Performance Engineering Services Ltd.

16/03/2026

15-6325 Chainstay Studs. I managed to run a small batch of these over the weekend with Allan Gill minding the machine.
These will be sent off for plating.
I'm hoping as we maching new batches of studs, they will be made into kits with the nuts and washers supplied where appropriate.

25/02/2026

15-0541 Rear Brake Pedal Fulcrum Dome Nut. Used in various places on many BSA's upto about 1960. 7/16" x 20 TPI. They will be plated in zinc and clear, also zinc and black. We were buying them in, but these are better. Website to be updated.
https://pesltd.uk/?product=15-0541

17/02/2026

42-0095 BSA B33 Crank Mainshaft. Drive side. Getting a little bit closer. Another part that I expect only one person will ever want.

15/02/2026

First tailstock job on the Mazak, it doesn't get any easier. That said once you figure out how it's trying to stop you it does a nice job.

12/02/2026

Anita had a horrible job. Someone's friend offered to wire thread insert this BSA barrel. Drilled off center and poorly fitted inserts.
There were no reference details to work from, other than calculating the postions from the bore centers.
The holes were milled round on center to find a tapping size so that the holes could be plugged.
Once the damage was repaired, new holes could be drilled and tapped.

11/02/2026

65-0311 Dome nut. Although not a big fan of stainless fasteners, they have their place. For some reason rocker shaft nuts generally end up looking scruffy, so these will help. As usual with BSA the thread sizes often don't conform to standards. These have to be cut a little oversize for a good fit. The later unit singles rocker shaft nuts are slightly undersize.

09/02/2026

A little bit of valve seat cutting this morning. Who'd of thought when I purchased the Mira Valve seat cutter in the 1980's it would still be one of the most accurate systems. It's to fragile for many people and not easy to repair. Don't belive anyone who claims to repair them, I expect more harm that good will come of it. If you have one with problems, I'm happy to help and can obtain genuine parts.

07/02/2026

Here is something many of you have forgotten or just didn't know. For those of you that do a little off road, on road riding. These gears make a cheap upgrade to your BSA Unit Single Gearbox.

https://pesltd.uk/?product=PES0003 Read the page.

BSA Sliding Gear Wide Ratio Conversion PES0003 19T - New and Featured Products

04/02/2026

I've done some awkward rebores in my time. Once doing an "on site" job.(edit in my mid teens) Whilst honing the stones caught the main bearing housings and I slipped off the block I was stood on. I disappeared between the block and the chassis and landed in an inspection pit full of pig manure.
This wasn't as bad, but I'm too old for being creative with jigging.
Only those with experiance will understand.

02/02/2026

29-0410 Valve Collets. These suit BSA A7 A10 B31 Please don't loose them, they are a pain to make.

30/01/2026

G24 Layshafts for our unit single 3 speed gearbox waiting to be ground to final size. Life for Anita will be a grind for a while.

https://pesltd.uk/?product=g24

29/01/2026

Water fitting nut in stainless steel.