Hi All,

i am in the process of building myself a unit construction BSA either C15G or WD B40 for trials, my question is simply this.

how essential is the Wide ratio box.

I have a C15G, which has the standard road box in it, unfortunately the B40 GB motor i bought has had the Wide ratio gears robbed and a stub tooth B25, B44 road box in it, i was assured on buying the motor it was a standard B40GB with the wide ratio box, unfortunately the owner got his facts wrong, he has offered to have it back but for what I paid I would sooner keep it.

 

unfortunately a Wide Ratio box is going to cost in the region of £300, which is alot of money to me.  I am an average club level rider, using 1st gear most of the time, 2nd very occasionally, i  do very few road trials.  although top gear is the same on all later models i believe, so what is the advantage of much desired wide ratio trials box and do i need one?

I had a C15 trials using an early (1959) motor. It had standard road gears when I had it and I used it like that for some time. I didn't feel it created any gearing issues.

 

I then had the opportunity to acquire a trials box for it. In all honesty I don't feel it gave any advantage at all. With either box I could use 1st or 2nd gear when needed. If I remember rightly, it was slower on the road with the trials box.

 

I don't know how the two boxes in that earlier engine compare to the two in your engine, but In retrospect I'd be happy to have left it on the standard box.

I had a C15 trials using an early (1959) motor. It had standard road gears when I had it and I used it like that for some time. I didn't feel it created any gearing issues.

 

I then had the opportunity to acquire a trials box for it. In all honesty I don't feel it gave any advantage at all. With either box I could use 1st or 2nd gear when needed. If I remember rightly, it was slower on the road with the trials box.

 

I don't know how the two boxes in that earlier engine compare to the two in your engine, but In retrospect I'd be happy to have left it on the standard box.

 

Thanks Woody, hopefully a few others will share your experiences and comment accordingly.  i could probably spend the £300 on something more useful

It shouldn't be any disadvantage for the sections, just not as good for any road use. You should still be able to get the gearing you would want for 1st and 2nd.

I've got a B40 WD in standard trim (as they should be!) and to be honest it's a pain on the road, you have to rev the nuts off it in 3rd and then you change up to 4th and it struggles to pull it! In 30 mph zones it's either revving away or struggling in top! But it's a great bike and the wide ratio box comes into its own for green lanes and on the Beamish Trial etc. It just needs a little more power and a little less weight to ease the frustration!

as a clubman rider you ll probably only ever use first in a section so get your engine/ gearbox and rear sprockets right and you wont know the difference.

As stated above, it only causes a problem if you use it on the road  

Hencam,

 

The B40 FE Motor (350 Enduro Star) has the wide ratio box you require!  

These were only built for export to the USA between 1964-1965 but every now and again you see them coming up for sale in the UK.   

Better is the fact that generally you find the parts you require cheaper if you get them from the states!

Simply search 'BSA Enduro Star' in that well known auction site and see what turns up!

thanks to everyone for the advice.

 

i will keep an eye out for the enduro star g/box brentmain, if no joy i will work on using the std road box.

 

you will be fine with the std box unless we get some proper trials ..one lap 50 to 80 miles about 40 sections suitable for all classes with maybe a couple of harder ones to sort out the pot hunters ,lots of sticky mud , but lots of fun , this reminds me of something in the past come or have i been dreaming again

Hi hencam,

 

Did you get sorted? I have a WD B40 with the wide ratio box. I want to convert to close ratio for classic scrambling. Would you consider a swap? Where are you located?

 

Cheers

 

Terry