installing pro derailleurs on cheap bike

bassopotamus76 said:

Hello All,

This is my first post on this forum and I hope to be an active member for time to come. Right now, though I have been biking my entire life, I am still a newcomer to the in depth, amateur world of cycling affacionado's. I dont have much technical knowledge but I do love the sport.

I have a question that perhaps some of you might scoff at, but bear in mind that Im not made out of money and a fully pro bike is far out of my reach. Anyhow, I bought a cheap KENT bike from a K-Mart type store a while back. I tried to get the sturdiest bike i could find, considering I am a big guy (6'2'' 235 lbs), but I guess you really do get what you pay for...

The frame itself is really solid, lightweight aluminum. The tires, brakes, shifters, cables, ect. all work fine. But if I so much as jump up a curb (or off a curb...), the handling goes to [censored]. The gears start clicking, shifting of their own accord, snapping and catching, ect. I cant adequately describe the bedlam that ensues any strain put on the drivetrain.

This really destroys any joy in the act...

I cant afford an $800 TREK or something similar, so I had the idea of removing the crappy shimano derailleur and installing a very nice and expensive one in the back. and maybe the front, too. As a long tern project I could totally remove the factory parts and build practically a new bike. But for now I need to know if a new derailleur would fix the handling/drivetrain issue.

Any comments? Am I mad? I would really appreciate any help.

Don't waste your money.There are other issues besides the derailers.In fact,even the cheapest derailers can work very well.

I would advise against what you're proposing, simply because you could run up that $800 just installing parts on your current bike. My Dura Ace components cost as follows (and all bought at a significant discount):

Rear derailleur: $128
Front Derailleur: $60
Crank: $170
BB: $40
Shift/Brake levers: $255
Cassette: $90
Brake calipers... well, you see where I'm going with this. The cost adds up, assuming your bike accepts standard components.

IMO it's better to save up and keep an eye out for a deal down the road.

thanks for the suggestions. I just think it would be excessive to buy an entire new bike. But it would also be excessive to plug in a bunch of new parts, ultimately spending as much or more than I would have on a decent bike. However, I still think the frame, tires, shifters, and brakes work fine. the brakes and frame, especially, are really solid. So in the end I would end up installing derailleurs and a new crank/pedals. With good materials, this would end up costing around $300, still a far cry from the $800 to $1000 for a medium/upper level MTB.

But say I were to go ahead and just get a new bike, what would you recommend for someone of my size? I really would like something that wont break in half if I use it on a rough trail...

Thanks again!

bassopotamus76 said:

... so I had the idea of removing the crappy shimano derailleur and installing a very nice and expensive one in the back. and maybe the front, too.

Careful about comments like this 😎

Any low-end Shimano component will perform just as good as any high-end from other manufacturers if adjusted properly. Besides, from what cydewaze wrote, it ain't cheap (hey, it's a Dura-Ace🙂).

Have your bike checked by a mechanic before doing any major overhaul. If the problem persists, MAYBE then you should think about replacing parts.

Cheers

e_guevara

Well it's up to you and what you want
remember most of the newer parts would fit another frame
I'm puting a Shimano Sora crankset on my old Schwinn frame
it has Weinman rims and Shimano derailleur's
and if something happens to the frame before the parts wearout
then I will just get a frame
you dont have to get top of the line to get performance
but maybe yours has a lot of ware and needs replaced
also remember Shimano has some of the best made parts goin
the "Dura Ace" cydewaze quoted you are Shimano!

thanks again for all the input, guys.

The thing is, the bike started doing this immediately after I bought it. I took it to a bike shop in town and they adjusted it. The problem persisted, so I just took it easy on the thing. But I bought a mountain bike for a reason, y'know 🙂 and so far I havent been able to rough it because the clacking, snapping shifting problem comes up. sometimes the chain pops right off the cassette.

It doesnt seem possible that the problem is wear. I mean, Ive had the bike a year, and most of that time it has spent in a locker because I couldnt use it. Apart from the fact that it has had the same problem since day one, and also has been checked by the shop on more than one occasion.

By the way, Im sure shimano has a wide range of product, from low end to high. But I doubt they install high end components on a department store model Kent bicycle that costs $130... I wasnt trying to insult shimano, just the particular components on my bike. They are the cause of much frustration🙂 .

I guess my question boils down to whether a new derailleur would solve the inconsistency (well, consistent inconsistence) of the drivetrain when put under any stress. It seems logical to me, granted I am a novice, that a solid drivetrain would equal a solid ride, particularly off road. Am I wrong?

Thanks for all the help, it is much appreciated!

bassopotamus76 said:

Hello All,

This is my first post on this forum and I hope to be an active member for time to come. Right now, though I have been biking my entire life, I am still a newcomer to the in depth, amateur world of cycling affacionado's. I dont have much technical knowledge but I do love the sport.

I have a question that perhaps some of you might scoff at, but bear in mind that Im not made out of money and a fully pro bike is far out of my reach. Anyhow, I bought a cheap KENT bike from a K-Mart type store a while back. I tried to get the sturdiest bike i could find, considering I am a big guy (6'2'' 235 lbs), but I guess you really do get what you pay for...

The frame itself is really solid, lightweight aluminum. The tires, brakes, shifters, cables, ect. all work fine. But if I so much as jump up a curb (or off a curb...), the handling goes to [censored]. The gears start clicking, shifting of their own accord, snapping and catching, ect. I cant adequately describe the bedlam that ensues any strain put on the drivetrain.

This really destroys any joy in the act...

I cant afford an $800 TREK or something similar, so I had the idea of removing the crappy shimano derailleur and installing a very nice and expensive one in the back. and maybe the front, too. As a long tern project I could totally remove the factory parts and build practically a new bike. But for now I need to know if a new derailleur would fix the handling/drivetrain issue.

Any comments? Am I mad? I would really appreciate any help.

I completely agree with what others here have said. Don't dump your money into your K-Mart bike. Ride it until you can afford something better. Maybe you could find a good used bike that fits you? Try eBay.