BGM clutch - Any good ?

[TrackTen]

Hi Guys

I am considering options for a new clutch in an engine that will make at most 20bhp

What I am after above all is a clutch that wint drag and has an easy pull at the lever.

While the BGM is far from cheap I am wondering if the 10 spring setup will give me the benefits of the above without slipping and give a long life

so have you tried one ? If so how did you find it ?

[Warkton Tornado No.1]

Dependent upon your style of riding, a good quality ‘generic’ uprated Lambretta style will work well if you select wisely.

I say that, because if you are ragging the clutch like a racer, then the motorcycle derived clutches take that abuse best.

On the other hand, if you are a little more sympathetic to the transmission, a good six plate clutch centre with thinner corks & steels will work well without dragging or requiring undue force to operate.

Unfortunately, the scootRS set-up that I would recommend is presumably no longer available. My 241.5 cc Rapido powered SX runs that & the clutch has been in since 2012 with a 4.7 top gear ratio & I’m about to try a 4.45.

An alternative that would probably cope would be the use of CamLam’s thinner corks & steels which are very well manufactured hence expensive, though you’ll probably only manage to squeeze five plates into a set-up with a standard centre.

Recently, that set-up went into a TS1 with a 4.61 top gear ratio & the owner canes it everywhere but all seems great so far.

In both cases of either six or five plate clutches, you need to ensure that the crown wheel has deeper slots which are easy to do with the two part 46 T sprocket if you dismantle it. Reassembly (after slotting further) is best done by drilling/tapping to take high tensile socket screws (M5 I think!) button heads or countersink to suit.

I hope this all helps, but what I’m trying to say is that you don’t have to ditch the whole original Lambretta concept if you want to save a few quid.

I suppose I have learned a fair bit since the 70’s when my first attempt to uprate a clutch meant the Ancillotti ‘tangential’ slotted plates......I really should try & sell them to a collector along with the NOS Ancillotti 175 to 200 conversion ‘Dinamin’ Dykes ring piston!

[Fast n Furious]

An easy to use clutch is mostly attributed to the Lever, Cable, Actuation arm angle and condition of the operating cam.
Get these parts of your scoot right before throwing lots of unnecessary money at the clutch itself.
If it doesn't slip when you apply your 20HP then it is doing its job. Maybe more than necessary if you have too strong a set of springs in there?
There is a fair amount of good advice around the forum regarding this subject which you can search through.

[MickYork]

I use a 4 plate clutch on a 23hp motor with no slip and over 10 000 miles on the engine.

The plates are LTH from Lambretta Upgrades and the springs are (Mallosi ?) from the same place.

Personally I think a 4 plate clutch (set up correctly ) is good up to 25hp after that start forking out good money for a decent upgrade.

[TrackTen]

Thanks for the replies guys

Some really interesting and useful information there - brilliant.

It seems that maybe no one is running the BGM clutch though - I wonder if thats simply down to the fact that's its quite dear compared to some of the options

[Warkton Tornado No.1]

I think you’ve received some sound advice from the three of us that appear to be singing from the same hymn sheet, to a great extent

I would add a note of caution in that, having raced for years with what seems a lifetime, the longstanding benchmark figure of around 25 BHP (I forget the torque) & with that inevitable style of riding, then even seven plate clutches could get fried. I had surface ground (to roughen, thin down & make less distorted) the steel plates long before CamLam & the likes offered thinner ones & it became common practice among some Race Teams to really rough them up. Several times, I’ve witnessed other rider’s cooking their clutches on the start line with similar outputs.

Racing might seem a massive contrast to the use of a road bike, but experience gained @ all that.....

My ‘seat of the pants’ dyno meant that in my case I wanted a six plate clutch in conjunction with my 19 x 46 Pacemaker ‘box so that there was something ‘in reserve’ over what the best four plate might cope with in the (admittedly) unlikely circumstances of a steep hill start, two up loaded with gear.

[bike grim]

I have a TS1 230 that is around the 24bhp/18ftlb torque area. Running 19/46 and a pacemaker box (4.45). The 5 plate surflex in a deep crown wheel I had started to slip so not long after a rebuild so I bit the bullet and bought a AF Road cassette clutch. Straight swap, lighter at the lever and no slip. I also have an LTH 7 plate clutch in my other motor and haven't had to do anything with it in over 10,000 Miles. It is also very light at the lever and deals with 22ftlb torque and 4.12 gearing. Don't know anyone using the BGM to gain an honest comparison

[ULC Soulagent]

I use one on my 230, expensive but it's fit and forget. Used the medium weight springs

[Feersum Injun]

I bit the bullet and bought a AF Road cassette clutch. Straight swap, lighter at the lever and no slip...

I'm considering this option... did you swap the springs for MB type?

[Delboyli150]

Go for the Cassette clutch, easy to install, and no faffing with slip/drag. Works a treat.

[holty]

i have used the bgm 6 plate plates in my rotax canversion, along with mbd springs and i am very pleased with it, a very light lever and no drag, i nice bite, no snatching, looks high quality, i did fit an extra friction and steel to make it upto 7 plates, but i did extend the basket, its got a lot of pulling power. my mate has a bgm 4 plate in his tuned 175 and thats been perfect as well, if your after a standard type clutch they are good, the cam lam soft clutches are very good as well, grippy plates and soft springs mean easy to use, ive had one in my rb250 for a long time and works great.

[Fast n Furious]

I use the AF cassette clutch(the £250 one) on my Ts1 without any issues whatsoever. No slip, No drag and can be pulled in with 2 fingers. (Granted..... the modified Yammy clutch lever is making a huge difference here also). If you wrag these clutches, they do spread the metal out on the ears of the plates especially the plates closest to the bell but they are soft, so they don't wear grooves into the slots of the bell which is good. I redress them and swap them around on a major service to even out the wear and then its a mere £30-£40 for a new set of plates which I think is good value. Highly recommended.

[corrado]

I bit the bullet and bought a AF Road cassette clutch. Straight swap, lighter at the lever and no slip...

I'm considering this option... did you swap the springs for MB type?

The springs on the AF clutch are a bigger diameter than the MB or BGM ones. You can uprate the springs in the AF road by using the AF Race springs over the road springs. Race plates recommended too when you can get them, which isn't very often, that's down to Surflex not AF. I think Chiselspeed also do their own uprated springs for the AF clutch, the actual coil diameter of these is thicker than the AF ones so they go coil bound easier.

[Feersum Injun]

Cheers Martin

[bike grim]

Sorry Nick. I was away so slow to respond. I just used it as it came in the box and it’s been great. No fettling

[Feersum Injun]

Sorry Nick. I was away so slow to respond. I just used it as it came in the box and it’s been great. No fettling

No worries... this sounds spot on... no faffing!!! Cheers G

[Delboyli150]

Hi Fast n Furious

Just doing a quick service on my engine, that was a good little tip you shared!

' I redress them and swap them around on a major service to even out the wear '

[johnnyjarvis]

giving this a bump as Im looking to replace my clutch and im considering this one.

[bookertmgs1]

I use a reedspeed 5 plate kit which fits into a standard basket - its a great cheaper option than a cassette. Assume the BGM 5 plate kit is similar

Another thing to consider is the type of riding you do - if you are stuck abroad in the middle of nowhere and you need a set of clutch plates, then you ideally want to utilise a standard plate rather than something unique. The BGM cassette can use standard corks - the AF one doesnt. If its a Sunday 5 mile blast everyweek then this doesnt really matter.

[Scooterdude]

I know of an RB that makes over 30 bhp, been build for 9 or 10 years originally fitted with a fox hat 6 plate never been any bother and clutch action lighter than a standard 150. Maybe worth a look?