BSA Otter Dot Com's.

Foster BSA C15 Otter.

After a long wait we have now managed to acquire an Originally build Foster BSA Otter.

This not only comes at a very good time, so that we have a machine to

Be able to get every measurement right for the NEW Batch of "Foster Otter" frames.

But it is also a fulfilment in life that I needed to succeed in.

Owning an Original "Harry Foster built BSA Otter".


The 15/10/2016 was that day.



You can see that frame Number 27 Is in near original condition to when it was built, and that pleases me a lot.

We even have the original Foster Otter footrest arrangement, so that can be replicated if need be.



I believe that the pattern of the chain-guard fitted was the Original too.



The history of the machine needs exploring because it lived not that far from where the frame-kits were built.



Now if you look carefully, you can see that there is still an Original "Otter Products" head badge on the steering head.



Yes, the bike will need work to put it back into its Original build state, 

 but that was always what I dreamed to do, own a Foster Otter In Original build.


Photo Courtesy Lee Prescott.


The "Deal" was done. Thank you so much Richard, you have made an Old Man very happy...


Photo Courtesy Lee Prescott.

And Just Look at that Headstock Badge.

An Otter Product.

" A Match Made In Devon"



Here is a start, a pair of Armours Original chromed steel trials handlebars.









Photo Armours .


So watch this space for the the full strip down and rebuild, then a Trials test to see how she goes.


Well the 28/10/2016.

I spent a memorable four hours stripping down the new to the camp Foster "Otter".

I was on a tight schedule so could not take any photos, that is the trouble with darker nights.

Anyway every nut and bolt undid except for the couple holding the Sammy Miller seat in place.

The more I took the bike apart the more I could not believe the simplicity and well thought out bracketry, and don't forget Harry Foster made all of these by hand.

What I started to realise was that this frame has been built for lightness, and every tube is of sixteen gauge including the swinging arm.

Now this bike was built in the eighties, and I just undid the swinging arm nuts and pushed the swinging arm spindle out, with very little pressure.

The same with the engine, the bolts just undid and pushed out without pressure.

So what I thought a strip-down that would take at least eight hours, was accomplished in four.

Today Saturday I cleaned the frame at home, as it had a lift with me sat in the passenger seat of the car, bikes first I always say.

The steering head bearings were removed and the oil completely drained, so that it is ready to take to the powder coaters, at Redditch.

 I have got tomorrow, Sunday, to take templates from the frame for the New batch of frames. 

And I might add that knowing what I know now, there is no way that I would have got near to the detail on the new frames without having this machine.

Someone must be looking down on me and smiling, I know I am.


All Photos "Otterman".

You can see how clean the frame is, no damage and most of the paintwork is fine... and may not need powder coating...




Unfortunately, I have rubbed most of the headstock badge graphics off cleaning the frame.

But I know Carol Foster has some new ones, and I also was going to get some made.

Not only the frame, but the engine has now been stripped for rebuild...



Just had a quick blast with the cleaner to get the worst of the Aged Crud off.



Head off on the bench, and a peak inside the clutch case.



Well what a surprise.

With all of the oil now drained, it was quite obvious that the motor had just been rebuilt before it was laid up years ago.

The oil was still new in engine, gearbox, and chain-case.

Although, I don't think they have heard of gaskets in Devon.

The Head gasket was new, but there were no other gaskets fitted, just so called plastic gasket cement. I think silicone used to be named that at that time.

As you can see from this photo, the Clutch, all of it, was in new condition, although the plates were stuck together with the new oil, also the alternator is new, and will be retained as the ignition was Zenor diode for converting from AC to DC, and then a Boyer Bransden MK Three  Micro box and standard coil fitted.

I will just replace the Zenor diode and rectifier, for a Boyer Bransden single phase power box?

Well, I have a combined "Powerbox and Mk-three" on the Faber Mk One Otter,

 and I like the way that engine runs, it is not has sharp as PVL and Electrex-world.


The barrel is new, and bored out to be 60+ for the new high compression piston fitted.

Taking the timing case off, the same applies, the kick start spring is new, has is the ratchet and pinions.

Stripping the valves from the cylinder head, the same again, New Alpha valves fitted into Bronze sleeved valve guides.

So the head was soaked and cleaned for a day after I had de-coked what little there was in the ports. Then I just lapped in the valves with no pitting in evidence.

So do I strip the gearbox or leave it? Everything else has been reconditioned with new, and I can't see that being any different, there is no play in anything, and the gear engagement is crisp.

It just depends whether I can sleep the next couple of nights, to whether I leave it or not.




My new Valve compressor arrived this morning, so after struggling the other after noon, and saying to myself there was a better way than using a G clamp, so I ordered a proper compressor kit all for £8.50. Why did I not do this before? I have struggled for years using a G clamp and a piece of cut out tube. But with the studs still in the head it is impossible to get the cotters in.

And the last time I removed studs to do the job unnecessarily, the threads came out as well.


So after assembling the tool the first cotters were fitted in no time, and first go.

The only problem was the Tommy bar falling out a couple of times, so I fixed that  by putting a couple of wall plugs on the ends temporarily.



Exhaust valve cotters re-fitted, in the first atempt.




Two goes at the inlet valve, you always get one cotter that will not stay in place don't you.

Note: the wall plugs. I am going to turn two groves into the bar and fit tiny rubber O rings, that should sort it.



That's another job sorted, and quickly.



Even the de-coke gasket set arrived yesterday, so engine looks like being good again soon.




Why did I not buy one of these kits years ago... I just don't know.




So with doing the valve refitting so quickly I spent an hour on the tank, I used scouring pads and water with washing liquid to remove the aluminium oxide that had built up, this also achieved the removable of the old tank transfers, too.

And even the New filler cap arrived yesterday as well.


More Later ...

This Story Just Gets Better.


I had a mail from Tony Henbest,



Photo Courtesy Tony Henbest.


Hi Charlie,


We hope you are well.

Dad was looking at your latest Otter on the website, we believe there is a strong possibility from a number of similarities to the photo attached that the Otter in question could well be the first one made by my Father direct from Harry Foster when he lived down the road from us in Nomansland before moving to Devon, or at a time very close to this.  


The frame was delivered to Dad by Harry and Carol over Christmas, it sat in the lounge while they all enjoyed a cup of coffee!!.  My dad is certain it is his because the frame number '1-7' is similar to my birthday (1-7-72). 


Once dad had the frame he went to Allan Clift for the motor as a day out to Truro, collecting a C15 G motor, although at the time the much coveted C15G was not realised and to Dad it was just a C15!.


It is a long shot but if you study the only photo we have left of the bike there are many similarities. 

1) Firstly the obvious similarities of key components such as wheels, forks, fuel tank, Ossa seat etc.

2) The side panel/panels, in our photo not louvred, on completing the bike and using it in anger it got very hot as the electrics (blue bottle at the time) were all hid behind the panels.  The late Geoff Chandler suggested to my Dad cutting the louvres in the panels, which helped.  The side panel shape, size and fixing however is pretty much identical.

3) Small similarities such as the drilling of the chain adjusters.

4) The hand crafted folding kickstart.

5) On your 'photo 2' you can see where the coil was jubilee clipped to the tube just above swinging arm pivot.

6) The seat and silencer were originally purchased from Sammy Miller, although the bike now has the later SM creation fitted. 

7) Dad's memory is hazy but he seems to remember making the chain guard or copying it from a template lent to him by Harry, or he made it and then Harry copied it.

8) Mudguard stays and fixings, all very very similar.

9) Rear Wheel spacer timing side covering the bearing etc and the position and type of breathers, these large spacers are all traits of ours, trying to keep mud out.

10) You can see where the side panel was cut away from to accommodate the original tidy tucked away silencer. 



It would be good to know what you think, Dad sold the bike after approx 6 trials and moved on to the next project!!  It is possible it went straight to it's former owner, who you got it from.


Kind regards




My Reply.


Hi Keith and Tony.

Wow ,
You are so right.
That Is the bike, down to the last nut and bolt.
And that is the way it is to be restored.
I don't think the bike hardly did a thing after your dad sold it, the front forks had been reversed but that is it, the motor is like new inside, everything.
The guy I bought it from had only bought it three weeks before at a farm/garage dispersal sale, the barn was full of other stuff, including a girder forked AJS that was hung on a wall right at the top of the barn. and a trials car which he bought, along with the “Otter”.
I had a week from hell hoping no one else would bid on the bike and only bid at the last minuet for that reason, TWO seconds before it finished someone else was trying to bid just as I hit the keyboard a second time, I thought I had lost the bike and sat pondering a plan “B”,when an e-mail came saying I had won that item.
As I say WOW.
Thank you so much guys. The story continues.
Good Old "BSA Otter Dot Com" hey.
Regards Charlie.
Jan 2018.
We Now have further proof that this was indeed the bike built by Keith Henbest, and not only that, Keith has now purchased another Foster Otter frame that he has found, and sent photos of the frame for me to confirm it is a Foster Otter, and it is...
 So we will shortly have a New Page for the build up of Keith's Foster Otter too.


Much More Later on this story.




Progress at getting the Foster Otter rebuilt has been slow, due to using the frame as a back up pattern for the new frames.

 But I now have most new parts to reassemble the machine.

 I have struggled for a week trying to lace up a alloy second hand rim to the front wheel of the machine, with still no success.

 I will get a new chromed rim like I did for the back, and it would have been a lot cheaper with the hours I have spent trying to get the darn thing right.



The wheel is now laced correctly to the Alloy rim, and new stainless spokes. 

           The problem was that the Henbest spoke pattern, that I should have taken note of, was the reverse of the wheel above, "three cross" on the drum side, and "two cross" on the flange, and this is what confused me. 


 The wheel building page will have the story later.


So over the next few weeks I will try and get the bike back together. 

I have a show in mind for it in August, If all goes well.

 so watch this space for progress.



Well that show as you will now know was the one at Brackley that was cancelled.

We have now stopped using the frame as a jig reference, as we now have all measurements noted down...

 And the good news is, the engine is now ready to fit back into the frame, as are the pair of wheels, and the reconditioned forks.

 But the reason now to press ahead, not only with this Foster build but also a couple more of the bikes, is that there may be an event in the spring that we will need the machines complete for... So that is just the boost we need to get the bikes put back together quickly...

 So Watch this space...


Unfortunately the event mentioned above was cancelled because of the Covid Virus.

 It was going to be a gathering at the Winchcombe Hill climb, to commemorate the lives of Carol and Harry Foster, and organised by nephew Mark Foster. Mark was going to hand over a cheque left by Carol Foster in her will for the West Country Air ambulance...

We only hope we can accomplish the task next year in 2021...



Dick Ramplee  and passenger showing off their sidecar skills..


Carol Foster observing with the Clip board...


More on the bike build later.