Bottom bracket for classic Ritchey Logic compact cranks

[ViveLemond]

Hi,

I've poked around but haven't found a definitive answer to this. 

I have the sugino made classic compact Ritchey Logic compact cranks (from the 90's I believe, I bought them used and they've been in my garage for well over 10 years). I'd like to use them as a double on my Nordavinden conversion, but I'm having bottom bracket issues.

I don't fully understand JIS versus ISO issues, but these do not sit correctly on a standard UN-52 110mm bottom bracket- they don't go on nearly completely and would have a huge Q factor. They have 22-32-42 rings: again, I plan on using them as a double (although I could have a bailout triple, but I don't think it's needed with my 12-36 cassette).

Can someone recommend a specific bottom bracket I should buy that would work and yield a nice road double chainline?

Thank you very much. Can't wait to get my Nordy out on its maiden ride, hopefully this weekend.

[Kieran J]

I once set these Logic Compact cranks up on one of my bikes as a wide-range double with a 102mm ISO-taper BB. They had an acceptable Q-factor, but was wider than what I preferred. They do flare out more than the 110/74BCD Logic cranks.

KJ

[Alex Wetmore]

They need a very short BB to be run as a double.  I use them on Shimano 7400 Dura/Ace BBs, which are 103mm.  I actually remove the lip on the right side of the BB (easy since it is aluminum) and shift the whole BB about 3mm to the left to get a better chainline.  If you run them without doing that it works, but the chainline isn't ideal.  

Phil Wood makes a 98mm square taper BB that is probably ideal, but I have no experience with it.

It is worth the hassle, they are great cranks.

alex

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From: 65...@googlegroups.com <65...@googlegroups.com> on behalf of ViveLemond <samkru...@gmail.com>
Sent: Wednesday, February 21, 2018 2:23:45 PM
To: 650b
Subject: [650B] Bottom bracket for classic Ritchey Logic compact cranks

 

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[satanas]

As a mountain *triple* I've mainly used 107 UNxx BBs, but a 103mm 7410 with a 2mm spacer on the RHS works too, and moves the LH crank in 4mm, good for me. Using a Dura-Ace 7400 LH crank with a 107 achieves the same end.

As a mountain double with a 135mm hub, a 102mm Campag ISO BB works well.

For a road double, I'd either do what Alex suggests or hunt up a Phil Wood 96 or 98mm BB. I emailed them about this recently but got no response; if you find anything out please post it here. A 7400 LH cranks would help keep the LH Q under control here too.

BTW, if anyone has any surplus 172.5 Logic Compact cranks and would like to swap them for 175 or sell them (even RHS only!), please contact me.

Later,
Stephen

[Stephen Poole]

PS: I meant using a 7400 LH crank if a 103 spindle was used and moved to the left. If a 96-98 Phil BB was used this would almost certainly foul the BB shell and so not turn.

I'm sure Nick will chine in on the Phil BBs soon.  :-)

[njh...@gmail.com]

If these are the 94BCD cranks, a Phil Wood 98mm BB gives a good chainline. Here's a photo of the 94BCD Ritchey Logic cranks mounted as a double on a Phil Wood 98mm BB:

Nick

[ViveLemond]

Thanks for the input. Seems like there's some kind of design flaw with these, or I am not understanding the whole picture. What concerns me is on a standard UN-xx type BB, they just don't fit right - they don't slide on the way a crank normally does. Per Sheldon Brown's page, these should be JIS and fit fine, but they don't.

At this point, I'm simply going to transfer the current 105 crank from my old bike and get this thing going - it seems like I'd probably have to go through a few trials to get it right and I don't have the time.
Thanks again, I'll revisit these later I'm sure.

From Sheldon Browns BB taper page:

J.I.S.
J.I.S. taper

J.I.S. is the Japanese Industrial Standard, and is generally used on square taper cranks made in Asia. All of the common black spindles identified with standard numbering use the J. I. S. taper. Many of these have a threaded boss for a nut on each end, rather than being hollow and threaded internally for a bolt.
J.I.S. models include:

Ritchey
S.R. Sakae Ringyo
Shimano (except older Dura-Ace)
Specialized
Sugino (except N.J.S. track models and some older units.)

ISO
ISO taper

ISO square taper spindles run longer, and taper down to a smaller end than J.I.S. spindles do. Most European-made square-taper cranks and bottom brackets use the ISO dimensions.
ISO models include:

Campagnolo
Older Stronglight
Nervar
TA
Japanese N.J.S. track parts, such as Sugino 75
(Note: Old Ofmega/Avocet spindles were quite a bit skinnier/longer even than ISO. There are no modern bottom brackets that work with old Ofmega/Avocet cranks.)

[Alex Wetmore]

I've had 3 of these cranks (2 are still in use) and they were all JIS taper.  The slide onto a JIS BB with about 1-2mm of hollow between the crank and end of the BB spindle after being installed.  I've always run them as doubles.  Mine were from different production runs and all have subtle differences in finish and details.

The Shimano BB that I use and modify is the BB-7410 from old Dura/Ace groups.  They are just like a 90s UN-71 or UN-72 with a hollow spindle, aluminum cups on both sides, but with a 103mm long spindle.  Q-factor is about 145mm give or take a couple.

If you aren't getting them to draw all the way up on a JIS taper then I'd check the cranks for any signs of damage on the taper.  Maybe the previous owner rode them lose and damaged it.

alex

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From: 65...@googlegroups.com <65...@googlegroups.com> on behalf of ViveLemond <samkru...@gmail.com>

Sent: Thursday, February 22, 2018 1:44:50 PM
To: 650b
Subject: [650B] Re: Bottom bracket for classic Ritchey Logic compact cranks

 

[Stephen Poole]

I second what Alex says: IME they fit Shimano UNxx and 7410 spindles just fine. I've used mine for a marathon XC series, trail riding, touring in India, etc with no problems. Ritchey cranks (in both 110/74 & 94/58) also work well on ISO taper spindles, or similar; I've used Campagnolo, SR Royal & Sugino Mighty.

They should be okay on just about any taper; length is another matter.

PS: I had Avocet/Ofmega CX cranks back in the day and they were fine on older cup and cone spindles like Campag/SR Royal/Sugino Mighty. The difficulty might be finding a current spindle or BB with a suitable length, but there are still plenty of old BBs out there gathering dust.

Later,

Stephen

On 23 Feb 2018 8:54 am, "Alex Wetmore" <al...@phred.org> wrote:

If you aren't getting them to draw all the way up on a JIS taper then I'd check the cranks for any signs of damage on the taper.  Maybe the previous owner rode them lose and damaged it.

alex

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From: 65...@googlegroups.com <65...@googlegroups.com> on behalf of ViveLemond <samkru...@gmail.com>

[Igor Belopolsky]

I have the 110/74 Ritchey cranks on a 115mm BB right now (UN-55) and they seem OK, I can certainly go shorter. How short can I go? 46/36 rings

[Igor Belopolsky]

Sounds like 107 would work. 110 has same RHS spindle as the 107 eh?

[Stephen Poole]

Yep, no reason to use 110; I've got thousands of km on 107 JIS/109 ISO (Campag). Shorter would probably work too; Logic road BBs were ~103mm. However, some nominally 103mm JIS BBs have larger tapers than UNxx, so Q might be the same with those.  :-(

On 23 Feb 2018 12:52 pm, "Igor Belopolsky" <belopol...@gmail.com> wrote:

Sounds like 107 would work. 110 has same RHS spindle as the 107 eh?

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[Igor Belopolsky]

Good deal. 107mm on order. Will have it Saturday.

On Thursday, February 22, 2018 at 8:59:07 PM UTC-5, satanas wrote:

Yep, no reason to use 110; I've got thousands of km on 107 JIS/109 ISO (Campag). Shorter would probably work too; Logic road BBs were ~103mm. However, some nominally 103mm JIS BBs have larger tapers than UNxx, so Q might be the same with those.  :-(

On 23 Feb 2018 12:52 pm, "Igor Belopolsky" <belopol...@gmail.com> wrote:

Sounds like 107 would work. 110 has same RHS spindle as the 107 eh?

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[Adam Paiva]

Hi
2 questions on the fabled Ritchey/Sugino 110/74 triples used as a low range wide double:

1. Has anyone used these with a 142 mm rear hub (so 46 mm optimal chain line)? What bottom bracket Spindle length? I want to use in a 2 x 11 drivetrain

2. What chainrings for an 11 speed drivetrain? This is a burly bikepacking mostly off-road bike so 46/30 is probably a bit high. Maybe 42/26 ?

[satanas]

142mm thru axle hubs have exactly the same cassette position as 135mm Q/R hubs, which is pretty much what the Logic cranks were intended to go with. (Yes, Bridgestone used 130mm hubs, but they were an outlier.) The original BBs were 120mm, with an unknown-to-me taper; I've never seen one.

However, a 118mm Shimano UNxx BB gives an entirely satisfactory - and possibly identical - chainline. Still if you're planning on using the inner two rings as a double that implies ok might want to move things further out, depending on the desired shifting pattern.

You could also use a shorter spindled BB if you want to reduce LH Q; Campag NR BBs (or clones) are good for this.

Later,
Stephen