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New Cyclist, need help! Replacing Suntour rear derailleurs with Shimano and more

post #1 of 11
Thread Starter 

Hi, I'm new to this forum and I made an account specifically to ask this question

 

I have a Suntour XCT rear derailleur that came with my old Giant Rincon 21-speed mountain bike (7 rear rings with 3 front rings)

I wanted to know if I can replace it with "Shimano Tourney TX75 6/7 Speed Rear Derailleur
I have Suntour shifters and Suntour front derailleur 

 

I also want to replace my current crank set which is Sakae PowerRing 175mm 48/38/28t with "Shimano FC-M171 Altus Crankset 170mm 48/38/28T 6/7/8 Speed"

 

Will these things work with this bike chain? "Ventura Bicycle Chain 1/2-Inch x 3/32-Inch"

 

 

Will a knowledgeable cyclist tell me if this set up will work?
(if using cycling words, please define? I am not too savvy on cycling vocab yet, still learning)

 

Thank you in advance! I hope you guys can help me :)
 

post #2 of 11
Thread Starter 

Bump?

post #3 of 11

Paging Alf Eng...paging Mr. Alf Eng!

post #4 of 11
Quote:
Originally Posted by hiTimothy View Post
 

Hi, I'm new to this forum and I made an account specifically to ask this question

 

I have a Suntour XCT rear derailleur that came with my old Giant Rincon 21-speed mountain bike (7 rear rings with 3 front rings)

I wanted to know if I can replace it with "Shimano Tourney TX75 6/7 Speed Rear Derailleur
I have Suntour shifters and Suntour front derailleur 

 

I also want to replace my current crank set which is Sakae PowerRing 175mm 48/38/28t with "Shimano FC-M171 Altus Crankset 170mm 48/38/28T 6/7/8 Speed"

 

Will these things work with this bike chain? "Ventura Bicycle Chain 1/2-Inch x 3/32-Inch"

 

 

The parts you suggested are compatible ...  

 

BUT ... there will probably be very LITTLE BENEFIT ...  

 

Sight unseen, I would say that Cleaning & re-Lubing the components will probably be more beneficial than the components you have suggested ...   

 

A few drops of 3-in-1 type oil on the derailleur's pivots AND TIME will resolve most rust issues (repeat the application of 3-in-1 every 24 hours, as needed, until any rusted or "frozen" parts loosen up and continue until rust is not apparent when flushing the pivots with a few drops of oil)

 

Buying the tools needed to remove the current crank & Bottom Bracket (which you will need to remove it to install the new crankset) will alternatively allow you to re-pack the bearings with fresh grease ... (eventually, you will want to replace the bearings ... the cost is certainly less than $2 for new [loose] bearings which you could put in the existing cages)

 

(Re-)Lubing and/or replacing the cables & housings will probably be very beneficial.

 

Shimano makes some great components, but I strongly recommend that you NOT buy one of their Tourney rear derailleurs and that you alternatively opt to spend only a few dollars more & minimally get an Shimano Acera rear derailleur ... a (plain) Shimano Deore would be better ... a USED Shimano XT 750 which is in good condition would be even better (probably ~$30 on eBay).

 

IMO, Square Taper cranksets lacked anything approaching a true standard other than the angle of the taper ...  

 

The odds are that you will need a different Bottom Bracket (BB) for the particular crankset ...

 

At that point, while I still have mixed feelings about them, I would recommend you consider installing either a Shimano Hollowtech II or an FSA MegaExo crankset & BB on your bike as a replacement ONLY IF there is more than a cosmetic reason for changing the crankset.

 

BTW.  Other than a mechanical advantage-or-disadvantage in crankarm length, I reckon that the odds are that you will not notice a difference in the "fit" by going to a shorter crankarm length unless-and-until you are at a point where you need to optimiize your bike's fit for competitive riding ... 

 

Because, after you install different length crankarms, you should (will need to) adjust the fore-aft & height position of the saddle, accordingly ...  

 

And, if you are not using Drop handlebars, then (IMO) the "hip" angle will not be adversely affected by the slightly longer, 175mm crankarms which your bike currently has.

post #5 of 11
Thread Starter 

Thank you for your reply, alfeng! I was hoping someone would come and help me :)

 

I went to the bike shop and got my bike tuned up (before I posted this question)

and then I looked and read things online on maintenance and care for mountain bikes I saw that chain wear and whatever can damage the teeth of the front chain ring over time,

and I have noticed that indeed the chain is worn out excessively and the teeth are really worn too,

which is why I wanted to change the crankset

(is it possible to change the rings only? it doesn't matter to me)

Is there a crankset that I can just install without having to buy new BB? Or is that a necessity?

 

I looked at the Shimano Acera rear derailleur on Amazon and didn't find any that were 7 speed or "long cage" (I forgot to mention that in my original post. Does that make a huge difference?)

 

 

This isn't part of the original post, but my shifters are sometimes "hard" to shift into a lighter gear while it's extremely easy for it to shift back into a more difficult gear. Is that normal? Or does it just need lube?

post #6 of 11

Chain wear is not based on cosmetic appearance ... it is based on "stretch" which is a consequence of elongation when the holes which the rivets are in become elongated and/or the rivets wear down enough to change the chain's length by a measurable amount (see www.sheldonbrown.com for a wealth of background information on bicycles ... most is correct, but there may be a few 'errors') ...

 

Since your bike just came back from a shop & you paid for a tune up, I would like to think that if there was wear which required replacement that they would have told you.

 

Chainring wear is past when the tips of the teeth on the chainring (or the Cogs on the Freewheel/Cassette) become "pointed" -- a "shark tooth" shape is a frequently used description.

 

Again, I suspect that your bike's components are not close to that point, yet.

 

With "normal" pull rear derailleurs, you will have to impart more force to move to larger Cogs because you are working against the derailleur's return spring.  

 

Again, if there was something out of the ordinary, then one would like to think that someone at the shop would have mentioned something to you.

 

I believe that the ACERA rear derailleurs only come in what is considered to be a "long cage" even though the actual cage may not appear to be when compared to the cage on a more vintage (pre-2000) rear derailleur.  Essentially, the larger-than-normal pulley wheels yield about the same chain "capacity" that a longer physical cage with 10t pulley wheels would.

 

Depending on the crankset, the chainrings may-or-may-not be replaceable ....  

 

The chainrings on some cranksets are riveted to the crank ... on some cranksets, the chainrings are an extension of the spider which is riveted to the crank arm.

 

  • if the Chainrings & spider are one-piece, then your options are very limited unless you are willing to put a lot of DIY work on the crank
  • if the Chainrings are attached to an alloy spider with "bolts" into which you can insert a 5mm Allen Wrench, then they are replaceable ...
    • Chainrings can be sometimes be incredibly expensive ...
      • it helps to be a wise shopper
    • the size of some cranksets have an obsolete bolt circle diameter (BCD) 

 

It's certainly "okay" to buy from Amazon.  But, it may be better just to use them as a reference resource & to buy the item through an eBay vendor -- compare prices.  There are also mail-order places to buy from.

 

If you have the time (and "extra" money OR if you are incapable of doing the work on your bike), then your bike shop may be a place to buy parts from.

post #7 of 11
Thread Starter 

I don't believe the people who tuned up my bike did the best of jobs, because now I have to bring it in again when it started making clanking noises when I brought it home (the shop was closed just as I brought it home, so I couldn't go back right away)

It didn't seem too much that they were concerned with my bike but rather than how much the could get from me, which was quite a lot since I had no idea about anything at the time.

 

But regardless, I think I'd have more peace of mind if I were to change just the chain then. Would that be okay? 
I'll do what you told me in your first post with lubing it with the 3-in-1 and everything, so I won't NEED to change/replace any parts for now

post #8 of 11

Sorry to hear about your recent experience with your bike shop ...

 

Regardless of the type of bike shop a person has access to, it is good to know what is actually involved and/or how to do the work so a person can know if the shop is being honest with them.  

 

Some bike shops are great ... some are good ... some are just "okay" ... and (as you apparently experienced), some ARE just trying to pad their bank accounts OR they may simply be incompetent.

 

In addition to www.sheldonbrown.com, check www.parktool.com and YouTube for more general-and-maintenance bicycle information.

 

 

FWIW. I recommend (that is, my preference is for) Shimano chains ... why pay more?  

post #9 of 11
Thread Starter 

Thanks for the website recommendations! Those are extremely helpful

The Ventura bike chain I mentioned is cheaper than the Shimano ones I have seen on Amazon.com. Is it as good as the Shimano? 

post #10 of 11

I am not familiar with Ventura bike chains.  

 

Some people say/believe that most bicycle chains are made by only a few manufacturers.  I don't know.  

 

I do know that Shimano chains are exceedingly reliable.  

 

For me, having used other chains which are also good, it's mostly a "why pay more?" situation ...

 

  • And, while probably not immediately applicable in your instance, the WIDTH of the chain matters ...
  • AND, Shimano's indexed shifting is fairly finicky, so using other brands like SRAM or Wipperman (to name two popular alternative brands) is undoubtedly part of the reason that some people have encountered dodgy shifting.
post #11 of 11
Quote:
Originally Posted by hiTimothy View Post
 

Will these things work with this bike chain? "Ventura Bicycle Chain 1/2-Inch x 3/32-Inch"

 

 

 

While a 1/2" X 3/32" chain will work on a 5- or 6-speed freewheel, it will most likely get hung up on the narrow 7-speed spacing of your freewheel. 7-/8-speed chains are narrower while still working with the same cog width. SRAM's PC850 or PC870 should fill the bill.

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