roadie derailluers

[troome]

recently my Shimano Deore LX rear derailleur somehow snapped and ended up in my spokes bending everything in the area. I ride a Kona Roast 04 and do some DJ'ing.

I went to a bike shop and the guy there said that putting a roadie derailleur and cassette would help.

Is this a good idea?

Would it help?

Thanks

[bikeman_baldrik]

if you are running a single ring setup up front, it will help.
The road derailleurs will give you a) a shorter mech and b) better chain tension.

The cassette will give you a closer gear range.
I'd do it if i were you and you can afford it.

[dhd]

we ran exactly that configuration on our team DH bikes last year and had no probs.......well, that they told me of anyway!

[lotec]

recently my Shimano Deore LX rear derailleur somehow snapped and ended up in my spokes bending everything in the area
i think you'll find the derailleur snapped AFTER it ended up in the spokes, probably from not having the limit screws adjusted properly but its a bit late to fix that now eh? :wink: if it was me i would definitely go a roadie derailleur and cassette, even something cheap like a shimano 105 derailleur and low end cassette will shift 10 times better than your lx ever did, just make sure the limit screws are adjusted properly or it will probably happen again :)

[troome]

my chain snapped aswell which could have had something to do with it. looks like the chain ripped the derailleur into the spokes. but it could have had something to do with the limit screws.

If you are doing a lot of racing and want better pedaling ability at high speed when you are rattling over rough ground I would go for a 105 derailler and cassette. Because the gear ratios are closer you will find you have more useful gears at high speed because you will be less likely to find one gear that is "too easy" and the next is "too hard".

You also get less chain slap because there is less chain flapping about.

The trade off is that you will lose most of your ability to ride up hills.

You also should not use a road derailler with an MTB cassette as the swingarm cannot cope with the change in chain length between the largest and smallest cogs.

Check out most of the race guys (who are not using SRAM) and you will see that road deraillers are quite common.

[troome]

Are road derailleurs made as tough as MTB ones. will they last as long after taking a bit more of a beating than on the road?

[lotec]

while a roadie derailleur might not be "built as tough" its a lot smaller so there's a lot less to get his on things and if it does hit something there's a lot less leverage on it as well so its less likely to bend i wouldn't worry about a roadie derailleur failing before a mtb one seriously... also 105s are cheap as so if it does break a replacement is very cheap (comparatively)

[ajay]

Generally. if you give a derailuer a good hit it wont matter if its a mtb or roady one, it'll get trashed eventually anyway, its worth the swap over for the better shifting etc...

[bazza]

my tiagra is still going strong. awesome deraliur. also running a random road cluster and teh shifting is AWESOME! i would recomend it for a purpose dh bike. not so good for a 'trail' or ride around a lot bike. but i guess it would build up those leg muscles having to pedal around in the higher gears?? yer go for it i say. my tiagra has been going strong for a full year now with no problems. i destroyed 2 deore's in like 6 months before that. so yeah. go for it.

[troome]

Thanks for all the help guys. Think i'm gonna go ahead with it. See how it turns out.