Bottom Bracket & Crank Upgrade, Chain Extension

Here i will provide the other information that is missing...What is the size of the Crank Arm Fixing Bolt?

For now, read on!


Parts upgraded in this page

1. Bottom Bracket Upgrade
2. Crank Upgrade
3. Chain Extension

Bottom Bracket Upgrade

This Bottom Bracket is ordered from Chain reactions UK, including postage it costs £18.99
It arrived in about 3 weeks.

Well, i did it because the Pound vs SGD was low at 1.79

I chose to use square taper ones because it is available cheaply compared to hollowtech ones where more parts are available on the second hand market.

The crank arms have to be removed to measure the end to end length of this new bracket.
For the Tahara, it is Dia 68 x L118 mm British thread.

http://www.chainreactioncycles.com/sg/en/shimano-un55-square-taper-bottom-bracket/rp-prod71369

Measure your existing crank length 'L' (See below)

Installation

To install, you would need 2 tools
a. Crank puller for S$3.45
b. Bottom bracket tool for S$3.10

Both can be bought cheaply and even cheaper than carousell.
From Ebay, these are sold from Hong Kong / China and price includes postage to Singapore.

Of course you will need a 14mm box spanner to remove the old crank and bottom bracket.

Here comes the important info that i mentioned above.

What is the size of the crank arm fixing bolt Y15507000?

Its M8 x 1.0 x L25mm
To use the L25, flat washers and spring washers would be needed else the bolt would be too long.

Bolt shops sell the high tensile ones for $1 each.

Remember to grease the threads before installation to prevent rust and seizure over time.

Crank Upgrade

Upgrade crank from 42T to 52T

Chain Extension

The upgrade of the crank needed the chain to be longer. Hence i joint the KMC chains with the stock chain and trim to required length. Joining with the KMC missing links. I could do so only because they are the same thickness. The excess chains are trimmed off with my DIY chain breaker.

Diy Chain breaker (DIY)