Vintage, yesteryear and retro biking
23 posts • Page 1 of 1
I have picked up an old Simplex dutch station bike. I'm not doing a full restore, but want to make it a good functional bike. The bottom bracket is in good condition but the chrome has come off the shaft resulting in play in the cranks, soon after installing a new cotter pin. I have never had much luck with cotter pins anyway (being pretty heavy) so my solution was to replace with a square taper bracket, but I have never seen one of these bottom brackets before.
Does anyone know what it is called, how to remove it, and once removed, are there options for replacing with a square taper bottom bracket.
Thanks in advance for any information.
I will tentatively raise my hand, it looks like an old-fashioned cartridge bearing bottom bracket somewhat like a modern Shimano unit. They came in several flavors.... One type slipped into a plain tube (no threads) bottom bracket and was held in place by a lockring on one side or lockrings both sides. Another type had cups that screwed in to a normal b'bracket and held the bearing unit (aka Shimano-ish) but generally they had a lockring both sides so you could adjust the chainline. Sometimes the 'lockring' was part of the threaded cup.
That fitting looks like it has a lockring both sides so it might be a one of the second type (possibly an EDCO unit?) if you are lucky. If so you can just undo the lockrings/cups unscrew/remove the unit and replace it with a standard Shimano unit,
If it is of the first type with no threads you might find it harder to get a replacement without doing some engineering. There were a few other variations on this but the above cases would cover most types more or less.
I will clean and look for the lock rings. There is no thread I think as the plastic inserts just seem to spin freely. Anyway....of to the shed.
.............Nope....No lock ring, the plastic inserts just seem to be holding sealed roller bearings in place. The plastic has clicked into place and I cannot work out how to get the plastic inserts out without breaking them, perhaps a special tool?
Oh-Oh that sounds like a variation on type 1. I would hazard a guess that the plastic flange has a ring with teeth that fits into a groove either in the inside of the b'bracket shell or in the outside of the bearing unit so when you push the plastic retainers in from both sides of the b'bracket they 'click' into place holding the bearing unit into the bracket.
I suspect you are right ans there is some special tool that squeezes the plastic ring so the teeth come free of the groove. Not recommending this at all, but if you get desperate then try gently tapping the end of the axle with a hammer to see if the plastic bit might pop out? This would probably bust the bearing/axle and you might not get to replace it.
Might I suggest Loctite on the cottered axle as a solution?
Yes I think you are right Richard. i tried tapping the axle......and no movement. I tried to lever the plastic clips and broke part of the plastic flange. I might have to destroy them and then look for an alternative bottom bracket. If I am going to ride the bike old cotter pin cranks really won't do. Thanks a lot for your suggestions.
What about a threadless cartridge like those used on bikes with damaged threads? If the bore of the shell is larger it shouldn't be too hard to get some sleeves turned up (probably split sleeves).
in case you havnt worked it out, my guess is that the white plastic tabs are all one part and extends to the other side of the bb, if you spread those tabs outwards i think you will be able to use a rubber mallet to tap out that whole axle and bearings as one piece, if you were making a quick fit set up then you would push the plastic part in first which when pushed all the way in has tabs on the non drive side that click and hold it in place, then when you push the bearings and axle in all the way the little tabs have a small lip that stops the bearing from moving. it would be a saving time in the factory thing, and i recon that would be it. can you give us an update?
steel is the real deal.
Thanks for your thoughts mark and scott. I put the removal on hold while I got on with bits I could do. I was hoping someone would know more so I dont create more problems. Both plastic inserts spin independently so it is not one piece. They do look like they click in place and my attempts so far have begun to damage one. I am not surprised as the plastic is old and getting brittle. I am guessing I will wind up breaking rhem. I did not realise press in bottom brackets were made back then. I am guessing the bike is 70s but I have no clue really. I will work up courage to have another go later this week or perhaps not until next weekend. I will photograph the mess!
Hey thanks for that. It looks like it's threaded on one side and a tapered locate on the other. I don't think the simplex has threads at all so i suspect it won't work without modification, but I'll let you know - probably after the weekend. I haven't worked up the courage to force the plastic inserts as I'd love to be able to save them. Still hoping for inspiration. I tried making a little clamp out of some wire to squeeze the plastic.....which was unsuccessful.
I don't know for sure, but this looks like a Thompson (or Thun) BB. A bit like an Ashtabulla BMX one. If so, the locknut threads onto the axle. The bits look like this:
Installed one below:
Best of luck. The replacement ones on evilbay all look to have cotters....
I finally got impatient and broke the plastic lugs of one side.....then hit it with a mallet from the wrong side and took all the plastic lugs off. It is two roller bearings pressed in place on the axle with a plastic case that holds it in the frame. The bottom bracket is completely smooth and about 3mm wider than a standard threaded bottom bracket, but not as big as the BMX or American style ones. Perhaps a Thompson bracket could replace it - but then I'd still have cotter pins. A Mavic track bottom bracket almost fits, but I think with my weight it will come loose as it seems to be on the outside of the tapered lock rings (Duh...as it's 3mm wider!). I will hunt around on the weekend for options. Many thanks for all the interest. I will take a picture of it on the weekend. I certainly have not seen one of these before.
dv you sound like you've had some bad experience with cottered cranks. I don't think you can blame weight or power though, they're strong enough. Re-using cotter pins seems to be a bit of a no-no so get yourself some newies. Correct installation is important. Drop me a PM if you need to borrow a cotter pin press.
Thanks RobertFrith, I knew someone would have a better idea after I had decided to force the BB out! In any case I think the problem is that the chrome has come off the axle and there is now a small amount of play (hence I think the crank has probably stretched a bit also). With cotter pins being softer I think it will be inevitable that they will move and come loose if I try to reuse these. This has been my experience, though if there are ways to overcome this I am all ears. When cotter pins cranks and shaft are in excellent condition, I agree, they work fine (I do still have one bike with cotter pins).
Anyhow - here is the BB. A weird looking thing with strange dimensions (but I am no expert with push in BBs). The plastic bits seem to fit quite loosely and can spin independently of each other. The roller bearings are pressed tightly on the shaft - and some gently persuasion with a hammer (I do have one) won't budge them. Looks like it was designed for a one way trip, though if the chrome had not come of the axle the bearings still run smoothly and it could have done another 20 years?! (maybe).
Hmmm, looks like an old lower end model EDCO cartridge b'bracket, not seen one exactly like that before tho'.
EDCO are still in business last I heard and do make a 'threadless' cartridge b'bracket which may fit your dimensions.
Do a quick search around the Web and you may come up with a valid replacement, especially from a shop in The Netherlands or Belgium.
It will be square taper tho to take 'modern' cranks.
Chris Hemsworth holding a "cotter pin press"
When man invented the bicycle he reached the peak of his attainments- Elizabeth West.
Bit of a thread hijack, but this reminded me of a bike frame I have hanging in the shed. This Dutch Phoenix looks like it has the same BB as Johnj mentioned earlier, the outer cup on the non-drive side spins with the cranks. Before I get to it I need to borrow the hammer pictured above to remove the very stuck cotter pins.
LG = Low Gear
23 posts • Page 1 of 1
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