drivetrain upgrade help
 

Anyone have advice for a novice MTB rider looking to upgrade some parts?
I have a 2001 Giant Rincon with a 7spd drivetrain. I want to uppgrade it a bit to a 8-9 spd but don;t know if that is possible. I have minimal knowledge of major components but I can perform many smaller maintenance projects. My rear hub has a spoke protector so it look slike there is room for more rings but I don't know for sure. Is changing the rear cassette a hard thing to do and how do I know if I can even change from 7 spd to 8 or 9? How does this effect my derailleurs?

I also want to put new cranks but I don't know if I should... My BB is square taper but all the new stuff is "splined". Are cranks designed for specific speed drivetrains or can I use any MTB crank?

Anyone have advise?

you're asking quite a bit. First of all, prioritize what it is you want to uprgrade and have some legitimate rationale behind your decision. Maybe you don't need an upgrade at all, but rather a tune up.
A well running 7 speed machine is infiniely more fun to ride than a crappy running frankenstein 7/8/9 monstrostity of mis-matched parts.

The 2 big items could be the shifters and rear wheel. If your 7 sp hub is a screw on type, you can pick up an 8 sp freewheel pretty cheap.(need the right tools for freewheel removal) Most frames will spread a little if needed (might need a washer). Or you can get a more modern 8/9 speed freehub type wheel. Most 8 sp shifters should work with either of these setups. You should go ahead & get an 8 sp chain as well. 'Afterthisnap' is correct, however, you can probably pick up an 8 or 9 sp bike and get more value for your money. The activities described above are for people that like to work on the bike as much as actually riding.--Rob--

If the bike is 2001 it has 135mm spacing in the rear, no need to respace. If it is Shimano, 100% sure, then you can buy a new 8/9/10 cassette freehub body and swap and redish the body to be centered in the frame. Sometimes mfg's used 9/10 freehubs with 7 speed and spacers. Best to pull the cassette off and check for sure, maybe save some money. The rest is simple bolt off bolt on as far as BB, Crank, and derailleurs. Good luck. IMO buy a new bike.

Tim

Let me join in with Marshe13 with my view. I would fully agree with AfterThisNap re the usefulness of a buggered up 9/10 spd vs a crisp shifting 7 speed. I was loaned (hopefully forever) a '90 Trek 820 Antelope, 7 sp, Shimano Altus c10 groupe. It was trashed and looks to have many off road miles due to badly worn rim surface where the brakes (canti) contact. I've taken the whole thing appart (I own the tools already from road bike work) and restored her to the best of my ability. Going MTB riding with it this weekend! Wish me luck!!

Like Marshe13 I am new to MTB but commute 100 miles week on my road bike. From limited MTB rides I've been on, it is nice to get the gear you want instantly whereas in road biking the urgency is not as high. I want to learn how to tune/upgrade my drive train so it shifts flawlessly and would appreciate guidance on the following:

Can the lower price point Altus be made to work? Or does it wear out faster than XT? Is there really a difference? Should I hunt on eBay for a NOS FD shifter since I can't get mine to behave? My RD works flawlessly!

Marshe13, I'd suggest using the Giant as a platform to learn how to TUNE your bike and get the most out of it...maybe in preperation for that new MTB bike that lies waiting in the future. 7 vs. 9? Corolla vs. Porsche in a traffic jam! Everyone gets there the same time. It's what's spinning the pedals that make the difference. My road bike is still a 2x5 and those guys with 2x10 are right next to me.

I think you and I both would benefit from some input on how to evaluate what we've got and how to judiciously tune/upgrade. If the bug bites, then we will face the music and buy current technology. Hopefully there are some folks on here who can shed some lite on our old, low end gear.

Thanks!

[QUOTE=robhunterx]If your 7 sp hub is a screw on type, you can pick up an 8 sp freewheel pretty cheap/QUOTE]

An 8-speed freewheel?

1. I know that they exist but that might not be an easy part to find.
2. If you do find one - not on my bike! Can you say "bent axle"?

I'm thinking that I have jumped the gun in hoping to improve my bike beyond it's purpose.

Listening to all the reply's has made mee reconsider and I think I'll get a good tune-up and maybe replace the BB, cassette and chain for new (same) parts. It's 5 seasons of dirt/sand/water that are slowing me down.

I was thinking that I could get better components like XT to help reduce weight on my bike and at the same time gain some more gears... A newer/more advanced bike is in my future...


Thanks!

[QUOTE=Retro Grouch]Pretty easy to find an 8 speed freewheel on ebay. Since this is a 2001 Giant, I rather doubt it is an axle bending freewheel hub.

If the chains stretched, likely new chainrings.

My points -I doubt 7-8 will do much as an increase of gears. Try gear range..11-30.
Suntour makes a 11-30 7spd -cheap too!
Going 8 means new shifters, hopefully you have seperate shift\brake levers.

A hooped chain will wreck both cluster and rings.
A new drive can be swapped if the next bike you do is a build up. My bikes a parts stash.

Cheap?...if you run a triple, just replace the mid ring and ride that.
Some derailers are 7-8, and a derailer can do say 2 more teeth than max stamped on the arm.
My 28T max does 30 fine.
A square taper cartridge bb is no harder to find.
Square taper new cranks would be hard to find. I'd keep the cranks and spyder.

A simple setup is a single ring front mounted mid spyder, to 7 new rear cluster.

The chainring teeth count can be adjusted to the weight or riders ability.
As a heavy offroad may run 34T, I run 38T as a speed XC bike.

Chianring 30$
Chain 20$
Cluster 30$ and you are riding a new drive.
As a form of weight reduction I do not use a front derialer.
So no cable\lever\der and minus ring.
The front derailer can be used as a chainguide.

If you are to upgrade parts, buy with the intention of using on a newer bike.
If you build a new wheel, do an 8, new crank arms? different bb axle.
I doubt you'ld need to change the derailer in a 7-8 conversion, just the shifter.

I'd trade weight over gears anyday. Only beef I have with 7spd is Shimanos crud rapidfire shifter bodies.
I don't care, a road friction shifter would be fine.

[QUOTE=Retro Grouch]I have a real nice Sach 12-21 8 speed freewheel. Would be willing to part with it also. Probably not the correct gearing for a MTB though.

Tim

So, that is useful and maybe old news. These 7 spd rapidfire shifters are not reliable? Or just the shifterbodies? Can you pls elaborate. Thanks!

Lowgrade plastic bodies, mechs wear quick. I get 1 yr a shifter.
Maybe 7 is best gripshift. Or friction. I've not seen any nice seven rapidfire shifters -if you know of some post up.
Doubt if SRAM has a 7 shifter. ?

Thanks Jeff! I hear ya on the relative need for a FD. Long ago when touring Nova Scotia I came upon this guy with a very odd bike. Front brake only. RD shifter only with a bedroll on the back. And he was riding the whole Island of Cape Bretton for 30 days! For the FD he said he uses the following technique. When he needs to jump down, just angle your heel in and knock the chain off the big ring. When the going gets eaiser and it's time for the big ring simply stop peddaling, reach down and lift the chain onto the big ring. Quite easy when no FD is in the way!

I digress, but I can't see this approach as optimal when off roading trying to keep up with the guy infront with a $2,000 bike and it's a tripple :eek:

I see so much stuff on eBay for minimal $$$ I thought it might be worth a stab especially since it's obsolete 7 spd and independent from the brake giving more flexibility as so many are V brakes now. No rush but wanted to hear from some more experienced folks. Can't believe it would be that hard and I have the rest of the bike working GREAT!

Marshe13,

Here's the crux of it: more cogs does not buy you a greater gear range.

You can purchase a 7-speed, 11-34T cassette or freewheel. (or 11-28T if you don't need the stump-pulling 34T)
http://www.sheldonbrown.com/harris/freewheels.html#7
http://www.sheldonbrown.com/mega7/

That 7-speed, 11-34T freewheel will have exactly the same gear range as my 8-speed 11-34T cassette equipped bike. (not taking into account front chainrings)

If you have a 7 that works fine, all going to an 8, 9 or 10 does is make the gear spacing tighter - you'd end up with slightly smaller gaps between certain gears.

I have no personal experience with this next bit but I hear 9 and 10-speed cassettes have significantly higher wear rates; long live the 7 and 8-speed cassette/freewheel.

Hope this helps!
CJ

I run a 38T ring to a 11-30 cluster, 20 something lb bike.
I do use a tensioner and bashguard (46T ring with the teeth ground off).

As noted above, 7 wears long, chains don't snap, parts are cheap.

If the drives worn -the chain and cluster\rings are wear mated =run them to crap.
All drive teeth and chain need to be replaced @ the same time.

You have a 5 bolt standard spyder\cranks? Keep em, replace the bb with taper axle.
If you have been riding mostly mid ring AND the chains been replaced once in a while....
maybe you only need a mid ring.

As far as new cranks.....how about a double? Means a different front derailer but, to me, a set up with 34\42 to a 11-30 cluster is all I'd would ever need.
The bb axle length has to be correct for the double crank to sit right for the chainline.