Hello
I have had to take a break from my B25 rebuild as my brain was beginning to fry. I have done engine and then front forks (of the damper rod variety). Then I got to the front wheel and found that BSA used a shorter Triumph axle and wheel set-up that was only used for one year on that model (or so I suppose). I had a previous (or later) wheel with the longer (BSA?) spindle and when I came to fit it I noticed the bolt groves did not line up with the bolts. Grrrrrr. So I knocked out the old spindle and bearings and obtained a shorter Triumph spindle. I did a test reassemble and now the groves on the spindle line up with the slider bolts correctly. Great! :0)
Then I noticed the wheel was not centred between the fork legs. I figured this must be down to the fabled wheel rebuild "offset value" that I see mentioned but did not have any experience of. I now have two TLS front wheels for a BSA neither of which seems to be centred when fitted. Deep joy.
So I can:
1- get the wheel rebuilt to the correct specs.
2- find an original wheel (or one to original spec)
3- give up and ride with an offset (no don't do that - ED)
4 -something else...
Does anyone have any knowledge or experience of renovating or fitting new wheels to a 1968 B25 with damper rod forks. If so do you have any advice or recommendations on rebuilding or obtaining replacement wheels.
And what advice do members have about brands of black enamel paint for touching up the frame. Having tried it Hammerite seems a bit under par for the job. Scratches easily and does not adhere well. I have cleaned, sanded and de-greased but no improvement. What do members use?
Wheels, yes I'm sure many feel your pain. I now do the offsets on the bike once everything is assembled and done up.
Get a spoke spanner or a 1/4" AF (check yours may be different) take the tyre off, clamp a pointer to a fork leg and get comfortable as it will take about an hour to ease the rim across to central and true (you'll soon find you can do it in half the time, but there's no rush). Check the run out now, its probably between 1/8 and 1/16. You should be able to get better than that. You are only moving it across so you are not starting from scratch.
Check the rear wheel too.
Paint - I use synthetic enamel - sometimes sold as tractor enamel.
Hi,
Doesn't the offset only apply to the '69/'70 A65s with the TLS brake. The forks and caps were dot punched so that the correct one was fitted ie one dot for one side and two dots on the other.
Dave.
That could explain something. My A10 has a 8"TLS front brake in what may or may not be A65 forks. The wheel is '68 style and was very clearly offset. I think I had to shift the rim over at least 1/4" to be centred on the forks.
Hi,
On the A65 the off set was more to do with the axle being held on a very slight angle from perpendicular to the forks hence the matched end caps. I think it was only shuttle valve forks that have this.
Dave.
Thanks for comments everyone. My current two front wheels are "flange hubs" rather than the specified "barrel" hub. The difference being one side has a "vertical" flange on the NS to attach the spokes. I presume this would require two different lengths of spoke. The other hub is just round and all spokes are fixed from the barrel of the hub. The parts book says that is the original for 1968
All I can say is that this was a managerial clusterf**k in 1967/68 during BSA's merger with Triumph. As these wheels and hubs were essentially Triumph items I have been looking to see if there is a Triumph front wheel that I can use together with a TLS brake plate. The T90 with its similar sized wheel is an obvious starting point but their might be other options. I am currently looking through the parts catalogues for BSA 250 and Triumph front forks/wheels from 1967-1969. The part numbers sometimes align and sometimes don't. I figure that if I can find a wheel that uses similar forks or yokes then I have a chance to just buy and fit.
Otherwise it seems I must readjust my current wheel as limeyRob suggests. As always there are time constraints and the two front wheels that I have are less than prime specimens - and may need some new spokes anyway. Deep joy.
I note that Mr Ration has a photo of the required hub/spoke pattern/rim in Fig 5.33. I have two of the wheels shown in Fig 5.34. On page 130 the 7" full width hub rim offset is given as 3/16" - I presume that is for the SLS. The TLS hub (with flange) is given as 1/4"
Once more unto the parts list, dear friends, once more...
It is a mess and there doesn't seem to be a pattern (or not one I can see) as to which parts are shared between BSA and Triumph and which are not. It doesn't help that neither seem to be able to make their mind up about fork bottoms, spindles and yokes.
I recently bought a 7" full width front wheel because I wanted the alloy rim for the rear of my A10. When I got it apart the rim, spokes and drillings were identical to the A10 and it was a straight swap, a pleasant surprise as I'd budgeted for spokes and nipples. I suspect as you say it was managerial *** with one camp looking to maintain differences and another trying to get savings from harmonisation and each trying to undermine the other.
Hmmm. Difficult to know what to say as this is all history and we are left to identify what they did in a moment of madness. It seems BSA just changed the layout of the sliders, specifically the position of the spindle clamps, to accommodate the new shorter Triumph spindle/wheel. Which is madness. Why not just use the longer BSA spindle with the original sliders. As far as I can tell it would fit. I have fitted the shorter Triumph spindle to the wheel with no problem. So they seem interchangeable. It seems the management wanted to move to the Triumph shuttle valve forks and front wheel thus changing it all again in 1969. And 1970, 1971.... its seems to be an excellent example of hoop jumping.
The real problem is that it is quite difficult to identify the correct wheel and hub to fit. Unless one is lucky it seems the only way to get an authentic front wheel for the 1968 B25 is to build one from identified components.
The closest fitting option seems to be a Triumph T90 1967 front wheel. The T100 is very similar but with a 19inch wheel.However these wheels have the wrong dimple pattern on the rim (Oh err...). The B25 has a 2 by 2 dimple pattern whereas the Triumphs seem to have 1 by 1 pattern. Not that that is a show stopper but it adds to the uncertainty of knowing what to select.
I have been looking online at a number of BSA 250s from 1967-1968 and few if any have the authentic front wheel set up. The 1967 models have a half width hub, so they are easy options to discard. I'll write if I find any solution. It may boil down to limeyrob's advice to recenter the existing wheel after replacing bearings, etc.
On the subject of bearings, I suppose if one uses a sealed wheel bearing then the "grease guards" put in after the original open bearings are not needed when reassembling the bearings and spindle?
I got caught out with spoke patterns recently. The full width hubs with drilled spokes only fit one rim pattern (never mind the dimple angle) where as the hubs with a flange can have the spokes moved round one and fit most rims because the spoke can face forwards or backwards.
Re sealed bearings, yes I think so but watch out for the flinger also being a spacer.
It may be too simplistic, but if the hub is now compatible with the forks, why not just move the rim to the required off-set?
Ten minute job with the wheel (less tyre) mounted in the forks.
That's my preference, its not a big job, at worst a bit of angle grinding on the nipple heads and a new rim tape.
After some repeated "dry assembly", as model makers used to say, and a lot of bespoke nipple tweaking (steady...) I have sort of got something usable. I say sort of because I am not entirely sure the shorter (1968) spindle fits entirely correctly in the (1969/70) flanged/TLS hub. It generally fits but I am not sure the original hub was the same width and so I am not sure if the various shoulders on the spindle are in the right place for the later flanged TLS hub.
My main concern is the fact the shorter spindle slips left and right by a small amount (1/8"?) in the wheel when the brake plate is not fixed. When one fixes the TLS brake plate and tightens the fixing nut onto the spindle then the movement stops. Which I can understand as that large nut pulls the spindle towards the plate until it makes firm contact with the O/S bearing (or the grease catcher circular thing if fitted). I note what limeyrob said about these "grease catchers" also acting as spacers (1/8"?), hence my number of dry runs using all combinations.
As far as I can tell, the brake plate side (O/S) is the "fixed side" of the spindle and the N/S is "floating" in the bearing. There seems to be no "fixed" position or way to procure that, other than tightening the brake plate retaining nut. Both bearings are of course fixed to the wheel, one by the retaining screw cap and the other by a circlip, plus a mild interference fit to hold the bearing outer race against the side of the hub.
For reference here is a picture of a "standard" 1969 TLS spindle, my "old" TLS spindle and a new 1968 SLS spindle.
B25Spindles.jpg
Note the "bodge" end groove treatment(s). The N/S shoulder on the new spindle is not the same as the other two. The O/S thread and bearing shaft is not so long as the other two. The only real difference seems to be the threaded end (not as long).
Very useful. When I got my A10 with a 8" TLS I checked the lug engagement and it was OK. But the rim was offset so I took the wheel out and found the brake plate nut was only on by 1 turn. Ended up stripping it all to bits and found a home made 1/8" spacer behind the bearing shoving the wheel over to engage the brake lug. I got the brake plate built up with weld and took the spacer out. But the take away is that, yes it seems that nut is critical and doing it up is what pulls the wheel into position. And keep and eye on that lug engagement.
A quick end note - I got my front wheel fitted nicely. A 1969 TLS hub with TLS brake plate fitted with a 1968 spindle on damper rod forks. I used sealed rubber bearings (6204-2RS) so didn't need the "grease catcher" plate on the near side. The brake plate side has an internal spacer that goes behind the bearing and is important for positioning. The brake plate to fork spacing was good and the "peg" on the fork leg engaged well with the slot on the brake plate. Seems good to go. I bought some new Stainless end cap bolts. And here it is:
(https://i.ibb.co/FjZRn0Z/wheel-Side.jpg)
(https://i.ibb.co/zTLDppvK/wheel-Front.jpg)
While on the subject of wheels - does anybody have recommendations for inexpensive tyres? All other things being equal and the rubber looking OK - how old can a tyre be before unsafe to use?
5 years is the recommended life for bike tyres. The ones on my B32 were around 20 years old when I bought it. I replaced them with Heidenau (https://heidenau.com/en/) K67s which I thought were reasonably priced. Mitas (https://www.mitas-moto.com/en-gb) also do arrange of tyres that will fit classic bikes, again reasonably priced.