JIS BB question

[skiezo]

I have steel rando frame that has a english threaded BB. I have incoming a Suntour XC Pro triple on the way with 46/36/24 rings. It will be used with a campy triple FD. I plan to use a 13/27 or 13/29 10 speed mid cage chorus RD.
What length of BB and spindle will I need for this set-up?
Thanks Brian

[oldpotatoe]

Originally Posted by skiezo

I have steel rando frame that has a english threaded BB. I have incoming a Suntour XC Pro triple on the way with 46/36/24 rings. It will be used with a campy triple FD. I plan to use a 13/27 or 13/29 10 speed mid cage chorus RD.
What length of BB and spindle will I need for this set-up?
Thanks Brian

Google foo says 125.5mm...But I'd google-foo some more.

[skiezo]

I did do an extensive google search and came up with many different opinions.
I did find some info that said 125,123, 118. I emailed Rodriguez to see if they could help out any.
Once the crank arrives I will take the frame,wheels w/ cassette, RD and crank and see if he can figure it out.
I have a Phil BB but I am thinking at 106mm it is to short.

[AngryScientist]

i have measured for proper length before, it is not that difficult to approximate.

i used a wood pencil as my "gauge".

the good news is that shimano UN55 BB's are excellent quality and very cheap, so if you pick the wrong one, it's not the end of the world, if you need to guess once or twice.

[cnighbor1]

What length of BB and spindle will I need for this set-up?
I just install what I have on have Dry and if it works
I do have a Superbe BB but for doubles

[kingpin75s]

Sounds like you have the standard (non-MD) version so 123 to 125 range should be correct. I always go on the low end to minimize my Q-factor a bit and just make sure my chainline remains within a couple mm of optimal.

As Angry stated, I usually keep some UN-55 BBs just for fitting and then replace with Phil (or not) as appropriate once dialed.

[NHAero]

FWIW - I run vintage Sugino AT cranks on three bikes all with English threaded 68mm BB.

On my Bob Jackson, I run the cranks as intended, as a triple. I run a Phil Wood 125mm R+5 BB - the right side is longer than the left by 5mm, so it is 65mm long from the centerline. Rear hub is 130mm spacing, and I'm running Shimano 105 10 speed with STI (ran 9 speed with DA barcons for a long time, much less fussy!).

On my Anderson, I'm using the crank as a double, no inner ring on the 74BCD. This bike has a hub with 135mm spacing but I run the Ultegra 11-34 cassette that sits inward on the 10 speed hub. The BB is a 122.5mm Shimano square taper, symmetrical. So instead of the right hand spindle being 65mm long from centerline, it's 61.25mm. This puts the chainline right where it should be. That bike has Shimano RS-685 STI 11 speed shifters.

[bikinchris]

Just get a 123 or so Phil bottom bracket and you can adjust the chain line to perfection.

[NHAero]

Agree. Having both cups shoulderless is great on the PW BB, allowing small adjustments side to side.

Originally Posted by bikinchris

Just get a 123 or so Phil bottom bracket and you can adjust the chain line to perfection.

[NHAero]

Where are people buying Phil Wood BBs these days? Used to get mine from Licktons but they don't have much.

[choke]

It is very possible that you need a spindle that is shorter than what the specs say. Those specs were designed around a MTB frame which typically has a wider BB shell, larger chainstays and wider hub spacing than a road bike.

I am using a Campy Centaur MTB crank (triple) on a bike with an Italian BB. The specs for this crank say a 124 or 132mm spindle length. I tried a 111mm BB first and while it may have worked the granny ring was closer than I was comfortable with so I use a 115.5mm BB. That's 8.5mm less than what is specified.

I also have the same crank on another bike with an English BB, though this crank is set up as a double. It's on a 102mm BB and while the inner part where it goes over the spindle is very close to touching, it has been fine for many years. The rings and arms have loads of clearance.

If that crank is spec'd at a 125mm, IMO 118mm would be a good length to try.

[bikinchris]

Maybe you could place the rear wheel in the frame and measure the chain line to the center of the cog set. Place a straight edge in the center of the cogs and measure from the center of the BB shell. Then you set up the crank so the middle ring is centered on that measurement.

[oldpotatoe]

Originally Posted by NHAero

Where are people buying Phil Wood BBs these days? Used to get mine from Licktons but they don't have much.

Local Bike Shop??
Or Direct?
https://phil-wood-co.myshopify.com/c...m-bracket-cups

[ultraman6970]

Skiezo... 106 will be too short, they recommend 125 ish??? depending on the frame you can go shorter but that IMO is more like a personal opinion thing because someguys like to have everything perfect... for example, you found 118 and 123 could work aswell.

From 118 to 125 you have 7 mm... 3.5 mm per side, if the small chainring doesnt touch the stay you are ok IMO...

From 123 to 125 you have 2 mm difference, 1 mm per side, that should work aswell, but again depends a lot of the frame.

Sure you will be able to find a suitable shimano BB, they have them in several sizes. BTW, the BB needs to be asymmetric or symmetric? What do the web site says???