GN250 Custom Project FSM

[chemohelion]

Thanks for the link. Had a look but I didn't think bar end mirrors would suit the bike style I'm going for.
So for the cost of one 10mm nut and bolt I made my own mirror extender.
Attachment 291485Attachment 291486

Hey there Kiwikk, I'm also working on a GN250. Did you do anything with the rear suspension? I want to raise it up a bit and straighten the bike. Also, are the handlebars the original? Where did you get that extra piece across them?

Thanks

[kiwikk]

Hey there Kiwikk, I'm also working on a GN250. Did you do anything with the rear suspension? I want to raise it up a bit and straighten the bike. Also, are the handlebars the original? Where did you get that extra piece across them?

Thanks

Hi Chemohelion,
I've modified the original rear suspension units to give them 35mm more height without having to modify the mounts and without altering the dynamics. Check my profile posts which talk about the issues. The back of the tank and seat front have also been raised by 35mm and the forks dropped by 35mm and preloaded. The bike now handles much better. I can PM you some further details if you like.
The handlebars are new off the shelf MX widest low rise items for a Yamaha by Accel. (The single most expensive part of the project at $65 NZ) The crossbar comes with the bars and is removable for road riding but I'm leaving it on. The front brake reservoir mount is part of fixed casting so it can't be rotated resulting in a bit of a steep angle but the braking is unaffected.

Good luck with your project. Look forward to seeing the results.

[ruaphu]

Nicely done project, had a few of these lil beasties way back. The changes loom great. How does it handle now? Could be a good back roads bike now eh.


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[kiwikk]

Nicely done project, had a few of these lil beasties way back. The changes loom great. How does it handle now? Could be a good back roads bike now eh.

Thanks ruaphu,
The handling is much improved although I'd only rode it once in its original form after I bought it so I didn't get a fair performance baseline. The upright stance certainly allows a lot more control. It's now capable of coping with any situation that you could get a GN250 into.
I don't think it'll ever be great because of the long soft non-progressive fork springs. I've added 25mm of preload to them and whilst it hasn't affected the compression rate, it does seem to have firmed things up a bit. I wouldn't trust that stupid fork retaining circlip arrangement to hold down any more than the extra 25mm even if you could find some safe way of compressing the spring to get it back in without it taking your eye out.

And yes, it makes a great back roads fair weather bike, just exactly what I'd planned it to be.
Maybe see you out around the back roads of New Plymouth eh?

[ducatilover]

Hi Chemohelion,
I've modified the original rear suspension units to give them 35mm more height without having to modify the mounts and without altering the dynamics. Check my profile posts which talk about the issues. The back of the tank and seat front have also been raised by 35mm and the forks dropped by 35mm and preloaded. The bike now handles much better. I can PM you some further details if you like.
The handlebars are new off the shelf MX widest low rise items for a Yamaha by Accel. (The single most expensive part of the project at $65 NZ) The crossbar comes with the bars and is removable for road riding but I'm leaving it on. The front brake reservoir mount is part of fixed casting so it can't be rotated resulting in a bit of a steep angle but the braking is unaffected.

Good luck with your project. Look forward to seeing the results.

How did you raise the rear bro?

[ruaphu]

Thanks ,

Maybe see you out around the back roads of New Plymouth eh?

Yep no worries, We're out and about on our behemoth regularly, easy to spot. It's a large maroon kawasaki 2000cc Vulcan all kitted out with the plate '2L VN'.

Take care on that cool liddle
bike eh, cheers




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[kiwikk]

How did you raise the rear bro?

Bazinga!
My secret revealed:
Picture 1 = Before and after rear suspension height comparison. Looks better without shrouds but they'll be necessary later.
Picture 2 = Components left to right a) 35mm preloader fashioned from hardwood. Lightweight alloy turned billets would be preferrable.
b) 25mm long coupling nut with 10mm fine thread and 14mm flats. Rare as rocking horse shit, so I got them with normal thread pitch and recut using a 10mm fine thread tap. Not ideal so if you've got access to a lathe, make some. (my local bike engineer couldn't be bothered so he scared me off with high price)
c) 40mm of 10mm dia fine thread bolt with head cut off.
Picture 3 = Coupler on. (note use of ratchet straps as spring compressors)
Picture 4 = Preloader on. Essential to get the spring action back where it should be.
Picture 5 = Shroud on. It hides the woodwork.
Picture 6 = Putting top mount back on. (Careful releasing those ratchet straps, keep hands clear or they'll have you)

Also as I've mentioned in previous posts on this subject, the right rear footpeg and exhaust mount subframe will need gently bending outwards by 12mm to clear the now lowered swing arm. Oh and also the brake lever arm will need trimming and the back wheel will no longer clear the ground when on the centrestand and the sidestand will also struggle to reach the ground so it'll need some help.

Worth it?.....

I think so.

[kiwikk]

And here's the left side before and after views.
I've kept the original paint and graphics to confuse people and help the WOF guy

[Kickaha]

If it was me I'd shorten the front guard up a little

[ducatilover]

That's the same way I was considering doing my shocks (mine weren't worth using) before I did the swingarm swap, cool to see it worked and the bike looks much nicer for it

[kiwikk]

That's the same way I was considering doing my shocks (mine weren't worth using) before I did the swingarm swap, cool to see it worked and the bike looks much nicer for it

Cheers mate.
And there I was half expecting a batch of piss taking responses to my cheapo woodwork solution

[ducatilover]

Cheers mate.
And there I was half expecting a batch of piss taking responses to my cheapo woodwork solution

I've seen worse


And done much worse

[kiwikk]

Thanks for the link. Had a look but I didn't think bar end mirrors would suit the bike style I'm going for.
So for the cost of one 10mm nut and bolt I made my own mirror extender.
Attachment 291485Attachment 291486

Update.
That bracket I made helped but the short original mirror crank of 100mm was always going to be a problem. Lengthening the bracket any more would allow too much vibration at speed so....

Christmas pressie for the bike, $29 aftermarket mirror. Same style only bigger.
Gotta keep an eye on those plonkers behind.

[Lower]

looking good man. How have you found the bars? Its the last thing I've got on my to do list before I sell, just want to find something a bit more comfortable. Still liking them or would you of gone for something different?

[kiwikk]

looking good man. How have you found the bars? Its the last thing I've got on my to do list before I sell, just want to find something a bit more comfortable. Still liking them or would you of gone for something different?

The bars were top of my list as they were key to the style for all the other mods and they're perfect for me. The elbows-out riding style might look a bit aggressive for a low power bike but it gives much better control and that means a more confident and enjoyable ride, especially on the twisties.

I'm guessing a bar change alone (without seat raise) might end up a bit cramped

Only downside of the bars is the airbrake effect of your body. GN's can't really afford to lose any power