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First breakdown in my 66 rebuild.

4K views 31 replies 15 participants last post by  DAVE M 
#1 ·
Minor but still leaves you stuck and stranded.

Clutch cable. The little nub that goes into the handle broke on my ride today. It seems my clutch always was tough to pull. I thought it would free itself swine after 1k miles. Why would it be tough to pull? Pinched?

Is it hard to replace the whole cable? And who's a good supplier?
 
#2 ·
Hi Chief, I can most strongly recommend Barnett clutch cable. They have steel crimped ends which so far have proven to be the strongest I've found. Stronger than original Triumph, Venhill, or possible the worst is Emgo.

I had several cables break on me, so I have some experience & know what you are up against.

When adjusting your pressure plate springs don't go deeper than top of head flush with stud. To adjust for wobble, back off adjuster. If you must go tighter on one of them don't go more than 1/2 turn deeper. At full lever pull the springs are nearly coil bound so we don't want to go too deep on adjusters.

Barnett lubed with any of the cable lubes or just motor oil or trans oil the cable friction is as good as Venhill. Personally I found Venhill to be quite good at first, but then Teflon liner starting wearing, then the end pulled off at the clutch lever end. Finally to solve all I went to a genuine Norman Hyde 7 plate clutch. Just 7 friction & 1 extra steel. No need to use special pressure plate, just reuse the normal steel one. Then you can use 500cc springs & the lever effort is much easier & no slip.

The Hyde friction plate steel part is same thickness, but friction pads are thinner & narrower. This makes installed thickness of 7 plates same as normal 6 plate so all adjustments stay the same. The narrower pads concentrate the pressure so no slip & it releases really well also. Of course the 500cc springs put much less stress on cable as well as your fingers. Or you can back off the 650 pressure plate adjuster nuts 2 turns out from flush if you don't want 500 springs. 500 springs will be installed nuts flush.
In any case get the Barnett cable & lube it before you install it.
Don
 
#7 · (Edited)
Thrasher is right, not a breakdown , just a minor inconvenience, clutch not needed. Back in the 60's half my track bikes had broken clutch cables, we couldn't afford new cables so we just rode around the problem. Eventually my older brother showed me how to re attach cable nipples.

I once was a passenger in my Uncle Huey's 3 speed Vanguard "Spacemaster" :surprise:

He drove 200 miles with no clutch. Easy. All he did to start off was put it in first, ignition on & hit the starter, it would kangaroo hop down the road but kept going with me giving a push as well then leaping in before he floored it. Every time I watch Burt Munro saying push ya bastards, faster faster, I think of old Huey. To stop at stop lights he'd brake in neutral, switch off & repeat. To change gear he just rammed it through:grin2: Good Ol Uncle Huey, knew everything, loved an argument !

But he didn't know his slave cylinder was leaking, I did know that & I was only 14 LOL. I told him but he already knew everything and ignored the kid :grin2:
 
#8 ·
Chief, be a risk manager and buy two cables.

Cable tie the spare to the frame and you'll be right then should it happen again.

Same goes for throttle cables. :smile2: RR
 
#10 ·
I guess the breakdown part is do to me hitting stop lights behind cars with no shoulder. If it was just stop signs I would of rolled through hem slow. But 6 lanes of traffic was a little scary to go through a red light.

When I popped her in gear is when she would jump then die. If it would have been a less busy street I could have ran and jump stared her. But it was just to hairy for a Sunday to risk it. I called a buddy who had a truck. Ironically when I was sitting in the parking lot a got a thumbs up from a guy who liked my bike. I just smiled and waved back not knowing I just held up traffic to find an open parking lot pushing her on the side of the road.

Still love her and can't wait to get her fixed:)
 
#12 ·
Wow! I replaced it myself:). And saved a few $$. Pretty easy. Had to lift the tank. The old one was zip tied to the frame. I chose to leave it free flowing so if it breaks again it easier to replace.

Pull feels better. I would prefer it a little easier but it's better then it was when it before it broke.

Actually it's kinda fun to work on these older bikes:)
 
#14 ·
Hi Chief, Yes working on these old bikes is quite fun. I know the kind of traffic you talk about. It's a death wish to ride no clutch in this case.

The 1st time mine broke I was across town & was able to limp back to a relatives house & he drove me home. Wife drove me back & I installed cable there. That was in 1975. Was nearly impossible to find a cable for the high US bars the bike came with. Finally found one miles away & drove car to get it. The next time I was only a short distance from home & limped back. Handle bar end came off both those times. Then the next one, ball end came off at lever inside trans, 3 blocks from home. Then I dug up one of the old cables I'd repaired with a home made end. On that one, I started feeling spongy & I could see it fraying at the trans end & ready to break. Then a new Venhill. The lever end pulled off that one as some of the others had.

Finally I got the Barnett from a friend's recommendation. I road a while with the stock clutch, then finally decided to install the Hyde, mostly to reduce lever effort. I like to do all day rides & also go far from home in remote areas with no cell phone service. So I always carried a spare cable in a back pack or saddle bag. My friend has several thousand miles on his Barnett with stock 650 (1969 Bonnie) clutch & no breakage. The guys at Rabers say Barnett is by far the strongest.

I just checked my records & Venhill lasted 2800 mi. which may be better than the prior stock cables. So far I have 1500 mi. on Barnett. Bike just turned 16k original miles this week. So far the Barnett has not shown any pull out of ends or fraying of strands. I installed Hyde clutch just 200mi. after Barnett cable, so we'll see how it does over time, but with less force even the others may have done well. So far this year I've covered 3k miles on bike.

The 750 twin came with much stronger clutch springs than 650s which is part of the problem. Lever ratio is different to reduce lever effort, but still very hard to pull. With the 650 springs & my lever my clutch effort feels like a modern bike, meaning you can hold clutch in at stop lights & all day ride doesn't tire my hand.

On a 650 with stock motor I'd switch to 500cc springs as suggested by Hyde. In USA was about $160 for clutch, shipping, exchange rate fee.

Where is Cypress? The island below Turkey or a town somewhere else?
Don
 
#20 ·
The 750 twin came with much stronger clutch springs than 650s which is part of the problem. Lever ratio is different to reduce lever effort, but still very hard to pull. With the 650 springs & my lever my clutch effort feels like a modern bike, meaning you can hold clutch in at stop lights & all day ride doesn't tire my hand.
Don
Would you have a part number for the 650 springs?
I'm finding springs that are marketed for 650/750 so I'm guessing they may be the heavier ones claimed to suit all.
 
#16 ·
I used to use Barnett cables ...After using a Venhill I won't be using Barnett...The Venhill gives a better "feel" in my opinion.
 
#18 ·
CypUs is the island
I'm with TR7V man, I had him on the island. :laugh2:

I cannot recommend a brand, other than to say that a cable from TMS, Nottingham has served me for 10'000 miles over 6 years. I consider this OK.

It's 'gonna break next trip now :frown2: RR
 
#19 ·
"Pull feels better. I would prefer it a little easier but it's better then it was when it before it broke."

I'm sure you probably thought of this but figure I'd bring it up since nobody mentioned it. I believe the standard UK spec handlebars are about 26 inches wide tip-to-tip. The US spec handlebars are about 32 inches wide with a 5 inch rise. Clutch and brake cables are offered in smaller sizes for UK handles and larger for US ones. The smaller cable would be able to hook up to US handlebars but it would definitely feel a bit too tight/not give you a lot of play when turning the front wheel/using the controls. Make sure it's the proper cable for US handlebars!
 
#24 ·
The OE p/n is T1830.

My cable ferrule end broke at the ball ramp lever attachment after I had rebuilt my clutch and installed new springs. The new springs were stiffer and I think the added stiffness finally caused the cable to break while I was adjusting the clutch for runout.

I was happy it happened in the garage and not on the road but then panicked when I realized the little nub fell off in my gearbox.

Those little extension magnet sticks are life savers! : )
 
#26 ·
7 plate clutch and SRM pressure plate



Yep, 7 plate clutch plus SRM alloy pressure plate is definitely the way to go. My '73 T140 clutch is 100 times better than what I used to struggle with on my 1968 Trophy back in the day. For reducing the strength of pull required on the clutch lever you can move the clutch lever mount about 2cm inwards, this means your hand is getting a bit more leverage near the outer end of the clutch lever (nearer the ball end). This helps a bit.
 
#28 ·
Hi Beemie, Yes many list one size fits all springs, however, that is not correct. 500,650,750 springs are all different. 500 is weaker, 650 medium, 750 stronger, by a margin. I put in 57-1830 from Rabers. I laid all 3 out on counter to compare visually. I put Hyde clutch 7 plate +1 kit in my bike. I ended up slackening off 650 springs to about 1/2 to 1 turn looser than flush with dome of adjuster. I used stock pressure plate Hyde & Johnitoc suggested no advantage to alum. plate. In fact all the alum plates I looked at were smaller dia. than stock. I would want a larger diag. I flattened the steel press plate with emery cloth. Adjusted to no wobble as normal. The stack height of the Hyde clutch pack is exactly the same as stock clutch was. The extra thickness of the extra plate is compensated for by the friction pads being very thin compared to stock clutch. I mean very thin. While Triumph smooth plates are etched & rough, the Hyde smooth plate is very smooth, no etch whatsoever. They say no need to etch.

Regarding adjustment of springs being too tight I did much experimenting to test that. Depends on the springs, with 750 springs binding sooner, once you get 2 threads of stud protruding from adjuster head you are in danger of spring bind. I do not have & did not test 500 springs. Spring binding puts great strain on the clutch cable as you can imagine. 650 springs gave a dramatic reduction in lever effort in my case with my stock '73 lever assembly. For clutch rod adjustment I'm running 3/4 turn out from touching rod (not plate lift) on my center rod adjuster screw.

Take up point on the clutch lever is not a product of pressure plate spring adjustment, but rather cable adjustment. However rod adjustment must be at least close before cable adjustment.

Amount of lift of the pressure plate is most important. You need at least .110" for good release under all conditions. I found .115-.120" was better. Assuming clutch rod & cable adjustment are correct lift is mostly a product of the lever pull ratio you lever set has. This is dependent on the distance from pivot screw to clutch cable end. So far as I can tell many of the earlier, such as 69-70 levers pull a good 1/8" more cable which translates into a good .025-.035" more lift with lever pulled to handle bar grip. This lever has less leverage however, so effort is greater. But again plate lift is more & works better.

My lever has a shorter pivot/cable distance by 1/8". So far as I can tell the '71-75 levers all have this leverage ratio. It gives a much easier pull, but less cable travel resulting in only .074" plate lift. This is with just a trace of cable free play. Even with Hyde clutch, this was not very good & when very hot plates might drag slightly getting into neutral. But... the lever effort with 650 springs was really good.

To get more plate lift I needed more cable travel. Since I didn't want to change lever assembly I got another lever perch half from Rabers to experiment with. I cut 3/16" off the alum. off perch such that the lever could move closer to the clutch cable. Had to grind out the slot with Dremmel so lever could move further towards cable. Of course now the lever was farther from grip by 1/2-3/4" or so. The reach is farther, but visually you don't see it. While riding bike the extra reach is not an issue because much of the reach is the required free play in cable & the springs are not so hard to compress until lever is closer to grip. With just under 1/8" cold, & a full 1/8" cable free play hot I now get .117" hot. Finally the clutch is perfect & I can get neutral easily even when smoking hot it town. It took me 2 years to get it all right.

This is interesting observation. When I backed off the springs I took the plates out to look at them just for fun. The etched steel plates had no visible wear from the Triumph friction pads. However the Hyde friction pads looked like they were wearing the etched plates slightly, but not the smooth plate. Again I've had no cable/rod adjustment change to speak of so wear is slight. Wear mostly on steel where inside dia. of Hyde pad contacts steel plate. Press plate contact is centered for stock frictions, but biased inwards for Hyde, because Hyde friction has much larger inside diameter. Still clutch works good though. Seems to me smaller dia. alum press plate would be even worse, but again users find them to work good.

I've covered over 2000 miles with this set up now, in both icy & very hot conditions, short & all day rides & I can say it's working perfectly & Hyde clutch has not needed much adjusting. If plates wear the cable free play gets less & rod adjustment gets less as well. So far the adjustments have been holding good. One thing I've noticed on the Hyde clutch is it's just slightly notchy on the take up cold. Not a problem at all & doesn't effect selecting neutral or shifting but with taking off bike starts to move & then the last bit of lever movement the clutch is ever so slightly grabby. After the chill gets off the engine (1-3 min.) or maybe 2 or 3 take offs, the clutch is silky smooth.

Now... Here's an interesting take. My friend John put a full Hyde kit all friction & the smooth steel plates in his '69 Bonnie recently. Hyde suggested to him 500 springs were too weak. They suggested new 650 springs backed off a bit. He got the same Raber's 650 springs I got (SRM). He backed them off as suggested & had clutch slip at times. He then went just slightly looser than flush & no more slip. He has very good release with the Hyde also. He flattened the stock steel pressure plate as I did. His lever effort is similar as before. We both have well lubed Barnett cables. I cannot explain why his clutch had a tendency to slip. He was/is running Type F ATF in primary, I'm running Mobil1 V-Twin 20-50 in primary.

Regarding the Raber's springs, I made a spring tester & found the Raber's new 650 springs were slightly stronger than some old 650 springs I had laying around. My original 750 springs were way stronger. Visually 750 spring wire is much fatter & spring is shorter uncompressed that 650 spring. Even with your fingers 750 spring is much stronger to compress.

That's my experience.
Don
 
#29 ·
Don,

Thanks for the detailed rundown.
My T140v has fairly new Surflex disks and a new Venhill cable that both function well but could use a bit less of a struggle with the lever effort.
Since things are not all that old a change to seven disk setup doesn't seem cost effective about now.
Perhaps just a try with the 650 springs might be a worthwhile winter project. Weather is long overdue to break for the worst around here.
 
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