Braze-On Front Der Won't Adjust Low Enough for 50t Ring.

Frame - Trek OCLV 5500. I want to install a compact crank but the 6500
Ultegra braze-on front derailleur won't adjust low enough for the 50
tooth big ring. It will only get to within a half inch or so.

Any suggestions? Can I modify the bracket in some way? Is there an
adaptor or a different hanger somewhere to be purchased? Is filing the
slot or getting a custom made hanger the only option?
Thank you in advance.

55/Rad

55/Rad wrote:
Frame - Trek OCLV 5500. I want to install a compact crank but the
6500
Ultegra braze-on front derailleur won't adjust low enough for the 50
tooth big ring. It will only get to within a half inch or so.

Just get it within a half inch and ride the bike. The front derailleur
will shift the chain between the chainrings just fine. It does not
have to be exactly 2mm above the outside ring to work. Nor does the
curvature of the derailleur cage have to precisely match the curvature
of the outside ring to shift properly.

Ummm ok. However, the last time I rode a bike with enough space to
throw the chain, guess what...it threw the chain. And I ended up in the
hospital getting sewn back together. So I'm sure you'll understand why
I'd like my der to be a little closer that just "in the neighborhood".
55/Rad

55/Rad wrote:

Frame - Trek OCLV 5500. I want to install a compact crank but the 6500
Ultegra braze-on front derailleur won't adjust low enough for the 50
tooth big ring. It will only get to within a half inch or so.

Any suggestions? Can I modify the bracket in some way? Is there an
adaptor or a different hanger somewhere to be purchased? Is filing the
slot or getting a custom made hanger the only option?
Thank you in advance.

I've said it before, I'll say it again:

Front derailer braze ons are the work of SATAN!

Sheldon "Retro Me Satanas!" Brown
+---------------------------------------------+
| Whatever you say, say it with conviction. |
| --Mark Twain |
+---------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

On 29 Dec 2004 16:13:03 -0800, "55/Rad"
wrote:

Frame - Trek OCLV 5500. I want to install a compact crank but the 6500
Ultegra braze-on front derailleur won't adjust low enough for the 50
tooth big ring. It will only get to within a half inch or so.

Any suggestions? Can I modify the bracket in some way? Is there an
adaptor or a different hanger somewhere to be purchased? Is filing the
slot or getting a custom made hanger the only option?
Thank you in advance.

55/Rad

I got a 50 tooth chain ring on my Trek OCLV. The "special" Trek
bracket appears to be a re-worked stock one. So if you're handy with
simple metalworking, I recommend you consider carefully extending the
slot downward.

Sheldon Brown wrote:

55/Rad wrote:

Frame - Trek OCLV 5500. I want to install a compact crank but the 6500
Ultegra braze-on front derailleur won't adjust low enough for the 50
tooth big ring. It will only get to within a half inch or so.

Any suggestions? Can I modify the bracket in some way? Is there an
adaptor or a different hanger somewhere to be purchased? Is filing the
slot or getting a custom made hanger the only option?
Thank you in advance.


I've said it before, I'll say it again:

Front derailer braze ons are the work of SATAN!

How would one braze a derailleur mount to a carbon fiber composite frame
tube?

--
Tom Sherman - Near Rock Island

55/Rad wrote:
Frame - Trek OCLV 5500. I want to install a compact crank but the 6500
Ultegra braze-on front derailleur won't adjust low enough for the 50
tooth big ring. It will only get to within a half inch or so.
-snip-
Sheldon Brown wrote:
I've said it before, I'll say it again:
Front derailer braze ons are the work of SATAN!

Tom Sherman wrote:
How would one braze a derailleur mount to a carbon fiber composite frame
tube?

It's the jargon of our industry. We call anything that
doesn't encirle the seat tube a "braze on". Even when it is
a stainless steel plate bolted to threaded inserts on a
carbon frame. (Which, by the way is still the work of Satan.)

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

I resolved this problem by taking a Mavic br-on front der and drilling and
tapping threads above the factory hole.

Mavic has a lot of extra material so it is safe. Other fr ders that I've
considered don't seem to be able to be safely modified.

If you want a Mavic fr der contact me.

I recently erred in specing a br-on on a bike I had built for me. I was
possessed by the devil. Definitely a mistake.

Gary Jacobson
Rosendale, NY

Frame - Trek OCLV 5500. I want to install a compact crank but the 6500
Ultegra braze-on front derailleur won't adjust low enough for the 50
tooth big ring. It will only get to within a half inch or so.

Your dealer can order the new "compact drive" front derailleur bracket from
Trek; just got some last week. Haven't yet installed one on my own bike (a
5900) so the front shifting is probably a bit less than optimal, but still
seems to work quite nicely.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com

Russell
Perhaps we're talking apples & oranges here, but I've always had one
hell of a time getting a f. derailer to work when not as cllose as
plssible to the big ring. In fact I've usully fornd the f. derail hell
to adjust period. much harder than a rear, except for the last XT (a
2003) I installed. Probably spent 10 min installing & adjusting.
Worked perfectly in the stand. I figured 'yeah, sure, soon as I ride
it, I'll end up spending hours getting it to work'. Worked absolutely
perfectly. Didn't have to touch a thing. Couldn't f'ing belive it.
You must be incredable good, or incredabaly lucky to get f. derails to
work w/ 1/2" gap & not throw chains.
John