Cook Brothers RSR Crank Questions

[Canuckbiker]

Hi RB experts, I'm looking for some answers on the Cook Brothers RSR Cranks I won an action on yesterday. Not sure if I paid too much but I'm excited to get my hands on them, I've never owned a set but always loved the dog bone versions and the RSR version is nice with the hidden bolt and milled out bits. I paid $190USD plus shipping. Finish is not too good but I'm very handy at polishing cranks and may go silver polished with black spider, add some decals too.

Have a look at the pictures below. The seller never answered my question as to the length, I'm pretty sure they are 176mm and not 181mm. I've done some image scaling comparing to known 176 and 181 photos. Any opinions on this based on pictures?

Big question: what bottom bracket can I use? I'd rather avoid a pricing Cooks unit. I have read "2 degree tapered". I'm hoping JIS (Shimano) works, I assume longish, spindle around 120-122mm. Can anyone confirm if Shimano tapers are compatible?

 

[kingoffootball]

IIRC, 125mm is the stated length for the bottom bracket spindle, but a lot of people on here seem to run them on 122 mm spindles with no problem. It will depend on the clearance on your frame. I'm pretty sure they are JIS, but someone else should be able to confirm.

 

[Magpiegifts]

I recently posed a similar question. But with regards to cqp cranks. I read they are ISO taper BB.

 

[Betsy]

I've been trying to figure this out too.. it's like cracking the enigma code

 

[Canuckbiker]

Thanks for the replies, my seller finally confirmed the ones ordered are 176 (not 181), a relief, I'm not sure 181s would feel right. I believe from pictures supplied the spider is 110/74 BCD and not compact drive. I'm looking into rings as well. I figure if I go silver polished black rings would be the way to go, especially considering they will most likely go on my silver polished C-Dale.

Hoping someone will chime in on the taper question with certainty. Always nice lining up parts while waiting for delivery. My C-Dale is my featherweight ride, I'm hoping to not break the bank with the BB and still keep it under 250g

 

[pw_pw_la]

A question people hate to answer here, for some reason...

 

[kingoffootball]

Bike Pro say:

The crank arm set will work with any standard 2 degree tapered bottom bracket, and naturally Cooks recommends their own sealed bearing bottom bracket.

Every 90s onwards Cook Bros. bottom bracket I can find is JIS (mentions of different taper for the very early cranks) but that's still not definitive.

 

[Magpiegifts]

Bike Pro say:

Every 90s onwards Cook Bros. bottom bracket I can find is JIS (mentions of different taper for the very early cranks) but that's still not definitive.

Thanks for that.
Would you share some advice on which taper BB would these cranks require. I'm thinking ISO but I'd really love someone more knowledge than me to give their opinion

 

[kingoffootball]

Thanks for that.
Would you share some advice on which taper BB would these cranks require. I'm thinking ISO but I'd really love someone more knowledge than me to give their opinion
View attachment 624383

Based on this discussion:

https://www.mtbr.com/threads/cqp-cranks-compatible-with.296147/
it sounds like the taper is closest to ISO on the CQP ones, so I would use an ISO bottom bracket, unless you could find a Cooks one of the same era as the cranks.

 

[Magpiegifts]

Nice one @kingoffootball it was that discussion you linked that led me to think ISO BB.
Why does the old stuff here to be so complicated