engine spocket sq4 1939 4G

[Henning G]

HI, I wonder if anyone has experience regarding engine sprockets on iron4G sq4. I have 24T at the moment, but I will drive mostly solo. Cold 26T be an option, and where do I bay one..regards Henning

[will_curry]

The parts list show sprockets of 22, 23, 24 and 25 teeth, the latter being 1341-37.

Bruce Longman is the man to ask about sprockets and his contact details
should be in the front of Cheval.

For what it's worth I run a 26 tooth sprocket on my solo Mk 1 and it works well.

[JohnnyBeckett]

hi i would try Geoff Brown the clubs gearbox and clutch spares if you have no luck with Bruce Longman he had some sprockets

[paul.jameson]

I run 25T on my 1937 4G which suits it well, for the type of riding I tend to do on it. I also had 25T on the 4G which son Rob now owns and again that worked well, even with a sidecar attached. Its a balance between keeping the revs down when travelling at speed and being able to go slowly enough on steep slippery surfaces and avoid the power getting the better of you.

There are two types of engine sprocket which could be fitted to your bike. The originals run directly on the crankshaft and have 3 lobes for the shock absorber. These were suoerseded by the later type and are pretty well unobtainable as a result. The later type use a sleeve between crankshaft and sprocket. have 2 lobes for the shock absorber and spare sprockets are easier to find.

[john.davies]

I run a 26T sprocket on my 1946 4G having felt the 24T was a little to low geared. It has the 3 lobe cush drive so buying one off the shelf was not an option therefore I bought a 26T plain sprocket from BearingsRUs. I also had a worn out 24T sprocket so got a friend to make one up for me by removing the old teeth, machining a hole in the new sprocket to tightly fit the old one and then welding them together. The one I bought off their web site was https://www.bearingsrus.co.uk/p08b1-26

[Henning G]

Hi, I will definitely change to 25 or 26 teeth sprocket. Thanks for shearing you knowledge’s with me, and thanks for the address for the sprocket..you are great guys..

[john.davies]

The other option is to change the clutch sprocket to one of Drags 40t ones instead of the standard 44t. https://draganfly.co.uk/shop/63219/clut ... t/#3380-91

[Henning G]

Hi John, I didn’t knew that 40 teeth sprockets was available. I have ordered a 26 teeth sprocket from “bearingsrun ”Thanks for info, believe the 4 teeth difference on the clutch wheel is almost the same as one on the engine shaft.