New To The Market: Triumph & BSA 250 Pistons

New To The Market: Triumph & BSA 250 Pistons

As time goes on original and new old stock parts will get harder and harder to obtain

Luckily we have brands like EMGO that can have new pistons made for our old machines

Allow us to introduce the newest piston to be produced by JCC for our classic Triumph and BSA 250 singles 

We are excited for this new product announcement, if you have a 250 this is big news for such a small bike

Lets dig right in..


Who is JCC?

 Piston Factory


JCC the piston manufacture, is located in the heart of Taiwan - they supply quality pistons and rings for motorcycles, tractors, vehicles and industrial equipment since 1973 inside there 25,000 square meter facility 

The "JCC" brand is not new to our industry, in fact the name JCC has been around the "British motorcycle world" for the past 10 years (or more) and has gained a trusted badge from us in the industry 

Approx 90% of the new pistons on the market today for Triumph, BSA and Norton motorcycles are made by JCC (also sold in EMGO boxes)


JCC 250 pistons specs


 250 Piston Pin And Clips - JCC

The new JCC Triumph and BSA 250 pistons come complete with gudgeon (wrist) pin and (2) clips

Pistons are compatible with new and old stock rings -rings are not included which allows the installer to select there choice of NOS, JCC or current production Hasting rings that we stock..

Pistons are die-cast alloy which makes them the same as original pistons that Triumph and BSA use to offer back in the day


Below is a chart with more detailed info  

Manufacture CR (Compression Ratio) Material Sizes
JCC - Taiwan 9.5:1 Die-cast alloy STD - +.060


250 pistons where originally sold by both Triumph and BSA dealers under the same part numbers, some of which have been superseded over the years

Below is a quick list of parts numbers ranging from standard to +.060

  • 70-7998 / E7998
  • 40-0972 / 40-972
  • 40-0970 / 40-970
  • 70-8272 / E8272


A standard piston assembly weights in at 260 grams..

Which models do the new pistons fit?


1969 Triumph TR25W 250 Advertisement

The new 250 pistons by JCC will fit all Triumph and BSA 250 models that have the alloy "square barrel" and head just like example shown above


  • BSA 250 (C25, B25, etc) 1967-1972
  • Triumph 250 (TR25W, T25, etc) 1968-1972 (excluding the Cub)


Purchase your piston today



Piston For Purchase

Interested in purchasing a new piston for your classic Triumph or BSA 250 single?

Click here to purchase your new JCC piston and click here to purchase a new piston ring set to be used together  

Pistons start at only $89.95 and rings start at just $39.95 a set

It is important to measure your cylinder barrel bore prior to purchasing a new piston and ring set for your application 


Thanks for reading today

Thanks for taking the time to read today's post

If you have any questions please comment in the section below or feel free to contact us 

Ride safe! - Classic British Spares

1 comment

  • Danieltwimi


Leave a comment

Please note, comments must be approved before they are published