Rear Derailleur

Dazium said:

I have had problems with the read derailleur ever since day one, and today it broke off completely (screw came out of one part and I lost the cog thingy)

So, I got home and started researching what I will need to buy as a replacement, and I thought I was doing well until I read the Beginners guide, and I got even more so confused.

I am not to sure on where to start at all, which is making me go crazy 🙁

By your description, I presume you lost a pulley wheel + the bolt that holds it.

Depending on the derailleur, it may actually be cheaper (well, easier/faster) to buy a replacement rear derailleur off of eBay.

What kind of derailleur AND shifters does your bike have?
[INDENT]A picture is worth a 1000 words if you can't immediately identify either.
[/INDENT]

The best all around road bike derailleur for the money is the Shimano 105, it's a low costing unit but has very high reliability. But you need to know if you have a long, medium or short cage derailleur. As one poster said pics if possible would be a huge help. Or go to your LBS and tell them you want the 105 and they can install it quickly and set it for you.

If you have a mountain bike then consider the Shimano Deore is about the same league as the 105.

Thanks for the replies guys.

I do want to replace the derailleur completely, had a problem with it to begin with.

I have attached a few images of the derailleur, hope they are good enough, if not let me know!

The bike is indeed a mountain bike.

I have grip shifters, if I am understanding what your asking correctly, also took a picture to be sure.

Dazium said:

The bike is indeed a mountain bike.

I have grip shifters, if I am understanding what your asking correctly, also took a picture to be sure.

If you think that you may ever want to get a 'performance' rear derailleur, then the Shimano SLX may currently be the best value of the Shimano MTB rear derailleurs -- the SLX is marginally better than the Shimano LX rear derailleur, and almost as nice as the Shimano XT rear derailleur.

The SLX is only, AFAIK, available as a "Rapid Rise" rear derailleur ... Rapid Rise has less benefit with Grip Shifts.

LX is still available as either "regular" rise or Rapid Rise.

As suggested, you may want to consider a 'plain' Shimano Deore (vs. Deore XT) rear derailleur if you are on a tight budget.
[INDENT]BTW. Actually, the LX is comparable to the 105 and the Deore is probably better compared to the Tiagra.

[/INDENT]

This bike is pretty much just to get me started. So the cheapest option is probably my best bet, providing it is going to last a wee while.

As for cage sizes, how do you work out what size you need?

Thanks.

alfeng said:

As suggested, you may want to consider a 'plain' Shimano Deore (vs. Deore XT) rear derailleur if you are on a tight budget.
[INDENT]BTW. Actually, the LX is comparable to the 105 and the Deore is probably better compared to the Tiagra.

[/INDENT]

Correct me if I'm wrong, but isn't the LX a Deore? According to Shimano's web site the Deore LX has been split into two groups, the SLX for those who are into mountain biking, and the Deore LX for those into milder trekking. The Deore I was speaking of was just the basic Deore which is called simply Deore with no letters after it; this is a lower cost version of the Deore XT or LX but nevertheless very dependable.

And your right, the plain Deore is probably more comparable to the Tiagra and probably even closer to the Sora according to Shimano. The SLX is probably closer to the 105, while the XT is closer to the Ultrega.

If the poster really wants a low cost derailleur he may want to consider the Alivio. These are only about $25 vs $45 for the plain Deore.

Dazium said:

This bike is pretty much just to get me started. So the cheapest option is probably my best bet, providing it is going to last a wee while.

As for cage sizes, how do you work out what size you need?

Personally, I generally choose the derailleur with the longest cage ("SGS" in Shimano terms ... aka "Super Gran Sport" (or, something like that) which also means "touring"😉 because I don't mind dragging around a couple extra grams of chain ...

So, I almost always use a long cage (i.e., "GS"😉 Road rear derailleur or even a MTB rear derailleur which will usually be an SGS -- it doesn't look cool, but I'm not sure that I'm in a position to look cool AND it allows me to choose almost any cassette size I may want to use.

Froze said:

Correct me if I'm wrong, but isn't the LX a Deore? According to Shimano's web site the Deore LX has been split into two groups, the SLX for those who are into mountain biking, and the Deore LX for those into milder trekking. The Deore I was speaking of was just the basic Deore which is called simply Deore with no letters after it; this is a lower cost version of the Deore XT or LX but nevertheless very dependable.

And your right, the plain Deore is probably more comparable to the Tiagra and probably even closer to the Sora according to Shimano. The SLX is probably closer to the 105, while the XT is closer to the Ultrega.

If the poster really wants a low cost derailleur he may want to consider the Alivio. These are only about $25 vs $45 for the plain Deore.

You may be correct with regard to Shimano appending the LX label with Deore, now. In the past the hierarchy was simply:
[INDENT]XTR
XT
LX
?
DEORE
?
etc.
[/INDENT]Where DEORE was a name originally created by Shimano in the early 80s (late 70s?) ... "Deore" was supposed to be their premier non-Road group; but, Shimano clearly/quickly figured out that they could do better and eventually the XT was developed. What happened in between is for someone else to fill-in-the-blanks. When Shimano figured they could do better than the XT, the XTR was born (XT Racing) ... I don't know if the XTR was released concurrently with the XT or in one of the following years.

A USED Shimano XT 750 rear derailleur in good condition is frequently only about $25 + shipping on eBay.