Bottom Bracket recommendation
 

Just picked up my first track frame today and needed some advice on what bottom bracket to get.

I am running a shimano dura ace 7402 crankset and i'm fairly certain it is a British standard bracket on my new frame, would I be best off sticking with a shimano BB if possible to match the crankset?

Not sure how much difference in quality there is going up in price ranges with these BB bearings but i would like to keep it within either low or mid range if possible as I am building on a budget, but something decent I can commute with but also hit the velodrome occasionally, a good compromise.

What do you think?

Cheers

Any JIS square-taper BB will work (provided the correct spindle length -- I think it's 112mm), but I've found the Shimano units to be long-lasting and a good value, price-wise.

The original BB on my wabi didn't last one season so don't get one of those. I switched to the the IRD QB-95 several years ago and it's been holding up for me. 10 year warranty, so it will be worth it if it lasts that long.

Velobase is a great resource for information. It indicates 112mm is recommended for 68mm shell width. If the track frame has a BB shell of 70mm, then 113mm is the recommendation.

https://www.velobase.com/ViewCompone...d-fde77aff77c8

For the style of riding you are describing, I would think the basic Shimano BB would serve you well, although you might have to compromise and go with 113mm or size down to 110mm assuming there's enough chain stay clearance.

I've had a QB-55 in my fixed-gear since 2013 and it sees the most rain/snow/grit of any of my bikes. Still turns smoothly after <checks notes> 11,000+ miles. :thumb:

+1 for IRD assuming that is the correct spindle for your cranks. On my DA 7400 cranks I am running a Phil Wood B.B. and honestly while I love Phil Wood, I only did it because the frame is Phil Wood. Honestly I think the IRD QB-95 might be a tiny bit better at least easier to deal with.

Seems like the IRD's are quite a popular choice, I just checked then out but it seems only the 113mm spindle length is available for them though and on velobase it says aparently for 68mm BB shell I need 112mm spindle, does that mean they aren't compatible?

No, it just means the spindle is 1mm longer. Not a deal-breaker in my opinion.

Okay the IRD QB 55 looked like a perfect fit but is literally sold out everywhere, even went to the 3rd page of Google results which I haven't done since 2004

The price point was right on point, the 75 and 99 is a bit too much for me unfortunately, any other options that are comparable?

Boulder Bicycle has the QB-75 113mm BSC in stock for $46 + s/h, but their online orders are temporarily halted until 10/21. You can email them or call them to see if they’ll process your order.

I’ve purchased 2 QB-95’s from them and an assortment of parts for my vintage builds before. Their prices seem good and with the supply chain problems affecting everyone you may need to pay a little more or wait an indefinitely long time for the QB-55.

IRD QB-75

Oh hey, I just belatedly realized something! You're building a fixed-gear, but Dura-Ace 7402 was/is a road crankset. Therefore, the stock bottom bracket spec (112mm) is going to be WRONG for your needs anyway!

I assume you're going to want to run a single chainring on the outer position, since that looks best. ;) That means you'll need a shorter bottom bracket to bring in the chainline. You may have to experiment, but I imagine a 107mm, maybe even 103mm, bottom bracket will be needed.

(If you play with bikes a lot, it's helpful to have a variety of bottom brackets on hand for test-fitting. They could be old and worn-out, but still good for this purpose, so if you needed a reason not to throw away all of your old bottom brackets, here's one. :))

Ohh man i never even thought about that, i guess thats good on that case because there does seem to be more of the shorter size available i just couldn't find the 113mm length anywhere.

In terms of figuring out exactly what size I need, what am i best to do? I'll order a tool to remove my current bottom bracket to see if i can find out what size that is an use as a guide, apart from that is there anything else i can do to find an accurate measurement?

Cheers

Best way to solve this problem is buy a crankset meant for a single ring when one is building a tarck frame from scratch
IIRC Dura Ace 7600 track crank wants a 109mm BB
Good luck...

That's what Sutherland's (6th edition) says:

The Orgin8 Torqlite is a really nice bottom bracket, I've had a couple of them. Pretty light with a hollow chromo spindle and a decent price.

Okay I think once I get the tool to remove my current bb and check the size I should be good to go as current chainline is spot on, bearings have had it though.
Thank you all for your input

Good Sheldon Brown page about measuring chainline here: https://www.sheldonbrown.com/chainline.html You'll want about 42mm, but it doesn't have to be exactly that.

https://cimg8.ibsrv.net/gimg/bikefor...cd9be77c20.jpg
On my Fuji Del Rey conversion I used a Sugino 103mm BB, Messenger 48t crankset, Vuelta 15t cog on some generic double wall wheelset. Might have been Omega. Sram 1/8" chain. Specialized split mtb seat. Everything else was stock. Except the add-ons.

Got a really straight chainline with this combo.

It's off topic question, but what's the"Closest Taper End Size"
of "campy" means ?
I have a BB of "Double BB-7400 70W 113 ....Campy"
I want to use 80s Campy super record crank and found it's hard to find a proper campy BB for it.
Does this chart means I can use my DuraAce 7400 70W 113mm BB in stead ?
Thanks!

Ryan

I know this is an old thread, but I just replaced the bearings on my IRD QB-95. Merry Sales has them for $25. So the ability for me to replace the bearings myself with no special tools makes this the hands-down best square taper bottom bracket you can get.

Sugino used to make a moderately priced 103/68 bb. Coupled with Messenger cranks they make for a nice, straight chainline. The chainring was 48t as I recall.