Springer front end

[tomo256]

I want to fit a set of springers to my shovel, can anybody tell me the difference between offset springers and in line springers.

Ta

[panster]

Oh alright then..
offset springers were (are) de-raked a couple of degrees, inlines are parallel to the steering stem.
As far as I remember the first offsets were put on late Knuckles and the '48 Pan when the steering rake angle changed to 30*.
Looks wise I prefer inlines, but offsets give more ground clearance.
I've asked this question before when I was thinking of putting springers on my rigid Pan,I wanted opinions as to any handling differences but I couldn't get a definitive reply.
Hope that is some help.
J.

[45Brit]

most important thing with springers is the length. Shovels with spring frames need longer forks that ones with rigids.

If you fit 45 forks to a rigid pan, as I once did, you will need a 21" wheel to keep it off the ground at all. You will need a steering stem or bearing swap for this one. Mine had machined sleeves to match the 45 stem to the pan bearings.....

XA and early WL forks are about 2" longer and those are the ones you want. You will find them in the 45 Depot catalogue.

custom springers are a whole new world of problems.. my suggestion would be that the handling characteristics of the springer are best suited to the rigid frame. Springers on swing-arm shovels tend to provide the worst of both worlds, rough front-end ride, hopeless brakes, pogo-ing and floppy rear end, all at once.

you also have various issues you have to solve, relating to handlebar mounting. There are various answers to these, but you need to think about which parts you have got and make sure they fit together

[tomo256]

They are going on a ridid paucho frame. If i go with the 45 forks you say that there is some machining to be done, surely these parts can be bought off the shelf as this must be quite a common swap.

Tomo

[45Brit]

the 45 forks have a 7/8" stem and the Big Twin ones have a 1" stem. If you fit 45 forks to a Big Twin, you need to do some sort of swap on the bearings to suit and you need a new top nut to match up the stem lengths.

There is also a problem with the rockers. the Big Twin rockers are different to the earlier 45 ones and use a different wheel and axle.

swapping 45 forks into a Big Twin is the sort of thing which was done years ago when there wasn't much available, and parts from the US were very expensive and hard to get. I simply wouldn't bother these days.

personally, if I were building a bobber type bike with a custom rigid frame, which I take it is your intention, and I didn't have a set of forks right now, which I take to be the case; I would go to 45 Parts Depot and get a set with the right neck for your frame.

start by deciding what wheel and brake you want to use, which handlebars, and what frame you have; what length you want your forks to be; tell Kurt at 45 Depot what you have, and he will tell you what you need.

saves a lot of problems

[tomo256]

Many thanks for the advice, i am replacing the normal forks on my bobber which is up and running, i am well pleased with the ride height so i do not want to adjust this so i will take all the rellevent measurements an give the 45 depot a ring. Have you got a contact number for them or even better a web address.


Ta

[chopper]

i believe this is what you want

http://flatlandmotorcyclecompany.com

[Chiefy]

The most important thing to keep an eye on is the amount of Trail that you have.

It's the Trail measurement that make the bike steer and handle correctly.

Go to Tolle.se

Have a look in the "Technical Hints" area.

You can do amazing things with the lengths of forks as long as the Trail is right.

Doesn't matter what type or what length the forks are the situation is always the same.

[45Brit]

on the understanding that the idea is to fit a replacement set of forks to an existing bike, the trail will be whatever it is.

springers will use the same geometry as the existing tele forks. If they are too short, there will be ground clearance problems... my 45-springer-forked panhead needed a 21" wheel just to stay level, and it was plain dangerous to ride. If they are slightly over-length, 2" or 4", the trail will increase and there will be a small trade-off , an improved straight-line stability at the expense of easy low-speed turning. I wouldn't have thought there was an issue provided the changes were small, and subject to the overall qualification that whatever you do with springers, they will NEVER handle, ride or stop as well as tele forks.

Personally, if I was going to buy after-market springers to fit to an existing stock-repro frame, or at any rate a frame with more-or-less stock geometry, I would have the 2" or 4" overs and get the extra ground clearance


I once knew someone who had been involved with showing bikes at venues like the Cow Palace .. he told me that those 'aladdin-shoe' rockers you sometimes saw in the 70s and 80s were developed to make the bikes easier to handle at low speeds with the very strange fork geometries sometimes used. Because they were either never ridden, or only ridden a short distance at low speeds for promo purposes, they could afford to make changes only useful for pushing the bike around..... I realised then, and have never really changed the view, that choppers lost their way a very long time ago!

[Chiefy]

The statement of "Rigid Paugco Frame" suggested that this wasn't a standard bike.

You cannot defy the laws of physics with "weird geometry" to improve handling.

I run a rigid shovel with +20" overs and the steering is fine, obviously the overall length of the bike is an issue, but the steering and handling work well. I put reasearch and effort into getting the trail correct.

If the Trail is not correct the bike will not steer or handle well, regardless of ground clearance issues.

Choppers will remain as they always have been, a statement of someones individuality.