[GregBik3r]

I've got an 11-32 cassete and a 42t front ring on my DH bike. For 45 or less bucks, what am i going to get the best performance out of? I was thinking Ultegra Mid-Cage (RD-6500) or XT long cage. Would I be better off with a mid or a long cage? And should I go with a road der. or a mtb der? Thanks

 

[Sir_Crackien]

the road ders will not work well using a 32 tooth cog if at all. but you can get the xt in a mid cage. that is what i would do.

 

[Phatswalla]

I'm using a short cage road derailleur on a 11-32 tooth cassette and 22-32 in the front. I don't see any reason why the road derailleur shouldn't work for you, especially since you don't have multiple gears up front.

 

[DßR]

OK, I'm gonna play "how many times can I correct Sir_Crackien in one day".

Yeah, Phats is 100% correct, a roadie derailleur works JUST FINE with a 32t cog. It will also work alright with a 34t cog, but will rub a bit. Not a big deal if you really need that 22/34 combo to get up a hill on your heavy-ass bike. Run the B-tension all the way tight and it's cool.

Greg, IMHO you should save a few pennies and get the 105 shortcage. I use them on my DH bike and they work great until they get the sh*t bashed out of them on a rock. Definitely the DH der. of choice.

 

[GregBik3r]

sweet. thanks for the help guys

 

[GregBik3r]

one more quick ? ... do you know off the top of your head where the cheapest price for a 105 is?

 

[Rabie]

Originally posted by DßR


Yeah, Phats is 100% correct, a roadie derailleur works JUST FINE with a 32t cog.

Not always. I tried a GS cage 105 with a 32t cassette and it would not work at all, regardless of b-tension.

 

[GregBik3r]

Well, that creates kind of a problem...what's the verdict?

 

[Colin]

For Shimano pricing check:

www.comparisonpricing.com

 

[Phatswalla]

Both the Ultegras and 105s are speced to work with 27 tooth cogs in the rear. Both have worked flawlessly for me on a 32 tooth and shift better than an XTR. The cage length only changes how much extra chain you can run so you can run a wider arrangement of gear ratios not how large of a cassete it will shift on to.

If you adjust the b-tension screw out all the way like DßR said, have your L-limit screw adjusted properly and don't have a downward bent derailleur hanger it should work fine.

 

[kidwoo]

Originally posted by GregBik3r
Well, that creates kind of a problem...what's the verdict?

I had an ultegra med cage on my road bike and put an XT 11-34 tooth cassette on it whenever I was doing a century or a long social ride. It worked just fine. 105 derailleurs I don't think, are any different. I'm not positive though.

 

[Tweek]

//// N00B-like question alert //////

So other than (usually) being slightly cheaper and lighter, what are the advantages of using a road derailleur on a DH bike? Better shifting performance? If so, why -- better pulleys?

 

[Phatswalla]

The springs have more tension so shifting is faster and tighter and the shorter cage/chain length improves shifting.

 

[DßR]

Originally posted by Tweek
//// N00B-like question alert //////

So other than (usually) being slightly cheaper and lighter, what are the advantages of using a road derailleur on a DH bike? Better shifting performance? If so, why -- better pulleys?

My reasons are very simple: short cage = much much more better, for obvious rock-snagging reasons.

Roadie derailleurs are much easier and much cheaper to get in short-cage models than mtn der's - 99.999% of LBS's carry a 105 shortcage in stock, and an equal number will say "uhhhm, well we can order it" if you ask for an XT mid-cage.

Since I go thru a lot of 'em, I go for whatever's easiest and cheapest to replace.

As far as shifting performance, I dunno. I think they're about the same, some people seem to think the springs are stronger. They work on any size cog in my experience, including a 34t, so that's not a factor. Shimano's "max cog" specification has no bearing on what the derailluer can do in real life.

Originally posted by Rabie


Not always. I tried a GS cage 105 with a 32t cassette and it would not work at all, regardless of b-tension.

Frankly, I'm a little stumped - sorry to ask a stupid question, but are you sure the low limit screw was loose enough to hit that cog? I use my shortcage 105 with a 34t cog, and yeah it rubs some, but it shifts in and out just fine. It's not gonna last long enough with all the rocks around here for me to give a crap about the long-term effects (if any) of that rubbing....

 

[DßR]

Originally posted by GregBik3r
one more quick ? ... do you know off the top of your head where the cheapest price for a 105 is?

Probably JensonUSA, around $32 last I looked...

This usually ends up being a "support your LBS" purchase for me, since I always seem to bust one right before a race; no time for mail-order....

 

[Rabie]

Originally posted by DßR


Frankly, I'm a little stumped - sorry to ask a stupid question, but are you sure the low limit screw was loose enough to hit that cog? I use my shortcage 105 with a 34t cog, and yeah it rubs some, but it shifts in and out just fine. It's not gonna last long enough with all the rocks around here for me to give a crap about the long-term effects (if any) of that rubbing.... [/B]

Even with the low-limit all the way out it would not clear the larger cogs. I was confused, too, but it just wasn't happening. Works fine with an 11-27, though.

 

[Phatswalla]

Is your derailleur hanger in good shape?

 

[Rabie]

Originally posted by Phatswalla
Is your derailleur hanger in good shape?

It was reasonably straight.

 

[GregBik3r]

Does an Ultegra have noticeably better shifting performance?

 

[DßR]

Originally posted by GregBik3r
Does an Ultegra have noticeably better shifting performance?

nope. Just lighter.