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Messages - davidcumbria

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1
Looking good Ted - did you have the rear mudguard rechromed . - ££££££ !

2
In concept, the inner race of the bearings form one complete tube along with the other bits mounted onto the axle, tightening should clamp all those elements tight together in one continuous load path.

In production reality and tolerancing, the bearing "seats" in the wheel casting and the bearing spacer length would have to be very accurate OR individually shimmed to get an exact match once torque is applied at assembly.

What the common design does is to to use one reference bearing (usually the chain side on rear, often left side on front) to fully fix the outer race hard against it's hub shoulder, then retainer ring to keep it from moving.

The opposite side is usually left with some space between outer track and wheel shoulder, this to effectively "float" in the wheel axialy. That can then be used for tolerance of the assembly comprising of primary bearing, spacers etc. Not too critical in other words, the primary bearing controlling lateral location.

It SHOULD turn freely when all tightened, but will accommodate some bearing preload if need be (that would mean spacer total was less than the two hub shoulder in dimensions) with any significant drag being cause for concern and a look at just what components and their placing is doing in there.

If the rear wheel was tightened with no brake drag and no chain fitted, then likely you'd feel some small shift in rotation with anything significant causing more concern. They should spin reasonably easily, but not like a bicycle wheel does  :)

It's odd to describe and sounds like a "fudge" to say so, but unlike setting a bearing arrangement for preloaded by measuring turning torque etc, these are just meant to be assembled, correctly,  with no real methods except assuring the right parts are used and in the right place.

Judgement would give that any significant changes as it's tightened should raise questions, as Ted's done, then investigating exactly how the various parts are installed to try and make absolutely sure all is in the right orientation.

Bit long winded, but difficult to describe in a different way,, possibly  :)
Thanks for that helpful clarification. I remember now what the issue was on a front wheel. After shouldering the first bearing continued driving inward  of the the outer race of the non shouldering second bearing using a socket  jams the the inner race against the separating tube and introduces side load by pushing the outer race further inward. It’s a matter of feel to decide when to stop since there is no shouldering of the outer race. So to get a free spinning bearing I had to pull it out slightly again. When tightening the spindle with its spacers  fixed length of the inner race assembly prevents excessive inward movement of the outer race.

3
Good fettling Ted. Sounds like you’re getting close just as the weather is picking up👍

I’ve previously been confused by the interaction of the spindle clamping and bearing fitment on other bikes. . Inner races spin easily after bearing  fitment  but then are pressed against the spacer tube by tightening the spindle. I’ve changed bearings thinking they were tight only to find they were fine once removed. Am I missing something?

4
Project Board / Re: Making space for the bikes
« on: May 04, 2024, 10:14:49 AM »
Good luck with new shed. However big it’s never big enough. 👍

5
Other Bikes / Re: BMW R80
« on: May 02, 2024, 11:39:14 AM »
Thanks Flat four I’m going to have to keep an eye on that oil level! Looking into joining the BMW club. As always now there are some superb video tutorials on you tube an absolute god send and I’ve already stripped the bike and figured out what tools I need - virtually 👍

6
Out & About / Re: SOHC meet in Scotland
« on: May 01, 2024, 07:55:42 AM »
Apologies I can’t make it after all have been asked to help out at a police Bikesafe event. Next time.👍

7
CB500/550 / Re: Float height 500 k1
« on: April 30, 2024, 10:52:19 PM »
I’ve seen reports of worn carb body where needle jet seats allowing leakage around the jet. Worth checking.

9
Misc / Open / Re: BUSSO CEASING TRADING
« on: April 29, 2024, 09:13:31 AM »
Looks like an opportunity. On their website they only list a system  for cb500. Presumably no good for a 550 k1 ?

10
CB500/550 / Re: Rocker Housing - Stuck??
« on: April 29, 2024, 09:06:17 AM »
Agree Bryan  mine  didn’t move so I wondered what the point of the slot is.

11
CB500/550 / Re: Rocker Housing - Stuck??
« on: April 27, 2024, 08:12:15 AM »
Maybe remove  the tappets and refit the covers minus o rings to give you another handy place to knock. Or if want replace them ( very cheap ) partially screw them in leaving a lip to drive against taking care to protect the valve cover edge. Haven’t tried this but it might be worth investigating.

12
CB500/550 / Re: Plugs fouling at idle
« on: April 27, 2024, 08:04:26 AM »
If there's response by swapping the leads over (within one  oil pack) then analysis of why that could happen may give answer.

There's specific performance in the condenser relating to this (if the original system is in place) with it's ability to fire the mixture.

The opposite ends of the coil have slightly different spark characteristics,  with also the condition in cylinder from the live one to the wasted spark one maybe causing a bias to disadvantage the live cylinder on compression and give a shift in performance to that cylinder.

Swapping the leads checks for that, also the insulation of the HT too.
Thanks. the leads on my bike are very stiff. I’ve remade the cap connections but I’m not very happy with them. Definitely thinking of doing the Ash fix. On the other hand it starts well and has no high Rev mis fires which makes me think ignition is ok. I can live with the slight tendency to idle foul and my air screws are out  more than 1.5 turns from memory running on shell e5. I’ve improved no 1 cylinder running cool by installing #35 pilot jet and overall the bike runs very well.

13
Other Bikes / Re: BMW R80
« on: April 26, 2024, 08:15:28 PM »
Thanks Fellahs those are very interesting and helpful replies. I will start reading up on classic bike etc and could be interested in those tools Ian. Impressive that you have the skills and kit to make them. Nothing happening very soon on this but great to know you guys have got my back 👍

14
Other Bikes / BMW R80
« on: April 26, 2024, 07:03:41 AM »
Wanted to try something different to restore after the 550k1 so have got a slightly unloved but running 1986 R80,  not the faired touring rt  one just the naked lighter bike. My daily rider is 1999 1100 GS and I’ve owned several 1200 GS so I could see the lighter lower R80 as a bike I could enjoy long term. The 800 has a reputation as the smoothest airhead and it does have that feel.  Restoration will be next winter but my initial research makes me think self restoration of the gearbox is probably out due to special tools, intricate shimming and a press needed which is slightly disappointing and makes me reflect wistfully on the ease of doing the 550. Anyone here with any experience or thought on a BMW airhead ?

15
Project Board / Re: Doms CB550F1 project
« on: April 26, 2024, 06:40:19 AM »
Good progress Dom I like the way your design really gives more emphasis to the engine/ exhaust than the stock bike. Shame about the Daytona ( I have a street triple ) but unless you never ride your bikes or do anything in the garage these minor damage issues seem to be an annoying fact of life for most of us.

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