installing cook bros cranks

[gsy971]

i just scored a 95 trek 8700 zx which i want to build as 1x9 using my cook bros rsr cranks. problem is my middle 33T 110bcd HB ring which i want to use won't clear by a small bit. what is my best option?

1) use 94 bcd cook bros e crank to run a 32T? i am assuming that a 32T would clear
or

2) i am currently using a 113mm bb. can i switch to something longer althought the drive side spindle will only move out about 2mm or so i read and my q factor will be a lot wider (would it be that inefficient)

***NOTE*** scrapping my CBR cranks is not an option. either use existing rsr cranks with longer bb spindle or use cbr e cranks with 94 bcd 32T.

Hope this all made sense. be kind fellas
thank you in advace

 

[hamster]

A change in the BB length will have minimal effect. In fact if the chainring is hitting the chain stay it's too far left anyway.

 

[videojetman]

you need a longer bottom bracket.
you need something like a 125mm bottom bracket. ( not sure if thats the exact size though )
although i'd be interested in what the right size BB is for the rsr cranks.

 

[mikee]

cooks need a long b/b
think i have a 122.5 in one bike (trimble so no chainstay worries)
129 (or so)on a pace

 

[gsy971]

just started reading on the chainline
aw man! so will running a longer bb spindle greatly affect my chainline thus mess up my shifting on the cassette???
now i am even more confused

 

[pete_mcc]

just started reading on the chainline
aw man! so will running a longer bb spindle greatly affect my chainline thus mess up my shifting on the cassette???
now i am even more confused

No, it won't mess up your shifting. The RSRs were designed to be used with a longer BB. You are using one that is too short and hence your chainring fouls the stay. Surely the fact that the chainring is cutting into your stay is far more detrimental that moving your crank out a couple of mm.

Regards Q factor, your choice of shoe or pedal can have more of an impact and anyhoo I doubt anyone could tell the difference a couple of mm will make to how a bike rides, especially an old one using flexy cranks.

 

[gsy971]

just started reading on the chainline
aw man! so will running a longer bb spindle greatly affect my chainline thus mess up my shifting on the cassette???
now i am even more confused

No, it won't mess up your shifting. The RSRs were designed to be used with a longer BB. You are using one that is too short and hence your chainring fouls the stay. Surely the fact that the chainring is cutting into your stay is far more detrimental that moving your crank out a couple of mm.

Regards Q factor, your choice of shoe or pedal can have more of an impact and anyhoo I doubt anyone could tell the difference a couple of mm will make to how a bike rides, especially an old one using flexy cranks.

actually had a longer spindle bb that was on my klein with the cbr rsrs. moved that over to my trek and it clears nicely. thanks for the assistance

 

[Martin]

Just put a metal shim from shimano 10 speed (f.e. Ultegra) between BB (not the shim between the cogs but the one between cassette and freehub.. That it's jus 1mm and works fine. Used that on my Psyclone and worked great.

 

[Fudd]

Have you tried mounting the ring in the outer position on the spider?