Advice on sm250 please

[Niall-griffiths]

Hi all recently sold my ec300 to go to a supermoto route I've found a sm250 but have some questions

what is the differnce between the sm and ec apart from wheels and front brake? I guess perhaps the suspention is abit more firm??

How many hours/miles should I be looking at top end rebuilds? These are no problem for me but could I go once a year? Bike would only be ridden in the dry with warm weather and in the uk there ain't to much of it lol.

also can these things take half hour 60mph trips on and off without being under to much stress?looking at specs they seem to have the 6 speed box so if I gear taller I imagin this shouldn't be a problem?

this is the one I'm looking at do you guys think its reasonably priced??
http://www.ebay.co.uk/itm/2002-GAS-GAS-SM-250-BLACK-/151345628774

 

[gassergrant]

i converted my 300 to sm and have the best of both world.
i would not dare hold it open for 30 mins at 60 unless you really want to play with the sprockets larger front say a 15 and smaller back 45 ish to do that, i use a 13/14 front and i think its 45 rear i cruse around at 50 i even tried the motorway and shat my self when all lorrys over take blowing me around lol. there are good for short sprint around country lanes and are bloody good fun.
i would say the engines are the same, frame too not sure about the suspension valving tho

 

[gassergrant]

bike looks nice i recon its worth 1500 there quite rare, if i sold my one i would sm it up and try for about 1600

 

[Niall-griffiths]

Managed to get it for ?1200 with a years m.o.t

thanks for reply grant. Does it really struggle at 60mph? The guy reckons it maxes around 90 so I wouldn't of thought it a problem it wouldn't be motorway it would be 60mph on long roads to get places. Main use will be country roads tho.how long till you needed rings and piston on the road grant ??

 

[gassergrant]

i had 86 out off my one down hill lol it will sprint wright up to top say 90mph but you will have to back off.
1200 seams good mate. best thing to do is mate is get take it out for a burn and you should be able to work out what you can and cant do with piston and ring again i had my piston in for 2 years with over 100hrs im just in the process of putting a new one in now, wait until it starts loosing power or done over the big 100hrs
there good bikes tough as old boots hope you enjoy it mate sm rocks

 

[stian]

Cant tell you right now, but ive got some SM wheels on order for a EC300 2007.

Been driving KTM EXC125 on road for a couple of days. No problemo. Its common used where I live, so use it for everyday stuff, but its stressing at the highway.

13 or 14 - 42/44 sprockets. High speed, low rpm, longer wheelies.. haha

What front caliper do you have on the 250SM? Im looking for a 4-6pot front caliper, dont think the standard EC300 are going to hold up.
ideal "high" speed would be around 55-65mph.

 

[Niall-griffiths]

I rode my ec300 on road with x2 wr125s at 65 and it found it easy but I reckon gearing was tall 6th gear 60mph was no problem and right low I will have to see what speed it can do then work out if I'm happy or need to gear taller.think I wil put a piston kit in straight away anyway, although I have found a genuine 300 cylinder piston head gaskets for ?400 brand new so i am temped as the 300s tend to go longer on rings than a 250 and should pull abit easier top end

and stian when I was riding on my ec300 the brakes where pretty good on road but I must admit I did keep locking the rear on abit probably just because I wasn't confident with using the front to much espeshily with knobblies.

it's a Bremo 4 pot I think. I pick it up Sunday so will let you know how I get on and what caliper disc Ect.

 

[stian]

I rode my ec300 on road with x2 wr125s at 65 and it found it easy but I reckon gearing was tall 6th gear 60mph was no problem and right low I will have to see what speed it can do then work out if I'm happy or need to gear taller.think I wil put a piston kit in straight away anyway, although I have found a genuine 300 cylinder piston head gaskets for ?400 brand new so i am temped as the 300s tend to go longer on rings than a 250 and should pull abit easier top end

and stian when I was riding on my ec300 the brakes where pretty good on road but I must admit I did keep locking the rear on abit probably just because I wasn't confident with using the front to much espeshily with knobblies.

it's a Bremo 4 pot I think. I pick it up Sunday so will let you know how I get on and what caliper disc Ect.

60mph, thats probably 13/52 or something. I think I read that with 13/42 it does around 100mph/160kmh. Not that your going to do those speeds, but not to over-rev the engine all the time.

Thats what I thought. The EC300 enduro got 2pot I think, and thats not enough.

Take some pictures if your supermotarding it. Seems that people dont have the big intrest in SM a gasgas..

 

[WAZ]

I've tried 13/44, 40 and 35t on my SM'd EC300, and so far the 35t makes the most sense on the road. I used an on-line gearing calculator which gave a top speed on this gearing of 112mph (which given the aerodynamics it'll never achieve), in the real world I've had 100mph out of it. I may try a 14t front with the 40 rear next.

The standard 2 pot EC caliper is just about acceptable with a 320mm disc, but I have a 4 pot Brembo to go on when I get round to making a mounting bracket for it.

 

[slocalspode]

I am running 14/40 on my EC250SM and like it very well.

I did not know you could get a 35 tooth rear sprocket?!? wow.
40 was the smallest I could find when I was looking.

 

[WAZ]

The 35t was a one-off, made by Talon to fit the Aprilia RS125 wheels.

 

[Niall-griffiths]

I am running 14/40 on my EC250SM and like it very well.

I did not know you could get a 35 tooth rear sprocket?!? wow.
40 was the smallest I could find when I was looking.

Hi Mate what kind of speed does that gearing achieve for you ? Cheers

It's already a supermoto stain I sold the ec300 to get it,I'm wondering if there's much difference between the 250 and 300 in top end with same gearing?

nice bikes everyone where they much hassle to convert? Not many have done it so product info seems poor?

 

[stian]

The hassle is with newer designs, due to the front light-plastics assembly and form. As I know, you cant order SM frontfender new for this. Thats why the gassers often appear with Sm wheels and standard cross-frontfender.

If its a 2000-2009 (I think) you can just fit a universal Acerbis SM front fender, and just SM wheels with OK gearing.

Ive got a order for some Morad Wheels at Motocrosscenter, anyone knows what the sprocket that is on it is? Is it 40 or 42 or something?

 

[gassergrant]

I have a blue sm universal front guard got it of eBay for 20 quid and I use 13/14 with a 45 rear goes well and still wheelies like like a cat on a hot tin roof lol

 

[gassergrant]

Hi have the info for ccm wheels
Front you will need new spacers made.
The rear you will need to change a bearing on the sprocket side to suit the GG spacer
I used a ccm brembo with sm adaptor or one can be bought from motomerlin to suit the GG caliper
It's easy and bloody good fun it could do with some engine brake so it might be worth looking in to a thumb brake

 

[stian]

Hi have the info for ccm wheels
Front you will need new spacers made.
The rear you will need to change a bearing on the sprocket side to suit the GG spacer
I used a ccm brembo with sm adaptor or one can be bought from motomerlin to suit the GG caliper
It's easy and bloody good fun it could do with some engine brake so it might be worth looking in to a thumb brake

Whats the price of the Ccm wheels? Like ive said, ive got some on order for at crosscentral or what its called, but they dont have it in stock.
THe price with tires,rims,calipperadapter and sprocket + brake discs is 880 euro. Morad, black rims.

2010+ isnt any sm front fender that would match the headlightmask.

Sorry to say, but GG is a quite terrible manufacturer (opposed to for ex. KTM)

 

[gassergrant]

I agree GG are rubbish for after market stuff, it the only thing that puts me off these bike but I would rather give up riding than own a craptm.

soz em I got them off ebay for 350 if my memory serves me, husky I think fit nut then I put new tires on, get the brake and adaptor. and then get the spacers made
I would say 880 don't sound that bad, if you was looking at talon/exel hubs and rim. I recon it would cost that just for the wheels

 

[motopsycho87]

Mine cost ?100... Tzr125 front, gs500 rear no brake adaptor

 

[stian]

I agree GG are rubbish for after market stuff, it the only thing that puts me off these bike but I would rather give up riding than own a craptm.

soz em I got them off ebay for 350 if my memory serves me, husky I think fit nut then I put new tires on, get the brake and adaptor. and then get the spacers made
I would say 880 don't sound that bad, if you was looking at talon/exel hubs and rim. I recon it would cost that just for the wheels

Its standard GasGas, Morads, black rims.

So, looking for 4 pot front calipper for the 320 disc. Does someone know what calipper that got the same screw holes as the 2pot EC300 cal?

And not only rubbish for aftermarked, I was struggling to find parts in scandinavia, and not jus that; Part delivery from the factory is terrible.

 

[Anders]

Its standard GasGas, Morads, black rims.

So, looking for 4 pot front calipper for the 320 disc. Does someone know what calipper that got the same screw holes as the 2pot EC300 cal?

And not only rubbish for aftermarked, I was struggling to find parts in scandinavia, and not jus that; Part delivery from the factory is terrible.

Where in Scandinavia are you located? I live in Norway.

I doubt that you find a 4-pot with the same mounting holes as the OEM Nissin suitable for a 320 disk.

The GG SM bikes were delivered with an adaptor to fit "Brembo 40mm" and a Brambo 4-pot caliper.

THis is the part you need

"Brembo 40mm" is the old Brembo standard used by lots and lots of european street bikes in the nineties. E.g. any Ducati before 1998 had these calipers. Very easy to find secondhand.

The alternative would be to use this adaptor to move the OEM calipper out.

ISR, PVM, Spiegler and others make aftermarket calipers that uses Brembo 40mm fitment. If you choose to go for a 4-pot or a 6-pot, I presume your master cylinder might also need replacement, but I havn't tried running the OEM master with anything but OEM Nissin caliper.

My youngest son just built an EC300 SM, using the above mentioned adaptor and a ISR 6-pot caliper with a Brembo radial master cylinder. Works very well.