Anyone Used Thunder Engineering Lightning Conrods

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As stated above: Has anyone used Thunder Engineering Lightning Conrods? If so was there a requirement to have the crank, rods, pistons, etc dynamically balanced?

Is there a danger in fitting these rods and not having the crank assembly balanced?

Do standard shell big end bearings fit these rods?

Does anyone know the weight of the standard Commando (850) conrod?

If the new rods are a slightly different weight will that increase vibration much?

Thanks
Don
 
Just looked on their website, they look very well made.
Not an expert but any difference of weight against the counterbalance of the crank is likely to alter the balance. You may be lucky, in a good way but its a gamble. They look more substantial than standard so would imagine they would be heavier. If you are going to the trouble I would have it all balanced by someone who knows what they are talking about.
 
I knew someone who fitted a pair of these rods. The nuts didn't clear the crankcases and had the be reduced in the area of the hex, also I believe he had to remove some material from the inside of the crankcases.
 
They look rather neat, but why not use the standard forged rods (or, if you are really worried, steel Carrillo ones)? I've not heard any reports of problems with the standard rods, and there's probably no difference in price, even assuming that the crank does not need rebalancing.

I've always thought that a forged rod is better than a billet one anyway.
 
I would be careful about buying some of these billet alloy rods, I have a set here on the shelf for a Triumph which look identical to these and R+R rods..
The bolts, (they dont use bolts and nuts) screw into the rod, and they use shoulder bolts, nothing special. Now here is the problem, the 3/8" shoulder bolts have a 5/16" UNC thread. at the end of the thread before the shoulder the bolts are waisted as most shoulder bolts are. this wasted section is .240"
diameter. I'm sure shoulder bolts are made from good quality steel but relying on less than 1/4" diameter of bolt doesnt inspire confidence.
I dont know what bolts Thunder use, but inspect carefully.
Don
 
This rods are wider than original. You need to grind/mashine the opening of the cylinder skirt (easy to do). Also the crankcase needs to be mashined to accep the wider rods.
The big end half of the rod is also in aluminium, original ones have a steel buttom half.
The original conrods weight about 400g (sorry my scale shows just 50g steps).
You need to balance your crank, thats what i was told.
I selected this because the guy (he is doing a lot of BSAs) who did several mashining on my motor, advised them. I have not many miles on the bike jet and have no problems with the rods, but if i need new rods and own some spare money, i would think about some of http://www.jsmotorsport.com lightweight stuff.
 
The stock Commando rods that I've weighed average 390 grams total weight.

Ken
 
Thunderbolt,

I have these in my Dominator. A bit of overkill but will outlast anything else on the bike for sure. They were very well made and support from the company was great.

Play on the safe side and balance the crank, not sure how much the lightning rods weigh compared to the 850 say. Have only done 1500 miles on mine and havent had to pull the engine down so dont know the condition of them.

End cap bolts cleared the crankcases with no problems at all.

Did have to ream the little ends but that is part and parcel with fitting anything like that.

Regards

Connie
 
They do have a good name, I would not worry too much about using them. My only question would be why, when the original rods are still avaliavle from A-N, RGM, etc.

/Steve.
 
SteveBorland said:
They do have a good name, I would not worry too much about using them. My only question would be why, when the original rods are still avaliavle from A-N, RGM, etc.

/Steve.
Click to expand...

One reason may be cost.
 
Yep, new Norton rods arent cheap, but good used ones arent to hard to come by.and there are even some good 4340 forged billet rods available at a very good price!!!
 
I have used 2 sets of Thunder rods,in my old BSA A70 racing sidecar outfit. The rods are of excellent quality, and when I did damage one(turned out to be my fault),Steve could not of been more helpful, even matching a new one up to the one that did not break, so that I only needed to buy one.3 of us bought up 6 sets of these rods, and on weighing them, the biggest weight difference was a quarter of a gram.My new Commando motor will get a set,as soon as I finnish building the outfit.
One thing tho,make sure to check big end shell to pin clearance accurately.The big end eyes on the Thunder rods are honed to size,and as a result,are much more accurately made then original rods.
 
ok ok in that case 40 year old rods are suffering a little by now , but they have made it to the present time. in 40 years time i will be 100 years old . and best of all A/N make rods of a known good quality . so why use pattern stuff ?
 
They are not pattern,they are of his own design,and substancially stronger,designed for racing.
 
I used Thunder Engineering rods in my Dommie 500 cc race bike. Recomended by Dave Nourish after he stopped supplying his own.
 
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