about a year ago i excitedly bought my first road bike. i bought the biggest size that they manufactured and the best quality that i could find in my price range. after a year of riding i have found several problems with the bike, mostly because i chose the wrong bike and i am looking at fixing these problems.

firstly the biggest size they made is far to small and although i can get the saddle height correct it leaves the bars way too low. i am looking for a stem that perhaps has a steep angle that would raise the bars a little. i don't need a longer one becasue the reach is comfortable now. i'm actulally hoping for a specific model number that i can look up online as i haven't found anything in the local bike shops.

the second issue is the gearing, 52/39 and the front and 8 speed 12 to 25 at the rear. entered my first race yesterday and round that i didn't have gears anywhere near small enough to get up the 10% incliine withouth burning myself out in minutes. so my second question is can i simply unscrew the 39 ring and replace it with a 34 but still keep the original crank. i have checked out upgrading the rear cassette and i know this is possible in theory too.

the bike has shimano 2300 compenents if that makes a difference.

i know a complete bike upgrade would make more sence but the jump to the next level of bike is one i would like to hold out for if possible as its quite a jump in price.

thanks for any help you can offer...

if the bike is too small , forget about it and move up. There are too many bad things to list about riding a bike too small,,,just move on, look at it as a learning experience.

How tall are you, and what's the size of the bike?

Take your pick:
https://www.amazon.com/s/ref=nb_sb_sa...3Ariser%20stem

If reach is good now, go for a steerer tube extender instead and keep the stem. Easier to keep track of where the bars will actually end up.

I don't know offhand, and unless someone else chimes in the way forward is to figure out the Bolt Circle Diameter, BCD, which is what determines what rings will fit on which crank.
But ignoring this, there are a few other things to consider:
- guesstimating the ratios a little, dropping from a 39 to a 34 together with a 12-25 cassette is comparable to adding about one-and-a-half lower gear. And by the sound of things, that won't be enough to make you happy.
- Rings are a lot more expensive than complete cranks. Depending on what bottom bracket you have, you may be better off looking for a complete crank in another range instead. Fitness/hybrid stuff with a 46-48 big perhaps. Don't worry about losing the 52, you won't miss it until you're above 30 MPH. And coasting those precious seconds won't do anything important for your average speed and overall time.
- or swap in a MTB derailer and a "MTB" cassette. Or a triple crank. That'll give your gearing range the boost you seem to be asking for.

That's Shimano low-end. I'd expect a serious lack of bling value, somewhat crude finish but decent enough performance as long as it's kept clean, lubed and tuned.

If the bike is well and truly too small for you, then you'll quickly get in the range of "good money after bad", "can't polish a..." etc.
Shimano still offers a huge amount of interchangeability, so you might want to look at finding a used bike in a better size instead. Doesn't matter if the wheels are trashed, use your current ride as a donor bike and move the wheels straight over., etc etc.

hi, thanks for that reply.

firstly i'm 6ft tall and the bike is 50cm. i know that is seriously small but the manufacturer (merida) recomends (but doesn't maunfacture?!?) a 52 for someone my height and its not that uncomfortable so it may not be a standard 50cm.

another gear and a half would suit i think even just going up to a 28 on the back would do it, i just needed that one more gear...a triple would be a step to far i think and i do get up to 30 mph on a good road.

and yeah i thought about second hand but there isn't much of a market in china for second hand 'quality bikes' that aren't stolen.


thanks again

At 6 ft tall you should probably be on a 56-58 cm frame.

I dont think you will be able to replace a 39 tooth ring with a 34. theres different bolt patterns between a standard crank and a compact crank, you might be able to find one but be careful to get the right bcd.

It would probably be easier to replace your cassette but your rear deraileur may have a limit as to how large you can go. eg.my campy chorus short cage maxes out at 26 teeth, 27 and it rubs. you will need 2 special tools to do this or your lbs will for a fee.

i have the tools to do it, i've changed cassettes before. i read that my derailleur should be able to handle it if i adjust the b screw. the cassesstes are cheap enough to make it worth a try i think.

probably a better option than changing crank rings.

you may need to add a link to your chain depending on how much of an increase you make.

56, 58, 60 are probably the most common bike sizes. Strange that your model does not come in a size like that .... Or did the retailer just not have one in stock and talk you into the wrong size ? Check that you have enough seatpost still in the frame to be safe. There is usually a "minimum insertion" line on the seatpost.

its made for the chinese market, i checked with the manufacturer and 50cm is the biggest, same with most giant bikes made for the local market, strange because there are plenty of chinese taller than me.

plenty of tube still inside the frame, at least six inches

https://www.merida.cn/cn/prod/detail.asp?id=1526

this is the bike if anyone fancies a look...

In terms of the stem, have you tried flipping it over so it points up. Not the most attractive look, but it will get your bars higher at no cost.

A 2300 RDER is listed as having a 26T max cog size.
A 27T cog will "probably" work fine, but you "might" be pushing things with a 28???

IF this is an 8 speed, you may find your cassette choices very limited. It's hard to find a larger "big" cog without dropping to an 11T cog for the smallest.
This means you'll probably have a nearly unusable highest gear.
One option would be to install a triple crank/rings such as 28-38-48.
This would likely require a new FDER along with the left shifter.
Your RDER is rated at 35T chain wrap capacity, so assuming you have a 13-26 cassette, you would only be using 33T of that. (34T if you have a 12-26 cassette)

https://techdocs.shimano.com/techdocs/index.jsp

Man sell the bike to one of the many, many Chinese shorter than you and get another bike. It's not worth fussing around with a bike frame that doesn't fit you. No way, no how should a six foot tall man be riding around on a 50cm frame. That would be too small for my 5 foot 4 inch wife. You must look like a circus bear on one of those trick tiny bikes! Surely there is some shop in all of China that would be eager to sell you a larger bicycle.

Sounds like a great time to source a bike that fits you better and at the same time you can spec it with gearing that matches your particular needs. A win/win.

this is why i don't think its a standard 50cm becasue i don't look like a circus freak and it would be too big for my 5ft 6 wife. there are larger bikes but they are mostly top end. in my price range they don't seem to go above 50. 53 is the biggest i've seen.

guess i just need to start saving up...

Well lesson learned. Maybe the seller was a little too eager (greedy) to sell a novice a new bicycle even if he didn't have the right size. Now you know what to look for. Next time bring a tape measure with you and measure the seat tube to see if the bike is in the right ballpark. I'm 5ft 9in and I ride a 55 or 56cm frame. You should probably be in at least a 58cm frame. Of course test ride the bike as well. Good luck.

Measure the seat tube from the center of the bottom bracket to the center of the top tube. Thats the frame size.

At the very least you can replace the frame with a larger one for just a hundred bucks or so and swap over the components. This doesnt help w/ your gearing issues but im sure you pedal stroke will be more efficient which may solve your burned out legs problem.