Derailleur guard

thelonegroover

While chatting to my lbs about steel hard tails, I was advised against them due to the following reason: ‘if the derailleur hanger gets bent or broken, the frame is a right off’.

I know most if not all aluminium frames have bolt on derailleur hangers, some steel frames also seem to. My thoughts were: 1. Can a steel frame be bent back into shape or re-welded and 2. Why isn’t a derailleur guard fitted.

pte1643

A steel frame would certainly be easier to straighten than an Ali one.

yoohoo999

surely in order to completely protect the mech, the guard would have to be pretty solid and also fixed in such a way that it would not move on impact.

i would far rather shell out £40 for a new XT mech than run the risk of a guard damaging my frame.

how often are you damaging your mechs?

dave_hill

Thelonegroover wrote:

While chatting to my lbs about steel hard tails, I was advised against them due to the following reason: ‘if the derailleur hanger gets bent or broken, the frame is a right off’.

For which read, "we don't stock any steel frames and we'd rather not get one for you because we'd have to get up off our fat lazy arses and do something useful."

Whoops, there I go again with the cyniscism... :roll:

Thelonegroover wrote:

I know most if not all aluminium frames have bolt on derailleur hangers, some steel frames also seem to. My thoughts were: 1. Can a steel frame be bent back into shape or re-welded and 2. Why isn’t a derailleur guard fitted.

In answer to your questions - 1. Yes and yes. Why do you think that most long distance, round the world cyclists use steel frames? It's because no matter where you are in the world there's always going to be somebody in the next village with a gas welding kit. 2. It takes a hell of a bang to break/bend a steel dropout, so a guard is kind of redundant on a steel frame, the derailleur is more likely to break first.

Once of a day you could get a breakaway bolt for the derailleur - this replaced the main screw which held the mech to the frame and was pre-weakened by cutting a groove around the diameter. In the event of a crash, the bolt would break before the mech or the frame.

Anonymous

steel can be bent back into shape a number of times without weakening it. Aluminium, not so much.

ride_whenever

breakaway bolts can be fitted to a lot of modern mechs, although it doesn't look like the new sytle shimano stuff will take one as the bolt required is much shorter.

You could see if you can get the derraileur bolt as a spare from madison/ultimate pursuits and then machine a groove to act as a breakaway bolt. Generally they're held in with c-clips.

The Northern Monkey

surely the idea behind a shadow mech is to reduce the chance of this happening?

I've got a steel frame + shadow mech... I haven't even considered what would happen if I bent the frame, i'd probably just strip it and buy another frame :?

ride_whenever

why it's steel, bend it back!

Ideally using a tool as opposed to the mech

thelonegroover

yoohoo999 wrote:

surely in order to completely protect the mech, the guard would have to be pretty solid and also fixed in such a way that it would not move on impact.

i would far rather shell out £40 for a new XT mech than run the risk of a guard damaging my frame.

how often are you damaging your mechs?

I haven't actually done any damage yet, I was just cogitating on the issue, as a result of what the shop said. I currently have a Marin Alu hardtail, but will probably get a steel next, when the Marin gets handed down to thelonegroover junior!

daniel_owen_uk

See http://www.bikeradar.com/forums/viewtop ... 7&start=60

For steel frame bending