Hey there!

My bike was stolen not very long ago, so my insurance company decided to replace it with a Scott Sportster 40. I like the frame, tires, brakes and fork, but I feel that the derailleurs are wayyy too cheap. So I'm looking to upgrade both the front and back derailleurs!

So I have these three questions:

• What derailleurs are compatible with my Scott Sportster 40? I'm looking for a high end upgrade, something like Altus, Sora or 105. Click here for full specs
  
  
• What is the difficulty of changing these? Will I need any special tools?
  
  
• How much would upgrading the derailleurs benefit me? I bike 22 kilometers per day, mostly on asphalt but I ride on gravel/mud/dirt around 25 kilometers a year, without any big bumps.
  
  Stock rear derailleur: Shimano Acera RD-M390
  Stock front derailleur: Shimano Altus FD-M370
  
  to
  
  Upgraded rear derailleur: Shimano 105, Tiagra or Sora
  Upgraded front derailleur: Shimano 105, Tiagra or Sora
  

Thanks for reading

Question. Do you also plan to upgrade shifters? If not, why not? My view is, shifters are at least as important, maybe more so than are derailleurs.

Second, why do you want to switch from mountain to road groups? Wouldn't it make more sense to upgrade to Deore rather than Tiagra or Sora?

Edit. Maybe others will chime in, but I don't think you can put road derailleurs on your Scott without also switching the rear cassette.

You have a 9 speed MTB groupset on the bike, top end 9 speed MTB is Alivio, which is only just above what you currently have. Going to Deore will require (additionally) new shifters, cassette & chain, if going to a road groupset, you need to look at the cage length/max T count, all of this will be expensive, and none will result in any significant improvement in shifting.

Would do some research into the groupsets, their position in the Shimano hierarchy & compatibility issues if looking to mix & match, Sora is a low end road groupset, 105 mid range & Atlus (MTB)is a step below what you currently have on the rear.

The first thing to look at is whether your derailleurs are properly set up. It's not unusual to have break-in issues on a new bike, or it may not have been set up properly in the first place. Until you've checked that you can't assume the problem is low quality.

I was sort of clueless about the Shimano hierarchy - Had no idea that Sora to 105 were road, and that Acera to Deore were MTB.

Judging the replies it'll be a complete mess to upgrade to the desired components, and any upgrade that doesn't require upgrading the cassette, chain and shifters seems to be a very minor upgrade. So I think I'll just stick to my Acera and Altus components for now!

Thanks a lot for the replies, much appreciated!

I haven't received the bike yet, so I'm just going by what's on the spec sheet. I did some really fast research on the derailleurs and people seemed to agree on that anything below Deore = crap.

You might consider upgrading something different.

Like what? I don't have that much money at the moment so I can't really do a "bigger upgrade" involving cassette, shifters etc :/

Edit: Would this work without upgrading the rest of the components?

My wife's bike is equipped similarly and everything shifts fine on it. Don't worry about it until you've at least tried it.

As for anything below Deore = crap, that just isn't true. I would say that current alivio/altus is better than older Deore, and we didn't think it was crap back then. Shimano does a pretty good job of trickling down their improvements to the lower end, and keeps the latest in the higher end.

And it isn't true that upgrading to Deore will require all new parts. The entire line of products is compatible as long as you have the same # of gears, with the exception of 10sp MTB <> 10sp Road. So if you replace you 9sp derailleur with another higher model 9sp you'll be fine with the shifters. Dura Ace has a few exceptions too, but you're not going to DA, it'll cost more than the bike. 10sp MTB uses a newer system called DynaSys, and the cable pull ratio is different than all the others, so it won't work with anything else. But the cog spacing is the same, the chains are compatible even thought the DynaSys chains supposedly work better, and the front is even compatible to a degree.

Depends on what you are trying to do. I had this conversation recently at my LBS when I bought a used Trek 930 mountain bike from them. It was built up with new SRAM Attack 8 speed shifters and new Alivio RD. FD is the original Shimano STX from the 90s. I spoke to them about upgrading to Deore shifters and derailleurs front and back, or SRAM equivalent. Bike guy suggested just riding it first. He was right. While it looks plasticky, it shifts as good as anything I own, including the Tiagra I have on my road bike.

Deore is higher on the Shimano heirarchy. If you can afford it, get a bike with Deore components. But if you can't, modern Altus/Acera might be equivalent performance wise to older Deore.

Now, if you ride in exceptionally hard conditions, like snow, rain, mud, and dirt, your derailleurs might wear out more quickly than they would if you only ride in nice weather. In that case, replace the derailleurs when they wear out.

+1

My Cannondale Quick 4 has Altus shifters, Altus FD and Alivio RD and one of the reasons I chose this bike was because of how nicely it shifts. (no joke)

A little bit of tuning can make the lower end components work just fine IF they aren't already.
I have a hunch, without more expertise fitting & adjusting components, any "upgrade" you do will just be a waste of money.

On my hybrid, since I only run "road" cassettes (12-23 typically) , I thought a "road" RDER might shift better. I switched in a Tiagara for an Acera. It's actually slightly worse. I seem to be having to "tweek" the barrel adj. 1/4-1/2 turn on a regular basis.

people that believe that
either havent ever used components below deore
or
dont know how to set up and keep derailleurs adjusted

when new
and properly set up
even the cheapest of shimanos indexed derailleur systems
shift flawlessly

the difference between less and more expensive
is generally how well the derailleurs stay in adjustment after a couple of seasons use

btw
what sort of bike did you have in the first place
and why does your insurance company get to specify which bike you are getting
as this is certainly not how i have seen the process work in the past

I have ridden thousands of miles over 10 years on similar "crap" derailleurs (actually I think my FD is an even lower level C-101 or something), and other than needing to adjust the front derailleur once, they have shifted wonderfully. I have removed the RD a couple of times to clean it and lube the bushings while I was replacing the cables, and cleaned/lubed the FD in place at the same time. I bought a new RD, because I was thinking of replacing it, but decided it wasn't worth the time to fix something that wasn't broken... so now I have a spare in case it ever does fail (there are no signs that failure will happen any time soon).

I have seen 20-30 year old Tourney RDs that still shift fine when covered with rust... and Tourney puts the low in low end.

I strongly suspect that a significant portion of those who say anything below Deore is crap are just repeating what they heard from someone several steps removed from a sales guy who was trying to convince a cyclist to buy a higher level bike... Really, how many people do you think have done an objective comparison of the different levels of Shinmano components??? Maybe someone did, but the chances are more likely that Shimano (or the local bike shop) is good at marketing their higher cost components.

I think the better way to look at it, is that Deore is a sweet spot in the line from a cost/benefit point of view (as 105 is viewed in the road groups)... so, if you need a group, check them out. It definitely should not be interpreted as meaning that anything below that level should be replaced... unless you're a sponsored rider in which case, you should definitely insist on the top of the line!

I am loathe to admit it, but even the entry level Tourney on my wife's 7 or 8 year old Trek 7000 comfort bike still works fine. I would be inclined to replace them, along with the crappy 7 speed twist shifters as they really do look cheap, but they work. Not exactly light or high performance gear, and if she rode it more in wet or dirty conditions I am sure they would wear out eventually. I almost wish they would wear out. But for what we use it for, casual around town riding, and not every day, it works.

It will work, but I have that exact Deore RD on one bike, and I notice no difference in how it shifts compared to the Acera RD I have on another bike.

If money is an issue, ignore the posts you have read blaspheming anything below Deore, and ride what you have.

If it makes OP feel better about his purchase, it is his money. I don't remember doing this, but I may have upgraded the rear derailleur on my '97 Bianchi hybrid. It has an STX rear derailleur, but according to Bikepedia, the bike came stock with Alivio . I don't remember swapping out the derailleur, so it is either something the LBS did without my knowledge (do LBS do free hidden upgrades?), or maybe something I asked them to do but forgot about.

I have recently moved to trigger shifters from twist shifters, and I don't think I will ever go back, but they did do the job for me for a long time... So, yeah, definitely functional, even if it lacks the bling factor.

Even though I didn't mention it... I agree. And I have upgraded some things just to upgrade in the past. But I wish I would have asked in a couple of cases to get the opportunity to be told to save my money.

Just went through this issue on my Bianchi. 17 years old. Old SRAM grip shifters original to the bike. Brought it in late last summer to have the bike serviced so my son could ride it. I even budgeted to replace the shifters with SRAM trigger shifters. Mechanic comes back and says, good news. The shifters are fine. Perfect, actually. So I replaced the grips with Ergon grips for a little bling, and left the shifters alone.

The thing about bikes is, they are a huge collection of components and parts at a given price point. Upgrading a single component while leaving everything else the same will likely only offer marginal improvement. It is one thing to contemplate upgrades to a cherished old bike, yet another to start planning to upgrade your brand new bike before you even ride it. Upgrading a bike piecemeal is an expensive proposition. If that is your plan, you will likely save money by just buying a better bike to begin with.

The only exception to this is maybe wheels, which is likely the biggest upgrade anybody can make to a basic stock bike, and ironically, the one few people do unless their old wheels fail. Why? Likely because for most, a wheel is just a wheel. They lack the bling factor of a shiny rear derailleur.

I agree with much of what has been said above - don't believe everything you read on the Internet, as some people are very fond of blaming their troubles on somebody/something else. 90% of the bikes have "crap" components, yet somehow millions of people manage just fine. Besides, it's flat out ridiculous to prejudge a component before you ever ride it!

I love these kinds of discussions! I am a relative newbie but I am very mechanical and work as a machinist. I have mixed and matched stuff to suit my needs and run really old components with great results. My Raleigh Technium has a 8 spd mountain bike cassette(I spread the stays and have FSA wheels on it) and an Altus derailleur. It just spins up hills! I ran it for a year with the original 6 spd downtube shifters! I just put Sora STI on it. I also have put 5000 miles on a mid 80s Raleigh Olympian with it's original Suntour derailleurs just fine. I have an old Kabuki with Shimano Titlist derailleurs that I am sorting out right now.

The key point is maintenance and adjustment. All but the very sleaziest components will work pretty well if you take care of them.

I upgraded a bunch of components at once, including wheels, shifters, derailleurs, brakes. The sum total of it all is a much better ride. Would any one change make a difference? Maybe, but not the derailleur by itself. The wheels would be lighter with better rims, but the dynamo front takes away any weight advantage. The brakes OTOH are a real change, much better than the cheap canti's they replaced. But does that make the ride feel better? Nope. But as a whole package it is a much more enjoyable bike to ride. It just feels like a new bike instead of the 1990 clunker that it was.