EC300 Supermoto conversion

[motopsycho87]

Hopefully the gods of eBay will grant me a set of wheels, discs, tyres, spindles and spacers from a very common 17"er today (if not, another day very soon!!), in which this post will be my 'diary' for the process.

Stay tuned!

 

[jt633]

What is the benefit of the rm125 cdi?

 

[motopsycho87]

The benefit is that the EC300 CDI stopped working , though 125's generally rev higher and are timed to suit, so my bike may have super powers, won't know until I dyno it one day .

Anywho, I lost bidding on the wheels, so I bought another set of the same ones .

GS500





First hurdles will be the discs

Front disc -
EC300 - 260mm
GS500 - 310mm

Rear disc -
EC300 - 220mm
GS500 - 250mm

I'll start with the rear, in which I will either turn down the OD and see if there is enough meat left for braking, if not buy this cheeky little rascal
http://www.ebay.co.uk/itm/231126696887?_trksid=p2055120.m1438.l2648&ssPageName=STRK:MEBIDX:IT
and turn out the center clearance!

 

[motopsycho87]

http://www.bikebearingshop.co.uk/C8.htm useful bearing sizes

 

[motopsycho87]

Bearings required (to fit 20mm axles)

Front wheel, 2x 20x42x13 (60042RS), (this is supposed to be 20x42x14, but good luck finding that bearing, the centre spacer will be the same length, just the outer spacers +1mm).

Rear wheel 2x 20x47x14 (60042RS)
Cush drive 1x 25x62x17 (I'll keep this the same and make the spacer to fit)

 

[WAZ]

I've just done a similar conversion to my EC300, but with Aprilia RS125 wheels. I originally started off with Bandit 400 wheels but they were just too much work to fit. If I can work out how to post pics, there should be a photo of mine below!

 

[motopsycho87]

Very nice! Have you got any dimensions for the brake caliper adaptor at all? How does she ride?

 

[WAZ]

I just made up the adaptor as I went along! The two holes in the caliper and the offset were easy enough to measure, then I bolted it on and marked the fork hole in situ.
Here's a close up:

I haven't had it on the road long, but first impressions are it needs higher gearing and stiffer fork springs. Other than that, its a right giggle on twisty bumpy roads!

 

[gassergrant]

hi mate I did this conversion, I used ccm wheels and complete front brake which is brembo, and is used by early 2000 ktm's.

merlin motorcycles in surry can get brackets to suit the nissin caliper.
I had to get dome spacers made for the front and change one bearing for the back to suit the gg spacers

 

[slocalspode]

GG SuperMoto

Nice to see SuperMoto bikes getting some love around here.
Looking forward to see your build reports.
Cheers, Jeff

 

[motopsycho87]

Small update, was completely wrong on front wheel bearings,

25x42x9 was the size I bought in the send, doubled up on both sides. Going to make the internal spacer tomorrow, machine down the hub, brake disc, and new sprocket (disc and sprocket require countersunk bolts).

Can't wait!!

 

[Diggs345]

I've just done a similar conversion to my EC300, but with Aprilia RS125 wheels. I originally started off with Bandit 400 wheels but they were just too much work to fit. If I can work out how to post pics, there should be a photo of mine below!

How much work was it to get the Aprilia wheels in there .

 

[WAZ]

How much work was it to get the Aprilia wheels in there .

Quite a bit, mainly on the rear. The sprocket carrier needed a lot of machining to fit. I also needed to take 2.5mm off the hub on the brake side of the rear wheel, and the same from the disc mounting face. This allowed me to use the Aprilia disc and the GG caliper. The front only needed a couple of mm from the disc side of the hub to line up.

 

[Diggs345]

Quite a bit, mainly on the rear. The sprocket carrier needed a lot of machining to fit. I also needed to take 2.5mm off the hub on the brake side of the rear wheel, and the same from the disc mounting face. This allowed me to use the Aprilia disc and the GG caliper. The front only needed a couple of mm from the disc side of the hub to line up.

Thanks , not an easy fit then

 

[Harry]

Those Aprilia wheels look great.

 

[motopsycho87]

That was a pain in the ass! Report soon

 

[motopsycho87]

Righty,

Front wheel

TZR125 1990 - 1992

267mm front disc machined to 260mm


Rear Wheel

GS500

250mm rear disc machined to 220mm
Cush drive hub machined flush with sprocket
Sprocket bolts countersunk for clearance

Everything else was just spacers and bearings

 

[WAZ]

Looks good mate. I fitted a Polisport YZ supermoto mudguard to mine, a good match for the GG blue.

 

[Anders]

My son Fredrik's 08 Ec300 Racing with 2010 (?) black plastic and stickers. He bought some seconhand 17" wheels locally. Luckily, they appear to be OEM GG wheels so the conversion was pretty straight forward. He uses BT090 tires.
The fron brake setup is a 320mm brake disk, 6-pot ISR caliper and Brembo radial master cylinder.

Sent fra min GT-I9505 via Tapatalk

 

[Capz85]

Small update, was completely wrong on front wheel bearings,

25x42x9 was the size I bought in the send, doubled up on both sides. Going to make the internal spacer tomorrow, machine down the hub, brake disc, and new sprocket (disc and sprocket require countersunk bolts).

Can't wait!!

I'm looking to use these 25x42x9 bearings, I was just going to use one each side but I see you said you doubled up, did you have to modify the hub????