Originally Posted by
FatherAlabaster
Don't forget the cassette, handlebars (tape? stem? new cables?), possibly rear wheel, maybe bottom bracket depending on the cranks, and labor to get it all swapped out (unless the OP has all of his own tools and knowhow). Upgrading to ten speed road from eight speed mountain stuff is a big job.
I forgot to include the cassette but a 10 sp tiagra 4600 casette can be bought for $30 or less.
*The bb is typically included with cranks.
*Virtually all new hybrid wheels are 10 speed compatible since the hub body length did not chance between 9 and 10 speed.
*Cables are included with the
flat bar sl-4600 shifters.
*A flat bar hybrid would not need tape or a new stem/
Doing a total overhaul like you're talking about is very much like buying a frame and fork and doing a custom build - the expensive way to do things.
The resale value of the "new" components would cover the cost of a swap at a co-op or smaller lbs. Moreover, the price for tiagra/deore 9-speed would be
far less than the
race level ultegra components I listed. Upgrading to ultegra would also greatly improve shifting and wear over bottom-end 8 speed components (or mid range 9 speed).