Bicycle Mechanics - Sun Tour Replacements ???

My touring/commuter bike is an old 1992 Rocky Mountain Hammer with Sun Tour XC/LTD components and I am wondering what I can upgrade/replace them with. I will be replacing the chain this week and I am wondering if I will have any compatibility problems. In addition, I will be taking this bike on a long tour of Europe this winter and I would like to know what I could use for replacements such as Shimano or Campy if a problem occurs.

Thanks
Gordon P

Basically, you will need to buy an entire new drive train, your best bet would be Shimano.

Really? Everything is in almost new shape and I plan to replace the chain so the bike will be fresh for the tour. So in the future I will have to replace everything including the crank, derailleurs, rear hub and chain rings?

Just the chain, try Sram.

The bike has less then 2000 km. on it so I should be able to do this tour with the existing components, but in case of emergency it would be nice to know if compatible components exist. The chain I have is original and is still good, so I was going to slap on a KMC Z chain and take the old one for a spare.
Thanks for your input.

Suntour shifters will react strangely with shimaNo der's. The mix of the two does not allow for exact indexing. However if you are going to replace your chan you may need to replace your cassette or freewheel as well, as the chain may skip around on gears as well. New chains on old cogs will do this sometimes.
Also there are still resouces for old school Suntour componets like http://recycledcycles.com

The indexing is in the shifter, not the derailleur, so there may not be a problem. The chainrings, cranks, and BB will be no problem, and the front derailleur should be fine too. You shouldn't have to replace the freewheel yet. I have an 89 Cannondale M400 with Suntour XC-M, and it still runs fine. I replace chains relatively often, since they will wear faster with an older drivetrain, but it still runs and shifts without any major hiccups. Just a note for the future- it may be more cost effective down the line to replace the whole bike, rather than part by part as things eventually reach the point of no return.

DEMON

Questions are 1) Is it indexed or not and 2) is it a cassetted hub or not?

If a new chain skips on the old gears, you're going to have to replace them as well. If it's friction shifting and a freewheel you'll have minimal trouble, just replace the freewheel, they're readily available in 14-28 gearing.

If you have indexed shifting and a suntour cassette hub, you're in for more trouble. You will either have to find a suntour cassette or buy a new wheel. Since it's not necessarily easy to find Suntour cassettes, especially on the road, It would probably be best to buy a new wheel (Shimano does have the best options for commuters and tourists). However a new, non-suntour cogset in the rear is not going to work well with a suntour shifter, and possibly not the derailleur as well. In other words, you may be looking at a new wheel, cassette/freewheel, rear shifter, and rear derailleur in order to make everything work right.

My advice? Don't fix what ain't broke. If the chain measures OK and there's no significant wear on the cassette/freewheel, just use it and maintain it. A new chain would be fine for an emergency, but it may not be a permenant solution (sheldon brown has an excellent article on chain wear and replacement on his site).

When looking to actually upgrade, I would suggest a wheel with a cassette hub and replace the shifter with a friction shifter. It's not a convenient as indexing, but it removes compatibility issues and are much less suseptible to dirty cables, drivetrain wear, and accidents; all pluses for commuters/tourists in my book.

The indexing is in the shifter, not the derailleur, so there may not be a problem. The chainrings, cranks, and BB will be no problem, and the front derailleur should be fine too. You shouldn't have to replace the freewheel yet. I have an 89 Cannondale M400 with Suntour XC-M, and it still runs fine. I replace chains relatively often, since they will wear faster with an older drivetrain, but it still runs and shifts without any major hiccups. Just a note for the future- it may be more cost effective down the line to replace the whole bike, rather than part by part as things eventually reach the point of no return.

DEMON

dcyclist,
Suntour shifters had "slop" incorporated in them to allow for misadjusted der's due either to incompetence or riding time. Go ahead and try Suntour index shifters wiith shimaNo der's. you will see soon enough. Also it does happen that new chains skip on old cog whether freewheel or cassette, depends on usage and wear, but it does happen.

Hunter-

You may be right, but my point was that it MAY work. It depends how worn the geartrain is. As for slop, indexed shifting systems all have some amount of slop built in, they have just gotten more precise over time. Now they refer to it as "lever lash", where you have to push a little past the click to initiate a shift. Then there is the play built into the jockey wheels so that everything works even if the chainline isn't perfect, etc. So, my advice would be to swap the chain and se what happens, then go from there. And as far as replacement parts go, it may be easier to find some spares in Europe, since SunTour pulled out of the US before they disappeared from the radar screens entirely. I'd bet there are some shops over there that still have some NOS stuff around.

DEMON

Thanks for all of your replies and the link!
I read a post the other day by Bikeguru under Fixer shifter thread that said:

OTHER !!! I have suntour comand shifters with an 8spd supurb pro guts. Up the rear I have an 8 spd xtr 1st generation rear mech with an xtr 12-32 8spd cassette. Not many people know of the command shifters but they mount inboard next to your brake levers and are opperated with your thumbs.

So I imagine my Thumbies will work with Shimano components, but a friend of mine has an old set of Shimano thumb shifters I could take with me. So would a Shimano rear derailleur work with the remaining Sun Tour components if the need arises?

If you have the thumb shifters, there should be a "switch" to change back and forth from friction to index. You could use this if you damage your der(and it will not index properly) or if you need to use a non compatible der.
A trick you can use when mixing der and shifters: You can change the ratio of pull by routing the cable on the "wrong" side of the fixing bolt. This worked pretty good when mixing stuff in the seven speed days.
Gordon, while anything can happen, if your stuff is working good now, it is unlikely that anything will go wrong with it (I have a customer that put 8000 miles on a $300 mongoose before it was worn to the point he HAD to get it fixed.

...Up the rear I have an 8 spd xtr 1st generation rear mech with an xtr 12-32 8spd cassette...

This sounds rather uncomfortable!

Quote:
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Originally Posted by Gordon P
...Up the rear I have an 8 spd xtr 1st generation rear mech with an xtr 12-32 8spd cassette...
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This sounds rather uncomfortable!

Hey man that was a quote from Bikeguru, you wont find an 8 spd. Xtr up my butt! :D

Thanks Rev. Chuck for the good advice on the switch on the thumb shifters, I seen it but had no clue what it did. My components are 7 speed bu the way.

Regards
Gordon p

Personally, I think Shimano is overrated and like Suntour components better. Evne though Suntour components don't seem to be available in the US anymore, they are still available in Europe.