Front mech on a 50 40 30 mtb top pull
#1
Thread Starter
Newbie
Joined: May 2014
Posts: 2
Likes: 0
Front mech on a 50 40 30 mtb top pull
I have an issue with fitting a front mech on my mtb frame. I have a 50 40 30 chainring setup on race face mtb cranks for road use but I have had to stand off the drive crank by 5mm to clear the frame.
A shimano road triple mech only moves 12mm outward and cannot reach the outer ring. A shimano Mtb triple mech moves 17mm and can reach but the chain doesn't line up with the grooves on the inner plate and it gets jammed.
Ideally I need a mtb mech with a road cage. I have a 9spd setup on sl-r660 shifters
I have considered the SRAM 3.0 but it says its for 7/8 spd setups, would this make any difference?
Does anyone have any ideas?
Thanks
Justin
A shimano road triple mech only moves 12mm outward and cannot reach the outer ring. A shimano Mtb triple mech moves 17mm and can reach but the chain doesn't line up with the grooves on the inner plate and it gets jammed.
Ideally I need a mtb mech with a road cage. I have a 9spd setup on sl-r660 shifters
I have considered the SRAM 3.0 but it says its for 7/8 spd setups, would this make any difference?
Does anyone have any ideas?
Thanks
Justin
#2
Senior Member

Joined: Mar 2010
Posts: 1,585
Likes: 14
From: City of Brotherly Love
Bikes: Raleigh Companion, Nashbar Touring, Novara DiVano, Trek FX 7.1, Giant Upland
Maybe a FD-R453 braze-on type with a tandem specific braze-on adapter.
Edit: the R453 doesn't support 50/40/30 but it will work with 50/39/30
Edit: the R453 doesn't support 50/40/30 but it will work with 50/39/30
Last edited by Bezalel; 05-06-14 at 04:20 PM.
#3
Banned
Joined: Jun 2010
Posts: 43,586
Likes: 1,380
From: NW,Oregon Coast
Bikes: 8
you can open up the front derailleur options with a re direction pulley below the front derailleur and then use a bottom pull FD.
although the cable comes from the top .
Problem Solvers
I used a Campag Triomphe Liesure FD , & bar end shifters with my <C>50-40-(30)24//
although the cable comes from the top .
Problem Solvers
I used a Campag Triomphe Liesure FD , & bar end shifters with my <C>50-40-(30)24//
Last edited by fietsbob; 05-07-14 at 07:33 AM.
#4
Senior Member


Joined: Apr 2009
Posts: 39,897
Likes: 3,865
From: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Try setting the height of the FD (is it an FM in the UK?) basing it on the ramp position vs the middle ring, rather than the outer ring. That may solve the problem. Otherwise you might try a road triple, but there might be issues of cable response ratio. (I hate index front).
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
#5
Junior Member

Joined: Oct 2008
Posts: 114
Likes: 1
I started a winter project a couiple of years ago. I converted a Trek 930 mtb bike to a drop bar winter bike, using a triple crank, tiagra triple FD, and Shifters, (9 speed). To get the road FD to work, I drilled a small hole underneath the BB shell, attached a cable guide. Front shifting was perfect (50/39/30). It took a few trys to find the correct length bottom bracket with the Sugino AT crank, but after that, shifiing was excellent
#6
Thread Starter
Newbie
Joined: May 2014
Posts: 2
Likes: 0
All sorted now, I had to move the drive crank closer to the frame and I bought the SRAM 3.0 dual pull front mech which has flat plates. It's cheap heavy and ugly but it works and recommended if you have a custom chainset. I bought the problem solvers pulley adapter but the pulley wheel is too small and puts a unsuitable bend radius on the cable resulting in extremely stiff shifting - not what you want when you've just fitted the XTR PTFE cableset!
Thread
Thread Starter
Forum
Replies
Last Post
Erik_A
Bicycle Mechanics
12
12-31-16 11:48 AM





