Wednesday, May 2, 2012

Flat bar Conversion

A while ago I picked up a Soma Smoothie ES that had been put together with drop bars and  Ultegra components. The recipient decided they weren’t going to be riding the bike and gave the bike back. My wife had the opportunity to ride the bike and liked it but she did not like the drop bars. So this gave me the opportunity to do a flat bar conversion; this is basically a replacement conversion. To do a flat bar conversion you are basically turning your road bike into a mountain bike. The shifters are mountain bike shifters with a different model number. Like a mountain bike, the rear shifting is the same so you can use your old road derailleur, but the front shifting is different and even if you were to use a mountain bike front derailleur, the arc of the cage would comprise the shifting.  So it’s off to buy some bike parts. Below you see the following*.

Shimano BL-R550 Flat Bar Road Brake Lever, pair 
Shimano SL- R440+R441 (2/3X9)Shifters For Flat Bar Road Bike
Shimano FD-R443 Flat Bar Triple Front Derailleur (If you have a double crank the part number is FD-440)
And a Bontrager Crow bar from the parts bin.

* be advised that like everything else Shimano, there are different levels. These are the "4" or Tiagra level components; there is also the "5" or 105  level which seems to exist only for brake levers, the "6" or SLX (9 speed) level and the "7" or 10 speed Ultegra level. This web site spells out the Shimano flat bar components .


 Now it's time to take the old stuff off. Below are the drop bars (with a Shimano Flight Deck), Ultegra Brake/Shifter, and front Ultegra triple derailleur. The amount of cable pulled and needed for Shimano road front shifter and derailleur, needed for indexing, differs from mountain bike front shifters and derailleurs. Further mountain bike front derailleurs have an arc to the cage for shifting from/to a 44-48T chainring, which would comprise the shifting from/to a 50-53T chainring. The Shimano FD R443 is a cross between mountain mike cable pull with a wider cage arc for larger road chainrings.

First I installed the bar, brake and shifters. As I said before the shifters are mountain bike shifters, so if you have some lying around, you won't need to buy any for a conversion.  These flat bar brakes are simply cantilever brake levers, which work very well with side pull calipers, but will not work with V-brakes.

Next I installed the front derailleur and connected the derailleurs and brakes with housings and cables.

And here is the end result; hopefully mama like!