R1de4fun

I have a Nobly frame and I have read on this site the BB are either french, eng








lish,or swiss thread. Mine says Sake SR-SC-L and 35xP1 Japan. I think..my eyes aren't what they used to be. See pics.

They cranks are 170s and have a motobecane sticker on the front and say Japan SR on the back.

Anyone know what type of BB I could get to replace this one?

Bianchigirll 

Why are you replacing it?

Looks like a Frenchie https://www.bikeforums.net/classic-v...m-bracket.html

p is right or left thread. https://www.sheldonbrown.com/cribshe...mbrackets.html

As for a replacement you need a BB with the correct threading on tyhe cups and a spindle the same length and ofset as the one you take off.

R1de4fun

Sorry for the dup pics. I'd assume its english thread based on some threads I read here. Would this work as a replacement?

https://www.bertsbikes.com/product/s...t-329559-1.htm

agnewton

I have a '78 Moto project I am working on. The markings on my OEM bottom bracket (BB) fixed cup are "Sakae 35 x P1 Japan". That standard appears to be the thread pitch for French BB (Sheldon Link). Both Swiss and French BB use that pitch, but the French would be right-handed thread; Swiss would be left-handed thread. IRD sells alloy BB cups that you can use with their BB.

Bianchigirll 

I don't think so but hey maybe you have a English BB shell and incorrectly marked BB. Sounds crazy but stuff happens

agnewton

It might "work" as a replacement, but it won't be correct. The difference between English thread and French/ Swiss isn't huge, and you can start to "thread" an English bottom bracket into a French/ Swiss threaded BB, but there will be some play if you can get it all the way in OR it will bind before you can get it all the way on-- if you force it, then you ruined it. If you took the threaded cups off of the Moto frame, then I would assume that they are the correct ones (i.e. French/ Swiss).

If the fixed cup (drive side) tightens to the left, then it's Swiss; if the fixed cup tightens to the right, then it's French.

If the races and cups are not pitted, then I would reuse the originals. If you want a cartridge BB with sealed bearings, then your options are IRD or Phil Wood. IRD is the more economical option. If you want sealed bearings, then you'll have to buy a English BB and the Swiss cups from IRD for your replacement. I've done it for a Peugeot that I have. They are nice.

R1de4fun

I am looking for options to replace the BB because it feels rough when I turn the spindle. I took the bottom bracket out after I posted this. It is right hand thread. It had caged bearings. I cleaned every thing off and re greased. I rode it for about 25 miles but still feels rough. Maybe new bearings would help?

noobinsf 

Were the races smooth? If so, it’s just an adjustment issue — the adjustable cup needs to be backed out ever so slightly. It should feel smooth but have no play. Give that a shot if there was no pitting in the races.

New bearings may not be necessary, but they’re never a bad idea if you have them.

R1de4fun

Actually I just realized you guys said to check the fixed cup, which I did not take off. I'll check it tomorrow if I get time. Thanks for all of the help!

R1de4fun

No ,no pittinng. Everything looked pretty good. A lot better than what I was expecting 😁

R1de4fun

Were some of the old motobecane frames lighter than others?

noobinsf 

This kind of maintenance is often done without removing the fixed cup, but it ought to be cleaned while in place in that case. One other thing to double check— just make sure the bearing cages are oriented the same way as when you removed them.

agnewton

Righty-Tighty= French BB. There are slightly more options for French BB than Swiss. There are the aforementioned Phil Wood and IRD. VeloOrange sells French threaded BB and a threadless BB that would also work for your purposes. I had an email exchange with the IRD people when making my purchase. The only difference between the QB-55 and QB-75 BBs was the cups (55 has steel cups; 75 had alloy cups). The conversion cups are alloy. So, if you don't plan to use the English threaded cups, then buy the cheaper QB-55 and put the exotic conversion cups on. You'll have to be comfortable switching the cups yourself, but it's not too difficult.

If the bike is new to you, I would definitely replace the ball bearings. Either replace the ones in the cage or switch to loose ball bearings. If the cages are damaged in any way, then switch to loose bearings. Visually inspect the races in the cups and spindles to look for pitting. Take care to adjust the variable cup just so- if they are too tight, the bearings will grind.

R1de4fun

I dodnt get a chance to check the BB today. Will try again later.

I do have another MB question though. In the MB catalog they list the super mirage blue color, depending on year, it's either silver blue, blue or new blue. Which blue is this one?

agnewton

My guess is "Brilliant Blue" per the 1978 Motobecane catalog available here. Does that seem correct? If you explore the directory tree of that site a little bit, you can access the other years for many catalogs and the specific names for the blue flavors. Do the specs match your model? If so, you can be confident.

merziac

R1de4fun

Can we have a pic of both sides of the cool blue wrench shown on the fixed cup plz?

Looks like a good wrench to get the fixed cup off to do a proper service, it should come out to make sure threads are sound and not seized as well as a close inspection of the bearing track, clean and lube.

It can be a challenge but there are tips and tricks and it is a skill that will serve you well in the long run.

R1de4fun

I am hopefully picking this one up tomorrow . I did check your link for the catalogs. This bike looks to be the same color as the on I posted earlier, only it is blue and silver. Im thinking it might be a 76 or 77. I see the 76 and 77 is listed as having silver blue as a color option. I'm assuming it means silver and blue. I dont see silver blue on any other years in the catalogs.

R1de4fun

Hi Merziac. So the cool blue wrench , is not a wrench at all. It is just part of the chain guard hanger 😉. My first thought was what blue wrench? Then I looked at the pic and it does look like a wrench so I can see why you would ask.

merziac

Huh, well guess I should have seen that, the rest still applies.

And we still need a bigger pic of the whole guard.

thumpism 

Try using loose balls instead of caged bearings. If there is even the slightest bit of pitting, by using 11 balls per cup instead of the 9 in caged bearings, those 11 will not hit the pits the way the 9 do and any roughness will smooth out. Sounds crazy, try it.

3Roch

To sorta answer your question: Iike pretty much all makers they had different grades of frames, from "gas pipe" to the good stuff. I have 2 bikes I built up from Moto framesets. One from a Grand Touring (vitus tube) , one Le Champion (all db 531) . The Le Champion frameset was ~ 2 + lbs lighter. I suspect the grades below the GT might have been a bit heavier yet

steve sumner

didn't anybody read the stampings in the in the OP's cups? it says 35P1 and CR.L (French dia. and pitch
with a left hand thread meaning Swiss thread which is exactly what one would expect on a Motobecane.

a note to thumpisim: BB retainers come in 11 ball versions which are the best of both worlds ease of use and smoothness
try Campy's as they're matched (which is a whole other conversation)