IRD BB and compact crank compatibility with Shimano
I am doing my first build on a factory repainted 1996 Marinoni Corsa columbus
brain 59cm steel frame. I bought a new silver shimano 105 5700 10 speed
group set with compact crank (50/34), CS5700 12/27, FD5700 braze on, from
ebay. It is the Hollowtech II bottom bracket and crank.
I am thinking of using The IRD Compact Double Road Crank which requires a 115mm JIS square tapered BB instead of the Hollowtech II BB and crank. Here is the site:
Interloc Racing Design
My questions are: Are there any compatiblity issues with the Shimano 5700 105 group I have? And specifically with maintaining the recommended chainline of 43.5mm?
I did talk to IRD and they stated need 118mm to maintain 43.5 chainline. Also an email from Harris Cyclery and they felt 118mm was correct as well for chainline. He also stated that the only reason would go with all shimano is that it is engineered to work as a group and shifting could be fussy with a different crank. Makes sense.
He also felt the outboard bearing system was good and reliable. I was concerned I had read on the forums some negative comments such as water getting in with the outboard system etc and some other dissatifaction with them. I dont think there are alot of complaints with the square tapered. Plus I have to get my nice Frame faced. So still mulling it over. any other thoughts?
The current Shimano bb/crank system is MUCH simpler to deal with than square taper. Furthermore, while IRD makes some interesting products, I don't think the quality is equal to mid-range (105) Shimano. Why not use the crank you have? You can always change later if you aren't happy with it.