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What do I need to replace my front crank and rear cassette?

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What do I need to replace my front crank and rear cassette?

Old 05-29-20, 06:51 PM
  #1  
Oneder
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What do I need to replace my front crank and rear cassette?

I have 21 speed shimano altus right now and want my front to be a single with 45-50t instead of the super low geared triple crankset I have now. I also want to go to a megarange cassette on the back that gives me 12-34t range.

73mm English BB Shell
Shimano BB-CT91 with 120 mm spindle

Can I just install this chainring? If so, what tools do I need? It says 110/130 mm but I have 120mm spindle. Do I need a new spindle, too?
https://www.modernbike.com/origin8-s...mm-3-32-silver

Should I get a new bottom bracket while at it? This one is probably original and doubt it's in good shape.

Which specific park tools do I need for my cassette and for crank removal?

Thanks guys
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Old 05-29-20, 08:22 PM
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Originally Posted by Oneder View Post
I have 21 speed shimano altus right now and want my front to be a single with 45-50t instead of the super low geared triple crankset I have now. I also want to go to a megarange cassette on the back that gives me 12-34t range.

73mm English BB Shell
Shimano BB-CT91 with 120 mm spindle

Can I just install this chainring? If so, what tools do I need? It says 110/130 mm but I have 120mm spindle. Do I need a new spindle, too?
https://www.modernbike.com/origin8-s...mm-3-32-silver

Should I get a new bottom bracket while at it? This one is probably original and doubt it's in good shape.

Which specific park tools do I need for my cassette and for crank removal?

Thanks guys
the “130/110mm” on the chainring refers to the bolt circle diameter of the chainring, and is unrelated to the 120mm spindle length. It’ll fit your current crank if the BCD matches
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Old 05-30-20, 05:54 AM
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Originally Posted by Litespud View Post
the “130/110mm” on the chainring refers to the bolt circle diameter of the chainring, and is unrelated to the 120mm spindle length. It’ll fit your current crank if the BCD matches
Here's how to measure: https://www.wolftoothcomponents.com/...e-diameter-bcd
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Old 05-30-20, 06:50 AM
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Shimano Altus cranksets do not have removable chainrings. You'll need a new crank.
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Old 05-30-20, 08:40 AM
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Oneder
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https://www.modernbike.com/vuelta-pi...tx170mm-silver
https://www.modernbike.com/vuelta-cartridge-bb-68x110mm

Will these go together and with my bike? What size tool do I need for the bottom bracket removal?
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Old 05-30-20, 10:24 AM
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You need a crank removal tool for your existing crank, pedal wrench, socket for the bolts, correct tool for your existing BB, correct tool to install whatever BB you purchase.

The frame and crankset determine what BB type and size you need. You need a 73mm English threaded BB compatible with whatever crankset you decide on.
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Old 05-30-20, 11:01 AM
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Originally Posted by Oneder View Post
I also want to go to a megarange cassette on the back that gives me 12-34t range.
Your existing rear derailleur may not work with that set up. There may not be enough clearance between the 34t cog and the jockey wheel on the derailleur. In that case you'd need to change out the derailleur or use a derailleur hanger extension like this:

https://www.wolftoothcomponents.com/products/roadlink
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Old 05-30-20, 03:37 PM
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Looks like this oumer's tool can replace both cranks and BB, claims to fir everything. Anyone tried this out?

https://www.amazon.com/Oumers-Bike-C...DHKK1G24HBR1C6
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