JT Sprockets

Front Drive Sprocket

JT are the leading manufacturer of aftermarket motorcycle sprockets, with the largest and most advanced factory in the world.

Motorcycle Sprockets made the right way...

There's only one way to make a sprocket that meets the highest quality standards and thats hobbing, machining and drilling. This gives the closest tolerances and most accurate tooth profiles.

Close up of a JT SCM420 high carbon steel Front Sprocket

...with the right materials...

By sourcing the best quality raw materials for their motorcycle sprockets, JT can ensure the best quality end product.

All of JT's front sprockets are made with SCM420 high carbon steel which is fully heat treated. Other brands of sprocket may be surface hardened only, which means that once the protective surface is worn it exposes a softer metal underneath. JT front sprockets are hardened all the way through.

...to meet or exceed the highest quality standards

Each JT sprocket goes through 10 individual quality control checks before leaving the factory to ensure that it meets or exceeds the highest quality standards for the motorcycle industry. And a good quality sprocket means less wear on the drive chain.

Sprocket Gearing

For more information on sprocket ratios, see out sprocket gear ratio calculator

Delivery and Returns

We want you to be happy with your purchase. If you're not, just return the products to our warehouse. Unless faulty, we'd like this to be within 30 days of purchase. Exceptions apply to certain products.

Read our full returns policies

Sprocket Gear Ratios
SunStar Sprockets

In theory, increasing the number of teeth on the front sprocket and/or decreasing the number of teeth on the rear sprocket will result in you achieving a higher top speed, lower acceleration and better fuel economy. And vice versa: decreasing the number of teeth on the front sprocket and/or increasing the number of teeth on the rear sprocket will result in lower top speed, higher acceleration and worse fuel economy.

However, whilst generally true, in practice, this is always the case - mostly due to the power output of the machine at certain revs being higher or lower than at others. So, use the following table as a guide only. To achieve your desired results will often involve some trial and error.

It should also be noted that some models cannot accommodate larger front sprockets. Check before ordering. Often, the fitting of larger sprockets may require a longer chain. Check this too before ordering.

FRONT
R E A R		10	11	12	13	14	15	16	17	18	19
	30	3.00	2.73	2.50	2.31	2.14	2.00	1.88	1.76	1.67	1.58
	31	3.10	2.82	2.58	2.38	2.21	2.07	1.94	1.82	1.72	1.63
	32	3.20	2.91	2.67	2.46	2.29	2.13	2.00	1.88	1.78	1.68
	33	3.30	3.00	2.75	2.54	2.36	2.20	2.06	1.94	1.83	1.74
	34	3.40	3.09	2.83	2.62	2.43	2.27	2.13	2.00	1.89	1.79
	35	3.50	3.18	2.92	2.69	2.50	2.33	2.19	2.06	1.94	1.84
	36	3.60	3.27	3.00	2.77	2.57	2.40	2.25	2.12	2.00	1.89
	37	3.70	3.36	3.08	2.85	2.64	2.47	2.31	2.18	2.06	1.95
	38	3.80	3.45	3.17	2.92	2.71	2.53	2.38	2.24	2.11	2.00
	39	3.90	3.55	3.25	3.00	2.79	2.60	2.44	2.29	2.17	2.05
	40	4.00	3.64	3.33	3.08	2.86	2.67	2.50	2.35	2.22	2.11
	41	4.10	3.73	3.42	3.15	2.93	2.73	2.56	2.41	2.28	2.16
	42	4.20	3.82	3.50	3.23	3.00	2.80	2.63	2.47	2.33	2.21
	43	4.30	3.91	3.58	3.31	3.07	2.87	2.69	2.53	2.39	2.26
	44	4.40	4.00	3.67	3.38	3.14	2.93	2.75	2.59	2.44	2.32
	45	4.50	4.09	3.75	3.46	3.21	3.00	2.81	2.65	2.50	2.37
	46	4.60	4.18	3.85	3.54	3.29	3.07	2.88	2.71	2.56	2.42
	47	4.70	4.27	3.92	3.62	3.36	3.13	2.94	2.76	2.61	2.47
	48	4.80	4.36	4.00	3.69	3.43	3.20	3.00	2.82	2.67	2.53
	49	4.90	4.45	4.08	3.77	3.50	3.27	3.06	2.88	2.72	2.58
	50	5.00	4.55	4.17	3.85	3.57	3.33	3.13	2.94	2.78	2.63
	51	5.10	4.64	4.25	3.92	3.64	3.40	3.19	3.00	2.83	2.68
	52	5.20	4.73	4.33	4.00	3.71	3.47	3.25	3.06	2.89	2.74
	53	5.30	4.82	4.42	4.08	3.79	3.53	3.31	3.12	2.94	2.79
	54	5.40	4.91	4.50	4.15	3.86	3.60	3.38	3.18	3.00	2.84
	55	5.50	5.00	4.58	4.23	3.93	3.67	3.44	3.24	3.06	2.89
	56	5.60	5.09	4.67	4.31	4.00	3.73	3.50	3.29	3.11	2.95
	57	5.70	5.18	4.75	4.38	4.07	3.80	3.56	3.35	3.17	3.00
	58	5.80	5.27	4.83	4.46	4.14	3.87	3.63	3.41	3.22	3.05
	59	5.90	5.36	4.92	4.54	4.21	3.93	3.69	3.47	3.28	3.11
	60	6.00	5.45	5.00	4.62	4.29	4.00	3.75	3.53	3.33	3.16
	61	6.10	5.55	5.08	4.69	4.36	4.07	3.81	3.59	3.39	3.21
	62	6.20	5.64	5.17	4.77	4.43	4.13	3.88	3.65	3.44	3.26

Lowering the ratio increases top-end speed. Increasing the ratio increases acceleration and bottom-end power.

... Read more » Sprocket Gear Ratios

"...The sprocket your bike would choose..."

High stock levels held within the UK for swift delivery.
A tough, durable, long lasting sprocket.
Formed of the best quality Japanese-sourced materials.
Made with the latest sprocket manufacturing technology.
A longer lasting sprocket means a longer lasting chain.

Japanese company Sunstar are the largest manufacturer of OE sprockets in the world and since 1946 have supplied their top quality steel sprockets to the likes of Honda, Kawasaki, Suzuki, Yamaha and Triumph and more.

It's a combination of high-grade, high-carbon steel, and a heat treatment and quenching process unique to Sunstar, that makes Sunstar one of the strongest, most durable and longest lasting sprockets in the world. And a harder wearing sprocket means a longer lasting chain.

The first choice of most major manufacturers, more bikes leave the showroom with a Sunstar sprocket than any other make. Now Sunstar is available in the UK for a wide range of models from Wemoto

TRIUMPH Trident 900 T338 93

Sprocket Front - JT [AA2230]

Part Description