[Bmadd34]

Okay, I know this has probably been discussed a multitude of times. However, without a definitive answer given. what are the advantages and disadvantages of the 19 tooth front sprocket on the C5? Or going up one tooth on the drive sprockets? I would rather not get answers that include "Probably", "Might", "Theory", "Supposedly", "maybe", "Could" etc.. I would like to hear actual experiences from those that have made the change. Real numbers. Real results. I am considering installing the 19 tooth sprocket on my C5 in preparation for the ride to Florida. Hitchcocks isn't willing to sponsor my ride with one, so before I spend my money, I want to be sure it will be an asset. Thanks.

[Jako]

With a stock engine I wouldn't recommend changing gearing ratio's ,  I actually lost some top speed in 5th gear when I went up a tooth on my B5.   The stock engine doesn't have enough power to take advantage of the extra gearing. You might mistake the  lower revs at cruising speed as a happier engine but its really just overloaded and struggling to reach its potential. More gearing needs more HP .  Anyway if you were to change the gearing In my opinion the better option  would be the  larger diameter Dunlop K70  tires.

[Rattlebattle]

The trouble with this issue is that you’ll get opposing views....I have a C5 (not a B5), they are different in wheel sizes and standard sprocket size ( or they were; not sure about Euro IV models). I made the change and I wouldn’t go back. Key points: 1. I am not heavy. 2. I never ride with a pillion. 3. My engine is not stock - like many I have free-flowing exhaust and air filter, though in my case compensated via a carb rather than PCV or similar. 4. I don’t live in a hilly or mountainous area. 5. I prefer to use the gearbox rather than just put it in top and boo along. What I am saying is that there is no one-size-fits all solution; the accurate answer is “it depends...”. Personally the largest ie 20 tooth one would be too big for my bike; for me the 19 tooth one is ideal.

[2bikebill]

The easiest kindness you can do to the standard Enfield is change the stock silencer for a less restrictive one. You'll notice a slight performance increase. It'll lose quite a bit of weight too!
I can only speak for the G5, but changing from 17t to 18t front sprocket gives it slightly longer legs without any strain on the engine, happy all day at 60mph. The C5 has the same engine. Assuming the rear sprocket is also the same, I wouldn't want to go to 19t at the front. Might start getting a bit luggy.
There's a "might" for you right there. 

[Rattlebattle]

As I tried to make clear before, the C5 gearing is different to the B5 (and, apparently the G5 too). The C5 STANDARD sprocket is 18 teeth, so putting a 19 teeth sprocket on a C5 is NOT the same as doing so on the other 500 UCE bikes (again with the possible  caveat about the latest Euro IV models now being the same. The engines are the same but the rear wheel size on the C5 is smaller than the others, hence the differing sprocket sizes.

[Blairio]

I can only speak for the G5, but changing from 17t to 18t front sprocket gives it slightly longer legs without any strain on the engine, happy all day at 60mph. The C5 has the same engine. Assuming the rear sprocket is also the same, I wouldn't want to go to 19t at the front. Might start getting a bit luggy.
There's a "might" for you right there. 

When moving to the 18T front sprocket, did you have to lengthen your chain? Or did the available adjustment at the rear wheel accommodate it?
I am going to be pulling the RHS cover off to fit my Carberry anti-vibe (or is it?!) plate in a couple of weeks, so that would be the time to fit the larger sprocket. Mind you, I have a freer flowing exhaust (high level Hitchcocks scrambler one) however I still use the stock air filter. Maybe 18T is a tooth too far....

[Bmadd34]

I have fitted a freer flowing exhaust, bypassed the O2 sensor, and adjusted the TPS. My C5 has an 18'' rear wheel and 18 tooth drive sprocket stock.

[2bikebill]

Blairio - before I did any further upgrades (except suspension) I ran my G5 with just an open "silencer", 18t sprocket, stock air filter. It ran really well. No need to lengthen the chain for the 18t sprocket, although you have to pull the ends a bit harder to get the link in, but nothing tricky, and plenty of slack once it's on. I've just fitted a new 18t sprocket and chain, 101 again, no probs.

[Jako]

As I tried to make clear before, the C5 gearing is different to the B5 (and, apparently the G5 too). The C5 STANDARD sprocket is 18 teeth, so putting a 19 teeth sprocket on a C5 is NOT the same as doing so on the other 500 UCE bikes (again with the possible  caveat about the latest Euro IV models now being the same. The engines are the same but the rear wheel size on the C5 is smaller than the others, hence the differing sprocket sizes.

Yes the B5 has 19" rear wheel and 17 tooth,  but it seems most C5 owners opt for the Dunlop K70 tires once the originals have worn out , the K70 18"x 4" is 680mm diameter very close to the diameter of the 19" Avon's of a stock B5. Just saying to consider what tire you will be running in the near future before selecting sprocket size.

[Blairio]

Blairio - before I did any further upgrades (except suspension) I ran my G5 with just an open "silencer", 18t sprocket, stock air filter. It ran really well. No need to lengthen the chain for the 18t sprocket, although you have to pull the ends a bit harder to get the link in, but nothing tricky, and plenty of slack once it's on. I've just fitted a new 18t sprocket and chain, 101 again, no probs.

Thanks for the info. I reckon I'll give the 18t sprocket a go. At around 45 GBP it isn't a very expensive experiment, but  I need to be sure I have the correct socket for the sprocket nut (should do!).

[wildbill]

there were always mixed reviews on the forum if this 18t mod on a c5 was a worthwhile venture. I think the overall opinion was if it was mostly flat running it help calm the bike down and move vibration further up the top end range buy 3 to 5 mph.
if in hilly county I think there was mention you'd be working the gear box a tad more.
I actually bought the 18t from hitchcocks but never got around to fitting it on any c5. who knows maybe that time will come again..lol

[Rattlebattle]

You’d have wanted your money; C5 s come with an 18 tooth sprocket.... I’m still on the RoadRiders, which I’ll use again when the originals wear out.

[Rattlebattle]

...unless you are talking about a 2017 on Classic C5. Per Hitchcock’s:
Standard sprockets:
B5 and Electra all years: 17 tooth
C5 2009 - 2016: 18 tooth
C5 2017 on: 17 tooth
It appears therefore that the Euro IV 500cc models are the same with regard to gearing but they were different before. So putting a 19 tooth sprocket on a pre-2017 C5 like mine is similar to putting an 18 tooth sprocket on a G5 or B5. I hope this clears it up; if not I give up...

[Bmadd34]

When I contacted Hitchcocks they told me I needed a 19 tooth on my 2017 C5....

[johno]

I have an 18 tooth sprocket on my B5 (Original 17tooth) I have free flow air filter and free flowing exhaust.  a 102 chain fitted instead of the 101.
As may well know most of my journeys are of 100 mile plus on various road types.

Top end speed is not affected ie 82mph flat out
the resonance point has moved by 5 mph, which means comfotable 60+ mph cruising rather than 50-55mph. 70mph is a lot easier to maintain.
fuel economy remains the same

Hill climbing, as I can now achieve higher speeds in a lower gear it makes hill climbing ability on very steep inclines far easier, rather than sitting at 30 mph screaming the engine, I can get up to 40 in the same gear same revs if required.
Downside is that 30 mph in top gear is now to much of a struggle for the engine, so I wouldn't increase the gearing if your Enfield is mainly used at these lower speeds.

[Rattlebattle]

When I contacted Hitchcocks they told me I needed a 19 tooth on my 2017 C5....

If I were you the first thing I’d do is determine what size is actually fitted to your C5. If it is a 2017 model, it should have a 17 tooth one. In this case going up two teeth is too much IMHO. If,however, it has an 18 tooth sprocket then a 19 tooth one should be fine. It wouldn’t be the first time I’ve asked a question and been referred to another member of staff at H....

[Bmadd34]

Okay, can someone chime in here? My 2017 C5 has an 18'' rear wheel. short of unnecessarily pulling my cover, does anyone know what size sprocket I have??

[wildbill]

18t standard and here I decided to upgrade to a 19t -but never tried it

[Bmadd34]

Interesting find. Hitchcocks parts catalog say Classic 2017-on is a 17tooth stock sprocket https://content.yudu.com/libraryHtml/A43715/20182019HitchcocksMo/reader.html?page=56&origin=reader Page 57. I'm cofused….

[wildbill]

maybe but are they talking about the 2017 euro4 version-yours is euro3
I had the euro4 and they have quite a few changes  on the bike compared to a 3 series. they may have upgraded the sprocket as the bike did appear to run well

[wildbill]

looking back to mid 017 - the graphite chrome was a euro 3 bike. in December same year the other bike was euro4 with the screw on gas tank/pav system/abs/new swing arm/ ecu upgrade etc
I thought this bike ran pretty well from scratch -well for a short time...lol - so although I never heard anything about it - maybe it was running a 17t front sprocket
it certainly had pretty good puck up and I actually thought a faster bike than the graphite chrome.
I had the side cover off it when I fitted the vibration plate- I should have taken a geek...

[Bmadd34]

How can I tell if it's 3 or 4?

[GSS]

Going back to the original question, the T18 in the C5 worked well with the original 18” wheel and factory tire size, and a Hitchcock’s T19 helped smooth out the high speed vibrations without impacting top speed.  A subsequent upgrade to 4.0x18 Dunlop K70s upped the diameter to that of a G5 19” stock tire.....the T19 wasn’t so good any more....loss of top speed while going uphill and inability to accelerate in top gear.

Over the years I added SB/GHG piston/porting/valves etc. and regained performance, but ended up going back to stock T18 as it makes the bike more nimble.

 I haven’t seen a 2017 in person, but I am guessing that the change to a rear disk brake has likely altered the rear sprocket size and thereby led to a drop to T17, but this is just speculation on my part.  Maybe someone can count the number of teeth on the rear sprocket of a disk and a drum C5 and let us know.  Thanks.

[Haggis]

How can I tell if it's 3 or 4?

Euro 4 has abs brakes and a disc brake on the rear plus pav into the exhaust port on the head.

[Jako]

Okay, can someone chime in here? My 2017 C5 has an 18'' rear wheel. short of unnecessarily pulling my cover, does anyone know what size sprocket I have??

I think with  bike on centre stand and a torch you should be able to see the sprocket enough to mark one tooth and rotate wheel while counting  . I'm sure you'll find 18 tooth .

[Bmadd34]

I tried that yesterday. No dice.

[Rattlebattle]

Per Hitchcock's (am I the only one to have access to this??) on 500cc EFI bikes the chain size for 17T sprocket is 101 links; that for the 18T (and 19T) sprockets is 102 links. I can confirm the latter having changed from 18T to 19T and ordering a Renolds chain at the same time as the sprocket. So, no need to attempt to count sprocket teeth. If the chain has 101 links it has a 17T sprocket; if it has 102 links it'll have an 18t sprocket unless it's not a new bike and someone has already put on a 19T sprocket.

[Bmadd34]

Just got off the phone with hitchcocks. They are not sure either, being as all 2017 UK models are euro 4 compliant (ABS breaks, and a "bulge" in the header near the silencer) and US models early on were not. As I do not have ABS.

[Haggis]

I would say that you have a euro 3 then.?

[wildbill]

I bet yours is an 18t

[Bmadd34]

Hell with it. I'm gonna order a 19 tooth sprocket. If it's wrong, it's wrong.

[9fingers]

It's worth a try. If it makes it easier to cruise at 65 then it should be worth it.
9fingers

[Bmadd34]

Just placed the order. Fingers crossed Gents.

[Bert Remington]

Bmadd34 -- I have the 19T but haven't installed it yet.  During my research I found these two posts useful:

https://forum.classicmotorworks.com/index.php?topic=12825.0

https://forum.classicmotorworks.com/index.php/topic,22173.msg249311.html

While the second post is about removing the decompressor, it provides an excellent description on removing/replacing the right-hand cover.

Make sure you have Arizoni's community service torque values (https://forum.classicmotorworks.com/index.php/topic,26141.msg301550.html#msg301550) handy.  Don't have 1/4" and 3/8" torque wrenches?  Then be careful, very careful.

Recommendations vary but I think replacing the oil pump o-ring and the cover gasket are good ideas.

[Bmadd34]

Thanks for the great links Bert Remington. I do not have a 1/4'' torque wrench, but my friends over at Ultra Power Sports do. I'm sure they will loan on to me.

[Bmadd34]

Okay, What is the difference in BS3, BS4, Euro 3 and Euro 4? I'm thinking they are the same just different nomenclature.

[heloego]

I think they are just different ways of saying BullShit. 

[Blairio]

Make sure you have Arizoni's community service torque values (https://forum.classicmotorworks.com/index.php/topic,26141.msg301550.html#msg301550) handy.  Don't have 1/4" and 3/8" torque wrenches?  Then be careful, very careful.

For allen-head bolts and screws I use a bicycle torq wrench.  It has a range of 2.2 - 8.8 lb/ft, and works for those fasteners a larger (especially uncalibrated) torq wrench might over-do. Mine is the Topeak Combo Torq Wrench, and cost around 14 GBP. I bought it from the Wiggle cycle online store.

[Rattlebattle]

Okay, What is the difference in BS3, BS4, Euro 3 and Euro 4? I'm thinking they are the same just different nomenclature.

No idea what BS3 and BS4 mean but Euro 3 and 4 are most certainly not the same. They refer to m/c specific emissions standards in the EU. From 01/01/2017 all bikes manufactured must comply with the more stringent regulations. These also require new bikes to have ABS brakes. There are a few ifs and buts but that is the gist of it. That is why RE now provide the UCE bikes with a rear disc and ABS, and is presumably why the rear wheel size and final gearing has been standardised. Hitchcock’s differentiate the model years between pre- and post-Euro IV, I suspect, which is why there is uncertainty about 2017 models sold in other markets which may differ from a Euro IV spec one. Like I said, you only have to count how many links the rear chain has; if it has 101 it has a 17 tooth sprocket and is a Euro IV compliant bike. Simples.

[Bmadd34]

I have 102 links.

[Rattlebattle]

In that case you should have an 18 tooth sprocket, assuming it and the chain are both the original ones. The 19 tooth sprocket also takes the 102 link chain, but is not fitted as standard, whilst the 17 tooth sprocket has a chain with 101 links. So, as you ordered a 19 tooth sprocket you should be good to go.

[Jako]

Well do the post-Euro IV bikes with 17 tooth sprockets come with O ring chains ? Our pre Euro IV B5's apparently couldn't run a O ring chain with the 17 tooth sprockets because of clearance issues around the sprocket .

[longstrokeclassic]

I've never heard of a 101 link 'O' ring chain so I'm firmly in the NO camp on this question

[Jako]

I've never heard of a 101 link 'O' ring chain so I'm firmly in the NO camp on this question

Yea the clearance issue is probably a myth , I've never  taken a good look around the sprocket clearance when I've had the case off. More likely the 1\2 link (101 link length) is the reason for non Oring chain on the B5 .

[Bmadd34]

I thought chains always had an even number of links?

[Jako]

In certain circumstances a in-between length is required   so a half link is added

[Bmadd34]

interesting. Never mentioned that in school, although most of the bikes we used were belt driven.

[Jako]

This C5  must have the 19 tooth sprocket.

[no bs]

can't see her sprocket, but she has nice stems!

[Gesewa]

I've been riding with a 19 tooth sprocket for about 4 years on my 2012 C5.  I haven't had any power issues in any gear.  I'm 155lbs though and did also change out my stock exhaust for something 1/3 the weight if that matters.

[Bmadd34]

I've been riding with a 19 tooth sprocket for about 4 years on my 2012 C5.  I haven't had any power issues in any gear.  I'm 155lbs though and did also change out my stock exhaust for something 1/3 the weight if that matters.

How did your Vibrations settle in, and at what speed did it reduce (60mph now vibrates like 50mph etc.)? Did your top end capabilities change?

[Bmadd34]

My 19 tooth sprocket arrived today.  Pulled off the cover and low and behold.... 18 tooth stock. Got the new sprocket installed, buttoned her back up, and went for a test run. Let me say this; my theory was in fact correct. My rpms are down quite noticeably (actually almost forgot to shift into 5th until almost indicated 60mph (56mph). The vibrations at 60mph are at the level they were at 50ish mph, 70 is where 60ish was etc.. Top end did suffer a tiny bit topping out around 80 on flat ground, where it would snag an indicated 85 before. There are hills in the area, 15 -20ish degree or so (Some more of course), but I was able to maintain indicated 60-65 with ease. I did notice if I were under 55ish I had to down shift on a steep incline (I'm not the smallest framed guy at 6' 2'' and 230+-lbs). All in all, I approve. It should be a great help on my trip. In my opinion, going up one tooth in sprocket size is the best bang for the buck. Period. Thanks to every one for you advice, and expertise.

[9fingers]

Nice going Bmadd34! If I were going to do a lot of highway miles, I would do the same thing. Good luck and enjoy your trip.
9fingers

[hpwaco]

Who did you get your 19t sprocket from and how much was it?  Tnx. Hp

[Gesewa]

I noticed a 5mph difference in where it stars to get buzzy in 5th.  I bought my 19 tooth from Hitchcock’s.  I don’t recal the price.

[Bmadd34]

Who did you get your 19t sprocket from and how much was it?  Tnx. Hp

I got mine from Hitchcocks. http://accessories.hitchcocksmotorcycles.com/accessory-shop/Gearbox-Sprockets-EFI-English-Made/20893 It was 30 quid plus shipping. $53 US. It seems they are sold out for now. Must have been a rush on them.

[Bmadd34]

I noticed a 5mph difference in where it stars to get buzzy in 5th.  I bought my 19 tooth from Hitchcock’s.  I don’t recal the price.

What model do you have? What other mods have you done?

[johno]

Bmadd34,
glad you went for the larger drive sprocket, your initial experience seems to be the same as mine, and as I said earlier, for longer distances it is well worth fitting, for steeper long inclines, hit the bottom at 70mph and you will still be able to stay in top gear until 60mph when you can safely drop a gear and maintain speed, which as you have noticed the engine is now quite happy with.
On the other side, at 50mph fuel consumption is better as well due to the lower revs.....
I also fitted a DID 530NZ chain which provides good drive and has eliminated chain noise as well

[Bert Remington]

hpwaco -- I purchased my 19T sprocket from our sponsor along with its locking washer at about 300 miles.  Peter the cam guy suggested I hold off installation until 2,000 mile break-in (now 2,600).  I'm glad I did.

MapQuest's depiction of the fun part of my San Diego-to-Descanso run is http://mapq.st/2MlaJ4O.  I ride it as a track day in that I strive for consistency in my line, braking points, etc while keeping to the 55mph speed limit (60mph indicated).  I've been on the I8 four times for a total of 12 miles and above 70mph twice.  I8 is not a problem but its boring while being frightening.

The 18T is perfect for that 17.5 mile MapQuest run.  The RE is about torque and patience, not HP and fan-the-clutch.  The uphill and downhill runs use about the same gear change points.  One corner is 2nd gear; several are 3rd and 4th; and most are 5th.  Most drivers wave you by on double-Yellow straights.  Super fun, I'm grinning all the way.  I could go faster but I don't.  Since I'm polite and minding the speed limit, I'm not going to get a letter from my neighbors like the one just sent to the BMWOCSD from the Ramona folks.

Another thing I like about the 18T is the forgiving putt-putt-putt pulling away from a stop.  Let the clutch out just right -- the pull and sound are perfect.  Too quick due to rough road, etc -- don't worry about the engine stalling.

Anyway my 19T and washer are collecting dust.  PM me if you want to change that.

[Rattlebattle]

I’m similar in height and weight to Gesawa; I have also junked the heavy and bunged up monstrosity that is the original exhaust, as well as the downpipe and have put a resistor in the O2 sensor plug. Under these conditions and not living in the mountains a 19T sprocket on my C5 is a no brainer. The likelihood of stalling is minuscule; I’ve been riding for 50 years...As standard I found I was searching for another gear when in top gear. Also, given the very weedy power of these engines I never expected to be able to overtake and climb steep hills in top gear anyway. It rides more like a modern 125cc bike than a modern 500cc and use of the gearbox is to be expected really. It is what it is and I like that, but for seriously “pressing on” I ride something else. To me the RE would not be suitable as an only bike whatever the gearing.

[Bert Remington]

Rattlebattle -- excellent point.  I should have included key data: my weight ready-to-ride 190lbs; stock Avon RoadMasters 90/90R19 Front and 110/80R18 Rear; loud "cocktail" exhaust.  I suppose I must unlearn my half-century bicycle habits and not put my feet on the pegs before releasing the clutch.

[Bmadd34]

Here is a review of the 19 tooth front sprocket on the Classic 500, Plus two very important announcements. https://www.youtube.com/watch?v=eserbu-R2Vk Please like and subscribe. Thanks

[Gesewa]

What model do you have? What other mods have you done?

Mine is a 2012 RE Bullet 500 Military.  I haven't modded anything else performance wise.

[Bmadd34]

Mine is a 2012 RE Bullet 500 Military.  I haven't modded anything else performance wise.

Try a freer flowing exhaust.

[Bmadd34]

just over 2 weeks left.

[longstrokeclassic]

Wow, from the looks of that sprocket there's some serious misalignment going on somewhere.
I suspect the other side of that sprocket had a totally different appearance to the side shown in the video.

[Bmadd34]

Wow, from the looks of that sprocket there's some serious misalignment going on somewhere.
I suspect the other side of that sprocket had a totally different appearance to the side shown in the video.

Yes, The snail was one notch off.

[Haggis]

You do know the notches do not signify correct wheel alignment?
Aligning my wheels with a straight edge gives me 3 less on the left side compared to the right.
Use them for reference only after you have used a straight edge.

[Rattlebattle]

Mine are the same on both sides. You can usually assess approximate wheel alignment by listening to the chain as you turn the rear wheel and by how easily the wheel spins. It shouldn't click. Mine is one of the best I've had, maybe because there's no dragging disc pads. FWIW I bought Hitchcock's replacement chain adjusters recently but after trying to fit them I put the snail cams back. I have read of them snapping too. I wouldn't bother, in case anyone else is tempted. In my case they were at the end of adjustment with a nearly new chain.....