importance of replaceable rear derailleur hanger?

acid_rider · Nov 1, 2007

greetings all

My riding buddy fell off (low speed of ~15mph, no big deal) and bike landed on the side of rear derailleur and the derailleur hanger was bent. His frame has a replaceable rear derailleur hanger so it will be repaired (dont know how much yet!).

This got me thinking. I have a couple of carbon bikes: 2007 Time Edge First and also 2005 Madone 5.9. I think neither one has a replaceable rear derailleur hangers (?). So what happens if it hanger bends/breaks due to a fall/crash? Replace with new frame? Or super-expensive repair bill at least?

So how important is this feature of replaceable derailleur when you buy a new custom or off-the-shelf bike?

And if this is so important then why dont all high end carbon road frames have that feature?

Thanks!

MR_GRUMPY · Nov 2, 2007

I won't buy a frame without one (unless it is steel)

lemonlime · Nov 2, 2007

My steel frame (Orbea) doesn't have a replaceable hanger.

All of my other bikes do. Like Grumps, I wouldn't buy a non-steel bike without it. My kids knocked over my Look onto a carpeted hotel room floor and it was enough to bend the hanger. Luckily it was minor and bent right back.

fleck · Nov 2, 2007

yup, grumpys got it.

steel can be cold set. Any half decent shop will have the tools to do it and the bill should be nominial. 15min of labor max. If they bill you more question it.

pretty much any other frame material, alum, CF, Ti, Mag are a lot tougher to deal with. I'd seriously question buying any bike of those materials without replaceable hangers. I slipped on some mud going 3mph max and bent mine a few months ago. I was lazy and didn't replace the hanger but bent it cause i could. I'd never do that to my frame though!

Terrapin · Nov 2, 2007

I had my replaceable hanger break completely in half on my aluminum frame, this after it had been bent earlier. Fixing it was a $9 fix at the LBS.

I would seriously question buying a bike without a replaceable hanger. They get damaged REAL easy.

MR_GRUMPY · Nov 2, 2007

I've still have a hanger for my Giant, in my tool box, that I got when I bought the frame.

Always be prepared.

terzo rene · Nov 2, 2007

Steel or Ti no worries, both can be bent back multiple times. Al would be a big worry, as is Carbon with Aluminum dropouts. Carbon with Ti dropouts I wouldn't worry, all carbon really depends on how the carbon dropout attaches to the stay; some are easier to replace than others.

And if it's a superlight 750g carbon frame with carbon dropouts and you crash hard enough to break the dropout it's not likely to be the only thing broken so again you wouldn't need to worry about having a replaceable hanger.

jupiterrn · Nov 2, 2007

Never had to replace on my road bike yet but I can tell you that I have been through 3 on the MTB. Going to have to say very inportant spec to have period.

tdi-rick · Nov 3, 2007

just had to replace one on the road bike (Cannondale) thanks to chain suck (still haven't worked out exactly what came first) Ripped or wrecked half the drive side spokes, broke the RD and hanger. Would have been very exxy without a replaceable tip.

Interestingly, alignment of the the frame checked OK but still had to tweak the new hanger with the alignment tool when fitting to get everything square.

Export A · Nov 4, 2007

I haven't had a replaceable hanger on my last 3 bikes. Yes, there is definately an advantage of having them , however one small hit and the replaceable hanger might need replacing!

acid_rider · Nov 4, 2007

why would not all bikes have it?

thanks all for your replies.

if a replaceable rear hanger is such a good thing then why would high end carbon bikes such as Look etc not have it as standard on all their carbon frames? The cost must be next to nothing (extra $50 on $2000-$3000 frame?). Plain cost cutting or are there some disadvantages of replaceable hangers on carbon road frames? Strength? More likely to break than a "fixed/integrated" hanger?

thanks

mh3 · Nov 4, 2007

acid_rider said:
thanks all for your replies.

if a replaceable rear hanger is such a good thing then why would high end carbon bikes such as Look etc not have it as standard on all their carbon frames? The cost must be next to nothing (extra $50 on $2000-$3000 frame?). Plain cost cutting or are there some disadvantages of replaceable hangers on carbon road frames? Strength? More likely to break than a "fixed/integrated" hanger?

thanks

Can't quote the exact source, because it's been awhile since I read it, but the basic problem with the replaceable hangers was that they are a common cause of poor shifting in the rear. They can flex and move around, causing alignment issues with the rear derailleur. .

If the hanger isn't replaceable, look at how the dropout is attached to the frame. Some of them are just screwed to a fitting on both stays making them fairly easy to replace. Ridley recently went this route with a solid dropout/hanger assembly on some models.

HTH.

wim · Nov 4, 2007

acid_rider said:
thanks all for your replies.

if a replaceable rear hanger is such a good thing then why would high end carbon bikes such as Look etc not have it as standard on all their carbon frames? The cost must be next to nothing (extra $50 on $2000-$3000 frame?). Plain cost cutting or are there some disadvantages of replaceable hangers on carbon road frames? Strength? More likely to break than a "fixed/integrated" hanger?

thanks

Damon Rinard's (R&D engineer with Trek) June 2007 reply on this below. From what I can see, Trek's been doing a good job quickly replacing damaged dropouts under warranty.

Question: Is the rear derailleur hanger replaceable on the new Madones?

Answer: Yes, at our factory in Waterloo, Wisconsin.

For years we've long argued internally over replaceable derailleur hangers, and so far the solid one-piece drop out has won. It's clearly a lot stronger, so there's a range of bumps and accidents (such as routine shipping or a fall) that would damage a replaceable hanger that our one-piece drop out survives undamaged. We often see replaceable derailleur hangers that have been damaged lead to later, more severe incidents such as shifting into the spokes, that might have been completely prevented with an undamaged one-piece dropout.

A one-piece dropout also provides more consistent wheel mounting and rear derailleur adjustment, since it doesn't change shape and "flare out" as many replaceable ones do.

But perhaps the best reason we've stick with our one-piece drop out so far is that we see about as many *frames* damaged by failed replaceable dropouts as we see damage to one-piece drop outs. Just to clarify, that's not damage to the replaceable part; we sell lots of those; it's damage to the frame’s dropout itself.

- Damon Rinard

importance of replaceable rear derailleur hanger?

acid_rider

MR_GRUMPY

lemonlime

fleck

Terrapin

MR_GRUMPY

terzo rene

jupiterrn

tdi-rick

Export A

acid_rider

mh3

wim

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