Ricky Roma

Hello all.

I have a GT Avalanche 3.0 MTB, from 2008 I believe. I got it in 2017 with no wheels and no cabling. I've replaced almost all the parts on it apart from the front and rear derailleurs, and the bottom bracket.

I'm looking now to replace both derailleurs. Searching online the best info I can find is that the current parts are:
Front Derailleur - Shimano FD-M330 (Top Pull, Top Swing)
Rear Derailleur - Shimano Alivio

It looks like the FD-M330 is no longer sold(?) so what are my alternatives for this? Also, what rear derailleur should I be looking at? It's an 8-speed rear cassette.

Thanks in advance.

aggiegrads

Are you looking to keep the shift levers and chain? If you are replacing those, there really isn’t anything limiting you to 8 speeds.

As long as you stay in the same “family”, you should not have any compatibility issues. The most important thing right now is that you respond to every question to get your post count up so you can post photos.

The toughest thing to get right here is the FD. There are different mount options as well as different pull options. Seeing a photo photo of what you have will be helpful; but you likely have a clamp mount which will make things easier.

Ricky Roma

Yes, I'm keeping the shifters, and the chain is fairly new so that's also fine. Actually, I have two chains, both with a quick link, and I swap them over when one is getting a bit manky.

Both the rear cassette and front chainrings are also new-ish so I don't need to replace them.

I did take the bike into a local shop a few months ago and the guy there said the FD was "top-swing, top-pull" which matches the info I've found online. It's a clamp mount, 100%.

aggiegrads

Everything that is Shimano branded that has 8 speeds will work with what you have, and you can mix Altus, Alivio, and whatever else is out there. You do need to make sure that both derailleurs have enough capacity. For the RD, you need to know the smallest and largest cogs on your cassette as well as the sizes of the chainrings. Your RD must have enough “chain wrap capacity” for the gearing that is specific to your bike.

mitchmellow62

I'm not meaning to throw a wrench in the works (or perhaps I am, lol) but I catch myself questioning the need. Derailleurs last a long time. I'm still using an '80's sun tour long cage rear derailleur and a Shimano 600 tricolor front. Unless you want to upgrade components I really don't see how its necessary. Of course, upgrading to current 9, 10, 11 or 12 speed will involve shifter(s) plus cassette and increase costs dramatically. You could look for a good used 8 or 9 speed Deore LX, XT or XTR and it should work. However, Shimano tends to trickle down technology over the years and a more modern Alivio my be close in quality. Having said that, I own a circa 2000 XTR that shifts really nice and I hope to use till I stop biking.

dedhed

Any 7-9 speed rear Shimano mountain or 7-10 road with adequate capacity and chainwrap will work with your rear shifters.

Russ Roth

Personally, although my experience is that 9sp will work well enough with 8sp cranks and cassettes, sticking with a 7/8 speed der set is best. Both the catalogue and the tech said top pull top swing so you know what you need. In my experience Altus, Acera and Alivio work fine for people who just want to ride, even if they're riding a lot but aren't into worrying about how light and fast their stuff is. Not the greatest but just straight out reliable. Avoid tourney for all its worth, from what I've seen it goes from bad to total crap depending on the price point, and it has several. Looks like newer, Acera and Alivio front ders have gone to side swing, might work fine, might not. But I've given you 4 links to derailleurs that will work for you. If you think in the near future you'll toss on a 9sp chain, cassette and shifters I'd go with the 9sp ders now and they'll work. If not, stick with the 7/8 speed ders. The fronts come with adapters to it the 3 frame tube diameters and are dual pull meaning it can be set up top pull. Have fun.
https://365cycles.com/products/shima...ng-cage-silver
https://365cycles.com/products/shima...ong-cage-black
https://365cycles.com/products/shima...ont-derailleur
https://365cycles.com/products/shima...ont-derailleur

Ricky Roma

The front derailleur has had it - it's constantly clogged with dirt and is very stiff when shifting, even after I've blasted it as clean as I possibly can. I think the spring is the issue, it's goosed.

I'm not fretting over spending £20-30 on a new FD.

freeranger

Take a look at Microshift. Inexpensive, Shimano compatible. I replaced a front derailleur on my wife's 3 x 9 road bike and it works fine. Would expect their MTB offerings to be made as good. I wouldn't hesitate to purchase from them again if I need a replacement part for our older bikes. microSHIFT

Ricky Roma

Thanks for the advice so far, please keep it coming.

I've realised I've left out some important info.

The rear cassette is a Shimano HG-50 11-32, and the front chainring has 42/32/22 teeth. I replaced both of these personally since I got the bike so I know that for sure.

So, can anyone suggest a specific FD and RD (apart from the products suggested by Russ Roth) please?

Ricky Roma

Just to update, I've bought a Shimano Alivio RD-M3100 RD, so I'm now just looking for a top-swing top-pull FD.

aggiegrads

This Altus should do the trick. Top pull, clamp mount, low clamp (top swing) triple chainring.

https://www.universalcycles.com/shop...89&category=76

Ricky Roma

Yes, this is the one I bought, thanks.