CUSTOMER REVIEWS

Bought for 2016 GT. Straight forward swap out. Bike feels better geared in all gears. No massive top end gains but worth it for the increased rideability!!

I've just got my red set and they are top quality and more solid than I expected. A big improvement on the stock ones. Five stars from me!

Just upgraded to these coils, the uprated regulator, the uprated stator and ngk caps with iridium spark plugs. I have to say it made an amazing difference, the bike almost no longer needs choke (less than a minute and only on first start in the morning), acceleration has improved significantly and my bike is now charging (which was my original problem :p). Very happy with all items 🙂

It really does make big difference I’m just not sure about the front sprocket Because I see the one on shop it has 14teeth I recited 13teeth But I’m very happy about this upgrade Thanks Marcel

Really great. Low end acceleration is much better and gets up to 60 in 4th (used to have to use 5th for this). Got it up to 70mph, although it did take a while (previously only got up to 67pmh), but I ran out of road. Pretty sure it would have been up to 75mph+ on a longer carriageway

I've added this upgrade onto my bike it's perfect only thing I found was that the front sprocket was a little loose even with the washer. I'm hearing some noise but unsure if it's the upgrade so I can hear the chain go more now if if there's a problem. ============== Admin Reply: Thanks for your feedback, glad you love it like others do!💎 - If your font sprocket has a rattle, please investigate your drive shaft itself, we don't know if your own previous sprocket splines caused any issues to it etc, remember the original OEM sprocket from Hyosung is made in China, another owner made his bike chain adjustment too tight and he lost his engine shaft, so it was a mess! (his own fault) but the original sprocket was badly worn even inside the spline teeth connecting to the front engine shaft , so double check your setup! Remember to check chain slack and keep it lubed well!

Installed on RC 2018. Wing mirrors are excellent, exact replacement for the originals. Still maintain that sporty, angular look, as much as you can with bike mirrors. Service excellent as always from Marcel/Hyo riders team.

received my upgraded regulator from marcel today for my gt250r fantastic quality ,great service highly recommended micky m blackheath

New fuel lines are just awesome! After upgrade my bike starts immediately - my problem with starting is over now. Very good quality.

If you are debating whether or not to get the 520 upgrade then the short answer is YES...get it. If you want to know why you should, continue reading...... I was unsure if the expense would be worth the investment, after all the GV125S in it's self is a decent cruiser and with the stock sprockets I could achieve 67 mph if the weather was on my side. I found it slow getting there all the same and at top end the bike would be hurting.....you could hear that she didn't like being redlined. I contacted Hyo Riders and Marcel was so helpful in arranging the upgrade I needed. Once fitted I noticed I was up to speed much, much faster than previous and the gearing and revs seem more in tune. I find that 4th can be a cruising gear....enough pull to get you along and when needed take you to 60 mph , I only really use 5th for when I'm on open carriageways. I have achieved a top end speed with this conversion of 75 MPH and considering I am 12 1/2 stone , the bike has panniers and a topbox and I am fully kitted when riding, I think that is impressive from a upgrade. At this stage I'm sure I have covered most of what is needed to know.....and in fairness , the promises made as to what this 520 upgrade would deliver have been spot on. Well done Hyosung Riders 10/10. Again a big thank you to Marcel for all his help in this, you are a star....

Great item arrived well packaged and quickly loved the little notes that Marcel put on the items like the torque pressure thankyou so much hopefully it means I will be able to get my bike back on the road after failing it’s mot

After a little bit of a struggle I finally got the kit on! Thanks to the forum post that front sprocket was a right ass to get off! The bike feels much nicer to get up to speed, it feels a lot smoother and nicer to ride! So far I’ve noticed an increase of about 5mph on the top speed but I haven’t pushed it to see how far it will go but that extra 5mph gives a more comfortable carriageway experience. Highly reccomend!

Where do I start? The beginning I guess 😉 I bought this Beauty, a GV125-S last Month and was not happy with the Power and acceleration, or should I say missing Power of the 14 PS compared to my last ride a Yamaha XV 125 with 11 PS. Dont get me wrong I noticed the difference, but she was just laggy, screaming at me, and the Vibrations when going above 8000 Revs. In 5th gear she hit 10-11000 revs and just stopped power wise, not going any faster than 105 Km/h on the dial. In the German Group on Facebook it was suggested to upgrade the front Sprocket to one with 15 teeth, which I did, She run a little smoother through the Gears and the Engine sounded a bit quieter and wasnt screaming at me, but the loss in Power in the lower Gears, especially going from 2nd to 3rd, and the Top speed of 110 Km/h, which took me ages to get there, wasnt satisfactory, taking her up into the Red again to get here.. Then I saw Marcels post in that Group and decided to buy this Upgrade from the UK and have it shipped to Germany, thanks to Marcel here for the support. What can I say? I took her out on a 3 Hour ride to test, what a difference! The smaller front Sprocket (13) and the Larger Rear Sprocket (Dimension) and 520 Chain is the perfect combination. She shoots up through the Gears, no Jerking, no screaming Engine, next to no Vibrations, just smooth and fast, at 9-10000 Revs in 4th Gear she hits 100 Km/h and in 5th I had her at 120 Km/h and felt like there was still more .... plus it was a windy day 😉 I also ordered the NGK Spark plugs and HT leads which just finishes off a perfect combination. Thanks Marcel and Team, Season nears its end and I just cant wait to get out there next year, the Bike is so much fun now and I dont miss my Yamaha at all 😉

received today with the rest of my order will definitely order again in the future

These coils have transformed my bike. Highly recommended. Fast delivery to Spain. Excellent service from Marcel

When upsetting my GV125 this kit proved absolutely invaluable. Had I not purchased this we would still be struggling with rusty bolts and perished rubber seals. Thanks Marcel.

If you’re looking to improve your 6-7k rpm I would highly recommend this along with the needle that can also be found on this site. I had boggy type issues and after installing this and the needle it’s gone completely, very easy to install 10/10, great help from Marcel too answering all my questions when needed, top guy!

Just upgraded to these coils, the uprated regulator, the uprated stator and ngk caps with iridium spark plugs. I have to say it made an amazing difference, the bike almost no longer needs choke (less than a minute and only on first start in the morning), acceleration has improved significantly and my bike is now charging (which was my original problem :p). Very happy with all items 🙂 Bike is a 2003 gv250 carby model

MARCEL ROCKS! Not only is this kit is a must have upgrade for your bike, but the support and advice i've got from Marcel is amazing! You should now that this is my first motorcycle and I really love to make my hands dirty. I love my bike but the acceleration was a bit disappointing. I've read about a tooth more or less on the front or back sprocket, but i really didn't wanted to loose any top speed. It seemed to be one or the other (more acceleration more top speed). I talked to my dealer about this, but I didn't find any help there. So I contacted Marcel. He sent me the kit and the delivery was very fast (I live in Belgium) Then came the moment of truth: would I be able to do the upgrade myself? I succeeded with easy with some remote support from Marcel over messenger. His reaction time was very fast and I didn't loose time with the procedure if i had a question. Many thanks for that Marcel. The day after the installation came the second moment of truth. Would this upgrade perform as advertised? In short: IT DID! The test ride with these sprockets / chain exceeded my expectations . The acceleration in gears 1-4 is superb now. In second gear i can pull up to 50km/h - in 3th to 70 km/h without going in the red range! The bike pulls really fast now. About the top speed, with original chain kit my top speed was 107km/h on a steep downhill. Now on a far less steep one i reached 119 on display and gps speed was 107 !!! Speed record easily broken.

Upsetting should read Upjetting........ Maybe the two are interchangeable!😁

Highly recommend the kit. Easy to install and big perfomance upgrade.

This is exactily whet this bike needed, looks good to. Was posted on time. Excelent will be using again

Item arrived quickly, with everything needed. I was sent a 13 tooth front sprocket. Have had it installed for a few days and can say while I have not seen the full speed increase (my daily commute to work is along a road with many declines and inclines) I can say that my commute is a bit quicker with this installed and I have seen higher average speeds overall. Also taking off from a stop feels better with the kit installed too. Have seen about a 3 to 5mph (speedo) increase in the gears 1-4. First time installing something like this I had all the tools needed (torque wrench, impact gun, socket set and hammer) had it done within 2 hours having read the instructions the day before so it was a straight forward and logical install (mostly need instructions for the torque specs). Only thing I had help with was holding the rear brake while torquing the front sprocket nut. Only complaint about the kit on my bike with this is that the chain adjustment needed to be set close to the maximum adjustment to remove excess slack in chain. If I have the bike when it comes time to replace the sprockets I will be purchasing this kit again.

Ordered these from Norway. Fast delivery and fantastic support from the team. Bike start much easier and feels snappier in the throttle response. Fitted this together with NGK Caps and Iridium spark plugs.

I have to agree to pretty much all Moustache Man has to say. Not had the chance to hit the motorway yet but was running up hill at 55 in fourth. Previously would have been struggling to sit on 50 uphill, I am bigger than average so it is to the bikes credit that it manages this :p.

Took out the 125 for a test spin and wow i am absolutely amazed. I'm amazed at the rev range that it now provides, i can cruise at 2500rpm doing 30mph in gear 5, it actually hits 60mph in gear 3 which is crazy! I can cruise at 70mph at 8000-8500 revs, whilst beforehand I would only be able to just hit 70 at max revs, around 10500 to 11,000rpm. This means i can safely commute to work with the bike running at 7000rpm doing about 60 to 65mph which is fast and means the engine is under a lot less stress!! Those gains are insane, however, the top speed is even more impressive. I was under the impression that the sprocket kit wouldn't add power, but just shift the power band instead. Which is actually kinda correct. With the stock bike, I only managed to hit 70, barely 71mph. With the new kit installed, I managed to hit 80mph today on a motorway. That's insane! So fast for a 125cc! Thanks for your amazing customer service, keeping me updated throughout my delivery And thank you for the sprocket kit, it has sure made me happy this christmas. The bike is wonderful, and the acceleration too omg! It's crazy! It gets to 0-60 in no time Absolutely wonderful, would highly recommend this modification, so cheap and the chain is a lovely golden colour. Plus the chain seems a lot thicker than the stock one, so it'll definitely take a couple thousand more miles than the stock one. I love it!

Wow such a huge difference, finally changed this myself. Not too scary. Straight swap for old kit. Didn't even need a gasket. Much sharper gear changes and acceleration. I highly recommend. On a scale of 1 to 10 it's about a 6 in mechanical knowledge. Remember to soak the plates and don't over tighten the bolts. It's a full oil change so have at least 2 litres handy

Great plugs, much better than original ones, a must for a smooth running engine.

Arrived super fast. Plugged in my 125p started the engine, took it out for a ride, amazing indeed, instant noticeable improvement to start up, idle, throttle response 🤗 perfect. Thanks.

Installed on RC 2018. The crem de la crem of spark plugs. Engine smooth, power on demand has improved, acceleration unbelievable and a clean start. Worth the money, combine with the NGK caps for optimum performance. Matt