Project Thumper.

[Colin Sparrow]

What a cracking special. Those long rear shocks really improve the ground clearance, well done getting it all to come out level!

[dave higgins]

Hi, thanks for everyones interest in the bike & all the pm`s relating to it, just a little bit more info to bring the project to a close.
There was a problem with kick start travel in relation to the foot peg arrangement, i`ve had to refab it & bring the footpegs forward an inch, its only a small amount but gives a better movement for starting.
So that was that sorted, respray it, rebuild it & connect all the pipe work up, fill it with oil & then its gonna start!!..... is`nt it????..... nope, not a bean, not even a sniff of life!!!, poor quality methanol, ( i don`t know ).
After many hours stripping & double checking, i found nothing, so i decided to re jet it for petrol & try it on the standard settings.
She started fireing & then running, in the end it was basically a case of getting her running & cleaned through on petrol, then swapping it back to fresh methanol & playing about with the settings.
But i will say one thing, when its running right & everythings right with the bike, it makes it all worth while, you forget about all the crap bits & problems you have had & it sounds superb!! so lets see if she`s got legs on the track.
thanks again for all the input from fellow members. dave.

[Andy Z]

Hi, thanks for everyones interest in the bike & all the pm`s relating to it, just a little bit more info to bring the project to a close.
There was a problem with kick start travel in relation to the foot peg arrangement, i`ve had to refab it & bring the footpegs forward an inch, its only a small amount but gives a better movement for starting.
So that was that sorted, respray it, rebuild it & connect all the pipe work up, fill it with oil & then its gonna start!!..... is`nt it????..... nope, not a bean, not even a sniff of life!!!, poor quality methanol, ( i don`t know ).
After many hours stripping & double checking, i found nothing, so i decided to re jet it for petrol & try it on the standard settings.
She started fireing & then running, in the end it was basically a case of getting her running & cleaned through on petrol, then swapping it back to fresh methanol & playing about with the settings.
But i will say one thing, when its running right & everythings right with the bike, it makes it all worth while, you forget about all the crap bits & problems you have had & it sounds superb!! so lets see if she`s got legs on the track.
thanks again for all the input from fellow members. dave.

Hi Dave,

Please let us know when and where you plan to race this bike as I for one would love to see it on the track.

Cheers,
Andrew
#190

[dave higgins]

Hi andy, i normally ride in the south west, but will be taking it down to mortimer to meet a few of the lads that ride in the greeves series in june, i was hoping to line up along side the great Adrian ( de`coster ) dickerson, just to see what it compares like to a well tuned villiers engine.
If your gonna be there andy, it would be nice to see you. dave

[Andy Z]

Hi andy, i normally ride in the south west, but will be taking it down to mortimer to meet a few of the lads that ride in the greeves series in june, i was hoping to line up along side the great Adrian ( de`coster ) dickerson, just to see what it compares like to a well tuned villiers engine.
If your gonna be there andy, it would be nice to see you. dave

Hi Dave,

I'll be there alright!

Cheers,
Andrew
#190

[dave higgins]

finished bike (ish)

Just a couple of the finished bike pics,

[Pete Walton]

Project thumper

Well done Dave , "proper job" as they say, hope mine turns out as well.. Notice you've fitted a chain tensioner, any particular reason ??? Chain running a bit close to frame or something ???

[Nemosengineer]

Just a couple of the finished bike pics,

Wonderful job Dave, exceptional workmanship throughout. You have set a very high standard of construction that I am striving to achieve with my project, thanks for the inspiration and taking the time to document and post the photos.

Best Wishes: Mike

[dave higgins]

Hi pete/mike, thanks chaps, the reason for the tensioner, is because the chain runs close to the tyre.
The c15 motor is narrower than the villiers from the rear engine mount to the sprocket, so if you want to keep it all central, then it gets a bit tight getting the alignment right.
I tried it out at the bonanza & was very pleased, i had some problems that needed to be sorted, which are now & hopefully will get a good ride on it sunday. dave....

[Brian Catt]

Dave, you are not the first to have problems with the C15/B40 chainline! During my mis-spent youth....I attended several ISDT training events at Bordon, home of the Army School of Transport. Civvy riders and Army boys were all let loose on the wonderful Weavers Down area, only to see many of the Army boys fall foul of chain problems. Investigation revealed that they had put 4.00 width tyres on the standard Army issue bikes and had needed to mis-align the chain to avoid fouling. This put the chain under side strain and failure was inevitable. Removing the Army issue chain guard was a temporary fix, but the Army Team riders switched to Victor frames for some events and finally to Cheney frames.
I was there when the Colonel told the story of the accountant who found the invoice for these frames and started asking awkward questions!
I did a complete week of timekeeping on one occasion, and my memories of the Greeves effort was rather sad, as one by one, the Comerford's Challengers fell by the wayside with design faults, such as the ignition key-way failure.

[Andy Z]

Just a couple of the finished bike pics,

Hi Dave,

I'll look forward to seeing you and the bike at Mortimer - looks really nice. Possibly the lightest 4-stroke in the pre-60 class?


Cheers,
Andrew
#190

[Phil Hyde]

Thumper

Dave

Congratulations on Project Thumper. It really looks like it just left the Thundersley assembly line. A real credit. No doubt you are the man for all the queries on squeezing the BSA unit into a Greeves. Excellent.

Phil

[dave higgins]

Thanks andy/ phil, i am by no means an experts, but i will help anyone wishing to convert along simular lines. regards, dave.

[druid]

Greeves Thumper

Having just witnessed Dave's sterling efforts on his Thumper I'm sure he'll have loads of fun on it in the future. Hopefully we'll see a few more but no Methanol burning NEB C15 engines please.

Druid

[dave higgins]

Thank you druid, it was a pleasure to meet yourself & all other gra members involved in the event, can`t wait for next year??.... dave.)