Garage Night: New video - all about swingarm bearings
in [Motorcycles]
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From: Pete Fisher on 29 Mar 2010 18:01 In communiqu� <5a5630c3-3596-4c64-9123-f13657dea98c(a)g11g2000yqe.googlegroups.com>, antonye <antonye(a)ukrm.net> cast forth these pearls of wisdom >Andy Bonwick wrote: >> >> I wouldn't use heat or freezing on a needle roller bearing because >> there isn't enough surface area to make it worth the effort. > >I must admit that I've not had the experience of needle bearings, >but the sealed bearings that I've used on swingarms, wheels, >ride height adjusters and the like have all benefited from being >left in the freezer for a few days. > I bow to Andy's greater experience in these matters, but in my limited experience the heat approach certainly helps. At one point I just couldn't persuade one bearing to go in the last 10 mms, and I was conscious of just how fragile these drawn cup (pretty sure that's the type) full complement needle roller bearings can be. After re-heating the linkage, I was able to get it moving again with my lashed up coach bolt and nuts rig. >Of course, the biggest tip about bearings is to take the old >one to a decent bearing sales/distributor and to get them to >supply a new one based on the bearing number and not your bike >make/model, as it will 99.99% of the time be a fuckload cheaper, >and usually of much better quality too. > That's if you have much recognisable bearing left to take. I should have taken a photo of the grisly remains from the YZ. I took the easy Allballs kit option as they also supply all the required seals, bushes, spacers and thrust washers. A life saver when I realised the bottom shock mounting was also shot, as the kit included one. Pretty sure they are cheaper than Yamaha OEM. As to quality - they aren't going to get such a hard life as they used to. -- +-------------------------------------------------------------------+ | Pete Fisher at Home: Peter(a)ps-fisher.demon.co.uk | | Voxan Roadster Yamaha WR250Z/Supermoto "Old Gimmer's Hillclimber" | | Gilera GFR * 2 Moto Morini 2C/375 Morini 350 "Forgotten Error" | +-------------------------------------------------------------------+
From: antonye on 29 Mar 2010 18:14 Waz wrote: > > I think if the anodising has 'gone off' like mine had it's > likely you won't be able to restore the metal well enough > to make it worth re-anodising, and if you tried you'd be > disappointed with the results. > > In my case it definitely wouldn't have been possible to polish > the swingarm back to something that looked good enough to > anodise - hence powdercoating. Let's see how it stands up to > rocks, sticks and ruts! A good dip in a warm caustic soda bath will remove the existing anodising, at which point you're left with the bare metal, so any issue with the anodising itself will be gone at this point. You shouldn't need more than 10 minutes in the dip to completely strip any anodising. The trouble with anodising is that it is only a 25 micron or so coating, which is grown onto the original metal surface. Any nicks, cuts or scuffs will effectively stay in the metal, so after stripping the prep is vital to get rid of anything you don't want to still be there after anodising. This is the time killer, as you really want the best surface finish here to give you the best looking results; not much different to paint prep really! Once prepped you can re-anodise, and this just grows a new oxide coating onto the bare metal. After sealing (and optional colouring) you'll have a brand new anodised layer which should be tougher than powder coat. I've had the frame on the race bike (a Ducati 600SS with a 620SSie engine fitted by me) powder coated and was less than impressed with the results. Three years later and the surface has already dulled, sections worn away (my fault for using ratchet straps through the frame!) and generally looking scruffy. Obviously it being a race bike means it gets a lot more abuse than usual, but it still doesn't inspire confidence. > The clincher, though, was that the arms of the swingarm are > box section extruded or whatever, while what i'd call the > 'girdle' at the front is cast. So you'd get differing results > when anodised. I believe cast alloy doesn't anodise that great?? It depends more on the composition of the alloy than it does the formation method, but you normally find that extruded is indeed made up of a different composition than cast, which is where the differences come in. Having said that, any decent anodiser will be able to compensate their setup and should be able to achieve a good result no matter what. Home anodising isn't that hard - I've done small bit and pieces with no more than a few plastic tubs, an old car battery, an alu plate as the cathode, some alu wire, a 2 quid bottle of caustic to clean parts first and an 8 quid bottle of sulphuric acid ("One Shot drain cleaner") from B&Q mixed with distilled water as the anodising solution. You can buy anodising dyes off ebay for a tenner a bottle (makes 1L) so for a very small amount of money you can be doing your own parts at home ... maybe you should give it a try as a future video? ;-) A good guide here, if you're interested... http://www.focuser.com/atm/anodize/anodize.html -- Antony
From: antonye on 29 Mar 2010 18:18 Pete Fisher wrote: > antonye wrote: > > >Of course, the biggest tip about bearings is to take the old > >one to a decent bearing sales/distributor and to get them to > >supply a new one based on the bearing number and not your bike > >make/model, as it will 99.99% of the time be a fuckload cheaper, > >and usually of much better quality too. > > That's if you have much recognisable bearing left to take. Very true. Luckily for me it was head bearings for the SS frame and they match a rear wheel kit on a Fiat Punto or something, coming in at a bargain £7 or so the pair. -- Antony
From: Rob Kleinschmidt on 29 Mar 2010 22:25 On Mar 29, 12:55 pm, Andy Bonwick <nos...(a)bonwick.me.uk> wrote: > On Mon, 29 Mar 2010 13:44:10 -0700 (PDT), antonye <anto...(a)ukrm.net> > wrote: > >I've successfully used the bearing-in-freezer routine (they > >were left in for a couple of days) to make it easier to > >push them in on an interference fit. > I wouldn't use heat or freezing on a needle roller bearing because > there isn't enough surface area to make it worth the effort. If it's a bearing sitting in an aluminum housing heat definitely helps. Throw a housing in a low temperature oven and it makes removal of bearings much easier, sometimes allowing them to just drop out. Seems as if cooling both would work against you though.
From: Waz on 30 Mar 2010 06:48
On Mar 29, 11:14 pm, antonye <anto...(a)ukrm.net> wrote: > Home anodising isn't that hard - I've done small bit and pieces > with no more than a few plastic tubs, an old car battery, an alu > plate as the cathode, some alu wire, a 2 quid bottle of caustic > to clean parts first and an 8 quid bottle of sulphuric acid ("One > Shot drain cleaner") from B&Q mixed with distilled water as > the anodising solution I saw that One Shot cleaner stuff and was sizing it up for anodising! Is it pure sulphuric? I thought there might have been other shite in it that would cause problems. Did you use desmut with nitric in your home anodising set-up, or not worry about it? What I really want to know is how to recoat the bespoke steel bolts, axles, spacers etc on my bike in that original yellow finish, which I think is some kind of zinc plating. Waz |