Can you use a triple chainset with with double shifter??

lloydwilliams

Hi,

I have a flat bar hybrid that I want to convert to drop handlebars. I have got an old pair of drop bars with Shimano ST-2300 shifters which I know the 8 speed rear mech will be fine but was hoping to find out if I could take the inner ring off the triple crankset and use the doubel shifter?

supersonic

What is the model of the front derailer?

lloydwilliams

Its a Shimano Altus (bottom pull)

Hopefully you may also be able to advise if the Shimano ST-2300 shifters will operate Avid BB5 disc brakes aok?

rubertoe

lloydwilliams wrote:

Its a Shimano Altus (bottom pull)

Hopefully you may also be able to advise if the Shimano ST-2300 shifters will operate Avid BB5 disc brakes aok?

The Shifters and the Avids will work fine, provided that they are the Road BB5's and not the mbt BB5's.

Not sure about the derailuer though.

dgunthor

should work ok - the distance between triple rings is the same as double. a triple front mech is designed so it can shift the smallest (30T) ring too - not an issue for you.

only questionmark is whether the standard double front mech cage will move out far enough for the big ring

supersonic

MTB front mechs do not work with Road shifters as the cable pull is different. It may be 'bodgeable', but it certainly will not be perfect.

bikaholic

Here's one I built a couple of years ago:





A flat bar hybrid bike converted to a cross style bike.

The FD on the frame is a Shimano Tiagra FD-4503, triple optimised. Double setups are very similar and easier - a big help would be if you could play with the chainline (by having a square taper, ISIS or Octolink crankset) to pull the chainrings inboard to be in the working range of the FD.

On this particular Kona frame, the band clamp on the road FD interferes with the bottom bottle boss so I simply ground a small circle out of the clamp to fit around the boss.

lloydwilliams

Loving the Kona Bikeaholic, I've got a globe sport and this is exactly what I was hoping to turn it into. Looks like it won't be as easy as I'd hoped but I might still go for it. CRC are doing a alright Truvative double chainset for £25 and will try and get a FD off ebay and will have to get some road BB5's.

Anyone know if there is a cheaper road disc option other than Avid?

Here's a pic of the bike with the flat bars temporarily undone to see what the drop bars would look like:

Thanks for the info guys!


IMAG0018 by llwilliamsuk, on Flickr

bikaholic

Road STI brake levers are short pull - they will work with mtb mechanical disc calipers if you set the pads very close to the rotor.

But, the leverage (and hence, pull tension) will be very high so you will need to feather the brakes, otherwise, you risk locking up the wheels.

Give it a try before parting with your hard earned cash.

The Rookie

I have a clarkes that is road pull, not sure they do it anymore though, why not look at some CX bike specs?

gbsahne001

supersonic wrote:

MTB front mechs do not work with Road shifters as the cable pull is different. It may be 'bodgeable', but it certainly will not be perfect.

I was using a Dura Ace set of road shifters (double) with a 46/36 using a Deore front mech and it worked fine.

Edit; forgot to mention that the flat bar CX is using Deore LX shifters with a 105 front mech and a Tiagra rear with no problems at all, I would go as far to say that the set up is crisper than the paired gear shifting of the road bike which uses Tiagra shifters front and DA rear mech.