Suitable rubber - GT125 (18" rims)

[davebullet]

Ok guys....

OEM fitment on the alloy rims are
Front 2.75 x 18 (80/90/18)
and
Rear 3.00 x 18 (90/90/18)

AJ (is he still bucketing?) was running this Thai stuff called "vee rubber". I don't think the venerable BT39SS comes in an appropriate 18" size.

Are any of you mad enough to run 18" rims and those that are, what rubber do you recommend in an 18"? (apart from black round stuff)

[quallman1234]

Buy a new frame, put 17's on it... And get some slicks... Won't even be that much more than buying new 18" rubber and much better...

Promise ;)


For your information
http://www.cycletreads.co.nz/products/227-bridgestone_road/1510-bridgestone_bt_39_road_sport_t.aspx

[davebullet]

Buy a new frame, put 17's on it... And get some slicks... Won't even be that much more than buying new 18" rubber and much better...

Promise ;)


For your information
http://www.cycletreads.co.nz/products/227-bridgestone_road/1510-bridgestone_bt_39_road_sport_t.aspx

That's the long term plan. Short term is just to take it out as is and have some fun.

It's not legal anyway with dual 24mm carbs (presume I can just pay for the day and have a play). I have no delusions of actually riding well. I just want to stay upright, have fun and not collect anyone in the process :-) (that should all make you a bit worried).

Basically - have a go and if the bug bites and time allows, get more mechanically skilled and work up a nice little machine.

[davebullet]

For your information
http://www.cycletreads.co.nz/products/227-bridgestone_road/1510-bridgestone_bt_39_road_sport_t.aspx


Cheers... maybe I'm miss-reading things:

I thought the
B/STONE R 100/90 18 B39R SSTL
would be for an equivalent 3.25 or 3.50 rim (not 3.00)

I'm guessing the
B/STONE R 250 18 BT39SS
would be ok for my 2.75 front?

[sidwyz]

Iv'e used Bridgestone BT45 successfully, get a front for the back as well, just run it backwards.

[Drew]

I took one look at the bike I scored from AJ, took the motor out and filed the rest in the, "do not even think about riding this" corner of the shed. The tyres on it might be OK, you can have the wheels and tyres for a box of Heineken.

[gav]

Set of 17" rims right here http://www.trademe.co.nz/motors/motorbikes/parts-for-sale/wheels/auction-492803057.htm

[all4A50s]

Ok guys....

OEM fitment on the alloy rims are
Front 2.75 x 18 (80/90/18)
and
Rear 3.00 x 18 (90/90/18)

AJ (is he still bucketing?) was running this Thai stuff called "vee rubber". I don't think the venerable BT39SS comes in an appropriate 18" size.

Are any of you mad enough to run 18" rims and those that are, what rubber do you recommend in an 18"? (apart from black round stuff)

The BT39 do come in these tyre sizes and are the best option you can buy. My daughter is racing a GP100 and they are the tyres I'll be fitting.

[davebullet]

I took one look at the bike I scored from AJ, took the motor out and filed the rest in the, "do not even think about riding this" corner of the shed. The tyres on it might be OK, you can have the wheels and tyres for a box of Heineken.

Thanks for the offer Drew, but if they are 18" rims I will pass. Next step for me would be as said above (new frame / rolling chassis with 17" rims).

[davebullet]

Set of 17" rims right here http://www.trademe.co.nz/motors/motorbikes/parts-for-sale/wheels/auction-492803057.htm

Hmmm, my mechanical skills are limited and I wouldn't know where to start when it comes to fork spacing, rear swingarm clearance, callipers / disk replacement etc.... I might be better off with a rolling chassis and motor transplant

[Drew]

Hmmm, my mechanical skills are limited and I wouldn't know where to start when it comes to fork spacing, rear swingarm clearance, callipers / disk replacement etc.... I might be better off with a rolling chassis and motor transplantThe best plan, but measuring wheel spacers is much easier than fabricating engine mounts to fit an aluminium frame.

[crazy man]

just get some shin skins or what ever there called

[koba]

Thanks for the offer Drew, but if they are 18" rims I will pass. Next step for me would be as said above (new frame / rolling chassis with 17" rims).

Don't pass, If AJ put tyres on it they will very likely be much newer and better than what's on there; that'll help you get started.

[koba]

I might be better off with a rolling chassis and motor transplant

Great idea, also more engineering than most would credit in that undertaking too.

Just get started on what you have, no-one will care if you show up with the standard carbs to begin with.

[mossy1200]

Great idea, also more engineering than most would credit in that undertaking too.

Just get started on what you have, no-one will care if you show up with the standard carbs to begin with.

Unless your name is Drew..........

[Drew]

Unless your name is Drew..........

Fuck it, I'm chucking on my pair of 21mm flat slides now:baby:

[davebullet]

Don't pass, If AJ put tyres on it they will very likely be much newer and better than what's on there; that'll help you get started.

True that. Front tyre currently has no descernable brand and has extra tread on the sidewalls (ie. cracks).

Rear tyre is some wang chung or other chinese brand. has a fair amount of tread, but rubber has the same supple consistency as the lid of a tupperware container.

I think AJ was running Vee Rubber on his.... Would it matter if I was running the same profile front and rear - ie. 90/90? Normally, a narrower profile is run on the front (probably for agile cornering reasons) or wider on the rear (for grip / drive out of corners). Or maybe I shouldn't worry about it.

Clip-on bar conversion is nearly complete - ie. I've flipped the one piece ventura bar upside down...

Now I just need to:
a) hide the ugly wiring loom the removal of the headlamp revealed
b) nylon everything
c) lockwire the sump plug / filler cap

Then I can take my illegal bike to the track.

Do I need a race number if not competing for points? Presume not. 69 is looking rather tasty. Rationale: It will still be readable upside down when I crash

[koba]

Fuck it, I'm chucking on my pair of 21mm flat slides now:baby:

Where on earth would one get a pair of 21mm flatslides, MVX?

[koba]

True that. Front tyre currently has no descernable brand and has extra tread on the sidewalls (ie. cracks).

Rear tyre is some wang chung or other chinese brand. has a fair amount of tread, but rubber has the same supple consistency as the lid of a tupperware container.

I think AJ was running Vee Rubber on his.... Would it matter if I was running the same profile front and rear - ie. 90/90? Normally, a narrower profile is run on the front (probably for agile cornering reasons) or wider on the rear (for grip / drive out of corners). Or maybe I shouldn't worry about it.

Clip-on bar conversion is nearly complete - ie. I've flipped the one piece ventura bar upside down...

Now I just need to:
a) hide the ugly wiring loom the removal of the headlamp revealed
b) nylon everything
c) lockwire the sump plug / filler cap

Then I can take my illegal bike to the track.

Do I need a race number if not competing for points? Presume not. 69 is looking rather tasty. Rationale: It will still be readable upside down when I crash

The Vee Rubbers are no Teir1 MotoGP tyre but are likely to be waaay better than old shitty ones.

Put a race number on, its' not hard to make with a bit of paint, masking tape and real estate sign or similar plastic. Make 'em clear and check the Wellington numbers thread.

Old shitty bikes like that usually work a lot bigger with decent bar width, like a dirtbike; if you are half-crashing all the time you want wide bars to keep it together.

[Drew]

Rims and hoops are sitting here whenever you wanna grab them...IF you wanna grab them. The rear is a 100/90r18 Continental that seems not too bad. The front, is a ribbed unknown. It aint cracked and poked, but fucked if I'd use it if the weather forecast called for rain anytime in the near future.

[Drew]

Where on earth would one get a pair of 21mm flatslides, MVX?Yep.

I actually will be using them, just sleeved down to 17mm on the inlet side of the slide. Still gona fuel HEAPS better than the 17mm round slides in it.

Biggest problem is that they're down draft ish, and linkage operated, so I'll need to make up some elbow mounts and space them further apart.

[F5 Dave]

Think stds were 18, so they could be sleeved, but yes Keihins a much better carb, but downdraft not ideal if motor horizontal.

Anything Ribbed Tyre wise will be just evil. If It says Inoue (Inoue rubber company or IRC) then it will put you on your arse most every race, wet or not. the side benefit is that they never wear out so people don't replace them.

[Drew]

Think stds were 18, so they could be sleeved, but yes Keihins a much better carb, but downdraft not ideal if motor horizontal.Taken to my build thread.

[davebullet]

The Vee Rubbers are no Teir1 MotoGP tyre but are likely to be waaay better than old shitty ones.

Put a race number on, its' not hard to make with a bit of paint, masking tape and real estate sign or similar plastic. Make 'em clear and check the Wellington numbers thread.

Old shitty bikes like that usually work a lot bigger with decent bar width, like a dirtbike; if you are half-crashing all the time you want wide bars to keep it together.

If all else fails - I can get a pair for $112 including freight. As you say - not Tier 1, but I'm a tier 5 sort of guy anyway.

Presume the nylon is mandatory? Anyway I can get around these big fugly exhausts for a fang on the track without having to chop or otherwise put them higher?

Re bars- it came with a ventura so might offer a little bit more bend resistance than stock steel? Here's my attempt at inverting them to get a bit more of a crouch.
http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=266670&d=1342775658

http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=266671&d=1342775666

[davebullet]

Rims and hoops are sitting here whenever you wanna grab them...IF you wanna grab them. The rear is a 100/90r18 Continental that seems not too bad. The front, is a ribbed unknown. It aint cracked and poked, but fucked if I'd use it if the weather forecast called for rain anytime in the near future.

Cheers - I think the old girl is running an 80/90 rear so 100/90 should be a bit better.

Will pop around sunday likely. Beer at track as requested. Next meet 3rd sunday of August?

[koba]

Presume the nylon is mandatory?

Absolutely. It is critical to have real good track protection.

[koba]

Re bars- it came with a ventura so might offer a little bit more bend resistance than stock steel? Here's my attempt at inverting them to get a bit more of a crouch.

Maybe.

Try different things, have a go how they are then put them back to standard, see if that works better. You won't know without trying.