RD500 in a TZR250 3MA Frame

[Captaincosmos]

Can anybody tell me the main advantages and disadvantages of attempting this project? I want to keep the cost reasonable and I want to ride the bike on the road.

[tacky1]

Looks really, they look more like a GP bike, Handling might be a little better with the suspension rebuilt, resprung and set up, It aint gonna be cheap

[lost1750GTV]

"Look more like a gp bike"
Depending on the year /era

[tacky1]

"Look more like a gp bike"
Depending on the year /era

Cmon, we are on a vintage 2-stoke forum, So lets all agree \GP bikes back in the early 90s, 2-stroke GP bikes maybe!!!!

[lost1750GTV]

Hey, 2 stroke gp goes back a little farther than early 90's.
So not something I would agree on.

[silverstrom]

You do it because you can. Compare the RD500 frame and the TZR frame. The handling will obviously be improved, but that compact TZR frame is meant to carry 75 kg less weight, so there will be drawbacks, not to mention the expense. Lovely things when done though.

Every time we discuss this topic the same person starts an argument. Just wait for it.

[silverstrom]

Hey, 2 stroke gp goes back a little farther than early 90's.
So not something I would agree on.

Yes, but it's obviously safe to assume that using a late 80's/early 90s donor frame will be intended to yield a late 80's/early 90s GP rep. If you wanted a GP rep from back a little farther than early 90s you would use a donor frame from back a little farther than early 90s, unless your intent is to build a GP rep with no clear direction.

[tacky1]

Hey, 2 stroke gp goes back a little farther than early 90's.
So not something I would agree on.

You’re right. Sorry.
But they didn’t look like a TZR framed bike.

[Captaincosmos]

It’s not so much that I want a GP rep, I love two strokes but I want a better bike than the 80’s had to offer. Fast forward to the mid 90’s and look at the improvement in cycle parts and tyre technology. I’m hoping the 3MA frame dressed in more modern components, gives me a 2 Stoke that I can enjoy riding. Think about it, I bet there is more knowledge on this forum regarding geometry set up then Yamaha had in the GP team back in the early 80’s. That’s not saying that we are cleverer, it’s just that the development work has been done and we’ve learned from the mistakes of the ground breakers, to paraphrase Newton, we’re standing on the shoulders of giants. I can’t remember considering pro and anti squat in the 80’s but the short frame/long swingarm approach cemented with the introduction of the R1, had us all talking about it. From a practical standpoint, what are the issues if any, surrounding front cylinder clearance around the radiator and front wheel? I want to fit shotgun lower pipes so is there a preferred swing arm with the bracing on top rather than underneath? Is it worth pushing beyond a 160 back tyre?

[steveho]

From a practical standpoint, what are the issues if any, surrounding front cylinder clearance around the radiator and front wheel? I want to fit shotgun lower pipes so is there a preferred swing arm with the bracing on top rather than underneath? Is it worth pushing beyond a 160 back tyre?

I’ve got a 3MA RD500, and the front cylinder clearance isn’t too bad. I’ve even fitted an extra lower rad in between the tyre and cylinders. A 60 profile tyre helps, and short TZ spark plugs too. A 3XV swing arm looks the part as is ‘banana’ type, so GP pipes fit. A 180 tyre fits too. Go for it!!!

[ns86]

Many other examples, Member Dubsey's being one of the nicest!

http://www.nkracing.co.uk/n9.html

[Captaincosmos]

Just had a look on the nk.racing website and I was like a kid in a sweet shop. Mentally, I spent a small fortune in the first minute, then the reality of floating the cost past my better half sank in. My original thoughts were usable road bike and I think I’d better stick to that. I’ve been looking at the R6 again this afternoon, wheels, forks, brakes and some of the bodywork from circa 2008 look promising. I’ve had a look at your swing arm suggestion, it looks like a really good solution but is it long enough to Cope with the squat? And can you keep the front on the floor (some of the time)? I suppose the next step is finding a frame with a V5 for the right money, I’ll start looking.

[innovativems]

From a practical standpoint, what are the issues if any, surrounding front cylinder clearance around the radiator and front wheel? I want to fit shotgun lower pipes so is there a preferred swing arm with the bracing on top rather than underneath? Is it worth pushing beyond a 160 back tyre?

I’ve got a 3MA RD500, and the front cylinder clearance isn’t too bad. I’ve even fitted an extra lower rad in between the tyre and cylinders. A 60 profile tyre helps, and short TZ spark plugs too. A 3XV swing arm looks the part as is ‘banana’ type, so GP pipes fit. A 180 tyre fits too. Go for it!!!

you git a 180 on the 3xv swinger? details please!

[tritonpat]

i have built two of these i can assure you they will not weigh 75 kgs more mine weighs 150 kgs total, they are a lot of work but well worth the time and effort