skaunit

hello, this is my first post, and hopefully my first bike build.

First a little back story... I purchased an old Giant Sedona frame second hand from craigslist. I tracked down the exact model through bikepdeia and it turns out to be a 1995 sedona with an upgraded rock shox fork. https://www.bikepedia.com/QuickBike/B...2266&Type=bike. it has all the original shimano stx components, including integrated brake/shifter setup. This whole discussion is based off of the fact that the shifters are COMPLETELY shot, often times I won't be able to get them to shift at all.

the bike is used primarily for commuting. I like to pretend that I will get out to some good mountain trails on it, but in the 2 years I have owned it the closest I have gotten is a few gravel paths between streets, so I came to the conclusion that I really need to focus on lightening it up and simplifying it for road/commute use, but keep a cassette in the back in case I do want to swap on some knobby tires and go trail riding. I do NOT want to convert it to single speed, because if I go down that road, I want to try out a fixie, and this is definitely not the frame for that.

so, faced with the fact that I need to replace the shifters, I also know that my chainrings and rear cassette are highly worn and need help as well. my main questions are:

what would it take to convert this bike to a 5 or 6 speed? or what is most common for fixed crank gear?
all original drive train is shimano stx, could i or would it be a good idea to just replace my big chainring and take the other 2 off?
what would I look for as far as the cassette goes? would I have to change hubs? Sorry if I sound like a newb...

is this a dumb idea altogether? I am planning on putting some road tires on it and mainly commuting... any opinions and suggestions are welcome. If it turns out to be a horrible idea, I still don't really know what to look for or how to buy my cassette and chainrings. At least I can say my rear derailer and crank set are in good shape.

thanks in advance.


Cliff notes-
1995 giant sedona frame, upgraded rock shox fork, original shimano stx components all around
Shifters are integrated with brakes, she shifters are completely shot
thinking about converting to a fixed front gear and 5/6 speed rear cassette if possible/feasable, don't know what parts i need.

Mondoman

I don't see the point of converting to 5 or 6 speed. It's got a 7-speed setup, and it's easy and cheap to find 7-speed components these days (not true for 5 or 6 speed). Also, why not keep the triple crankset and FD? If you end up riding almost always in the middle gear of the 3, that won't hurt anything. Here's what I would get:

1) You can find a decent PC-830 chain for around $10 online.
2) New Shimano 11-28 7-speed cassette: about $19 https://www.amazon.com/Shimano-CS-HG3...sg_ai_-2_1_tit
3) New shifters. Either get replacement STX's for about $25, or perhaps consider something like grip shifters: $17 at REI: https://www.rei.com/product/737410
4) New brake levers; $20 or less - be sure to get "short pull" versions suitable for your cantilever brakes, not "long pull" versions designed for use with V-brakes.
5) A new crankset. Here's a Sugino 22/32/42 for about $40: https://www.amazon.com/Sugino-Impel-1.../dp/B001F6W4LG.

PS - check out spadout if you haven't already: https://www.spadout.com/c/mountain-biking/

Torchy McFlux

I'm confused as to what you're trying to accomplish and why.
If you never use the small or middle rings, I suppose you could go to a single up front, but you're definitely limiting the versatility of the bike. Much trail riding won't be an option. I recommend just putting a slightly larger big ring on and sticking with the triple.
There's no point to going from 7 to 6 or 5 speeds in the back. I don't see why you'd want to do that. Simplifying? I recommend just sticking with the 7-speed cassette.
You don't mention what exactly is wrong with the shifters. Do you have replacements already?

skaunit

i am mainly trying to simlify and save weight. I almost NEVER use my small 2 chainrings, so I'm pretty interested in changing that part... but both of you have a good point on the rear... there really is no reason to change the rear cassette to 5 or 6 speed... that was kinda silly. So, let me re-phrase then...
should I change to a single speed front crankset? Could I just replace my large chainring and remove the smaller 2?

also, is there any options when replacing my rear cassette? [maybe a slightly broader range of gears?]

I really am thinking trigger shifters, I don't really like grip shifters, but thanks for the suggestion.

Mondoman

Perhaps you could describe your goals more clearly. Dropping two chainrings and a front derailleur isn't going to significantly change the weight of your bike IMO.

Regarding a broader range of gears, you've already got an 11-28 rear cassette, so there's not much room to expand that (11-32 is the widest range I've seen, and you may have trouble finding an 11-32 7-speed cassette). That's where mutiple chainrings in front come in handy. You currently have a 42/32/22 front triple, meaning that your highest ratio is 42:11. Assuming that what you want is a bigger high ratio for the flats rather than a smaller low ratio for steep mountains, you could certainly pick up a bigger triple - I know 48/38/28 triples can be very cheap (here's one for $33: https://www.bikeparts.com/search_resu...p?ID=BPC350795 ). That would boost your highest ratio some 15%.

I guess my point is that I don't see removing the FD and 2 chainrings as reducing complexity any more than just not using the front shifter. The latter option is a lot simpler and preserves flexibility.

girona

Like others have said, you should be able to find 7sp shifters and cassette and chain. You are limited by your rear wheel as far as cassettes go: 7sp hubs are not compatible with 8sp cassettes, so you are limited to 7sp stuff and won't be able to install more modern 8sp and 9sp components.

I think that a 1x7 speed set up is plenty for city commuting with, say , a 46t chainring up front.
I like cranksets with 1 chainring and a thin bashguard to help prevent grease stains and pants getting caught in the chainring. But there is no real advantage over a 3x7 set up and a triple crankset may be easier and cheaper to find. (9sp chainrings are OK to use with 7sp chains).

If it is still the original shimano stx crankset from 95, I would replace it altogether. There was a Shimano crankset recall around that time and I've seen a couple of cranksets developing hairline cracks.

As fas as making changes to make your bike more commuter worthy I would:
-Replace the suspension fork with a second hand rigid fork. No need for suspension in the city and you will save a significant amount of weight. Get one with fender/rack eyelets and you will be able to install full fenders.
-Put 26x1.5 or 26x1.5 slick tires. It makes a huge amount of difference from riding knobby tires.
-Get some full size fenders, either SKS or Planet Bike if you ride in the rain.

Edit: you will also need new brake levers for cantilever brakes.

skaunit

this whole idea started from a suggestion from a friend, and I am not set on it, just looking for info. I also don't have much of a budget, so I thought that not buying a front shifter and a single chainring front might save me some money. I'm honestly hoping to do this whole upgrade for under $100 if at all possible. If not, whatever I can do for that and plan on more later....

Is it possible to replace just the large chainring on my shimano stx crankset? And is there any specifics to look for in a 7sp cassette or should they be basically universal? I know about the break levers, that is simple and I can find that for sure [i'll probably look on craigslist].

If I do replace my whole crankset, can anyone tell me how to figure out my bottom bracket? Typically you need to know the width and weather its english or itialian correct? or am I way off? I wish it told me on that bike pedia site but that part is blank.

thanks for all the help so far... im definately going to ditch the 5/6spd idea, but I'm still considering the single speed at the crank, but if its truly cheaper to stay with a triple, including the extra shifter, i'll go with that.

Mondoman

Yes (as long as your chainrings are bolted on instead of riveted on), but it may or may not be more expensive than buying a cheap new crankset.

I would strongly suggest buying either a Shimano or SRAM brand cassette - you'll be using the drivetrain all the time, so you want robust well-made components in it; in my earlier post I listed a Shimano for $20. Regarding the gear ratios, be sure to get one with 11t as the smallest gear, since that's your "high-speed" rear gear; even with that, you may find yourself spinning too fast on downslopes.
It's also worthwhile to look up the model number of your current rear derailleur (RD-Mxxxxx), which should be stamped somewhere on it, and verify that it can handle an 11t small gear and the full range of the cassette you plan to buy. Usually, this is not a problem, but it's worth checking before you spend money.

99+% it will be english-threaded for a Giant brand MTB. The two common BB *shell* (the open tube in the frame that holds the BB) widths are 68mm (majority) and 73mm (minority). Just use a ruler (or better, a set of calipers) to measure the left-right width of that tube part of the frame.

If you will be keeping the current BB, you will need to remove the crankarms from it (with a special screw-in "puller" tool) so you can also measure the BB spindle end-to-end length (often something like 113mm). Your current BB almost certainly has "square taper" style spindle ends for mounting the cranks. Any new crankset will need to match the current BB's spindle length and spindle end style; otherwise, you will have to install a new BB whose length and style do match the new crankset.

skaunit

Mondoman, Thanks so much for all your help.

after some inspection, I actually decided that my rear cassette is not that bad at all. However, my chainrings on my crank are well worn and torn up.
I have a 68mm bottom bracket size, and definately square taper spindle ends. I have to see if I can find a chainring bigger than 42t that's compatible with my STX crankset.

if anyone has any more suggestions for cranksets or chainrings, let me know. thanks alot for all the help so far.

DMF 

I was with you right up until number 5.

WHY are you suggesting a new crankset? I don't see it. If it's for wear, the front rings are the last thing to go - usually after cockroaches inherit the earth.



BTW, Welcome skaunit. Good first post. I bet you checked out the NEW POSTERS thread.

Mondoman

DMF, the OP wrote "...I also know that my chainrings and rear cassette are highly worn". Also, 2 out of 3 of the 90s-era MTBs I've bought off craigslist have needed new chainrings/cranksets.

DMF 

Maybe so, but I'd wait on the crankset. It might be fine so no need for the extra $$.

Mondoman

Fair enough

Panthers007

That was my line of thinking while I was customizing my Trek 7.5 FX. Ride the cheap 4-bolt cranks into the ground. But then I found a brand-new Shimano Ultegra triple Hollowtech II, at Jenson, for $160(!). Thus ended my plans to put off upgrading the crankset. They also has the Ultegra Hollowtech II bottom-bracket for $20.

Now to run across a suitable frame to build a bike to sell out of...

So if you find the perfect thing and the perfect deal - don't kid yourself. Buy it. Or kick yourself instead.

DMF 

I mean, isn't that what credit cards are for?

Retro Grouch 

Hmmmm. Beater bikes tend to evolve through time.

1. Examine carefully how the front chainrings line up with the rear cogs. My bet is that the middle chainring lines up perfectly with the middle of your rear cluster. If that's the case, remove all three chainrings and reinstall the big ring in the middle position.

2. I'm a believer in spending the money for new shifters and yes, you can buy the right (rear) shifter separately. That's the part that seems to wear out fastest so why take a chance on a used one. I'd install whatever separate brake levers I could find cheap.

That'll get you by in decent style for the time being. When the time comes, I'd replace the freewheel, chain and front chainring all at the same time.