my Lightweight monospine RD350- weight thread and musings

[Dvsrd]

I do have a few spool mx hubs in my possession for the rear.   

Most interesting. Any hint of what MX hubs are easy conversions? Preferably with a cush drive....
For My XS650 project, I ordered a new "Talon" brand KTM 500 hub, and had Central Wheel in the UK lace up a wheel with SS spokes and a 2 1/2" unflanged Morad alloy rim. Flanged rims look better, but are harder to keep clean

[m in sc]

i have some cr hubs available. i havent tried to be honest, they are just sitting on my rack at work.

[Dvsrd]

hpi now. compared to a banshee cdi its almost 4.2 lbs lighter if i recall. i never weighed it compared to the powerdynamo. i think it came in at 2.4? lbs. i had a picture somewhere cant find it right now.

i remember, the heads came in, thay added almost ~2 lbs, but the ignition dropped 4 ish, so it was a net savings of around 2.2 total.

I just checked the VAPE webshop, the PD kits kome in around 2.3 kg or 5 lbs. So the HPI definitely saves some weight.

I emailed HPI, asking for total system weightm incl RR. They replied 1.300 kg, so 1 kg or 2 lbs 4 oz lighter than PD/Vape. Which in itself is at least 2 kg less than oem alternator/ignition/R&R for a points RD.

[m in sc]

between the coil, and the box, regulator, wiring, etc, i know it was ~4 lbs (this was also a 200w aftermarket banshee unit i replaced). Over all doesn't matter, as I added 2 lbs back with the heads. lol.  I weighed it all at work on our scale , i have pics somewhere.


anyway,

few days ago i ran across a post from the uk aircooled group, guy selling aluminum rd head bolts. figure its been a while since i 'added lightness'. while id prefer titanium, my project budget has been slightly diverted in part to other projects, so i got these instead.  i think they cost me around 10 bucks each, posted from the UK.

[teazer]

Good choice.  TZ motors all run alloy sleeve nuts (anodized blue but they fade). I don't remember what the TD3 used.  Maybe Lyn can tell us.

I bought a set of alloy sleeve nuts for my GT750 drag bike from the UK.  They were anodized black.

Do you have a link for those?  I will need some if I change out the RD/TZ hybrid motor for an air cooled RD400 based motor.

[m in sc]

guys name is ‎Jeffrey Newton‎ , uk rd aircooled club, look him up on FB. hes also a friend of Derek Freegards.

Yamaha Aircooled RD Owners Club

https://www.facebook.com/groups/44878139642/?fref=nf

[Dvsrd]

guys name is ‎Jeffrey Newton‎ , uk rd aircooled club, look him up on FB. hes also a friend of Derek Freegards.

Yamaha Aircooled RD Owners Club

https://www.facebook.com/groups/44878139642/?fref=nf

Still happy with these alloy head bolts (sleeve nuts?)
I just sent Jeffrey a message regarding these.

[m in sc]

Yes. hes a bit prickly to deal with but they are beautiful and holding up well.

[Dvsrd]

Yes. hes a bit prickly to deal with but they are beautiful and holding up well.

BTW, congrats with the TZR purchase! Those are indeed beautiful bikes!
Anyway, back to the RD and these alloy head bolts: What type of head gasket do you use? O-rings, 350 style copper or 400 style copper?

[m in sc]

when i had the 'stock' modified heads, used 400 gaskets , chuck set them up for it. on the webco/rprd heads, they are o-ringed.
and thanks, that tzr makes me very happy. 

[JB Weld]

Gosh I remember the posts from the old forum about this build. Love it!! Might be blasphemy, and I wouldn't do it, but what about drilling some holes in the head fins? Might get some of that added weight back.

[m in sc]

Gosh I remember the posts from the old forum about this build. Love it!! Might be blasphemy, and I wouldn't do it, but what about drilling some holes in the head fins? Might get some of that added weight back.

I still have titanium axles i havent put in yet, probably wont. I gained 2 putting the heads on, but lost 4 going from a banshee cdi to an hpi, so im ok w that. lol. its almost too light at this point. (riding it that is). 

I did swap the top triple tree last year, used this unit from 'speed of cheese' (see the vendor section).



old:


new:



currently at 241 lbs with gas in it.

[Dvsrd]

What front brake setup do you have? "Blue Spot" caliper and floating disc? And what does disc and caliper weigh?

[m in sc]

believe the caliper is from an FZ1, rotor is from an fzr600. as far as weight... its  a LOT lighter than a stock one, thats all i remember.

[Dvsrd]

believe the caliper is from an FZ1, rotor is from an fzr600. as far as weight... its  a LOT lighter than a stock one, thats all i remember.

Thanks! On my 350, I have a drilled stock disc (saves maybe 150 g) and an alloy repop caliper from EC. Caliper is great, and a lot lighter than stock. I am considering a custom ISR disc for the stock carrier, but the weight saving potential is limited to 450 g/ 1lb or so, due to the pad track width. Going to a 4 pot caliper would allow a much lighter disc, even at a larger diameter. Will have to ponder this a bit......