Mark_C_GT4.0

Hey guys new to forum first post. I have a GT Talera 4.0 hybrid bike. I do mainly all road riding and love this bike. My crank and gearing is the following. SR Suntour NEX crankshaft with 170mm arms, 48T/38T/28T sprockets (8 speed rear w/ shimano altus derailer) and pretty positive my bottom bracket is 68 x 122 tapered square. Like i said i do mainly all road riding and find myself using my 48T sprocket 90% of the time. The other 10% I might go down into 2nd gear but I absolutely do not ever use 1st gear. I want to replace this crank with a better quality one and would like to just use 1 sprocket since I really do not use the front gears at all when riding. So my question is what do you guys suggest I go with as a setup. Do i just replace my crank with a better one amd use the same gear 3 gear ratio as stock or can I go with a 1 sprocket setup and maybe go to a 9 gear cassette? Looking for advice and what is the best for me. Thanks guys.

Maelochs

Anything is possible ... depends on how much you want to pay for it.

I looked at transforming one of my bikes into a 1X, but I wasn't thrilled with the cost of a dedicated 1X chainset. Specialty market, supply and demand .... From what I understand, 1X systems use a narrow-wide chainring tooth spacing to keep the chain on securely. Possibly you could just unbolt the inner two rings from your 3X crank and be fine. That's where I would starts.

You can go up to ten speeds in the back without getting a new rear wheel. And I'd say you would want the widest possible range back there ... you don't mention what cogs you have, but with a 48-tooth front I would want 32 or 34 in the back .... and I hope you are young and strong or don't see many hills.

The first step would be unbolting the two inner chainrings and seeing how that worked. If everything went well, you might try a narrower bottom bracket to get a better chain line, and take off the front derailleur/shifter/cables.

Changing a cassette is super easy ... but if you get more gears you will need new a shifter and a new derailleur. None of that should cost a lot and none of it is hard to replace.

Viich

I have a 48-38 crankset on my bike right now, same as the two bigger rings on that triple you have. I believe that this combo is called a cx crankset, mine is an FSA megaexo one. I'm using a fairly narrow 12-27 8 speed cassette - this makes up for fewer gears compared with a wider spaced cassette with more gears.

AlmostTrick

You can install a "narrow wide" chainring in the same position that your center ring is in now, and ditch the other two. I'd suggest a 42. You will need shorter chainring bolts to do this. There really is no need and little advantage to changing out your crank.

Changing the rear to nine or 10 speed will require a different chain I believe... and of course the cassette and shifter. I bet the existing derailer would work. Even so, I'd not bother doing this because to me, once you add it all up it's not worth the cost.

All my geared bikes are set up as 1x systems. Unless one is riding in the mountains it really does cover everything, and depending on the cassette you choose, even can have tight gaps between gears.

fietsbob

Consider buying another bike, add to your fleet.

you list desiring enough changes to be several hundred dollars worth, so It's N+1 time..

Mark_C_GT4.0

Hey fellas thanks for all the advise. I want to change my crank on the bike because it is a cheap Suntour crank that has some issues with it. The previous owner of the bike looks to of almost stripped out the pedal threads because I went to change the cheap stock pedals to a really nice set of Intey pedals and it was hard to get the pedal to catch the threads but I was able to and looks like someone took a hammer and tried beating thw crank arm from the inside of the arm which it is not never noticeable but I just would rather install a nicer Shimano crank or even a Suntour with a better bottom bracket then the one on the bike. I really enjoy this bike the size of the frame and quality, the look of the bike is awesome, and I grew up with riding GT brand bmx bikes and spending alot of money on bikes and parts as a kid (31yrs old now) so having a GT now brings back good memories. I love how the bike is setup as a hybrid with the 700c wheels but I plan on replacing the front end as in the front shock forks with a nice rigid carbon fiber and even new CF bars and stem to reduce weight and push my bars abit more foward with a longer stem. Should look really good when it all comes together. This bike will be my road bike and I am eventually going to add a full suspension mountain as well in the future. Well back to the GT I been doing some research and I would like to just stay with the 8 gear rear which is a Sunrace CSM55 8spd casette 11-32t. So I think I will go with replacing my crank for sure but i am still undecided if I should go to a 2 speed front with a 48t/38t or a 44t/36t combo and replace the bottom bracket as well with a better choice. I will still ride my bike as I do now and am really enjoying getting back into cycling since it has been over 15yrs since I was into fixing selling and riding bikes. I have to order a true bike repair tool set first before I do any of this I have alot of tools but dont have any of the right tools you need to work on bikes. So the tool set will be my first purchase and I can look into what crankset and bottom bracket I want to put on my bike.

Viich

Buddy - been down this road. If you want to do a custom build yourself, get a frame and parts. Swapping the crank on this bike is a good way to start learning, but don't get carried away. You can easily drop far more on this bike than it would end up being worth (even to you)

From what you describe you want, a frame up build would be easier with likely a better result. Look for cheap (or free) used parts - that way mistakes on part compatibility can be sold on at minimal loss.

Not to mention that you still would have a bike to ride while you are building.

Retro Grouch 

Just do it! As some of the other posters have suggested, it probably doesn't make the most sense economically but everything isn't just about money.

Origin 8 crank arms are relatively affordable and come in a huge variety of crank arm lengths and even colors. You'll need a new, narrower bottom bracket. A 9-speed cassette will easily swap in place of your current 8-speed but you'll need a new (relatively pricy) shifter and a new narrower chain. Dump your front derailleur.

You'll basically gain two things:
1. A bicycle that is uniquely yours.
2. The satisfaction of having done it yourself and the knowledge that you gained through the process.

Oh - and you have just entered the clique of obcessive compulsive bicycle tinkerers. I'm not sure if that's a good thing or not but you might as well go with it because, once you have it, there is no known cure.

Mark_C_GT4.0

Well I was riding this weekend and I started to feel my left side pedal feeling wobbly so I pulled over and noticed my pedal was loose in the crank arm. Here the remaining threads in the crankarm stripped out (not sure what caused it but I think maybe putting grease on the pedal threads didn't help with the threads already were messed up when I put the new pedals on), but I am now forced to either replaced the left crankarm or just replace the whole crankset. I know I could just go the simple route and replace the arm but there is no fun in just that! Money's not a problem when it comes to my hobbies I like to go extra, since biking is fun and I enjoy fixing stuff (bikes cars motorcycles etc) I am into making what's mine customized for me. For this bike tho I understand it is not a very high end bike to be completely switching up I think I will just go the safe route and replace the crankshaft itself with either a shimano or Sr suntour and keep the 3 speed front. Down the road I can do a complete frame buildup once I'm financially able to do that and just enjoy riding my GT while I do a build. A complete frame buildup makes more sense to do exactly what I want rather then tear down a decent build bike (replace crank, cassette, derailers, shifters, brake levers, cables etc). The bikes a great entry level hybrid and I think I will just keep it like it is but lighten the front w/ lighter forks amd maybe wheels but I won't get too invested into this bike knowing a frame up build would make more sense later on.

Viich

Assuming you have square taper bottom bracket, this one isn't bad. If you want to spend money, go for the megaexo version with external bearings.
https://www.chainreactioncycles.com/mobile/ca/en/fsa-vero-pro-compact-n10-11-chainset/rp-prod129455

Mark_C_GT4.0

Waiting for my bike tool kit to come in from Amazon so I can start to repair my bike with a new crank so I can start to ride again! I'm just gonna replace the crank arm itself for just $15 and save money to do a complete custom frame up build since ill have my GT to ride I can do a custom build. Hope to do it this winter. And have pics to show off my build.

Mark_C_GT4.0

Okay well since I have waiting for my bike tool kit to come in that I ordered on Amazon and haven't been able to ride my bike the past 2 weeks or been able to fix it I am have doing alpt of reading and watching videos online about different crankset and gearing. I am 90% sure that I want to change some things on this bike to make it more comfortable for my riding style. I am dumping the front derailer and going with a single gear front 42t or 44t. Am going to keep the squared bb on it. For now I am going to ride with the 8 speed cassette but eventually would like to switch to a 10 speed cassette/derailer/chain combo and switch out my Shimano brake/shifter levers for a single 10 speed trigger shifter and switching to hydrolic brakes. Think this bike will have a awesome look to it once I start customizing it as my hybrid citycross bike and will be looking in the future for a true full suspension mtg to ride in the woods/trails.

SANDBORNSTEVE

The cranks are probably coming from China.That's why it is taking so long.

trailangel

Left pedal is reversed threads. Sounds like somebody didn't take this into account.