Nut's and Bolt's

[balboa_71]

I'd like to start a discussion regarding the componets used in diesel bike building. For instance: Where do we buy our sprockets, chains, pillow block bearings (or flange mount), steel (angle, plate, etc.), fasteners, etc.? What grade of materials are best for our application? I see so many people asking for information (on the Yahoo groups discussion forum) regarding building aspects, but there is little information to be had.

There are many aspects involved:

Bearing quality and speed they will tolerate!!!!!

Bolt quality, what is best, harder (grade or lesser (yes, harder is not always better)???

Do we use standard chain, or go with motorcycle chain, or with better chain (more expensive)?

What materials are best for welding to existing motorcyle frame tubing, what is the best method of welding?

I can go on, but these are only a few of the questions I had to ask myself a year ago when I started my project. Little has been written regarding materials, and their quality!!!

There are more mistakes to be made....lets try to help by sharing info...

Cris

[Byrdman]

I don't know exactly where to start but I will say that the weights involved are typically higher than their gasoline brotheren so heavier guage bracketry is needed.

Also, the power delivery from a diesel is much more violent and less smooth than a gasoline engine so driveline components should be heavier as well. O-ring motorcycle chain is the least I would use and pillow blocks rated much higher than actual loading would be on my shopping list.

And as you mentioned, harder/heavier isn't always better. At Yanmar, we spent countless measuring vibration and resonant frequencies of assemblies. Diesel vibration, over time, will crack the meatiest of materials. Use the finger tip rule to start with and go somewhere from there.

[balboa_71]

Byrdman,
I read an artical written by the author/owner of Utterpower.com about a mower that was taken apart, and reassembled using grade 8 bolts, etc.. It wasn't long before it fell apart due to bolts/screws breaking from vibration , thus my comments on the best fasteners to use

The other thing that dawned on me after building my conversion was the pillow block bearings used to support my jackshaft: will the bearings handle upwards of 4,000+ rpm over life of the bike? On the other hand, mini bikes using jackshafts have little to no problems in this department and their bearings are cheap pressed units that self align upon assembly (simular to pillow block bearings, but not as heavy duty).

Cris

[Byrdman]

Byrdman,
I read an artical written by the author/owner of Utterpower.com about a mower that was taken apart, and reassembled using grade 8 bolts, etc.. It wasn't long before it fell apart due to bolts/screws breaking from vibration , thus my comments on the best fasteners to use

That is interesting. I guess bolt choice would depend upon load, allowable torque, and the type of vibration.

Byrdman,
The other thing that dawned on me after building my conversion was the pillow block bearings used to support my jackshaft: will the bearings handle upwards of 4,000+ rpm over life of the bike? On the other hand, mini bikes using jackshafts have little to no problems in this department and their bearings are cheap pressed units that self align upon assembly (simular to pillow block bearings, but not as heavy duty).

Working with diesels for many years I have seen the types of components and assemblies typically used in commercial equipment. Lawn mowers, tractors, log splitters, generators, etc... They are always overbuilt in my opinion but then again, the failure rates are probably low as well.

I would personally go oversized everywhere. If the bearing is rated for 4000RPM and X amount of load, I would go one size up.

[balboa_71]

Well, I went with 1" diameter shaft and bearings, most people go with 3/4".
But rpm is my main concern as I can find spec's on this.....sort of an after thought. As for the breaking bolts, it was guessed that the frame needed to flex (no suspension). Personally, I use grade 8 fasteners whenever possible, and self locking aircraft style nuts (all fine thread). These are my favorite for engine hold down bolts. On exhaust, I prefer stainless when available ($$$).

Cris

[Anorak_ian]

Pardon my ignorance but what is a pillow block bearing? And what's a jack shaft? I probably know what they are by other names.

Cheers

[balboa_71]

Ian,
I'm a transposed Yankee (being born in NYC) that spent a lot of time living in Turkey, Panama, and elsewhere....now having to live in Texas So my verbage may not be up to speed with others, so please bare with me....
A pillow block bearing is a device that holds a ball or plain bearing in a housing made of a cast material (iron?), and this housing can be attached to what ever machine you have. Its purpose is to support a shaft that rotates, the bearing is able to move in the cast housing so it can self-align to another device (pillow block bearing) without binding...... Two bolts (screws) are usually used to secure the pillow block to a flat surface.

A jackshaft, is the term I apply to an intermediate shaft between engine and rear wheel of a motorcycle/mini-bike used to provide a further reduction in gearing (normally). I did not coin this term, rather learned it from reading catalogs printed back in the early 60's that refered to mini-bikes being offered to the masses by US manufactures for hunting/ranch/farm/utility/pleasure??? purposes. These vehicals were the predecessor to Hondas trail mini-bikes offered after the middle 60's. I've kept the term, and used a hundreds of times. You're not the first person to ask me this

Cris