I am new to this sport, but I think I have this correct. I currently have a Trek 820 (love the steel frame) and am looking to upgrade to a 3x9 drivetrain from a 3x7.
To do this , I need a new
-9 Speed Cassette (SRAM or Shimano? I would like to get a SRAM cassette and have all the rest be SHimano components if possible).
-Rear Derailleur
-Front Derailleur
-Shifter Cables
-Possible a new crankset and bottom Bracket?
If I am missing something, please let me know. Thanks for any and all help.
Dan
P.S. The reason I want to do this upgrade in components is for reliability, not for any performance/racing issues.
It's hurting my brain a little because I haven't messed with 7-speed for so long, but I'm guessing you have an older (say 1993ish) Trek?
If I recall correctly, you're going to need a new rear wheel, or at least an 8/9-speed compatible freehub body. I remember some of the later 7-speed bikes were coming with 8/9-speed compatible rear wheels, with a spacer & 7-speed cassette, but that was just a quick transition phase.
Depending on the age of your frame, you may need to spread the chainstays a bit to squeeze a 135mm rear wheel into a space designed for 130mm. Not a problem with steel, and maybe not an issue at all if yours is a later frame.
Crankset, no problem. You'll probably want to look at new big and middle chainrings, since the pick-up ramps were redesigned to accommodate the narrower chain.
That, plus the stuff on your list, ought to cover it. Somebody will kindly jump in and correct me if I'm off on my wheel spacing.
Ok, thanks... I was under the mistaken impression (obviously) that the steel Treks died out and were all replaced by aluminum. I stand corrected. I'm surprised to see 7-speed on that bike.
So now I'm completely out of my element, but I wouldn't be surprised to find that you've got a 9-speed compatible rear wheel.
If you want to take the guess work out of it and still do the work yourself (I assume that's your motive here), you could take just the rear wheel to a shop, let them know you want to buy a 9-speed cassette from them, but then ask them to double check that it'll fit on your hub. Let 'em know up-front that you've got all the other parts at home, just so there's no misunderstanding between you and them.
If they give you a thumbs up and sell you the cassette, everything else is mostly a bolt-on deal (you'll need cable cutters and a cassette adapter & chainwhip, unless you let the shop install the cassette when you visit them).
if I remember my specs correctly the 08 820 is speced with a freewheel system not a freehub/cassette system in the rear. You won't find a 9 speed freewheel out there. So you'll deffinately need the new wheel, or at least a new rear hub. Also you'll need a new crank set as a minimum. The chainrings on the stock crank are not replaceable. And you'll likely need a new bottom bracket as well as it's getting tough to find reasonable quality square taper type cranks anymore. Can be done, but they are not that common.
As a minimum you will need:
Rear wheel or hub to accept a cassette
9spd cassette
Chain
Crank set
Shifters
Derailleurs front and rear (the stock models are pretty crappy)
Brake levers (stock levers are intergrated with the shift levers unless Trek changed the spec)
Just a word of advice. I'd go through the above list and price it out before considering this upgrade. Upgrading to 9spd on this bike could very easily run you more than you paid for it in the first place, afterall MSRP is only $290. The 820 is a good begginers bike with a solid frame. The parts spec though quite low end is reliable, though not geared toward performance or light weight. I would carefully consider the cost before making any really siginficant upgrades to the bike.
Yeah, I don't care if I go over the price of what I paid for the bike. I got it for $240, just to start riding. If I end up spending another couple of hundred, it won't matter, b/c then I will have the bike I want. Great advice, will probably hit up the bike shop this week to see whats up.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Mountain Bike Reviews Forum
15.4M posts
515.2K members
Since 1990
A forum community dedicated to Mountain Bike owners and enthusiasts. Come join the discussion about bike parts, components, deals, performance, modifications, classifieds, trails, troubleshooting, maintenance, and more!