Speedway front fork springs...

cfh

Well-Known Member
#1
I really like the 10" and 14" wheel Speedway mini bikes. But they both share a common problem... the front fork springs are too soft. Has anyone found a good replacement for these springs? The original compression springs for the front forks were 6" long, 1" OD, .775" ID, wire diameter .100" thick. Thanks!
 
#2
I've tried several springs with different wire diameters and the one that works best for me has a .135" wire dia. I also stack 3 washers on the bottom of the spring to get the right preload.

You can buy the SPEC springs from Associated Spring / Barnes Group.
Part # C1100-135-5000-M.
 
#3
Man I’ve been pricing springs and searching for months for this roper....so after many non fitting springs and many quotes frim century and allied etc, etc...I finally broke down and special ordered a set from McMaster Carr....made to my spec...not 700 each like the above mentioned quoted me, but still quite pricey....
 

cfh

Well-Known Member
#4
Last edited:

cfh

Well-Known Member
#5
On those speedway replacement springs C1100-135-5000-M, they are only 5" long (stock is 6" long.) So i see why you had to stack washers under them. they are also $47 each! well i guess if you buy 10 they go to $18 each. also the outside diameter is larger at 1.1" diameter (instead of 1", but not sure that matters.)
https://www.asraymond.com/round-wire-compression-springs/C11001355000M

Outer Diameter (Do) (in) = 1.100
Wire Diameter (d) (in) = 0.135
Free Length (L) (in) = 5.000
Spring Rate (lb/in) = 34.80
Load Length (L1) (in) = 3.346
Load at L1 (lb) = 57.51

1 To 9 = $47.89 each
10 To 24 = $17.52 each
25 To 49 = $9.58 each
50 To 99 = $5.87 each
 
Last edited:
#7
On my roper i used standard Ruttman chrome front springs which cost $5 each and are readily available. They are slightly longer than the stock front Roper spring, but that's good! it brings the front end up just a tad. I guess you could cut them...

http://www.pinrepair.com/minibikes/p/sears_roper_mine1.jpg

I also used the same springs on my All Terrain Roper too... again worked great!

http://www.pinrepair.com/minibikes/p/sears1972roper_allterrain_mine1.jpg
They wouldn’t fit in cups too big..and already painted...
 
#9
The Speedway springs I buy for my 14" wheel bikes are only 5" long and have a .125" wire dia. Maybe the 10" wheel bikes use 6" springs with .100" wire. The photo shows new and old springs.
 

Attachments

Last edited:

cfh

Well-Known Member
#10
very nice! are they much firmer springs? because 14" speedway models definitely needs firmer springs too.
But the 10" wheel models definitely use 6" springs...
 
#11
I'm sure you knew this, but the reason the springs are undersize, for either size bike, is because Speedway's Hydra-Ride suspension requires fork oil. The problem is that the forks are very low tech and leak, even when new, so the springs by themselves aren't stronge enough.
The spring swap recommendation was suggested to me a long time ago from a former Speedway dealer.
 

cfh

Well-Known Member
#12
yea i use the 2 oz of oil but i'm not sure that really makes them stiffer. i don't know.
maybe we should get a bunch of people together and get those springs in bulk. because the price really goes down as quantity goes up.
 

cfh

Well-Known Member
#13
I received this blue spring in the mail today. it was about $12 per spring, which is reasonable. I have to install it in the 10" wheel fork i'm working on, which may take a bit of time (the bike is all apart.) But it seems to have good tension. and it's the right length and diameter. My only concern is it may compress fully and bind (turns per inch is tighter.) picture below shows the new blue spring versus the original 10" wheel fork compression spring.
https://www.zoro.com/raymond-die-spring-medium-duty-1x6in-103524/i/G5108555/?q=G5108555 - 80 lb/inch

http://www.pinrepair.com/minibikes/p/speedwayspring1.jpg
 

f4radar

Well-Known Member
#14
This was my one good spring. I looked for a suitable replacement and ended up with something that was ok but Id replace them if I found something better.
 

Attachments

cfh

Well-Known Member
#19
I tried out the Raymond blue spring #103524 (80 pounds/inch) and Raymond green spring #302524 (50 pounds/inch) in my Speedway Scarab (10" wheels.) Note I am cutting 1/2" off both of these Raymond springs to bring the length from 6" to 5.5". Why? Because it removes the pre-load that is built into the Speedway design (stock Speedway spring length is 6"). With these new spring you don't need a pre-load, so removing a 1/2" is desirable.

The blue spring is *really* stiff. Too stiff for my taste. Which is too bad because the Raymond blue spring is readily available and cheap. I did order the Raymond green springs. Unfortunately they only come in packs of five, so it's more expensive (and an odd number to boot.) With 1/2" cut from the green Raymond spring, it's about right where I want to be. It's much firmer, but not crazy too firm either. The lead time on the green Raymond spring is a few weeks too (where the blue Raymond spring comes in 2 days.) But the green Raymond spring is the answer I was looking for! It makes the front Speedway forks really usable.

There is one other Raymond spring #302532d (38 pounds per inch) that I did not try. Again comes in packs of five. Also 8" in length, so it would have to be cut. But it would be a bit softer still. Might be a good solution too. I would try this one at 6" first though (opposed to 5.5"), as it may need the pre-load due to it being a bit softer.

https://www.zoro.com/raymond-die-spring-medium-duty-1x6in-103524/i/G5108555/?q=G5108555
https://www.zoro.com/raymond-iso-d-die-spring-uld-25mmx152mm-302524d/i/G5112405/
https://www.zoro.com/raymond-iso-d-die-spring-uld-25mmx203mm-302532d/i/G5151946/
 
Last edited:
Top