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[Gwilly]

19 teeth with the C/R internals is as far as you need to go with the four speed.. It makes for a relaxed 60-65mph cruise and a useful 3rd gear for slight inclines/overtaking..

Trouble with motorways is the trucks average 66mph and when gaining in your rear view mirror there is a tendency to push for 70mph which will break something if unchecked..

Improved breathing i.e. filter and exhaust plus slight up jetting will have the 500 coping reasonably with the 19 tooth..

20 tooth is right out squire, 3 reasons, 1st not enough omph in the standard comp/pistoned motor. 2nd the clearance between the primary case and the gear box may mean the chain MAY catch..
3rd the raising of 1st gear ratio via the c/r in combination with the 20 tooth final drive will create hellish clutch slippage trying to pull away on steep junctions etc..

[jefrs]

Thanks Gwilly.

Despite my bike having slightly improved performance, provided I can get the motorway fast cruise speed I need to keep away from trucks I shall be happy enough with the current gearing. I've yet to open the bike right up on a good stretch of motorway to find out.

It will more than likely pull and extra cog on any solo hill start but maybe not so much two-up. My current line of thinking is to replace the rear tyre with a larger profile as and when the present one wears out; there's less information about this out there, yes it alters the gearing.

I can drive a lorry, they're supposed to stick to 60mph limit on a motorway, most have engine limiters. In practice they're always driven flat-out, which means (as you say) ~65mph engine limiter or not and they don't like slowing down because it takes ages to speed up..

[jefrs]

Typos - "an extra cog" and "~65mph, engine limiter or not"


But clutch slip on this EFi is something I've only experienced when the oem indian cable decided to become sticky and wouldn't release fully, or did so all at once and had the front 4-ft up in the air, oops (sorted).

This clutch seems very, very strong, if anything too light to operate, the lever/cable travel almost too long for an easy grip.

[Beezabryan]

Gwilly, trucks by law have speed limiters fitted. The UK max speed is 60 mph for dual carriageway & motorway though the norm is to set the limiter at 90kh/56mph. A number of operators now set a lower limit of 85kh/52mph as a fuel economy measure. Reckon you might have an optimistic speedo
And before the scientific would be trucker with little knowledge of transport operation and regulation comes along with a pedantic response, I know that 52 mph is actually 83.6859kh not the nice round 85 that I quote.

[Gwilly]

Hi Bryan, I'm sure your right about the enfield speedo, probably 5mph out at best..

Interesting info on the speed limiters, I have a 2015 ford van which is limited to 66mph verified on the sat nav..

Usually fuel tankers and supermarket jobs seem to run mid 50's to 60mph but an awful lot of flat bed independents and the like seem to leave me in the middle lane, like some kind of formation wing man
unable to get clear, and its this kind of situation that makes you gun the old bike to safety..

Detrimental to say the least. Just to be sure i was wittering about the clearance on a 4 speed pre unit box, know nothing about EFI's unit running gear except what i read here..

[Beezabryan]

Gwilly, I guess your van is ex fleet for it to have a limiter.
Quite some years ago now I came across a contract hire company who had 70mph limiters fitted to all Sprinters going to a construction company, Fitxpatrick I think, to keep the users licences intact. By now I would think that Transits have about the same speed capability as the Sprinter which was/ is way over the national speed limit. Limiters on smaller vehicles is now becoming quite common.

[jefrs]

Yes my lack of a comma made it look like I was implying lorry limiters are set to 65mph. NOT.

A 14+tonne lorry going down hill can go faster than its limiter is set to, fully laden they crawl uphill. Drivers do not like to slow them down because they take ages to get back up to speed, which is why unladen trucks overtake them going uphill, which is forbidden in France btw. I got into lorry driving vacation work with a packing, storage and haulage firm years and years ago, more recently for moving dangerous goods which required periodic re-test by the company.



This afternoon I took the C5 EFi up the A34 dual carriageway (part of the longest continuous dual carriageway in Europe), the local bypass. No trouble at all keeping up with the traffic, nor overtaking. The normal car speed on that road is 70-80mph. Not the fastest thing on the road but didn't feel out of place. Fast cruise seems to be 70-75mph, 80 on full throttle but still nowhere near max revs, nor does it seem it want to rev higher in 5th. As an experiment 65-70 doable in 4th without over-revving. Performance comparable to family hatchback.

This is sit-up-and-beg position on stock 19/38T with 110/80-18 AM26 tyre

Strangely the slip-stream effect of the heavy traffic on the A34 took off the edge of the wind buffeting, which came back as soon as I got on the B4000 roman road (Ermin St) which is about as smooth as a theme park ride.

[jefrs]

TYPO Correction that should have been 18T/38T (gearbox and rear sprocket) - I do have arthritis and I hit the wrong keys.



H do say the 19T will fit but the 20T needs crankcase modification to the EFi. The B5 EFi std is 17T but does have 19-in wheel. It seems to me that a smaller gearbos sprocket would reduce the fast cruise on mine; won't bother. A larger profile rear tyre might improve it, guestimate half a cog, but there's plenty of rubber left on this one.

[Charlie bob]

I have brand new bullet efi abs 2017 done 1400 miles l can get 65 mph in 4 to but only 70 mph in 5 the dealer sent me a new spark plug kkng5 says this is what Enfield recommend now tried it no better any body any thoughts like should l change gearbox sprocket to 19 teeth but say that it is a lovely bike

[oldnick]

Current EuroIV B5 Bullet has an 18" wheel and according to H a 17T sprocket. See current thread on Bullet GB sprocket.