# Aurora Thunder Bike questions



## Boosted-Z71 (Nov 26, 2007)

I just picked up several Aurora Thunder bikes, I have never had any of these and the price was right so I picked them up, I have a parts break down and just wandered if there were any tricks other than the typical T-jet tweaks to get these to run correctly. I have one that runs decent, the other 2 were all green on the pick-ups & electrical's so I cleaned them in vinegar, but they were very stiff to roll the rear wheel & armature, so my guess is I need to spend some time on the gear train.

I am not looking for super speed / performance, just want them to run normal. Also looking for any information on what to replace the back tires with.

Appreciate any tips & thoughts 

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## alpink (Aug 22, 2010)

wow, never thought about what to replace rear tires with.
that is going to have to be an outside the box decision and I don't know where to start.
I have a couple, but have given most of mine and many new parts to Hank.
he is a cycle guy and loves anything associated.
the couple that I kept are curios and rarely see track time.
I'll be checking in frequently to see what ideas folks come up with.
will be studying in my mind replacement rubber for those rear wheels.
as for stiff drive train, C'MON MAN !!!!!
you make ultra fast cars all the time. getting that bike chassis loose as a goose should be no challenge! 
LOL


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## Boosted-Z71 (Nov 26, 2007)

I figured it was similar, just never had one, and did not want to fubar it up, too dang expensive to mess up

I will post what I find on "tars", another well known expert sent me some info on things to try.

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## 60chevyjim (Feb 21, 2008)

as for trying to get it loose . buy a bottle of liquid bar keepers friend from lowes it is less than $3 
on tjet cars take the chrome rims off first it will dechrome them ..
squirt it everywhere inside the motor and gears , axels and on all the copper on the chassis with the motor together. 
then turn the motor back n forth and it will loosen it up . I use a toothbrush on all the copper parts 
and then rinse it real good with hot water while turning it back n forth the whole time.
I do this with nasty old tjets and get them spinning nice and free .
I have several tjet bikes and a couple of the tjet bikes that were made into trikes 
they have 4dot hotrod wheels and some old time silicone tires on the trikes 
if you can get any rear tires off without breaking them .. 
someone should be able to make a mold and make some new silicon tires for you.
try weird jack he may be able to help ?


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## Boosted-Z71 (Nov 26, 2007)

I found this site for tire help

http://smokingtjets.com/blog/guest/aurora-thunderbike-back-tire-help/

Sent in my free registration request, but have not heard anything 

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## Boosted-Z71 (Nov 26, 2007)

I got the first ThunderBike going, it was an e-bay special, would not run out of the box, Had to re-solder the tabs on the com plate, since it was out I balanced it & straightened the com plate, cleaned everything up, soaked it in vinegar to clean the electricals and lightly lapped & polished the gears together, re-assembled & set the brushes in on 4 volts. I am now waiting on some buna-neoprene washers that I found to try as rear tires, but otherwise it runs great on the test block.

Kinda giddy to turn some laps on the glass ring with this, as I have never owned one of these before, Very neat bike / slot car. 

I will try to get some pics when I get the tars on it

Thanks for all the comments & help

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## alpink (Aug 22, 2010)

yeah, washers came to mind just at bed time last night.
not sure if they will be too hard.
if they seem to be, treat tread area liberally with oil of wintergreen


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## Boosted-Z71 (Nov 26, 2007)

Here is the info on the washers I ordered, everything is right but the thickness, mine measure .055 thick, these are .062 +/- .020, so if there on the low side they will be great, on the high side and I am going to be figuring out a way to sand & thin them down.

Product Description

Sealing Washer, Flat, Buna-N, Fits Bolt Sizes 1/4 In, Inside Dia. 0.250 In, Outside Dia. 0.500 In, Thickness 0.0625 In, Thickness Tolerance +/-0.020 In, Temp. -25 to 200 F, Color Black, Durometer Shore A: 50-70, Application Cushioning, Sealing and Vibration Resistant, Package Quantity 10


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## Boosted-Z71 (Nov 26, 2007)

Tire update: The above sealing washers are easily ground to the correct thickness, however at .500 OD they are just a bit small. I have some other washers coming that will need to be ground down on the OD as they are 5/8" OD. 

I am thinking I will stuff as large of diameter tire that I can under the bike, more like a .530+ OD or so and see where that goes, As for the material they seem like the durometer is good for traction, so I think once I get the OD dialed in they will work great. 

I will keep you guys posted, not sure of the interest but there is no info out on the web about tire replacements for these bikes. 

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## alpink (Aug 22, 2010)

thanx for the update


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## Boosted-Z71 (Nov 26, 2007)

I have cracked the secret to rear tires for the Thunderbikes for great traction, and still enough slippy to get a little sideways with them, and plenty of traction for hills and sharp turns, worked well on my tommy track and the routed track. 

It involves a little work but you can easily do it with either a tire grinder, like a Hudy modified for HO tires or you can do it by hand with a dremel tool / mandrel setup. 

Here is what you need to know

First you need some sealing washers, this is what I used 

Product Description
Sealing Washer, Flat, Buna-N, Fits Bolt Sizes 1/4 In, Inside Dia. 0.250 In, Outside Dia. 0.625 In, Thickness 0.0625 In, Thickness Tolerance +/-0.020 In, Temp. -25 to 200 F, Color Black, Durometer Shore A: 50-70, Application Cushioning, Sealing and Vibration Resistant, Package Quantity 10
Buna-N Washer, 1/4 In, 0.625 OD, Pk 10
By VALUE BRAND
Technical Specifications
Durometer: Shore A: 50 to 70	Thickness Tolerance: +/-0.020"
Item: Sealing Washer	Material: Buna-N
Thickness: 0.0625"	Application: Cushioning, Sealing and Vibration Resistant
Color: Black	Type: Flat
Temp. (F): -25 to 200	Fits Bolt Sizes: 1/4"
Inside Dia.: 0.250"	Outside Dia.: 0.625"
Zoro Number: G2954515	Mfr Number: 4PAH2

Here is where I bought them 

http://www.zoro.com/i/G2954515

They were $1.35 for 10, shipping is free now until Dec 24th, but they are reasonable anyway on shipping 

These are .0625 in outside diameter, you need to grind them down to .520-.522, I do the OD first. Then you need to thin the thickness down to .051-.052

I use a .282 mandrel (same as AFX Rear Wheel) to get to these numbers, The OD may change just a tad when put on the thunderbike gear/wheel, but that is ok, we want just a bit to work with on our very light final sand on the bike. 

And I do mean light as your looking for the tire to finish in .515 to .518 range, it does not take much. 

Any larger than .520 installed and the tire will contact the idler shaft on the big side & bind the crap out of the bike. 

As for thinning them down I used the same mandrel, and some 200 grit sand paper and just held it to the side of the tire to get where I wanted to be, sand, measure, sand, measure, it goes fairly quickly and the washers were a consistent .0625 to start with, a nail file would work well for this also.

On the Hudy I can make a set of tires in 2-3 minutes, completed and ready for final sand on the bike.

Good luck & hope you guys try this and get to finally lap some of those Thunder bikes they are a blast to tinker with and drive

I am going to dose a pair in some wintergreen oil to see how sticky they get, but the washers provide good traction over anything else I have tried on these bikes

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## alpink (Aug 22, 2010)

just the tread area with the oil of wintergreen.
if you treat the whole tire it might swell up HUGE.


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## Boosted-Z71 (Nov 26, 2007)

Thanks Al

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## Boosted-Z71 (Nov 26, 2007)

Hello Al, just wandered if you had any tips for adding the wintergreen to the bike tires, I used a toothpick and carefully applied just enough to get the road surface of the tire wet, all the way around without getting any extra on the sidewalls, 

How long do I need to let it dry before using it, or do I re apply

Any info anyone may have will be appreciated

Thanks

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## Boosted-Z71 (Nov 26, 2007)

The wintergreen oil worked great, even more traction, the thunderbikes run great on this tire setup

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## Boosted-Z71 (Nov 26, 2007)

Here is a short video with the new tires & treated lightly with the wintergreen oil

You can see it gets around the track pretty good 



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