New BB needed so might as well go for a new Crankset!

[rs2k]

Here's the story. Currently hit 1000 miles on my bike and the bottom bracket is starting to give. Fair bit of freeplay in all directions so its not long before the whole thing goes bang.

Obviously I'd like to replace it, but I've also noticed lately as Ive got back into shape I've run out of gears.

Heres the current bike:

The crank set is: SR Suntour 28/38/48

The rear cassete is: Shimano TZ31 Mega range 14-34

Now seeing as the BB needs to go I was thinking about replacing the crankset with a 50/34 compact one.

Would I need to change the derailer or should all be ok?

Cheers

RS2K.

 

[cyberknight]

Here's the story. Currently hit 1000 miles on my bike and the bottom bracket is starting to give. Fair bit of freeplay in all directions so its not long before the whole thing goes bang.

Obviously I'd like to replace it, but I've also noticed lately as Ive got back into shape I've run out of gears.

Heres the current bike:



The crank set is: SR Suntour 28/38/48

The rear cassete is: Shimano TZ31 Mega range 14-34

Now seeing as the BB needs to go I was thinking about replacing the crankset with a 50/34 compact one.

Would I need to change the derailer or should all be ok?

Cheers

RS2K.

Why not change the cassette for a closer ratio like a 13-28 assuming it will fit , that would give you a slightly higher gear and avoid a lot of mucking about with front shifter compatibility . I did read somewhere that MTb shifters have a different pull than road shfiters and you will not be gaining that much from a 48 to a 50


..goes to shledon brown..

48x13 gives you 96 inches per revolution of your front crank

48 x 14 = 89 inches

50x14 gives you 92 inches .

Assuming you spin your legs at 90 rpm you can get 25 mph on the flat out of a 48x 13 and 24 mph out of your current 48x14 .

 

[rs2k]

Cheers mate helpful info. I'll look into a new cassette for the rear.

Its only currently a 7speed. Any suggestions of what will fit?

 

[cyberknight]

A google search shows me that it is a screw on freewheel?

And not a cassette?

evans do one .


http://www.evanscycl...ampaign=froogle

you will need a freewheel tool


http://www.evanscycl...iglide-ec005475

Check this out before buying anything...
http://www.parktool....eewheel-removal

You will need a new chain as well.

Might be cheaper to take it to the LBS if you do not have the tools.

 

[rs2k]

Again, thanks for the info. Much appreciated.