Search found 333 matches

by packw
Tue Apr 10, 2018 1:14 am
Forum: Parts & Bikes wanted
Topic: Spokes for Rickman Wheel
Replies: 3
Views: 1133
Flag: Great Britain

Re: Spokes for Rickman Wheel

Hi beat,
Try http://www.central-wheel.co.uk/
They made a set of galvanised spokes for my identical Rickman wheel. They can make them to your pattern.
Cheers
Bill
by packw
Tue Jan 24, 2017 9:32 pm
Forum: Tech
Topic: B25/50 RH Fork slider
Replies: 11
Views: 1778
Flag: Great Britain

Re: B25/50 RH Fork slider

Triumph T140 with the single disc brake had a "lugless" slider in the right side as shown in the photo, but it is ribless and polished.
Cheers
Bill
by packw
Thu Jan 19, 2017 12:23 am
Forum: Tech
Topic: Cleaning aluminium
Replies: 8
Views: 1614
Flag: Great Britain

Re: Cleaning aluminium

There's always the dishwasher..........
by packw
Tue Jan 17, 2017 11:54 pm
Forum: Tech
Topic: Centering a new rear wheel
Replies: 7
Views: 1278
Flag: Great Britain

Re: Centering a new rear wheel

Hi again longstroke. One of the AMCA twinshock regs I noticed while looking at the front fork subject was that the rear tyre width must not exceed 4.5" (114.3mm). The 4.00 x 18 Pirelli MT43 trials tyre is 110mm wide, so a centrally built wheel and tyre would still have 15mm of chain clearance if an ...
by packw
Tue Jan 17, 2017 2:18 pm
Forum: Tech
Topic: Mx fork mods
Replies: 21
Views: 3870
Flag: Great Britain

Re: Mx fork mods

Agreed, longstroke!
I looked at the AMCA twinshock regs for pre '74. Apart from the Y*maha forks having too much stroke, being leading axle and not 35mm diameter, they appear compliant!!!!

The bike I've fitted them to is for "domestic & pleasure" use, so it didn't matter.

Cheers
Bill
by packw
Tue Jan 17, 2017 1:29 pm
Forum: Tech
Topic: Centering a new rear wheel
Replies: 7
Views: 1278
Flag: Great Britain

Re: Centering a new rear wheel

Hi longstroke, I built my conical hub rear wheel with the 90.5mm offset brakeplate to centreline dimension quoted in my earlier message. This centres the rear wheel with the frame/headstock and thus front wheel. The wheels run in line. Chain clearance to a 4.00 x 18 Pirelli MT43 trials tyre on a WM3...
by packw
Tue Jan 17, 2017 3:31 am
Forum: Tech
Topic: Rear wheel B50?
Replies: 10
Views: 1654
Flag: Great Britain

Re: Rear wheel B50?

Some identification points for the brakeplate you have. If the centre hole is 7/8" diameter and the brakeplate total thickness is 1.0" (external boss approx. 1/2" high) it is from a B25/B44 QD rear wheel. The thickness of an OIF brakeplate at the centre is 18.5mm. It has no external central boss. Wh...
by packw
Mon Jan 16, 2017 4:17 pm
Forum: Tech
Topic: Mx fork mods
Replies: 21
Views: 3870
Flag: Great Britain

Re: Mx fork mods

Per minety's suggestion here are the drawings and some pictures of the yoke mods required to fit the Y*maha DT125R forks to a B25/B50 oif frame. It uses an adaptor for the bottom yoke which is included with the drawings to enable the standard B50 stem to be used. The top yoke hole for the bearing ad...
by packw
Sun Jan 15, 2017 11:21 pm
Forum: Tech
Topic: Centering a new rear wheel
Replies: 7
Views: 1278
Flag: Great Britain

Re: Centering a new rear wheel

Hi pinky,
I believe the correct dimension from the centreline of the tyre and rim is 90.5mm from the brake plate face where the swinging arm abuts. I'd give you the dimension from the rim (which is easier to measure) but rim widths vary depending on their source.
Hope this helps.
Cheers
Bill
by packw
Sun Jan 15, 2017 11:07 pm
Forum: Tech
Topic: Mx fork mods
Replies: 21
Views: 3870
Flag: Great Britain

Re: Mx fork mods

Hi pinky, I don't know if it is allowed in your class of racing but I've just converted the front end of my B25SS/T100 to Y*maha DT125R forks. They are 41mm diameter and have about 225mm of travel. There's plenty of room inside the tubes for alternative springs. XT500 brake and wheel fits. These for...
by packw
Tue Jan 10, 2017 12:04 am
Forum: Project bikes
Topic: B50 MX for Bonneville
Replies: 420
Views: 55712
Flag: Great Britain

Re: B50 MX for Bonneville

Andy,
In case all of the above confuses, just stick with 0.02095 of a hogshead and you will be ok.

Cheers
Bill
by packw
Tue Dec 27, 2016 1:15 am
Forum: Tech
Topic: B50MX chain guide/brake arm
Replies: 4
Views: 1205
Flag: Great Britain

Re: B50MX chain guide/brake arm

Hi pinky,
Here is a picture of the torque arm I fitted to replace the original chain guide type.

The steel tube material came from an IKEA lamp stand, probably called Bjorn.

Cheers
Bill
by packw
Tue Dec 06, 2016 11:34 am
Forum: Project bikes
Topic: 1969 BSA shooting star
Replies: 5
Views: 1918
Flag: Great Britain

Re: 1969 BSA shooting star

Hi, I think that pushrod has been running on the outside lip of the follower cup instead of in the cup itself. I cannot see how camshaft endfloat could be transmitted through the camfollowers unless the crankcase bore for the follower is severely worn and that would be visibly obvious. I'd put it do...
by packw
Sat Dec 03, 2016 11:02 pm
Forum: Tech
Topic: 355 Victor
Replies: 10
Views: 2193
Flag: Great Britain

Re: 355 Victor

I hear that Mahindra has got the rights to make Jawas, too.
Does that mean we look forward to some Jawabsas?
.........maybe some work required on the name...........

Cheers
Bill
by packw
Wed Oct 26, 2016 12:40 pm
Forum: Tech
Topic: What is it really ?
Replies: 9
Views: 1991
Flag: Great Britain

Re: What is it really ?

I, too, thought the raised area was odd, but a search though Google images confirmed that at least some B40GBs have a raised pad.
Cheers
Bill
by packw
Tue Oct 25, 2016 9:02 pm
Forum: Tech
Topic: What is it really ?
Replies: 9
Views: 1991
Flag: Great Britain

Re: What is it really ?

The frame is pre-oif and the bike looks like a B40GB to me. Nothing too exotic, but rather nice.
Cheers
Bill
by packw
Mon Oct 17, 2016 11:20 pm
Forum: Tech
Topic: Speedometer choices
Replies: 12
Views: 1992
Flag: Great Britain

Re: Speedometer choices

If you fit a magnetic sensor type to the spoke and the pick-up on the forks, be sure that you can remove the wheel without the tyre or rim clouting it on the way out. You might ask how I know this...............! I have fitted a couple of these cheap Chinese bicycle types to motorcycles and they do ...
by packw
Mon Oct 17, 2016 10:22 pm
Forum: Tech
Topic: Conical hub, same size all models?
Replies: 8
Views: 1651
Flag: Great Britain

Re: Conical hub, same size all models?

Hi John,
The front wheel spindle for the T120 with 8" conical hub and the B50 are the same. Part no 37-3796. This would indicate that the fork centres are the same for both bikes.
It is the same spindle for the 6" conical hub, too.
Cheers,
Bill
by packw
Mon Aug 29, 2016 5:34 pm
Forum: Tech
Topic: Spindle movement
Replies: 13
Views: 2021
Flag: Great Britain

Re: Spindle movement

Some further clarification........ The non brake side does need the dust shield or the bearing can slide about 5mm before it contacts the circlip, but this does not account for lateral movement of the wheel spindle once the brakeplate nut is tight. The thickness of the inboard tin shield I mentioned...
by packw
Mon Aug 29, 2016 5:25 pm
Forum: Tech
Topic: Spindle movement
Replies: 13
Views: 2021
Flag: Great Britain

Re: Spindle movement

Have I missed something in an earlier post? Which front wheel are we talking about? On conical hub front wheels, the nut that tightens against the brakeplate pulls the spindle through until the bearing abutment on the spindle contacts the bearing inner, then further tightening clamps the brakeplate ...
by packw
Thu Aug 18, 2016 11:59 pm
Forum: Tech
Topic: The best way to get an honest 40hp from a B50
Replies: 20
Views: 3120
Flag: Great Britain

Re: The best way to get an honest 40hp from a B50

As clutch capacity is dependent on torque, not horsepower, the standard (weak) clutch will transmit higher powers. The torque capacity of the B50 standard clutch is around 63lb.ft based on empirical clutch data for the material and lube oil, and the engine develops 68lb.ft (peak) relative to the clu...
by packw
Thu Aug 18, 2016 11:33 pm
Forum: Tech
Topic: Starfire shocks, how thick springs?
Replies: 41
Views: 5887
Flag: Great Britain

Re: Starfire shocks, how thick springs?

Hi stew 79 & hhh, You are correct. The steeper the shock the less shock travel is needed for the same wheel travel for a vertical shock. This becomes obvious (even to me!) that if the shock was parallel to the swinging arm it would hardly need to move at all for infinite wheel movement. The steeper ...
by packw
Wed Aug 17, 2016 8:48 pm
Forum: Tech
Topic: Starfire shocks, how thick springs?
Replies: 41
Views: 5887
Flag: Great Britain

Re: Starfire shocks, how thick springs?

Hi Minety,
............I now understand your message. I'd missed the little thumbs up smiley.
Stupid boy!
Cheers
Bill
by packw
Wed Aug 17, 2016 8:43 pm
Forum: Tech
Topic: Starfire shocks, how thick springs?
Replies: 41
Views: 5887
Flag: Great Britain

Re: Starfire shocks, how thick springs?

Hi hhh, To clarify my statement about bottoming out more frequently. For 1" of vertical swinging arm movement a vertical shock will need 1" of travel. This assumes that the shock is on the wheel centreline. For 1" of vertical swinging arm movement of a 45 Degree shock it will need 1.4" of travel, th...
by packw
Wed Aug 17, 2016 11:27 am
Forum: Tech
Topic: Starfire shocks, how thick springs?
Replies: 41
Views: 5887
Flag: Great Britain

Re: Starfire shocks, how thick springs?

WM20, I've just re-read your reply to my earlier message advising nambo of his spring rate and your last statement: "A 100 lb/inch spring on a 45 deg shock will be a lot harsher than a 120 on a dead vertical shock" .......is incorrect. A 100lb/in spring mounted at 45 degrees will have an effective s...
by packw
Wed Aug 17, 2016 11:16 am
Forum: Tech
Topic: Starfire shocks, how thick springs?
Replies: 41
Views: 5887
Flag: Great Britain

Re: Starfire shocks, how thick springs?

WM20, The spring rate calculation was based on the spring dimensions provided by nambo and did not relate to the rear suspension geometry. Your earlier post relating to material properties being the most critical factor is misleading. Torsional modulus (G) is identical for all steels regardless of h...
by packw
Tue Aug 16, 2016 10:43 pm
Forum: Tech
Topic: Starfire shocks, how thick springs?
Replies: 41
Views: 5887
Flag: Great Britain

Re: Starfire shocks, how thick springs?

Hi nambo, From the data you've provided, the estimated spring rate of your springs is 110lb/in. I had to make some assumptions about free length. FYI: Norman at NJB recommended 70lb/in for my off road B50. Hagon must have made a million shocks over the years. I find it hard to understand how their m...
by packw
Wed Jul 06, 2016 10:13 pm
Forum: Tech
Topic: Taking the B50 out of storage
Replies: 6
Views: 1157
Flag: Great Britain

Re: Taking the B50 out of storage

..........also ensure that the engine oil meets JASO MA1 or MA2. This spec enables the engine oil to be shared with the clutch. Other oils can cause the already marginally adequate clutch to slip.
Cheers
Bill
by packw
Tue Jun 14, 2016 9:18 pm
Forum: Tech
Topic: Mk1 Concentric details required
Replies: 12
Views: 1891
Flag: Great Britain

Re: Mk1 Concentric details required

"The only difference is the main jet is bigger on the BSA (logical because it is a 441 cc as opposed to a pair of 325cc's)"

I think you mean a pair of 375cc's.

Cheers
Bill
by packw
Sun Jun 05, 2016 10:18 pm
Forum: Project bikes
Topic: The Jangos Saga, 1971 B50SS
Replies: 40
Views: 6896
Flag: Great Britain

Re: The Jangos Saga, 1971 B50SS

Apparently "superfoods" are purple. Seems to apply to B50s, too!
Cheers
Bill
by packw
Mon May 16, 2016 9:41 pm
Forum: Tech
Topic: B50 Removing front sprocket cover plate
Replies: 7
Views: 1071
Flag: Great Britain

Re: B50 Removing front sprocket cover plate

Hi roger,
You can get behind it with a length of wood from the gearbox side and give it a light tap with a bfh.
Bill
by packw
Mon May 16, 2016 9:33 pm
Forum: Project bikes
Topic: Hwan's BSA 250 Scrambler
Replies: 108
Views: 18727
Flag: Great Britain

Re: Hwan's BSA 250 Scrambler

I tried opening the Youtube video link but it was marked private. I haven't stumbled upon something unsavoury here, have I?
by packw
Mon May 16, 2016 9:22 pm
Forum: Project bikes
Topic: The Jangos Saga, 1971 B50SS
Replies: 40
Views: 6896
Flag: Great Britain

Re: The Jangos Saga, 1971 B50SS

Hi Jango, Unless you are looking for originality at all costs (despite that meaning you must retain some atrocious BSA features) I'd junk the completely superfluous aluminium box of tricks under the tank. All it does is add to the number of connections (aways a source of potential trouble, especiall...
by packw
Fri May 06, 2016 12:11 am
Forum: Tech
Topic: B25ss front brakes
Replies: 3
Views: 865
Flag: Great Britain

Re: B25ss front brakes

From what reference material I have it appears that:
All UK B25SS (Gold Star) had 8" conical 2ls brakes.
US B25SS and all B25T and all Trailblazer had 6" conical sls brakes.
.......but other forum members may have more definitive information.
Cheers
Bill
by packw
Wed May 04, 2016 4:01 pm
Forum: Tech
Topic: Steering head dimensions
Replies: 2
Views: 647
Flag: Great Britain

Re: Steering head dimensions

Stupid boy!
If I'd looked at the B50 frame drawing on this forum, I'd have seen that the taper roller cup bore in the steering head is 1.7805" (45.225mm).
Timken LM11949/11910 bearing cup is 1.781" (45.237mm) o/d, so the fit can be calculated.
Cheers
Bill
by packw
Wed May 04, 2016 1:11 pm
Forum: Tech
Topic: Steering head dimensions
Replies: 2
Views: 647
Flag: Great Britain

Steering head dimensions

I feel another project coming on! I have some Y*m*ha DR125R front forks, XT500 front wheel, Rickman rear wheel, B40 engine and a H*nda CBR600 monoshock rear end lying about in the garage. To mate them all together I'd like to make a new frame similar to a Faber trials bike. It will use the B25SS/B50...
by packw
Wed May 04, 2016 12:35 pm
Forum: Parts for sale
Topic: ELECTRICAL BOX ANTI-VIBRATION PEDESTAL MOUNT
Replies: 6
Views: 1867
Flag: Great Britain

Re: ELECTRICAL BOX ANTI-VIBRATION PEDESTAL MOUNT

Hi aminto, It is surprising how many rubber mounts are very similar. I suspect Dunlop (Metalastik) were the original source followed by Trelleborg, etc. Do you have the supplier and part number of the mounts you found for those who might need them? I've thrown the purposeless box away so have no nee...
by packw
Mon Apr 25, 2016 9:42 pm
Forum: Tech
Topic: b50 yokes in b44vs frame
Replies: 3
Views: 692
Flag: Great Britain

Re: b50 yokes in b44vs frame

Yes, but you'll need to sleeve the bearing bores in the B44 frame to take the taper roller cups.
You'll need some new steering stops, too.
Cheers
Bill
by packw
Wed Apr 20, 2016 1:08 am
Forum: Tech
Topic: B44 electronic tacho
Replies: 20
Views: 3807
Flag: Great Britain

Re: B44 electronic tacho

Don't some of the electronic ignition systems use the "lazy" spark system, i.e. they spark on both compression and exhaust strokes? Electrex World must be one because it is crankshaft driven. If so, this rev counter would read correctly. Also the twin versions of Boyer ignition sytems have two trigg...
by packw
Fri Apr 15, 2016 12:19 am
Forum: Project bikes
Topic: My B50SS project
Replies: 121
Views: 23011
Flag: Great Britain

Re: My B50SS project

Oooooooooooo that's nice. Great job.
Or being from geordieland; eeeeeeeeeeeeeee that's nice.
Cheers
Bill