Replacing the crank on a Giant Option
 

I was riding my Giant to work, when the chain was caught between the largest and middle chainring. I managed to free it, but I ended up bending the sprocket in the process. Now it rubs against the derailer cage, and if I try to shift out of top gear it falls between the sprockets and gets caught.

The crankset is a SR XR10 aluminum, 28/38/48 teeth. I was looking to get it replaced, but at the same time wanted something with more teeth for more speed.

Not sure what I should be looking for. Anyone have any ideas?

Is this the bike you have ?

Yep, that's the one.

You'll probably need something like this but it might be an idea to find out if it'd fit on your bottom bracket first.

If you want a crankset with larger chainrings you might have to get a new front derailleur too as they can have limits to what can be used with them.

No reason to believe it isn't a JIS square taper interface. A bike shop should be able to get you a new replacement for around $30-35. At this price range chainrings aren't interchangeable, and with more expensive MTB cranks your big ring will be 42 or 44 teeth. The other option is a road crankset, which will lead to a new front derailleur (more $) and shifter (even more $). Pedal faster or see if the shop can set you up with a smaller cassette or freewheel. They can look at your hub and tell you what the options are.

The front gears go pretty much unused. If I replaced the bottom bracket, would I be able to put a single speed crank on the front? I never change gears anyway, since I live in FL.

i would probably remove all the chainrings and get a 52 tooth 110 BCD (if that's the size of you current crank and you REALLY need higher gears than you already have) and mount it on the inside of the spyder with singlespeed crankbolts (get at LBS).

you can just get the bolts and use them to remount your current outside chainring on the inside of the spyder and throw away the bent middle chainring and smallest chainring. this assumes you have a somewhat standard five bolt 110 BCD triple crank on there. it is hard to tell from the pic in the link and i can't google anything on "SR XR10 crank".

if this works for you, don't for get to toss that old FD and shifter :lol:.

Thanks for the tip!

I heard its best to replace chain parts together, so would it be a good idea to get a gear setup like this? (I spend most of my tine now in 48 -14)

http://www.amazon.com/Sram-SRAM-Road...d_sim_sbs_sg_1
the 53t one

http://www.amazon.com/Shimano-MF-HG3...6111633&sr=1-2
13 - 28 freewheel

http://www.amazon.com/Shimano-CN-HG5...6111704&sr=1-2
new chain

chain looks okay,

i can't tell from the desc of the hub whether it is designed for a cassette or a threadon freewheel.
if you really have a threadon freewheel type hub that's a good freewheel to use.otherwise, you'll need a cassette. i have found very adequate ones for even less than an inexpensive freewheel on occasion.

the chainring may or may not work depending on the BCD (bolt circle diameter) of the chainring you are looking at and the BCD of your crank. cranks come in various BCD's (144, 130, 110, 94) and so do chainrings. i have found that it is of little consequence if it is designed for a triple, double, road or single speed. they all seem to work the same if only one is used. OTOH the BCD of the chainring must match the BCD of the crank.

BTW, the description of the chainring doesn't mention the BCD, i don't think. that would not be informative enough for me to make a purchase. you first need to find out the BCD of the crank (i couldn't find it) then google "nnn BCD chainring 52t" (where nnn is the BCD of your crank) or something similar to find matching chainrings. i often find them new on ebay for 20-30 delivered if i search a while.

It's definitely a thread-on freewheel. I was mostly wondering about the components playing well together. I've heard shimano and SRAM sometimes have compatibility issues. How would I best find out the BCD? Would it be stamped on it somewhere, or should I tame a Millimeter tape measure between two of the threads?

Putting a single chainring on there wont effect the chainline?

Thanks alot, you're very helpful!

if you will be running a single chainring with a freewheel in back and friction shifting or index shifting with a matching derailleur and freewheel (all 7 speeds for example), i have found that compatibility issues are minimal.

chainline is not an issue if you mount a single chainring in the middle position on a triple. you will be able to use all the gears in back.

BCD is defined as the twice the distance, in millimeters (25.4 mm per inch), between the middle of a bolthole on the sypder and the middle of the spindle.

i think most compatibility issues are a complication of indexed shifting. if you are moving to a single front chainring, shifting issues are not involved.