George

I'm going to convert to drop bars on my Jamis Coda Elite, which has disk brakes. The stem on the bike is for handlebars that are 25.4. I was wondering if I should go with a different stem and go to the 31.8 handlebars. I have big hands and I thought that the bigger bars may be better. The photos are to show the brake cables and if I would have a problem with where the bosses are. I read where some people have had some problems with the Tectro (spelling) brake levers and I was thinking about going with Shimano. It will have bar-end shifters as well. Thanks for any help.

Retro Grouch 

Doesn't matter. The 31.8 mm is only on the center clamp section. It doesn't apply where you put your hands.

George

Thanks Retro, do you think the cables would be a problem?

fuzz2050

Cable routing can sometimes be a little finicky when converting to drop handlebars, but I think your cable stops on the downtube should present no problem.

Brake cables, on the other hand,, especially with disk brakes, you might want to get some stick on cable guides for the fork. It's always a little messy when you use zip ties, and it can even interfere with braking.

George

Thanks fuss, I didn't know they made them. I have tie wraps on it now and that will help clean it up.

Retro Grouch 

I wouldn't think so. Your cable housings won't be the same length but I don't know if they'll need to be longer or shorter. I get the handlebar how I want it and then make sure I can turn it all the way to determine how short I can cut the housing. A little too long is better than a little too short but way too long looks goofy.

George

Thanks again, I wasn't going to use the old cables. I was more concerned about the bosses, but I think everything is going to workout.

George

I'm having a problem finding handlebars with the 25.4 diameter. I find them with 26.0, but then I would need a clamp right?

joejack951

25.4mm drop bars are out there:

https://www.universalcycles.com/shopp...p?category=635

There are many more options for 26.0 or 31.8 though so if you can't find what you want in 25.4, you will need a new stem. Luckily, you can find very cheap threadless stems in almost any configuration desirable.

George

Thanks I just found some at Jenson.
https://www.jensonusa.com/store/produ...Handlebar.aspx

Panthers007

Good choice there. Randonneur bars are wonderful. More hand positions and more friendly angle.

fuzz2050

It might as well be raised now, but do you know if your disk brakes are long or short pull?

If you have long pull disk brakes your going to need a set of specialized levers, Dia-Compe, Cane Creek and Tektro all make them.

George

I hope these work.
https://www.jensonusa.com/store/produ...evel+R400.aspx

tatfiend 

The Shimano levers are for road brakes and will probably not have adequate cable pull to handle most mechanical disc brakes. The exception would be the Road version of the Avid BB7 disc calipers if you have them. Probably not as they are typically factory fitted to bikes that come from the factory with drop bars and disc brakes.

I suggest that you go with one of the already mentioned brands of drop bar brake levers specifically intended for V brakes and/or mechanical disc brakes.

Abacus

I have just converted a bike to drop bars. I found the existing brake cables were too short. The cables exit the brake levers from the top and have to loop backwards and down, whereas flat bar brake levers exit horizontally.

If you have to get long pull drop bar levers look at the Tektro RL-520. These are basically the same lever as the Cane Creek equivalent and substantially less exensive. Both are higher quality than the original Dia Compe version.

George

Thanks a lot everybody. I'll call tomorrow and get the Tektro RL-520. You guys have been a great help and think this job will go pretty good.

Retro Grouch 

While you're shopping put some "compressionless brake cable housing" on your list. It'll make a big difference in the performance of your disc brakes.

George

Get right on it first thing in the morning, thanks.

zzyzx_xyzzy

You'll probably have to change the stem anyway -- when going from flat bars to drops you need the stem to have more rise and less reach. Which, hmm, that's already a lot of rise and not much reach on your setup, especially if you ride the lower half of the trekking bars (which it seems, as all your controls are there).

Abacus

I should have mentioned you'll probably be replacing the cables anyway. Most flat bar brake levers use a barrel shaped nipple versus the pear shaped ones on the drop bar brake levers.

George

I changed the stem a while ago to get more reach and to get the bars away from me. After taking the measurements it will be real close to my road bike. I'll have 33 inches in the cockpit with a inch an a half drop. I'll have to try it out and see, thanks.

dabac

If you want thicker bars there are pads that can be put under the bar tape, or you can run double layers of tape.

wrk101

+1 Nashbar sells some gel pads that go under the bar tape. Use more of them, and you can get the bars really thick.

George

I dont know if I have a problem or not, but will the Dura-ace shifters work with XT derailleurs.
Yes I do have some gel pads already, thanks.

tatfiend 

You should be fine if referring to current Dura Ace. Older 8 speed Dura Ace rear derailleurs were not compatible with other Shimano indexed groups. They used a different cable pull ratio.