Monkey Magic!

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supacool1

Original Poster:

663 posts

191 months

Friday 21st February
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As suggested by @benni on the Nürburgring bike thread, here is a brief build thread of my latest evolution of the monkeybike I've had since 2011.

I've always been fascinated by small bikes. My dad was a biker in India and have memories of riding on the tank of his highly modified Bullet in Mumbai in the 80's. His best mate owned a bike dealership. We'd visit it often and he and his friends would immediately gravitate towards the big sports bikes. I would immediately go for the smaller kids bikes. I still remember it even though I was around six or so.



I got my monkeybike in 2011 spring. It was something I always wanted and intention was to commute to work on it. I did some research and there were two schools of thought.
One was to stay original and get a proper Honda monkey, but there were limitations. Those being non hydraulic forks, 80-110cc engines and drum brakes. Plus the cost was a little higher to buy and modifiy. The other was to buy a chinese copy such as a Lifan, Hongda (lolz) or Jeng Cheng or similar. They have disc front brakes and proper forks on the front. And I wouldn't feel bad for modifying it with non Honda parts.

This was all before the resurgence of the New Monkey, Grom/MSX or Dax from Honda.

Evo 1 - I got a Lifan 50cc, which was a non runner due to the ineptitude of the previous owner. I wanted a registered 50cc as I can ride one on my legacy license (I had done CBT years before and in 2013 I got my full bike license) I was lucky to have an awesome neighbour and mate-Nigel who was very handy and into bikes and motorsports. Dropped off the bike at his. Within minutes he had it running. The previous owner couldn't start it as there were two taps for the fuel. He hadn't found the other one, but had taken apart the headlight and wiring to trace the issue-the dipst. I did a total of 5 miles on the 50cc-which could only just manage 30mph and got it MOT'd.

Evo 2 - As Nigel was pit crew for Lovelock Racing ( Sidecar outfit ) he had access to a lot of spares. He had already found a free pitbike engine that was surplus. It was a 125cc unit. We fitted a bigger 19mm carb and an exhaust. Power had climbed from 2.5 Bhp to a heady 6 Bhp! He cleaned up the wiring as the original 50cc was electric start. With it geared for cruising it could reach a heady 65-70mph on the flat and if I superman'd it. Which was super sketchy on such a short wheelbase-but as this was my first bike I got used to it and doesn't faze me. Tyres changed from the Chinese death trap knobbies to some Michelin Scooter tyres in 8 inch size. I fixed and painted the tank from the 'Regular' orange to Ford Electric Orange after my now ex wife bumped into the bike in the garage and it fell over denting the tank.

Picture not available as I can't find it on my current network.

Evo 3 - I rode it to work and back for a few months over the summer and autumn. Engine was ace with good power and cruised nicely at 50-55Mph on the way to work using B roads that are hilly in places. Looked well daft but I didn't care. I had a great time grinning inside my helmet! I found a community on the internet called 'Monkeyrunners'. They were a forum-remember them? of people around the country that had and rode their bikes in large organised rides. I completed a monkeyrun in the New Forest, Isle of Wight and the Ace cafe/London monkeyrun. It was amazing!
One day when going to work I could not select 2-3. It eventually went in but was getting stiffer to engage the shift. Then it proceeded to make some odd noises and slipping in and out of gear. It was time to spend some money. I'm a believer of change parts if necessary, but upgrade when you can. What I didn't know was that the selector fork on the gearbox was bent 90 degrees for some reason....The engine was repaired and used as a go kart engine for someone a year later.

Evo 4 - I bought a new 140cc racing pit bike engine with a 21mm carb. Rated at 11 Bhp it was a mild power unit and didn't spec the cam as the power was nearly double. I changed the engine and got it all wired up. Went for a spin-was a hilarious disaster. The extra power with the original swingarm made the front wheelie everywhere soon as you touched the throttle. It was time for more mods.
I bought a +10cm rear swingarm and a mono shock. Changed from the Scooter tyres to something more chonky. As the front brake was a basic single pot caliper I wanted something beefier. There was a mod where you can retro fit a Yam scooter caliper which was a twin pot caliper. Removed the folding handbar set up and cleaned up the controls.
Pic below is was taken many years after it was installed...hence the cleaner orange striped wheels.
Nigel and I installed it. It helped braking and looked cool. We also put heavier fork oil into the fronts to give it some more stiffness and better resistance to dive.



I rode around on evo 4 for a couple of years, then I lost my garage due to life happening and moving house. I didn't want to leave the bike outside or under a cover as I adored it and will never sell it. So it went into long term storage at Nigel's dad's lockup sandwiched between a Ducati 998 and an R1 Yam. There it sat for 8 years, until it was time to bring out of hibernation

Evo 5 - It was awaken from it's slumber with a plan to take it to the next level. There were some issues when in storage. Things got a little scabby and tired.

Time to upgrade!

It's an Ohst original with some adjustment on the spring. Nigel wanted to do some fabrication work as he hated the battery was on one side of the frame and didn't like the aftermarket shock mount. So he made the battery fit in the frame and custom made the rear shock mount. In doing so he also cut and fab up a new way to mount the rear shock.

[url]
Changed the chrome luggage rack and grab rail to a black one.
|https://forums-images.pistonheads.com/163705/202502214463206[/url]
Got a new better looking but more uncomfortable bobber style seat.

Tidied up the wheels

New Grips

26mm Nibbi Carb


And painted and decaled the tank in it's signature colour...Not the greatest paint job as was done in the garden but looks pretty good from 5 feet.



I rode the hell out of the bike as much as I could that summer as it had been 8 years since back on the road! Nigel wanted to further refine the bike and make the rear end cleaner by replacing the exhaust to an under belly one. I take all my new bikes to take 'The Photo' so I packed a rucksack with the drone and some snacks and rode to Goodwood from Basingstoke. It was an epic day. And I got my photo. I also added a Tacho that reads hours run on the engine and has a max RPM light. It's not the best but have integrated it well on the fat bars.



On the 10th year anniversary of me doing the Ace Cafe/London monkeyrun, I managed to hear about it happening for one last time by the organiser, Hal. While the Monkeyrunners website forum was no more the scene was slowly but surely dying and moved to facebook groups. I managed to go on the hottest day of the year in the big smoke. It was amazing to behold and I loved being part of it and seeing some familiar faces. But in the heat it did highlight some issues with the placement of the oil cooler. We were boiling and the engine is air cooled and stuck in traffic and 20mph limits didn't cool the engine well. Something for the next evo....





Evo 6 - I wanted to hop up the Mildly tuned 140cc YX engine. So I bought some bits over the off season. I got a high comp piston, a high lift cam and we were going to get the head ported and polished. As the current 140cc lump is running well with no issues it didn't seem right to break open and build the only engine I had. We went looking for a replacement unit. On the FB groups there was a chap in Portsmouth that was selling all his parts and culling his bikes down to a more manageable amount. He was selling a 140cc YX engine. I picked it up cheap and brought it home.




What I didn't know made for a pleasant surprise....That it was a 00 Racing unit tuned to stage 3. Which means a high comp piston, Beefy gearbox, lightened flywheel, high lift cam, ported and polished heads! We were over the moon. It was partially stripped down to change a couple of gaskets and freshen up and inspect.



We installed the engine into the frame and started it for a trial basis to see if it ran. Oh boy did it run. Fired up on the first kick, sounded more aggressive on revving and revved faster. It was an angry lump!
https://youtube.com/shorts/b_0gEsqwTMw

We took this opportunity and changed the position of the oil cooler so it was behind the headstock and in the airflow. This is going to be very much needed to keep the highly tuned engine in rude health. Power is estimated to be in the 16 + Bhp range. It's a bit of a pain to start now, but once you get the knack it starts up first kick. If you get it wrong it'll destroy the starter shaft and or kick back brutally through the kick starter.

And the only other minor change was a change of tyres and got some G Craft wheels. Unfortunately I got the width wrong and the tyres look a little thin but grip well. Below where I am at currently, with plans for Evo 7.


Evo 7 - Mapped out in my head but way behind due to working through tidying up my e39 M5 for a May Germany trip....can you guess where...? Anyway, originally planned to be a huge change but I've run out of time. The ohst rear shock is too soft and am gonna spend some money and get a better one installed. I've already spoke with some people and getting a heavy spring unit with damper adjustment. Also going to fit new seals on the engine as there is a weep of oil from the gear lever shaft and get the engine inspected and valves adjusted.

Future state - I want to change the entire front end and put USD forks on, change the old school style chrome headlight bowl. We want something modern looking and square LED lights, clean up the wiring as all the wiring runs into the headlight bowl and change the speed to something modern with a built in Tach. I've read and seen some vids from custom bike builders that use Moto Gadget Mo.unit to control the electronics and has bluetooth. It all looks soo cool and is feature rich, but can be pricey as the Mo.unit is £350, plus you will need wiring and you can option various things where you only have three or four buttons that do everything depending on length of button presses etc. Some really cool stuff but can get expensive. I might treat myself to it in the winter once all my car road trips are done....

Thanks for reading and showing interest.





Edited by supacool1 on Friday 21st February 14:39

supacool1

Original Poster:

663 posts

191 months

Monday 24th February
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3DP said:
Great evolution there - I bet it goes really well with that power! I must get along to one of the Monkey runs.

My plate on my modern Monkey has this thread title on it smile

Noice. I had a brass plate made up with 'Monkey Magic' by some friends who had a CNC machine and some spare brass plates from work. You can see it one of the earlier evolution pics.
But I much prefer Monkey Spanker....biggrin


As for modifying it to evo 100 and having a MT07 - Why would I do that...? MT's blow...rofl

supacool1

Original Poster:

663 posts

191 months

Monday 24th February
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Benni said:
Hello Supacool,

thank you for the great intro / evolution of your small bike.
Consider yourself lucky that all those mods are legal in GB.
In Germany only very old vehicles are custom material, as the noise and pollution regs of the year of build apply,
any modern stuff from 1989 on is quite restricted and all "foreign" parts require certificates and E-Numbers.
( This is why I am in the process of Dax-Maxing my 1973 ST70 to 175cc with a bored and stroked "Honda Nice" engine. )
What kind of USD forks are you looking for ?
The Skyteam 45mm looks beefy but is a glorified moped unit, does not even have a damping piston inside.
Maybe your friend can shorten a "real" USD. I have seen Monkeys with shortened Honda RS125 racing forks,
but those parts are very rare and expensive, fully adjustable though.
Some USD from Pit Bikes can be adapted, but good quality has it´s price.
OOracing seems THE place to go for chinese material, not all is shoite and some parts can be modified & beefed,
they know their business and are enthusiasts themselves.
If you know small computers, an Arduino can be built and programmed for many electrical control functions.
Please keep us updated, I post some pix of my build when a step is finished in "a picture a day" here in BB.
Hi Benni. The Germany TUV regs are brutal and I kinda understand the reasoning behind it, but still hard to swallow. I want to retain 8 inch wheels to keep it original looking (Lolz) as the 10 inch wheels to my eyes look a little oversized and brings it closer to the modern stuff. Even though it opens up a lot more choice on the tyres.

Ideally I'd like adjustable USD's but they are not really a thing in the monkebike world. Unless we get a Grom/MSX front end, upgrade and modify it. Which I am open to as the next Evo will be the biggest change and I want to transform the look. As for the cost, I'm not that fussed on it as it's my most favourite thing in the world and makes me smile when I see it and ride it. So it's worth it.

They do post up on the Facebook groups about Monkeyruns but it's a bit hit and miss with the FB algorithm.

Thanks for the comments and positivity.


supacool1

Original Poster:

663 posts

191 months

Thursday 13th March
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HTP99 said:
I am a non biker, I see these Monkey bikes about and often wonder what's the attraction, they look odd with a grown man on them they look bloody uncomfortable and look just downright dangerous, I asked a bike riding colleague about them, he didn't get them either.

What's the appeal?
The appeal is they are fun, always put a smile on your face and make you enjoy riding again. As it's not about speed-65-75mph max. But when you do get up to NSL speeds the scale of the bikes is that small it feels like you are doing 180mph! Yes there are some issues such as if you caught behind someone dawdling at around 50mph or so overtaking them can be a bit sketchy and has to be planned, but in those cases you just sit back and enjoy the ride. But when you do commit to an overtake and complete, it's immensely satisfying!! Also helps if you are feather weight or have a built motor!

I've always enjoyed riding the monkeybike. As it was my first bike I had got used to the handling traits and the almost telepathic way it dips into a corner just with the slightest weight through your feet. There isn't anything as fun as a bunch of fully grown adults (who might be a little husky) riding these small bikes in a group having the most amount of fun. You can't help but smile and if you happen upon a run and see a bunch of runners riding towards you, I defy anyone not to have a smile on their face.

The 2012 Ace cafe/London monkeyrun riding through Portobello market. Can you spot me?
https://www.youtube.com/watch?v=fB0NXn0b-3A

2015 Ace cafe/London monkeyrun
https://www.youtube.com/watch?v=_PpCg8zv7r0

2011 Heartbeat monkeyrun
https://www.youtube.com/watch?v=hm_yURa1DF8

As with most types of biking, it can be dangerous, but no more so than usual. You will always have some prick pulling out from a junction even though they've seen you. But that happens regardless of any type of bike you're on.

I am glad you all have enjoyed the thread and that I might have inspired some to go down a rabbit hole.


supacool1

Original Poster:

663 posts

191 months

Thursday 13th March
quotequote all
3DP said:
Their handling is crazy entertaining as they weigh little and have small wheels, but function as a motorbike, rather than a scooter.

They can be used off and on road and have you giggling the whole time.

They are simple to work on, cost buttons to run and are endlessly modifiable.
Exactly this! That's a great selection of bikes there!

supacool1

Original Poster:

663 posts

191 months

Thursday 13th March
quotequote all
Parts are arriving for Evo 7. New adjustable heavy sprung pitbike rear shock. And it's serendipitous that the spring colour matches the wheel colour! I've received the engine seal kit for the built YX140, so will be stripped, inspected and refreshed with new gaskets as well. As mentioned not the biggest evolution but still making progress.





supacool1

Original Poster:

663 posts

191 months

Thursday 13th March
quotequote all
shirt said:
Great thread and build!

And timely, as I came into the forum to ask about Monkey’s! Feels silly to start a new one so hope the OP doesn’t mind me intruding.

I just bought this one for £500. Haven’t seen it yet and this is the only pic but I know the guy who’s selling it, he says it’s mechanically sound just a little scruffy and needs tyres.



The plan is to give it a spruce up and have it as a runaround for my OH.

From the tank script and bars, is it possible to date it? I’d like to read up and understand what mods are desirable without going too silly. I’d like to buy all the bits and hopefully get it done in time for her birthday.

We live on a steep hill so some more power would be nice but I don’t want to end up needing longer swingarm etc. some pep and additional rideability, and then some bling.
Hi Shirt. Nice bike. To my eyes below all that dust it looks to be a Honda, but then you can get repo Honda Bits and stickers on a Chinese copy-as you paid half a bag of sand for it, I suspect the latter. But none the less it's a decent start.

Cheapest way to get more power is either to get a barrel kit to make the 50cc into an 85 or a 110cc. https://www.ebay.co.uk/itm/196950164871?_skw=barre... this does mean taking apart the head, getting it timed correctly and all the rest of top end fiddling. Or you can get a whole new 110 semi auto boxed engine. They are about £200 new on ebay but look on facebook groups for monkeybikes and something cheap might come up. They won't set the world on fire so you should be good with the standard length swing arm. But would recommend you change the rear shocks to something a bit beefier to cope with the extra power.

You can find barrel kits and Honda parts at https://www.shirebikes.co.uk/ if it is a Genuine Honda. The bits are interchangeable but will be pricey.

Put https://ooracing.com/ as a favourite as you'll need to compile a shopping list. One thing I will say is make sure the charging circuit/stator is at full health. We've made a franken-stator from the original 50cc engine and the first 125 with the broken gearbox fork into a double coiled beast for redundancy. As the original one was struggling with running the lights at idle. And as the build brief was for me to commute on ( I worked shift ) I needed reliable power/lights. Pretty much overkill now as everything on the bike is LED and draws less power.

We had toyed with the idea of going to a capacitor instead of a physical battery to lose to weight and better aesthetics-but we couldn't get it run right and kept risking blowing rectifiers. One of the joys of kick start! Soon gave up on that though and moved the battery into the frame. But a cheap lithium lightweight battery is calling.....

Have fun on the start of your monkey modifying journey!

supacool1

Original Poster:

663 posts

191 months

Monday 17th March
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shirt said:
It is home



Engine runs sweetly, if about as noisy as an electric toothbrush. Tyres don’t hold air so need to source some and I’m going away for the next 6 weeks so I anticipate a build up of tuning parts in my absence! It’s kickstart with dynamo electrics and appears to be genuine jdm Honda.

That is amazing! It's a good original one. I'd be inclined to get it running well, semi restore it and ride it standard. Or change the engine to get some extra power if that is the build brief.

supacool1

Original Poster:

663 posts

191 months

Monday 17th March
quotequote all
NITO said:
Thanks for posting, an enjoyable read, Nigel sounds like a God send!

It’s great to see you enjoying it like this, takes me back to being a youngster. I’ve sat on a Monkey and Grom and considered one for fun, and often see a little pack of them out and about. I also quite liked the VanVan, although I look like an ape sat on one of them wink

Keep enjoying and having fun…

To the owner of the black Grom, it looks like a mini StreetHawk!!

I always loved the Baja Honda Monkey that looks like an Africa Twin, but they fetch big money!


Nigel's a dude all right. Always up for tinkering with something and getting the spanners out. And as the bike is (relatively) small he can bring it into his house to tinker in the warmth in the off season. He really enjoys working on it and is always up for the next Evolution.

supacool1

Original Poster:

663 posts

191 months

Wednesday 16th April
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AceOfHearts said:
My Baja Monkey replica is starting to take shape party

That looks amazing! Good work! Is it going to live in the house or will it get ridden?

Mine is getting a refresh for this years evolution.

supacool1

Original Poster:

663 posts

191 months

Wednesday 16th April
quotequote all
AceOfHearts said:
The plan is to take it to Malle Mile this year, and use it as a pit bike at Silverstone Classic this. Its not registered so will be off road only,

Edited by AceOfHearts on Wednesday 16th April 15:42
Awesome dude! You'll be the coolest guy there riding that around.

supacool1

Original Poster:

663 posts

191 months

Thursday 17th April
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Bob_Defly said:
I would honestly be scared riding something that small amongst busy traffic.
It's not too bad - a beefy exhaust helps, as does a loud horn should you need to make your presence known. And if you have a little bit more power to squirt around traffic it's not at all bad. You do get people that will be blind when pulling out of junctions but no more so than on a 'regular' sized bike. The only time I was scared when I took a wrong turn onto the A34 and had to ride to the next junction on a breezy day.

supacool1

Original Poster:

663 posts

191 months

Wednesday 23rd April
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Evo 7 - Update.

The monkey is with the Legend, Nigel getting fettled. The replacement rear shock is on and is looking great...am in two minds whether to cover it with the shock sock or let it be open to the elements. It does look great with the blue wheels! And as it's adjustable it should make a huge difference.


But there was some bad news. The oil leak was a little more serious than initially thought. I thought it was leaking out of the gear lever shaft seal. Which was weaping to be fair. But when flywheel side of the casing was opened up there was some misting behind the flywheel. So needed to be take off and inspected if it was the seal-lucky for us it was the seal and as I had bought whole seal kit it was included.

But there was an issue getting the flywheel off. The specific puller wasn't getting much purchase on the threads as someone had tried to take it off before and gakked some of the threads. Luckily with some thought and perseverance Nigel managed to get it off with minimal damage to the thread on the flywheel. You can see the fresh seal on the gear lever shaft on the pic below...


It was noted the original brake disc was quite glazed and I've always complained about the wooden feel of the brakes on the front. When we did the Brembo caliper install I had put in a set of sintered pads. They were always wooden in feel and only had a decent feel when there was a bit of heat into them. I changed the pads to fresh ones last year but with no great improvement-I ordered standard road pads but kindly the seller had sent me the sintered pads free of charge. Anyway, a new standard disc will be bought and installed after a debate was had regards potentially changing the master cylinder as an upgrade...Remembering that over winter we're fitting a new USD set up and will come with new brakes...so might not go ahead unless Nigel can find something cheap.

Will update soon as I have more. smile