Date: Jun 2010
Location: 122W 37N
Posts: 2,442

Bikes: too many

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 38 Post(s)
Liked 16 Times in 14 Posts
a road front is designed for a shorter chainline than a mountain bike. that derailleur probably won't reach the big chain ring.

just use your mountain derailleurs. it should work fine with a 48T trekking triple, I know my Tourney cheapo front does.
pierce is offline  
Old 01-22-13, 11:28 PM
  #9  
bobotech
Senior Member
Thread Starter
 
Join Date: Jan 2012
Location: Spokane, WA
Posts: 2,255

Bikes: Specialized Sequoia Elite/Motobecane Fantom Cross Team Ti/'85 Trek 520

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by pierce View Post
a road front is designed for a shorter chainline than a mountain bike. that derailleur probably won't reach the big chain ring.

just use your mountain derailleurs. it should work fine with a 48T trekking triple, I know my Tourney cheapo front does.
The problem is that road front shifters don't pull nearly as much cable as mountain bike shifters. So if you road shiftes (like I'm planning on doing with the STI brifters), then you won't be able to shift easily into the highest gear. If you are going the other way around, say converting a drop bar bike that has STI shifters to a flat bar bike using MTB shifters, you can sometimes get away with using a road derailleur if you put the slack into the cable when it is in the lowest position but I'm going the other way.
bobotech is offline  
Old 01-22-13, 11:56 PM
  #10  
Jeff Wills
Insane Bicycle Mechanic
 
Jeff Wills's Avatar
 
Join Date: Mar 2008
Location: other Vancouver
Posts: 9,398
Mentioned: 30 Post(s)
Tagged: 0 Thread(s)
Quoted: 619 Post(s)
Liked 226 Times in 147 Posts
Originally Posted by bobotech View Post
The problem is that road front shifters don't pull nearly as much cable as mountain bike shifters. So if you road shiftes (like I'm planning on doing with the STI brifters), then you won't be able to shift easily into the highest gear. If you are going the other way around, say converting a drop bar bike that has STI shifters to a flat bar bike using MTB shifters, you can sometimes get away with using a road derailleur if you put the slack into the cable when it is in the lowest position but I'm going the other way.

Exactly. I would try a "road" front derailleur and see how it works. The bugaboo is that the curve of the cage won't be a good match to the smaller MTB chainrings. I thing the IRD Alpina is what you need for road brifters and small chainrings: https://store.interlocracing.com/alfrde.html

Also bear in mind that your MTB has a longer top tube than a similar road bike. You'll need a very short stem for correct fit with drop bars.
__________________
Jeff Wills

Comcast nuked my web page. It will return soon..
Jeff Wills is offline  
Old 01-23-13, 09:37 AM
  #11  
digger531
Senior Member
 
Join Date: Feb 2011
Location: St. Cloud, MN
Posts: 592

Bikes: Soma Double Cross DC, Salsa Vaya, Redline D440, '87 Schwinn Super Sport

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I had a 9sp xt mountain crank with ultegra 10sp triple shifter on my Soma dc and it was a bear. I tried a xt 9sp derailleur first but had tire clearance issues before I could tell how far off the shifting was, than tried an Ultegra 10sp triple which was a no go. I finally used a Tiagra 9sp that did get the job done (and was cheap) but it was never perfect. I finally switched to a 46/34 double with a 12-36 cassette (not cheap and not related to the question that was asked but whatever) and that works wonderfully. If your shifters are 9sp ultegra I think that tiagra derail would be the answer.
digger531 is offline  
Old 01-23-13, 10:49 AM
  #12  
Spld cyclist
Senior Member
 
Spld cyclist's Avatar
 
Join Date: Nov 2011
Location: Springfield, MA
Posts: 1,060

Bikes: 2012 Motobecane Fantom CXX, 2012 Motobecane Fantom CX, 1997 Bianchi Nyala, 200? Burley Rock 'n Roll

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Retro Grouch View Post
My general philosophy is that, if I'm buying parts, I'll hold out for stuff that matches. If I already own parts, I'll try it and see if I can make it work.

You are in the perfect situation to test my theory. I know that lots of folks are going to say the road shifters won't work with a mountain front derailleur and they might be right. One other thing that I know for sure is that in the 1990's it was common for tandems and some hybrids to come from the factory with mountain shifters and road front derailleurs so the opposite has been done.

If it was my bike I'd bolt up the Ultegra STI's that you already own and see if I could make them work with the existing front derailleur. The worst that could happen is you won't be able to get them to work to your satisfaction and you'll be exactly where you are now.
+1. I'm using a SRAM X9 mountain FD with a triple crank and Tiagra STI shifters, and it shifts beautifully. What you have might work, and it costs nothing to try it.
Spld cyclist is offline  
Old 01-23-13, 11:18 AM
  #13  
WMcCready
Senior Member
 
WMcCready's Avatar
 
Join Date: Dec 2010
Location: Greater Chicago Area
Posts: 79

Bikes: Surly-LHT,KM, Schwinn World,Tempo,High Sierra,Trek820,Raleigh Sports

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Trekking bars, worked well for me on two MTB, brakes and thumb shifters, ended up close to frame center line, leaving outer bars for hand positions.
WMcCready is offline  
Old 01-23-13, 11:25 AM
  #14  
Shimagnolo
Senior Member
 
Shimagnolo's Avatar
 
Join Date: May 2008
Location: Zang's Spur, CO
Posts: 8,905
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 2190 Post(s)
Liked 1,334 Times in 722 Posts
Originally Posted by Jeff Wills View Post
Exactly. I would try a "road" front derailleur and see how it works. The bugaboo is that the curve of the cage won't be a good match to the smaller MTB chainrings. I thing the IRD Alpina is what you need for road brifters and small chainrings: https://store.interlocracing.com/alfrde.html
+1
I have two bikes with 48T chainrings and triples that use the Alpina D.
I initially tried to use an Ultegra triple FD, and due to the curvature of the cage being designed for larger rings, the shifting sucked rocks.
Shimagnolo is offline  
Old 01-23-13, 04:44 PM
  #15  
bobotech
Senior Member
Thread Starter
 
Join Date: Jan 2012
Location: Spokane, WA
Posts: 2,255

Bikes: Specialized Sequoia Elite/Motobecane Fantom Cross Team Ti/'85 Trek 520

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Jeff Wills View Post
Exactly. I would try a "road" front derailleur and see how it works. The bugaboo is that the curve of the cage won't be a good match to the smaller MTB chainrings. I thing the IRD Alpina is what you need for road brifters and small chainrings: https://store.interlocracing.com/alfrde.html

Also bear in mind that your MTB has a longer top tube than a similar road bike. You'll need a very short stem for correct fit with drop bars.
Actually I think that is part of my fit problem. My main ride is a Univega Via Carisma that when new, came with flat bars and 700c wheels. It was an early hybrid. I ended up converting it to drops with STi shifters and I love it. I have very short legs (29" inseam) yet I am almost 6' tall and have fairly long arms. Most of the time when I get on a bike that has good family jewel clearance, I end up feeling very super cramped. I even put a fairly long stem on the Univega and I ride on the hoods quite comfortably.

So I think having the drops with the longish stem will stretch me back out again and help with the fit, well that is my hope anyway.
bobotech is offline  
Old 01-23-13, 04:45 PM
  #16  
bobotech
Senior Member
Thread Starter
 
Join Date: Jan 2012
Location: Spokane, WA
Posts: 2,255

Bikes: Specialized Sequoia Elite/Motobecane Fantom Cross Team Ti/'85 Trek 520

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Shimagnolo View Post
+1
I have two bikes with 48T chainrings and triples that use the Alpina D.
I initially tried to use an Ultegra triple FD, and due to the curvature of the cage being designed for larger rings, the shifting sucked rocks.
Well I guess I could put one of my 50t triples on the bike. Its not like I'm using it for actual mountain biking and it still has a 28t rear cog so I could still climb if needed.

I have plenty of cranks and cassette to choose from. The front derailleur is the wildcard for me.
bobotech is offline  
Old 01-24-13, 08:50 AM
  #17  
dave s
Senior Member
 
Join Date: Oct 2008
Posts: 107
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I built up an early 90's trek 920 mtb bike into a drop bar road bike. I used an old Sugino AT crank with 48/38 Biopace rings, I did not need the 28T little ring, so did not use it, a Deore RD, added a clamp on down tube cable stop, used a set of Tiagra 4503 brifters, and a Tiagra 4503 triple FD. I drilled a small hole in the BB to screw on a cable guide. I tried several mtn FD, but was having shifting issues. this combo shifter perfectly both frt and rear.

dave s
dave s is offline  
Old 01-24-13, 09:39 AM
  #18  
Yo Spiff
Carpe Velo
 
Yo Spiff's Avatar
 
Join Date: Dec 2011
Location: Fort Worth, Texas
Posts: 2,515

Bikes: 2000 Bianchi Veloce, '88 Trek 900, '88 Schwinn Prologue, '92 Schwinn Crosscut, '03 Diamondback Tandem, '94 Yokota Grizzly Peak

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 7 Times in 7 Posts
Originally Posted by bobotech View Post
I now remember why I hated riding my MTB. My hands hurt like hell and were numb after only a 2 mile ride.
Same reason I decided to convert my MTB to drops.

What about taking the easy route and throwing a set of bar end shifters onto it?
Yo Spiff is offline  
Old 01-24-13, 10:43 AM
  #19  
Retro Grouch 
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 29,964

Bikes: Catrike 559 I own some others but they don't get ridden very much.

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 1466 Post(s)
Liked 392 Times in 235 Posts
Originally Posted by Yo Spiff View Post
What about taking the easy route and throwing a set of bar end shifters onto it?
He already owns the STI's?
Retro Grouch is offline  
Old 01-25-13, 12:05 AM
  #20  
bobotech
Senior Member
Thread Starter
 
Join Date: Jan 2012
Location: Spokane, WA
Posts: 2,255

Bikes: Specialized Sequoia Elite/Motobecane Fantom Cross Team Ti/'85 Trek 520

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Retro Grouch View Post
He already owns the STI's?
Yeah. Its kind of lame but I think that STI shifters look cool and would be very different on a mountain bike. Might get me some "street cred". LOL

Plus I just love how they shift. I feel comfortable using them. Its funny, when I first built up my Univega, I was all worried about using the drop bars and put a set of interrupter brake levers on it as well. I rarely ever use them now.
bobotech is offline  
Old 01-27-13, 10:59 PM
  #21  
bobotech
Senior Member
Thread Starter
 
Join Date: Jan 2012
Location: Spokane, WA
Posts: 2,255

Bikes: Specialized Sequoia Elite/Motobecane Fantom Cross Team Ti/'85 Trek 520

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Well I finished the conversion today. Came out nicely. I ended up trading a nice short cage old Dura Ace rear derailleur for a really nice 105 long cage rear derailleur. Got the Ultegra front derailleur. I am still debating on the brakes. I put a set of Tektro mini-v brakes on the front since I have a front suspension and didn't have a canti brace on U. Put cantis in the rear. Surprisingly enough, the front brakes stop the bike VERY well, better than cantis. I didn't put the other set of mini-vs in the rear mainly because I have a fender back there that will be in the way. But the more I look at it, i think I can make it work. I was able to notch the front fender enough to allow the mini-v brakes to clear. I just wasn't sure how the mini-v brakes were going to work with the STI brake levers.

I put a nicer crankset on it that has a 48-38-28 compared to the factory Trutiv riveted set with the 42-30-26 (or whatever it was). I could not get the 42-30-26 to work with the road Ultegra derailleur at all for obvious reasons. I was able to get the Ultegra to shift nicely with the 48-38-28 but I had to give a higher gap between the top of the teeth and the cage. If I gave it a millimeter or so of gap, the cage rubbed on the inside of the middle chainring. I guess that happened because the cage was expecting a 52t chainring as the minimum so putting a larger gap between the 48t and the cage tricked it into working better.

I hate how much rolling resistance the big knobby tires have compared to my road bike. That part I did not like one bit. However after a 4 mile bike ride, my hands were not numb or hurting at all. I was pretty pleased with that.
bobotech is offline  
Old 01-27-13, 11:54 PM
  #22  
pierce
S'Cruzer
 
pierce's Avatar
 
Join Date: Jun 2010
Location: 122W 37N
Posts: 2,442

Bikes: too many

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 38 Post(s)
Liked 16 Times in 14 Posts
so get some less knobby moutain tires, maybe 26x1.75 or so. you really only need knobbies in seriously soft stuff on hills, and there's a narrow range where if it gets much worse (beach sand, etc) nothing will help short of big balloon tires.

I always liked the mountain tires that had a rib down the middle, or had the blocks staggered and overlapped such that if you're going straight, they are smooth. yes, with this sort of tire, its a bit disconcerting when you lean and get onto the knobs, but you get used to it pretty quickly, and they generally behave predictably.
pierce is offline  
Old 01-28-13, 12:10 AM
  #23  
bobotech
Senior Member
Thread Starter
 
Join Date: Jan 2012
Location: Spokane, WA
Posts: 2,255

Bikes: Specialized Sequoia Elite/Motobecane Fantom Cross Team Ti/'85 Trek 520

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by pierce View Post
so get some less knobby moutain tires, maybe 26x1.75 or so. you really only need knobbies in seriously soft stuff on hills, and there's a narrow range where if it gets much worse (beach sand, etc) nothing will help short of big balloon tires.

I always liked the mountain tires that had a rib down the middle, or had the blocks staggered and overlapped such that if you're going straight, they are smooth. yes, with this sort of tire, its a bit disconcerting when you lean and get onto the knobs, but you get used to it pretty quickly, and they generally behave predictably.
Well I will be riding my road bike with slicks on it if the weather is good. I am riding this bike specifically for the bad weather like if there is snow on the ground. I actually had tires like the ones you are talking about , the ones with smaller knobs and a rib down the middle before but I changed them out for the knobbies for the bad weather.
bobotech is offline  
Old 01-28-13, 12:23 AM
  #24  
pierce
S'Cruzer
 
pierce's Avatar
 
Join Date: Jun 2010
Location: 122W 37N
Posts: 2,442

Bikes: too many

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 38 Post(s)
Liked 16 Times in 14 Posts
rain doesn't need knobs on bicycles, they can't go fast enough to hydroplane with the narrow contact patch. but yeah, snow and ice, then you want studs or something.
pierce is offline  
Old 01-28-13, 12:31 AM
  #25  
bobotech
Senior Member
Thread Starter
 
Join Date: Jan 2012
Location: Spokane, WA
Posts: 2,255

Bikes: Specialized Sequoia Elite/Motobecane Fantom Cross Team Ti/'85 Trek 520

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by pierce View Post
rain doesn't need knobs on bicycles, they can't go fast enough to hydroplane with the narrow contact patch. but yeah, snow and ice, then you want studs or something.
Exactly. I ride my slicks all the time in rain, that isn't a issue. But the snow and ice, I want something more substantial. I wish I could afford studs but that isn't in the cards right now for me, too poor. So I got the best looking knobbys that I could find. Not big giant lugs, but a lot of smaller lugs with thinner carved out sections. More like a heavy duty all seasons style tire than an actual offroad knobby.
bobotech is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.