Daytona 675 track gearing & 520 chain conversion

520-rear-49The 520 chain conversion on my Daytona 675 came about because I wanted to change the bike’s gearing to get faster drive out of corners. Although this isn’t necessarily that important on the road it is pretty useful on the track.

While the sprocket changes would produce the gearing change I desired, switching to a 520 chain (from the standard 525 chain) at the same time would also allow for bigger choice of sprockets, and lighter ones too. Less weight in the rear sprocket and chain means less rotational mass which helps make direction changes a little easier and faster.

The standard chain and sprocket setup on the Triumph Daytona 675 (for 2006-2012 models) is a 116 link 525 chain with a 16 tooth front/gearbox sprocket and a 47 tooth rear sprocket. Most people who want the same improved drive recommend going down 1 tooth on the front and up 2 on the rear, so that you end up with a 15 tooth front and 49 tooth rear.

The table below gives you an indication of the gearing changes you can achieve by changing either the front or rear sprocket or both together.

Front Rear Ratio Torque Speed
15T 47T 3.13 +6.3% -6.3%
15T 48T 3.20 +8.2% -8.2%
15T 49T 3.27 +10.1% -10.1%
15T 50T 3.33 +11.9% -11.9%
15T 51T 3.40 +13.6% -13.6%
16T 45T 2.81 -4.4% +4.4%
16T 46T 2.88 -2.2% +2.2%
16T 47T 2.94
16T 48T 3.00 +2.1% -2.1%
16T 49T 3.06 +4.1% -4.1%

The baseline (standard) gearing for the Daytona 675 is 16/47. In gearing changes, the tradeoff is between torque and speed. In 3rd gear at 12750RPM the Daytona on standard gearing will reach 110mph (178kph), while at the same RPM it can (in theory) reach 152mph (245kph) in top or sixth gear. Using a 15/49 gearing, top speed in 3rd is reduced to 100mph (160kph) and 137mph (220kph) in sixth gear.

front-sprocketI decided to go with a pair of Renthal sprockets; a lightweight 15 tooth steel sprocket for the front and a light but hardened 49 tooth anodised gold alloy sprocket for the rear.

rear-sprocketAlthough worried about using an alloy rear sprocket I was assured that the rear will last as long as the chain and front.

There are various chains available on the market, but motorcycle mechanics that I’ve spoken with rate the DID chains over Tsubaki and others. A product description for the DID VX-GB chain that I ended up chosing describes it as follows:

VX-GB Series Chains have superior strength to withstand the tremendous horsepower of current high performance motorcycles. A patented low friction X-Ring is used for maximum performance. D.I.D VX-GB X-Ring chains feature gold side plates and reduces friction by twisting between the side plates instead of being squashed. Normal O-Rings and other makers’ modified O-Rings have squashed points that increase friction. The twisting resilience of the X-Ring’s four sections greatly increases its sealing performance. This keeps the dirt out and the lubrication in much better than any other O-Ring. X-Rings have the greatest wear resistance of any other type of O-Ring or Non-O-Ring chain

When ordering the chain, the sales rep was surprised that I didn’t select the race version of the chain, the DID Road Race X Ring Gold Drive Chain as he thought this would be more appropriate for a track bike. Since the race chain cost over twice the amount of the VX-GB chain, I figured that I would just have to replace the chain a little more frequently if necessary. I’ve no doubts about the DID VX-GB being plenty tough enough for the Daytona 675 – in fact I read that the 520 chain has a higher tensile strength than the 525 chain!

The standard 525 chain length is 116 links. Because the new rear sprocket is larger then the original one I knew I would need a longer chain in order to be able to keep the rear wheel spindle in the same place as before – you want to do this to avoid changing the bike geometry. I wasn’t sure how long a chain to buy and ended up settling on a 120 link chain. This was slightly too long and I ended having to remove at least one link (and possibly two, I can’t remember now) using an angle grinder.

chain-linkOne of the annoying things about the 520 DID VX-GB chain is that a split link is provided to join the chain instead of a rivet link (like the one shown here). I only found this out after I went to join the new chain which resulted in a trip down to the nearest dealer to buy the rivet link. I don’t think using a split link on a high performance road or track bike is a particularly good idea.

Here are the parts for the whole conversion:

Part Description Cost
385U-520-15 Renthal 520 15T lightweight front sprocket £14 (US$22)
456U-520-49HA Renthal 520 49T alloy rear sprocket £30 (US$48)
520VXGB-120 DID 120 link Gold/Black chain £92 (US$147)
? DID 520 rivet link £10 (US$16)

After fitting the new chain and sprockets I test rode the bike on the street and to be honest I couldn’t really notice a massive difference between the old and new gearing. However, the first time I tried the new gearing on track I immediately noticed two things. Firstly the bike’s acceleration out of corners was much (10%) better than before. In fact a couple of riders at a Cartagena (short and twisty) track day remarked that they struggled to keep up with my Daytona as it out accelerated them from the same starting speed on corner exits. The second significant difference was that in (hairpin) corners where I would normally have to use second gear, I could now get away with third. In fact in four days at Cartagena this year, I only used second gear once on track and that was by mistake!

On short and twisty tracks, the -1/+2 gearing change is well worth doing. For faster circuits, it may be worth trying a lesser change in order not to compromise your top speed on the straights so much. In fact I might consider buying another 16T front sprocket to use on track days at faster circuits. Why a front? Because changing the front sprocket is generally quicker than changing the rear one.

One by-product of the gearing change is that my speedo now over-reads by 10%. Since this is going to cause the bike’s odometer to overestimate the bike’s mileage, I’m going to fix this by changing the gearing parameter in the bike’s ECU. I’ve documented this in my post on using TuneECU to recalibrate the speedo.

Cartagena (Hottrax) February 2014

RYE_5639_CThis was my second visit to the Cartagena circuit on a four day event organised by Hottrax. I was last here three months earlier with Hottrax and enjoyed myself so much that I booked again!

Back in October the weather was in the high 20s C (80F) while the temperature in February remained around 17C (63F) except on the last day when it climbed to around 20C (70F). One worry had been that it might rain during the four days, but thankfully it remained dry the whole time with the exception of a few spots of rain right at the end of the third day.

After two miserable months in the UK, it was fantastic being outside in the sunshine and back on a race track. Although initially rusty from not having ridden on track for three months, it didn’t take long to start blowing the cobwebs away again.

Day 1

cradleThe first day at the Cartagena circuit began with unloading of the bikes from their cradles. This photo shows how much stuff you can actually get onto a double cradle, although it will depend on what the other rider is bringing too. The best rule of thumb is to try and pack lots of smaller soft bags in order to get all your stuff packed around the bike.

Having got lost (?!!) on my way to the circuit and arriving half an hour later than I intended, I found my bike looking a little lonely on its own in a double bike cradle. With the garages filling up fast, I located some empty space in garage 14. Within half an hour, the same garage was full with 7 bikes; three of which were owned and ridden by people I had met back in October last year at the same circuit. It was great to say “hi” to familiar faces and it seems that I’m not the only one that likes this tricky little circuit!

Calm before the storm

Calm before the storm

After a 9:30 briefing the fast group went out at 10am. The day runs from 10am to 5pm with a one hour lunch break between 1 and 2pm. There were quite a few “offs” and accidents that first day including one serious one where an Inters group rider crashed on the second lap of his three sighting laps. Apparently he hit the brakes and ended up falling forward over his brand new looking Fireblade onto his face! The medics were unable to wake him up at the circuit, so he was carted off to hospital leaving the circuit was closed for an hour and a half while the ambulance was away. Luckily he wasn’t badly hurt, suffering a broken collar bone as his only lasting injury. But he did cut a fairly forlorn looking figure as he packed his bike and things back onto the cradle ready for transport back to the UK.

After two to three months away from a track, it’s so easy to get sucked into making a mistake while forgetting that there are still four days of track riding availble. Most riders that came off were lucky enough to either keep their bikes upright in the gravel, or to suffer minor damage which could be repaired at the track. In our garage of seven bikes, two were unlucky enough to have come off at one point or another, reminding the rest iof us of the need to be a bit circumspect!

The weather was sunny and warm at 17C (63F). I started the day running 31 front and 30 psi in my rear tyre. By the end of the fourth day with more pace and lean angle, I had reduced those pressures to 29 front and 28 psi in the rear tyre. If the weather has been warmer still, I’d have been tempted to drop another psi. I was running the same set of Michelin Power Pilot 3’s from last year. I think these tyres are pretty decent on track and you can read my previous review of them.

In the garage next door, I met Alex riding a stock 2008 Triumph Daytona. He came over for a chat after the first session not looking too happy with his lack of progress around the circuit. Despite my lack of talent and ability I offered to show him the lines as best I could. I decided to use one gear only and no brakes for as much of the circuit as possible while doing so. What I found was that without having to worry about changing gear or using the brakes, I could focus exclusively on my lines and I think I actually did a reasonable job showing these to Alex. In fact I must have done something right because by the end of that first day he was really comfortable on track and went flying past me with depressing (for me) regularity!

RYE_6275_CI enjoyed riding in one gear (third mostly) using minimal brakes so much, that I spent most of that day’s sessions’ repeating the same exercise. Apart from allowing me to concentrate on the lines, it also allowed me to work on my throttle control and to see just how much corner speed you could carry without it feeling either particularly scary or dangerous. That first day’s riding in warm conditions was great fun and I finished the last session feeling pretty spent; both physically and mentally.

Day 2

Riding in one gear and no brakes feels really smooth and I was curious to see what kind of lap time it produced. Repeating yesterday’s exercise resulted in a time of 2:20 which is about 6 seconds a lap slower than my last visit the previous October using more gears, throttle and brakes! By the third session that morning, I had managed to match by best time of 2:14 from the previous time at Cartagena. I did this by holding the throttle open for longer on the straighter bits and using the brakes to wash off speed on the corner entries.

RYE_4239_CThat afternoon, I tried more of the same. However I now found that in trying to ride faster I was blowing my lines by riding in a more ragged manner. I was rewarded (?!) with a slower lap time of 2:23 in the first session after lunch! With an increasing wind in the afternoon gusting up to 25mph, I could only manage 2:18 as my best time for the afternoon. The wind was really disconcerting because not only was it blowing sand onto the track, but it had a tendency to push you off your line mid corner and even on some of the corner exits.

There were quite a few red flagged sessions that day through a combination of increasing (over-) confidence and nasty wind conditions which made riding the track harder than it should have been. Fortunately, most riders that came off managed to rejoin the circuit without incident.

Day 3

The three sessions in the morning were dedicated to getting qualifying times for those riders taking part in the afternoon’s endurance race. The remaining 40% of riders not taking part continued to use those same 20 minute sessions to get more practice and improve their lap times.

The race started after lunch at 2pm and lasted for two hours. The winner was be the team that accumulated the most laps in the time available. One of the lead bikes managed to turn in a lap time of 1:36 – just 4 seconds off Tommy Hill’s lap record on a Superbike! Because the race also included some brave souls from the novice group, there was a huge disparity between the fastest and slowest riders. This was shown quite clearly on the rolling start lap where the last of the riders passed the start finish line almost 30 seconds behind the leaders after just one sighting/warm-up lap!

RYE_1225_CIt was obvious once the race started that the field spread out enough that seldom would a slow rider find themselves in a situation where 2, 3 or 4 faster riders would be barreling into the same corner as them. In fact, most riders I spoke to said that the endurance race had been great fun and that they hardly ever felt bothered by the faster riders who tended to give them a reasonably wide berth whenever possible.

Despite the fact that I opted out of the race because of concerns about how seriously some of the riders would take the event, I got to mix with some pretty fast riders in the hour long open pit lane session after the race! I found that for the most part the faster riders were considerate when passing, although that isn’t entirely surprising when you consider that they would only be only alongside for an instant before they headed off for the next turn. Being overtaken by Gary Johnson on a CRT bike was one of the high points of that open pit lane session. I heard him long before before I saw anything as the noise from the CRT engine and exhaust was far louder than anything else out on track!

I rode with Darren, one of Hottrax’s instructors for a couple of laps towards the end of the session until grey skies and spots of rain put paid to it. During the short debrief after the session, he indicated that my lines around the track were mostly OK, and that he could hear me getting on the gas out of the turns which was reassuring. He pointed out that the extra speed and quicker lap times that had eluded me this trip would only come when I really started to trust in the bike and tyres more. He reminded me that the bike was capable of far faster turns and higher lean angles that I was currently managing and that by gradually making more use of the bike’s capabilities (and more of the track) I would safely be able to turn in faster lap times. Provided I didn’t panic brake or overload the tyres through hamfisted riding, there was no reason that a crash would be the result of riding harder and faster.

Day 4

For the first session of the day Tamara, one of the faster riders in our group, kindly agreed to follow me for that session with my camera. In turn, I filmed her following behind with her camera mounted on the tailpiece of my bike – you can see some of the footage from that session below.

Tamara was joined by her husband James and son Ashley on track. It was brilliant to see a family doing a track day together especially since all three riders seemed to be really quick and smooth riders out on track. Even their youngest Sophie who wasn’t riding got involved by travelling to different parts of the circuit (which would be off limits in the UK) with her camera. In fact many of the brilliant photos in the gallery for this event were taken by her – there’s a link at the bottom of this post. Thanks Sophie!

RYE_3061_CAs this was the last day of the trip, I decided to throw caution to the wind for the remaining five sessions and to try to improve my lap times by braking later into turns and getting on the gas earlier exiting the turn. As the day wore on, there were fewer and fewer bikes on track as people started packing up to leave which meant that for many of those sessions I was riding pretty much on my own interspersed with the occasional excitement of being overtaken by a faster rider.

Despite my determination to rider faster, I managed to make no improvement on my best lap time in those final sessions. It does feel as though I have hit some kind of plateau in my riding at the moment. I suspect that I’m only going to break through this either by a radical change in my riding style or by going for small incremental improvements. The first would probably come with some decent one on one instruction while the latter will come from more focused practice on track.

While the lack of improvement in my lap time was frustrating, there were many other aspects of the trip that I really enjoyed. The 520 chain conversion that I made to the Daytona so that it now runs a smaller front sprocket and larger rear sprocket has given the bike brilliant acceleration out of the corners. In fact it allowed me to run a higher gear round most of the track compared to Alex’s standard 675 – where he had to use second gear, my bike was happy in third and I could still out accelerate him from corners.

RYE_2440_CAnother aspect of my riding that has improved (slightly) is my body positioning. Although it’s not yet where I want it to be, I am definitely more relaxed on the bike and more comfortable moving around and hanging off to make cornering easier. Speaking of cornering, another aspect of my riding that has improved is my determination to look well ahead through the corners. I am constantly amazed by my bike’s ability to get around a corner safely and at speed just by looking well ahead at where I want the bike to go. The few times I forgot this vital technique, I ended up nearly coming off the track as I panicked, rolled off the throttle and all because I looked at where I didn’t want to end up instead of looking through the corner!

Reviewing the video I can see that one area that really needs some attention is to properly open the throttle on the sections between the corners. I estimate that I could be losing up to 8-10 seconds a lap just but not doing so and this is something that I’ll be working on more over the summer. Riding in the open pit lane session was also eye opening for two reasons. Firstly, it showed how smooth the faster riders are. You can barely see any pitch change in the bike as they go from full throttle to brakes to turn in at the corners. Watching them ride makes the whole thing look effortless! The second thing that the faster riders highlighted for me is how quickly they can make direction changes – this was especially apparant between turns 2 and 3 and through the chicane. If you watch the video above at 5:05 you’ll see Darren, one of the Hottrax instructors carve a beautiful left/right flick through the chicane. I think Keith Code once stated that you can quickly determine a rider’s ability by how quickly they can change direction. This is definitely another aspect of my riding that I’ll also be working on this summer.

RYE_6097In our garage, I was often ended up talking with Anders who was riding a Ducati 848 Streetfighter. On the third day he had switched from a set of Pirelli Diablos to a set of Super Corsas. He ran a softer SC1 on the front and a slightly harder SC2 compound on the rear. He raved about the confidence that the track tyres gave him over the original Diablo supersport tyres he had used on the first two days. In fact he even became a bit of a celebrity on the event as he was the only completely street legal bike running in the endurance race yet he was running consistent times both above and below the 2 minute mark. He was pretty easy to spot around the track as his was the only unfaired bike running a headlight!

rear-tyreIn terms of tyres, I was pretty happy with my Michelin Power Pilot 3’s which I still had on from my previous track day at Cartagena last October. With the exception of one slide from the rear when I gave it too much gas exiting the chicane (turns 4 and 5), they performed admirably. However on day 2 in the afternoon, I did start to lose confidence in them, but that was soon fixed by reducing the tyre pressures to 29 front and 28 psi in the rear. They felt a lot better after that simple fix. What’s really amazing is how much rubber they still have left on them having done the equivalent of 800 miles in eight track days and they look as though they could do the same again! Having listened to Anders rave about the Super Corsas, I am intrigued enough to try a sticky set of track specific tyres at some point this year, although I’m not sure what those tyres will end up being.

This trip I went to Cartagena on my own. In some ways I enjoyed the trip more as a result because it forced me to chat to more of the other riders. I met some really interesting characters and had a brilliant time to boot. I rate both these Hottrax European track day events that I have been on really highly; both in terms of value for money and fun. If I had one complaint that would be that we could have done with a couple more instructors riding in the novice group each day as I only managed a few laps with Darren, one of the instructors, on the third day and I probably could have done with more help each on the other days too.

Despite the fact that I’ve been to Cartagena twice now, I still want to go back for more. The track is awesome, the weather (generally) brilliant and the company good. I sincerely hope that I can make it back there again at the end of October this year too!

You can also view a gallery of photos taken on the event.