Shop Hepolite piston sets, UK-made piston rings, oil pumps, main and big-end bearings, valves, tappets and oil seal kits for classic Triumph, Norton Commando and BSA motorcycles. Hepolite dates back to 1907 and the Bradford engineering firm Hepworth and Grandage. Each listing shows model-year fitment, bore size and original part numbers, and most pistons and rings come in oversizes to +.060″. We offer free shipping to the lower 48 states.
Triumph 750 Complete Low-Compression Piston Set w/Rings Genuine Hepolite 1979-83 PN# TBS-20432
$168.49 – $170.98Price range: $168.49 through $170.98
Triumph T100 Complete Piston Set Genuine Hepolite 1958-1966 PN# TBS-15123
$168.36 – $168.49Price range: $168.36 through $168.49
Triumph 650 Complete Piston Set w/Rings Genuine Hepolite 1959-72 PN# TBS-17844
$168.48 – $170.86Price range: $168.48 through $170.86
Triumph 750 Complete Piston Set w/Rings Genuine Hepolite 1973-78 PN# TBS-19255
$168.48 – $168.53Price range: $168.48 through $168.53
Triumph T100 Complete Piston Set w/Rings Genuine Hepolite 1967-1974 PN# TBS-18786
$168.49 – $168.53Price range: $168.49 through $168.53
Triumph T150 T160 BSA A75 Hepolite Piston Ring Set 1968-1975 PN# TBS-R23020 70-6838 70-9739
$128.23 – $135.37Price range: $128.23 through $135.37
Triumph 750 1973-1982 76mm Piston Ring Set Genuine Hepolite 71-3690 UK-Made PN# R26490
$89.48 – $92.51Price range: $89.48 through $92.51
Triumph 650 1959-1972 Piston Ring Set Genuine Hepolite 70-6864 UK-Made PN# R11050
$89.48 – $90.70Price range: $89.48 through $90.70
Hepolite Triumph 650 750 Connecting Rod Big End Bearing Shell Set PN# 70-3586 H
$44.95 – $44.96Price range: $44.95 through $44.96
Triumph 500 T100 5TA ’59-66 Hepolite Exhaust Valve(s) PN# 70-4013 H
$46.79 – $90.52Price range: $46.79 through $90.52
BSA A65 Lightning Hornet etc ’62-72 MK2 Hepolite Exhaust Valve(s) PN# 68-0663 H
$42.50 – $80.35Price range: $42.50 through $80.35
Triumph 650 750 Hepolite Exhaust Cam Follower/Tappet(s) PN# 70-8801 H
$75.57 – $144.15Price range: $75.57 through $144.15
BSA 500 650 A10 A50 A65 Hepolite Brand Big End Bearings Shells Set PN# 67-1430 67-1431 67-1432 67-1433
$44.95 – $44.96Price range: $44.95 through $44.96
Triumph 650 750 Inlet Cam Follower(s) Genuine Hepolite PN# 70-3059R H E3059R
$64.09 – $121.58Price range: $64.09 through $121.58
Table of Contents
Hepolite: A British Piston Name Since 1907
The Hepolite story began in 1907, when Hepworth and Grandage was formed. The company moved to Bradford in 1916 (Hepolite). Its piston rings were used in the Napier Lion aero engine of the DH9 biplane by 1919, and by 1937 it was making “Hepolite” pistons, rings, gudgeon pins and cylinder liners (Grace’s Guide). A 1926 Motor Sport article described the Hepolite split-skirt piston, designed to run close clearances without piston slap.
At its peak, Hepworth and Grandage made over a million piston rings a week at its 90,000 sq ft St. John’s Works in Bradford. In the early 1960s it built a factory in Sunderland that would make all Hepolite rings (Hepolite). In 1961 the company had 5,000 employees and factories in Bradford, Saltaire, Leeds, Yeadon and Sunderland (Grace’s Guide). The Yorkshire Film Archive holds a film of the company’s Golden Jubilee, including a wartime factory visit by Winston Churchill.
In 1947 Hepworth and Grandage became part of Associated Engineering (AETC). The group later passed to Turner & Newall and then Federal-Mogul. In 2011, Wassell bought the Hepolite brand, trademark and goodwill from Federal-Mogul (Wassell). Today Hepolite supplies pistons, rings, liners, valves, camshafts, shell bearings, valve springs, oil pumps and connecting rods for classic motorcycles and cars, and many of its products are still made in England (Hepolite). See the full range in the Hepolite catalog.
Hepolite Piston Sets for Triumph Twins
Each set includes two pistons, rings, gudgeon pins and circlips, in standard size and oversizes to +.060″:
| Set | Bore and compression | Fits |
| Triumph T100, 1958–66 (TBS-15123) | 69mm, 9:1, beveled crown | T100 with “squish-band” heads; not for 5TA |
| Triumph T100, 1967–74 (TBS-18786) | 69mm, 9:1, domed | T100 with hemispherical heads and 1-17/32″ inlet valves |
| Triumph 650, 1959–72 (TBS-17844) | 71mm, 9:1, domed | TR6 and T120 with alloy heads; not for 6T |
| Triumph 750, 1973–78 (TBS-19255) | 76mm, 8.5:1, domed | T140 and TR7 after engine numbers XH22019 (T140V) and AH24040 (TR7V) |
| Triumph 750 low compression, 1979–83 (TBS-20432) | 76mm, 7.4:1 | TR7V, T140D and T140E; also earlier 750s if lower compression is wanted |
For a lower-cost alternative, see our piston sets with Grant rings.
Hepolite Piston Ring Sets
These UK-made sets have a PVD chromium-nitride faced top ring, a black phosphate second ring and a two-piece oil ring with an expander spring:
- Triumph 500, 69mm, 1960–74 (R13570): all 500cc unit twins
- Triumph 650, 71mm, 1959–72 (R11050)
- Triumph 750, 76mm, 1973–82 (R26490): not for early 1973 bikes before engine numbers AH24040 (TR7V) and XH22019 (T140V)
- Triumph T150 and T160 and BSA A75 triples, 67mm (TBS-R23020): six compression and three oil rings, in +.020, +.040 and +.060
- Norton Commando 750, 73mm (R26260): for pistons with an oil ring groove about .180″ deep; not for original pre-1972 pistons
- Norton Commando 850, 77mm (R26730): Mk2 and Mk3 models
- BSA A65 650 (VAR-R17350): all unit-construction A65 years
Learn more about how piston rings work.
Hepolite Oil Pumps
- Triumph unit twins oil pump (70-9421): made in England and CNC-machined from solid brass rather than cast, with precision-ground pump pistons
- BSA A50, A65 and A70 cast-iron oil pump, 1962–72 (71-2449): UK-made in the later cast-iron pattern BSA introduced during 1971. Early alloy pumps could distort at the mounting face, which contributed to wet-sumping.
See more Triumph oil and air parts and BSA engine parts.
Hepolite Bearings, Rods and Bottom-End Parts
- Triumph and BSA 650 and 750 drive-side main roller bearing, MRJA 1-1/8 C3 (70-2879): C3 clearance for worn aluminum crankcases
- Triumph and BSA 500 and 650 main ball bearing, MRJ 1-1/8 C3 (70-1591): pre-unit and unit engines through 1971; not for Triumph 750 twins
- Triumph 500, 650 and 750 big-end shell set (70-3586): standard and undersizes. Also see L.F. Harris shells.
- BSA A10, A50 and A65 big-end shell set (67-1430 to 67-1433)
- Triumph 650 forged H-beam 4340 steel connecting rods (70-9525): 1956–72 650s with 1.623″ crank journals, with ARP 2000 rod bolts
- Triumph 650 hex sludge tube plug (70-3905): 1959–68 B-range crankshafts
- Triumph 650 and 750 5-speed high gear bearing (60-4100); see more Triumph transmission parts
Hepolite Valves, Tappets and Valve Springs
- Triumph 500 T100 and 5TA exhaust valve, 1959–66 (70-4013)
- BSA A65 exhaust valve, 1962–72 (68-0663)
- Triumph 650 and 750 valve spring set (99-7037): UK-made, for four valves
- Triumph 650 and 750 exhaust “R” tappet (70-8801) and inlet “R” tappet (70-3059R)
- Exhaust tappet guide block, 1969–79 (70-9353) and inlet tappet guide block (70-9352)
For more valve options, see G&S Valves and Kibblewhite.
Hepolite Oil Seal Kits
- Triumph T120 and TR6 650 4-speed engine and gearbox seal kit, 1963–71 (TBS-61-361)
- Triumph 350 and 500 unit twins seal kit, 1963–74 (TBS-61-360)
- BSA A50 and A65 complete seal kit, 1962–72 (99-9958)
- Triumph and BSA unit singles seal kit, 1967–72 (TBS-61-355): B25, C25, TR25W, B44 and B50
Pair your seals with a gasket set from our Triumph gaskets, Norton gaskets and BSA gaskets categories.
How to Choose the Correct Hepolite Part
- Find your engine number and year. Some parts change mid-year. The Triumph 750 pistons and rings, for example, depend on your engine number.
- Check your parts book. Match the original part number before ordering. See why the parts catalog matters and shop Triumph parts books.
- Measure before ordering oversizes. Have your bores measured and pistons fitted by a machine shop. Measure crank journals before choosing undersize shells.
- Match the cylinder head. The early and late T100 piston sets suit different heads, and the 650 set isn’t for the 6T.
- Use the right tools. See our Triumph service tools, BSA service tools and workshop tools.
Read our guides Triumph T100 Top End, Triumph Top End Sealing and Eliminating Triumph Oil Leaks. Shop more Triumph engine, Norton engine and BSA engine parts, or contact our team for help.
Shop Hepolite Engine Parts
Browse the Hepolite parts above, or see all the brands we carry. Orders ship free to the lower 48 states, and weekday orders placed before noon Mountain Time ship the same day (Shipping and Returns).
With a name that has been synonymous with quality and a 100+ year legacy, “Do the job right, fit Hepolite!”
Hepolite Engine Parts FAQs
Who makes Hepolite parts?
Are Hepolite parts made in England?
Many are. Hepolite says many of its products are still made in England (Hepolite). Our listings show the piston rings, Triumph and BSA oil pumps, valve springs, tappet guide blocks and MRJ main bearings as UK-made. Check each listing for country of origin.
Which Hepolite pistons fit my Triumph?
Choose by model and head. The 69mm 1958–66 set suits T100s with squish-band heads, the 69mm 1967–74 set suits the later T100 head, the 71mm set suits 1959–72 TR6 and T120 650s, and the 76mm sets suit 1973–78 750s (8.5:1) and 1979–83 750s (7.4:1).
Do Hepolite pistons include rings, pins and circlips?
Yes. Each Hepolite piston set includes two pistons, piston rings, gudgeon pins and circlips, in standard size and oversizes to +.060″.
Will Hepolite rings fit my original Norton Commando 750 pistons?
Not always. The Hepolite 750 ring set is made for pistons with an oil ring groove about .180″ deep and is not recommended for original pre-1972 Commando pistons with shallower grooves.
Why upgrade to the cast-iron BSA A65 oil pump?
Early BSA unit twin oil pumps were made from a zinc alloy that could distort at the crankcase mounting face, which contributed to wet-sumping. BSA introduced a cast-iron pump during 1971. The Hepolite pump copies that later design.
What is special about the Hepolite Triumph oil pump?
The Hepolite 70-9421 pump for Triumph unit twins is made in England and machined from solid brass instead of a casting, with precision-ground pump pistons.
Which main bearing should I use in my Triumph 650 or 750?
For the drive side of 650 and 750 engines, the Hepolite MRJA 1-1/8 C3 roller bearing (70-2879) has extra internal clearance, which can help in worn aluminum crankcases. The MRJ 1-1/8 C3 ball bearing (70-1591) suits many 500 and 650 engines through 1971, but not Triumph 750 twins.
Do you sell Hepolite oil seal kits?
Yes. We stock Hepolite seal kits for 1963–71 Triumph 650 4-speed twins, 1963–74 Triumph 350 and 500 unit twins, 1962–72 BSA A50 and A65 twins, and 1967–72 Triumph and BSA unit singles.
Do you offer free shipping on Hepolite parts?
Yes. Orders ship free to the lower 48 US states with no minimum order. Weekday orders placed before noon Mountain Time ship the same day.
To find other supplier brands, click here.
