Some news! About: - Speedo drive - Key contactor - Slipping clutch As I was gradually extending my riding radius, feeling more and more confident, I first started to experience some speedo needle inconsistencies, due to a broken speedo drive tang. Not too uncommon if I believe my various readings… Not realizing I could remove and order a new tang separately, I ordered a complete brand new unit from Gowanloch. Notice any difference? As the guys from Gowie seem to be pretty honest about things, they advertise this aftermarket unit with a less robust casting than the OEM ones, and therefore will not last as long. My OEM one only has 21.000km… So I looked closer and found the hidden circlip allowing to remove the tangs. Woohoo! After oiling and cleaning it, I now have a fairly new looking Veglia OEM unit. With that, I decided to go and test big city riding, going to meet friends for lunch in Lyon. Well, as I was swiftly cruising under the river in one of the north orbital tunnels, I suddenly lost all power. Like everything gone (engine, lights…) all at once, in a fast traffic tunnel. Stressful, dangerous even, but I was amazed at how quick the bike and I got rescued in there, and how professional everyone was. By chance, a police motorcycle patrol was less than 2 minutes behind me and stopped and quickly put their blue lights on to give high visibility to the bike. 10 minutes later, the motorway agents were on site with cones and more flashing lights. 25 minutes later, bike was on the emergency truck, homebound. Truly impressed… What then? Well, after checking the usual suspects (fuses, battery connectors, etc.) to no avail, and as this felt exactly like if I had removed the key while riding, I decided to start my investigation with the key contactor. Always found it a little wobbly, to be honest… And that’s what I found.. After a bit of gentle rubbing, it started to look better and better. I put it back together (not simple with those little springs and 3mm steel ball) and on the bike and « Let there be light » again! However, I ordered a new contactor as this one still feels wobbly and I lost trust in it. So bike is no longer out of juice, but I am not going anywhere until I have a brand new contactor on it. Finally, I have been experiencing a slipping clutch when going wide open throttle, to overtake for example, or in steep climbs around our hills. After much tinkering with the clutch set up options, both at the lever and the pressure plate, I decided to make the bike and myself a nice present : a brand new Surflex S1425 discs kit. Man this is looking so good. Check the ribbed discs! Now why did I buy this? Well, even though my old OEM discs didn’t look that bad when I checked them during the bike overhaul, they have been standing still in old oil for… 20 years. Oil that came out black as stout when I flushed it. So that may well be part of the problem. Also, these Surflex kits are upgrade to the OEM solution. Look it up. We’ll see how that goes. Stay tuned!
https://www.stein-dinse.com/en/duca...vel-drive/item-2-1428020-speedo+drive--2.html Don't ever bother with those Indian copies of Veglia drives, you will be lucky to get to the end of the road. I used to stock them but 75% were returned within a week seized with the tang chewed up.
They all do that sir.... in addition to oiling the drive itself remove the drive cable from it's outer, clean it off, replace it and then run a little thicker oil from the top down the line. That helps to stop the needle bouncing about. They all do that sir.... I used to have a Guzzi V50 that did the same but only when cranked over going round a roundabout But that wasn't anywhere near as bad as your case... sheesh glad to hear you & the bike came out of it unscathed. Might be wise to take the black plastic cover off, the one just behind the headstock, and give the wiring/block connectors a quick once over. And if you have the time & inclination have the tank off and check the back of them as well. The wires are all pretty crammed in there. They all do that sir.... mine has been slipping since I got it on the road but have noticed it's got much better with time & also gets much better with a properly warm engine. When it was apart I noticed the clutch drum splines were slightly notched and with the last big slip there was a definite off/on transition which could have been the plates sticking on the notches. So it might be worthwhile checking the same on yours when it's apart. I'm not going to bother with mine until I rest him up for the winter.
try putting a thick washer under the head of the screw holding the clutch spring or get some stronger springs. suflex used to do uprated spring kits for bevels but you can also buy them from stein Dinse. Worn clutch drum splines are common but only alloy so can be cleaned up a bit
@Paddy Barratt The Surflex kit I just got came with stronger springs, but unfortunately, they are the shorter ones (27mm or so), where I have 40mm on the Darmah. I will look into stronger springs from Steindinse, though, thanks for the tip. @Andy Bee « They all do that, Sir ». I sort of figured that one out, I guess… I did have the entire wiring loom out on the bench when I restarted the bike during spring and was able to check all the cables, terminals and connectors. Everything is in really good shape and I must admit I was impressed. Here, it’s really just a case of loosy quality contactor… Regarding the speedo cable, I changed it during the overhaul as the old one was kinked, and I use Teflon based grease (the one I use for the chain) to lube all cables on my bikes : Speedo, tacho, throttle, choke, you name it. It’s supposed to be better as being dry, it doesn’t collect grime between the cable and the sheath (is that a good word here?). I understand sheath are made of teflon now, anyways? Finally, I did thoroughly check my clutch components when the left side cover was off this spring (had plenty of time to do it while I was rewiring the pickups…) and everything looked pristine in there. Only the disks were dirty and oily, but I didn’t think much of it and simply wiped them. Apparently, with time, oil can get into the friction compound making it useless…
Back in the day I used to fit 450 single clutch springs to stop the slip. Also found that the plain plates were warped so had them surface ground flat. I guess the modern replacements are better made. The engine was around 1020cc which didn't help
Oh and of course, always tank off when messing with electrics on that bike… It’s very simple to remove anyways.
I'm never 100% sure what the spring length should be but 40mm doesn't sound right. Back to classics quote 32mm for the Darmah(s) & Mdina Italia quote 27.5 mm for the 450. This is sortov confirmed by Bevel Heaven n.b. much of the spring strength is in the thickness of wire rather than the length per se, see https://store.bevelheaven.com/Engine-Related/6-Clutch-Springs-Various-Bevel-Drive-Kits/ Ah yes... I forgot you had mentioned it before. Nice. Yeah, I'm thinking the same. The plates had been sitting for years and were probably oil soaked plus the change from mineral to semi synth not helping either.
I measured the clutch springs back in February, so may have confused memories of what that length was. I will have them out again soon and all will be clear then. I didn’t use semi-synth oil, but mineral.
So, no more spring length confusion. My old OEM springs measure just shy of 30mm. The Surflex kit reinforced springs, with 27mm work just fine. With these on, the clutch lever is significantly harder… Wasn’t especially soft to start with. Now it’s like pressing a rock. Slipping seems very unlikely… The new discs are absolutely fantastic. 40mm total thickness, just like the OEM discs. The steel discs (non-friction) are actually engraved with a perfect spiral, which I didn’t realize at first. Centrifugal oil drainage. You got to love that stuff… Can’t take my eyes off this!
Be interested to hear how you get on with this set up. Btw notice the difference in the spring wire thickness between the two. Still on topic I did some good miles yesterday, 120+, and drove him hard up a really long steep hill (coming out of Bath & chasing a BMW 330d ho hum...) with no hint of clutch slip even when changing up into top with a full throttle. So, for what ever reason, it does seem to behave itself with a really hot engine.
He-he-he... that's the one... it's a road I know well as I travelled it for 5 years or so as part of my daily commute. And 'ol Reggie the Raptor used to biff up there even faster. The camera is on the downhill side, they always put them on the downhill stretch were it's real easy to speed, although I'm not entirely sure it actually works. Adrenaline & a non slipping clutch got the best of me officer.
I think that one may have got me last week, it’s just after a bridge and I didn’t see it. I was doing’s about 54 but it didn’t flash so I don’t know if it works or not.
Ah... I know the one you're talking about... it's on the same A4(6) but heading west and as you say the sneaky gits placed it in the verge just after the bridge. The other one is further back on the steep downhill (Solsbury) section and handily placed just after the road widens to two lanes when you're giving it some beans to get past the lorries & caravans you've been stuck behind for 5 miles.
Guillaume, It is well worth checking the bolts too. I took a bike to a Dyno near me and for the first time, its clutch started to slip. I got home financially poorer and thoroughly pissed off with a Dyno reading way below standard, instead of substantially higher than standard. So I ordered new plates and springs. Once they arrived, I dismantled the clutch and found every bolt had stretched ..!!
Hate that hill if it’s the one I’m thinking of, whenever I come back from Westbury. Actually I hate that whole trip to Westbury there isn’t a nice road to be had when you’re in a van.
@Borgo Panigale, are these the basket bolts? The ones that need to be tightened with sealant? How many miles on that clutch ?
Those bolts are the ones that are tightened down onto the springs. I don’t know the mileage on the clutch, it is on a bike I bought used and discovered the stretched bolts when I was changing the discs, as described above. The slipping clutch was obviously partly down to the stretched bolts and maybe the original discs were OK, but having bought replacements, I didn’t look too closely at the removed discs.
