Need some help with non-standard bearing replacement

RedTea

I have a Dahon folder with 20" wheels. The bearings needed replacement so I did some research and ordered some parts online. They need some small fully cased bearings, called R4 bearings. See the pic.

So i eventually got around to trying to replace them and the outer ring of the bearing casing is stuck inside the hub - and it seems to be really stuck. I've tried tapping it from the far side but no joy.

So I was wondering has anyone any bright ideas on how to get it out. Its been suggested that a Dremel like tool (a spinning cutter) could be used to cut the bearing casing - anyone know where i could get use of one of these?

Attached are 3 pics - one a new bearing unit. another of how the bearing should look when installed and then one of my problem.

Parts are very non standard - so sourcing a new hub or wheel means buying online and getting shipped over. Front fork spacing is 74mm not the normal 100mm. If i could get the remains of the bearing out I may not have to go to such extremes.

Any 'constructive' suggestions appreciated.

Thanks

seamus

Can't remember where I saw it, but I heard of a trick for a very similar type of bearing. The bearings themselves afaik rely on the tight fit between the bearing and the hub casing. So gently heat the outside of the hub with a blowtorch (on a low heat!). The outside of the hub should expand just enough for you to get the ring out. It would always be useful to have a second person - both to continue heating while you tap/grip the ring and to avoid burning yourself!

You can use a similar trick to get the new bearing in position.

penexpers

I can't help you but maybe if you look over at

www.dahon.com/forum

you might have some luck.

RedTea

I've been on the Dahon forum for advice and they suggested the cutting tool.

Guy in the local bike shop suggested the blow torch approach - but it could end up damaging the spokes and wheel as the hub expands. Plus I dont have a blow torch handy at the moment.... ( I tried a cup of boiling water - like you would with a jam jar lid - but it didnt quite work )

cubix

What part of the town are you in RT, if you have no joy I can get my hands on a dremel. IF you have a jigsaw with a slim metal bit, that might also work. As Seamus mentioned that might only be half your problem, if it takes to much force to get the new ones in you could damage them.

Cubix

kona

dont use a blowtorch, you will, definatly , warp the hub and it will be useless, not to mention changing the strength of the hub and spokes.

these things as mentioned are like the wheel hub on a car, and rely on a very tight fit.

i wouldnt cut it either as you will be risking damaging the hub.
best thing will be to try and drift it out with a hammer, a flat screwdriver and a bench vice. using little but firm taps in a circular motion around the metal.

doozerie

The best tool for removing sealed bearings is one like this. I have a more industrial version that I use for the (larger) sealed bearings in my hubs. It relies on just as much brute force and ignorance as some of the alternatives, such as a hammer and screwdriver, but is far less likely to damage surrounding parts. In the sutation that you are in I don't think anything else will work.

I actually bought my tool many years back from that site that I link to, but I don't see it there now. It's a great tool, just the right balance of applied proper engineering and controlled violence! Using it does make you wonder though why the vast amount of money that goes into bike design can't come up with an alternative to beating certain bike parts together/apart with a glorified hammer.

studiorat

doozerie wrote: »

The best tool for removing sealed bearings is one like this. .

+1
There's a right tool for every job.

kona

studiorat wrote: »

+1
There's a right tool for every job.

+2
very true. couldnt agree more,
however

NASA in the 1960s spent millions developing a a pen to write in zero gravity,
what did the soviets do???

used a pencil:D:D:D:D

some tools are expensive and somthing you wont always have, in fact id bet most bike shops wouldnt have that tool for 20mm bolt thru.
if careful the screwdriver and hammer will work fine.

kenmc

kona wrote: »

NASA in the 1960s spent millions developing a a pen to write in zero gravity,
what did the soviets do???

used a pencil:D:D:D:D

I'll call bullsh1t on this one.
http://www.snopes.com/business/genius/spacepen.asp
http://urbanlegends.about.com/library/bl_zero_gravity_pen.htm
http://www.museumofhoaxes.com/hoax/weblog/comments/4140/

niceonetom

kona wrote: »

NASA in the 1960s spent millions developing a a pen to write in zero gravity,
what did the soviets do???

used a pencil:D:D:D:D

and regretted it... do you know what electrically conductive graphite dust does to electronics? in a zero-g capsule that sh1t gets everywhere. :D:D:D

rob1891

At a particularly well equipped bike shop/rental place in Wales I borrowed one of these:

http://www.toolfetch.com/Category/Shop_Equipment/Pullers/OTC4581.htm?utm_source=&utm_medium=GS&utm_campaign=toolfetch&cm_ite=

to pull a bearing that had disintegrated in the exact same fashion as yours had, except that there was no possibility for hammering from the rear. The slide hammer with collets is the ultimate tool for this job! The collet will be able to grip the rear of the bearing race if it is accessible and if not even the groove that the ball bearings run in will suffice.

If you don't trust yourself to not damage the hub body find a bike shop with this tool (I guess somewhere that regularly services full suspension mtbs would have one, as they tend to have lots of sealed bearings that need to be replaced frequently ... The Bike Rack?).

kona

niceonetom wrote: »

and regretted it... do you know what electrically conductive graphite dust does to electronics? in a zero-g capsule that sh1t gets everywhere. :D:D:D

and you think the soviets gave a ****???

the amount of accidents they had:D and thats the one we know about:D

kona

kenmc wrote: »

I'll call bullsh1t on this one.
http://www.snopes.com/business/genius/spacepen.asp
http://urbanlegends.about.com/library/bl_zero_gravity_pen.htm
http://www.museumofhoaxes.com/hoax/weblog/comments/4140/

i call bull**** on your bull****:D
one of your links says, millions was spend on development etc., just not by nasa, still a valid point and not BS

niceonetom

kona wrote: »

and you think the soviets gave a ****???

probably. they we're spending massive money on these projects, so to have them fail because of penny-pinching would have hurt them just as much as the americans. their reticence in reporting failures to the public is beside the point, they still had to stay in the game. i'm just pointing out that a pencil very definitely wasn't the right tool for the job and nasa weren't being as silly as you imply.

if you cite popular myths that have been debunked/explained you have to expect to be called on it. this is the internet.

RedTea

Thanks for the feedback and suggestions. Unfortunately I don't have all the tools to do this job properly myself - vice etc.

I might try drop in on another couple of bike shops to see if they could give me a hand. I'm based in the Rathmines/Harolds Cross area, so if you have any suggestions on places that could be worth a visit let me know.

Here's a instruction on how to remove that bearing type which I did find. I think it needs more than the 'light tap' suggested.

doozerie

RedTea wrote: »

Thanks for the feedback and suggestions. Unfortunately I don't have all the tools to do this job properly myself - vice etc.

Here is the type of tool that I have, available from the UK. It isn't cheap, but might be comparable to the cost of a replacement hub plus getting a new wheel built up (and in the longer term it certainly works out cheaper). If this can't remove the bearing, then nothing will. It handles openings as small as 9mm so should be able to cope with your bearing.

That same site has the cheaper tool (same as the one I linked to earlier) here, but with that you'll still need something solid to fit through the hub which you can then beat with a hammer.

In either case you won't need any other tools such as a vice, etc. This really is one of those situations where, with the wrong tool, you are screwed, whereas with the right tool no finesse or real skill is needed i.e. a bike shop won't be able to do any better a job than you can unless they happen to have the right tool themselves. The tight fit of bearings like these make the hammer and screwdriver approach the wrong choice - each time you tap one point on the bearing the opposite side will try to rack and jam it even tighter so that you end up butchering the hub. For some jobs, all you need is a bigger hammer, for this job you need the right hammer.

RedTea

Thanks for the links and feedback. I had another go this morning at getting the bearing case rim out with an improvised tool to bang it out - and it worked. It was a process of getting lined up correctly and 'tapping' around as suggestted.

So problem solved. I think it was a matter of tackling the job with the wrong tools in the first place - I'll live and learn.

kona

niceonetom wrote: »

if you cite popular myths that have been debunked/explained you have to expect to be called on it. this is the internet.

wat are you talking about??? nothing was debunked or disproved.
links given said usa spent alot of money!! just wasnt nasa.

my point to soviets was, statistically soviets recorded more accidents and failures, in ww2 they , won purley because they threw men at the germans, with total disregard for their life.
soviets thought less of human safty in space than the yanks, also the yanks spent more time in space.

niceonetom

kona wrote: »

wat are you talking about??? nothing was debunked or disproved.
links given said usa spent alot of money!! just wasnt nasa.

my point to soviets was, statistically soviets recorded more accidents and failures, in ww2 they , won purley because they threw men at the germans, with total disregard for their life.
soviets thought less of human safty in space than the yanks, also the yanks spent more time in space.

read what you quoted again. explained, kona, explained. pencils in space are a BAD idea. geddit?

WW2 = tangent.

oh, and the russians spent more time in space.

you do not take contradiction well do you?

kona

niceonetom wrote: »

read what you quoted again. explained, kona, explained. pencils in space are a BAD idea. geddit?

WW2 = tangent.

oh, and the russians spent more time in space.

you do not take contradiction well do you?

yes bad idea, so is re-entering the atmosphere with a hole in the heat shield.
as is lift off with damaged seals, and being told not to.

still happens:rolleyes:

No you are wrong, as per mercury, gemini, apollo, the yanks logged more hours in space FACT. of course we are still talking pre- space station era.

ww2 is a tanget, BUT used to give a example of soviets not giving a bollix about safety and/or human life.

kenmc

I was just going to let sleeping trolls lie, but no....

kona wrote: »

i call bull**** on your bull****:D
one of your links says, millions was spend on development etc., just not by nasa, still a valid point and not BS

Actually no, your point is not still valid.
You have 2 inaccuracies in your post:
1:

kona wrote:

NASA in the 1960s spent millions developing a a pen to write in zero gravity

No, they didn't. Fischer did. NASA never asked them to, Fischer absorbed the costs of R&D and then presented the product to NASA.
2

kona wrote:

what did the soviets do??? used a pencil

Only until Fischer invented the space pen, at which point the Soviets adopted it as well. Prior to that both the Soviets and NASA used to use pencils.

Your post quoting the urban myth implies that NASA wasted millions of dollars spending money on developing the space pen, whereas the Soviets simply used a pencil; but the reality of the story is that both nations used a pencil until the right tool for the job was developed, independently, at no development cost to either space agency, at which time they both adopted the new technology.

But of course you're probably right, sorry.:rolleyes:

niceonetom

kona wrote: »

No you are wrong, as per mercury, gemini, apollo, the yanks logged more hours in space FACT. of course we are still talking pre- space station era.

we are?

pre-space station era? sheesh, that doesn't even count as moving the goal posts, that's just deciding the penalty area is the goal and therefore you're the winner. well done.

finishing sentences with FACT does not scare me.

kona

okay maybe i need to lay it out with small words.

1. i already conceded(too big???) that nasa didnt put the pen together. so build a bridge.

2.moving goal posts sorry mate, this would be you, i stated "In the 1960s" so this would refer to that era.

3. so at some stage the yanks were usig their fancy pen and the soviets still used a pencil??

4.incidentally the fact both used pencils, proved my point they were used in space.

5 tom i dont want to scare you, you might cry, your constant trying to get one over people is unbelievably irritating, cop-on.
you started to attack a post i made to highlight some tools are very expensive and in some cases another cheaper option is available.
to argue this is rubbish which had no bearing on the OP(it just served to highlight a fact).

back on topic please

kenmc

kona wrote: »

2.moving goal posts sorry mate, this would be you, i stated "In the 1960s" so this would refer to that era.

Wow another swerving goalpost. The only reference you made to the 60s was the mistaken post that NASA developed a pen then. There was no mention of the sixties when you are talking about time spent in space - you simply said "the yanks spent more time in space", not "the yanks spent more time in space in the sixties". You also mention WW2 in the same post, so it's understandable that our little brains get confused with all this time travel stuff.

kona wrote: »

4.incidentally the fact both used pencils, proved my point they were used in space.

Hmm. Can't say that I even noticed you trying to make that point before - I was sure you were trying to say that Americans wasted money on making a better pen!

kona wrote:

back on topic please

Well actually the OP has the problem solved (you might have missed that), so we can have at it as much as we like now

kona

kenmc wrote: »

Hmm. Can't say that I even noticed you trying to make that point before - I was sure you were trying to say that Americans wasted money on making a better pen!


Well actually the OP has the problem solved (you might have missed that), so we can have at it as much as we like now

no sorry you made that point, it just served to reinforce the fact that at a point the americans had a fancy pen, and the soviets used a pencil:)

and whose advice did he use?? i think he should name this bike shop in his op, so the lads here who use 20mm bolt thru Wheelsets avoid the place.

just goes to show some places dont have a clue:(:mad:

kenmc

I bet you will have to post something after this...... otherwise you won't have the last word.....

kona wrote:

and whose advice did he use??

Yours. He went with the pencil approach, whereas Doozerie suggested the nice fancy pen

niceonetom

kona wrote: »

tom i dont want to scare you, you might cry, your constant trying to get one over people is unbelievably irritating, cop-on.

it's really only you i pick on. i just can't resist, you never fail to rise to the bait. i shall try to restrain myself in future but you're just so much fun it's quite difficult no to rattle your cage every now and again.

you're welcome to the last word now...