steel to steel clutch

Hi all,

I was woundering what is the reason for a steel to steel clutch? i'm sure it must be of some benefit! also what size should i make the slits?

regards Mark

You can see some on Alan's old site

http://www.bsabantamracing.com/bantamracer/bantam_racer_3.htm

Some I have are drilled 5 mm and slotted with hacksaw, I think another lot I did with 1 or 1.5mm grinding disc and clamped about 5 or 6 together then de burred.

Someone will be along with detailed benefits of all steel clutch, remember burning out loads of the old surflex ones especially from Cadwell hairpin

Tony

ps You building a racer?

Hi Tony,

Yes i am building a bantam racer 175 with the BTW head and barrel (when I speak to Mr White), so far i've got a D7 engine and frame and the front end of the racer i think you built (No 256).
Its going slowly so far as unfortunately i don't have access to a lathe, so anything i need made or modified like the PVL mainshaft is going to prove costly! but apart from that it should be up and runing hopefully by the end of the year.

Regards Mark

Hi Mctay,
Not only the all steel clutch plates but to cope with the hammer you have to give it all, everyone uses 9 spring conversions and uprated springs, I even use extra assister springs in the middle of the uprated ones!
As Tony says sorting the steel plates is easy, I use the plates in soft form, but others have them hardened. It just means I need to empty the crap from the plates every meeting out of the gearbox and side panel, and use new oil.
To cope with the pressure you also need to modify the clutch mushroom to take a thrust washer as per the bantam racer articles, note from that period I now use a hardened washer against the top plate, and have expanded the thrust washer out to a 20mm diameter, and this is now trouble free. Just means you have to make a new shape of push mushroom to take it, so see the articles for further evidence!
Good luck with the build, and get to the practice day and meetings to see everyone!
Cheers,
Alan

Wow! Alan!
18 springs per clutch?! Could have done with that in my time -- every race at Cadwell meant new plates or springs... With Andy´s 250 ABS after a messy season of Albion cork clutch we went Greeves Silverstone clutch and that was marvellous... Wish now I could have had a couple more seasons on that 250 but ambition, status and money beckoned in Canada!
Have a good season...
JayBee for John-Boy!

Hi John,
It is a considerable clutch set up, but you need that with the torque these boys turn out! and best of all, I only get through one set of plates every two seasons, and really only change them for the sake of maintenance and reliability. the springs are thrown away every season regardless of what they are like!
I never get a clutch problem !! (now I have said that... sods law will set in!!)
Cheers,
Alan

I was wondering alan are you using a 3 or 4 plate cluch basket ? we are just about to rivet up our new pieces and was wonder which way to go,

some help or advice her would be good

or whats the theory behind using 3 against using a 4 plate baskets - anyone ?

Hi,

I have just built a clutch for my 175 engine.
I have gone for small 3 speed clutch basket, 3 plates (less rotating mass), 9 springs and steel to steel plates.
I have fitted a band to the top of the basket to avoid having to use the tin top plate and its 3 little screws !
Push rod mushroom and thrust bearing have been modified to suit.
Hope it works !

bettsd wrote:

I was wondering alan are you using a 3 or 4 plate cluch basket ? we are just about to rivet up our new pieces and was wonder which way to go,

some help or advice her would be good

or whats the theory behind using 3 against using a 4 plate baskets - anyone ?

Hi Derek

From what I gather most if not all use 3 plate baskets, mine and Ray's both have 3 plate baskets.

Good luck with the build, catch up soon


Tony

Wow Tony Thanks you old war dog you ! great to hear a comment from you on this, "ok" three plate basket, but how many plates ?
and what centre spline should I be using, three / four or modified , as there's more room with steel. I want to try and get this right first time, I have used all steel before but not with the same success other people were having, I mean Alan Brown one clutch in two years !! wow.

I went to mallory to watch the practice, and Alan brown gives his clutch a heard time, incredible really I want mine to be this reliable.

I was wondering weather oils used had anything to do with this, anyone.!!!

regards Derek

Hi Derek,
You are right I do give my clutch a tough time!! the set up I use is as follows:

3 plate clutch body.
3 plate clutch centre.
4 steel plates outer driven.
4 steel plates inner driven made from surflex plates with surflex removed and slit as per articles in bantam racer pages.
9 springs uprated (buy them from me at Mallory!)
9 assister springs inside others.
Clutch push room made special to 20mm diameter end and has a flat thrust washer and a plain hardened washer against the top pressure plate. The mushroom has a 5 mm centre boss that sticks through the pressure plate and stops the thrust washer from being dislodged.
I try to use simple and common to obtain parts as much as possible. Plus I do not harden the plates. the oil is cheap supermarket oil as the fancy stuff causes the clutch to slip!! as Nick has just found out!!! But be sure to change the oil every meeting without fail as the soft plates do leave a lot of swarf, and clean up the plates with the grinder every half season to get best results.
You too can have a clutch like mine! go for it....
Good luck and go well see you all at Mallory
Alan

Hi chaps,
my set up is close to Alans & i use the later centre hub with the 2 thrust washers & needle roller bearing, i think this is the 4 speed hub.remember to get the primary chain alignment spot on if you have a crank youve built.Carefull use of oil to as i found to my cost at Mallory.Tested new btw reed valve motor in my ex ted smith bike with continuous clutch slip & pinned it down to oil type! good luck with the builds. Nick

Hi Alan!
I wish I´d had that knowledge in 1968...
...
I loved that circuit but I remember Cadwell with the burning smell of a suffering clutch.
...
When riding Andy´s 250 in 1972 I complained about the Albion cork cluch slipping and dragging. That was at the end the season. The latter caused bad starts because by the time I bumped the saddle the dragging clutch had turned engine which always brought the piston up to compression.
Wonderful bloke Andy Boyle. He went down to Greeves place, near Canvey Island(?) and bought a Silverstone Clutch the difference was phenomonel.
...
Have a good season!
JayBee.