I had some problems with shifting. Tried the PR adjustment routine: verified Pressure Plate was properly Concentric, loosened cable, loosened lock nut, moved rod out and then in until contact. Then back off half turn.
No relief. I pulled rod and it was looking sad: some bluing indicating no full disengagement.
I was considering replacement with the two piece rod with the ball bearing between the two pieces. Claimed to be a harder material and provide and easier engagement.
Any thoughts of this piece vs old one piece rod manufactured by soliciting lowest bids from various suppliers in '70's??? This two piece unit is not much a difference in price. This one with the ball bearing is certainly higher, but not any sort of breaking point.
i just bought several pushrods from baxter, planning on cutting some length out of the middle and putting in two or three greased ball bearings to help keep my clutch rod from seizing. i'm running a dry unit that has no lubrication, and it's hard on the pushrods.
the rods from baxter are darkened at both ends from flame-hardening. i'll get a picture tomorrow when i'm down in the shop.
It is stiff. Recent history is a broken cable leaving me stranded and a flat bed home.
Replaced with one from Klemph's. British make and very nice quality. I oiled it and then installed. Properly adjusted I was looking for some improvement. No improvement. I'm sure the pull ultimately led to the demise of the cable. They have to design one capable of more than 43 years service!!
I adjusted the rod (half turn out after contact) and inspected the Pressure Plate. All looks in order.
Anyway, Just wondering if there were those noticing some degree of improvement in the lever pull with this special Push Rod. Easier, smoother or.....
broken cable Replaced with one from Klemph's. No improvement.
Risking stating the obvious, worn pivot (lever and/or bolt) can cause a heavy clutch pull, sometimes only noticeable when cable is attached to clutch.
Between lever pivot centre and cable nipple centre should be 7/8". John Healy has posted previously that replacement original parts haven't been available for many years and the two pattern levers and 'perches' (Harris and Emgo) have different pivot-to-nipple distances (1" and 1-1/8") that aren't interchangeable.
How much bolt thread protruding through the "Pressure nuts"?
Correct springs? John Healy and others have posted previously that there are different springs that 'fit'.
Stuart, thanks very much for the reply. I see there are many, many opportunities for failure! Don't know which to focus on first as such further investigation requires cover removals.
Lever: Stock OE lever.
Pressure Plate Springs: I didn't remove them so I don't know if serviceable or weak. I was satisfied the Pressure Plate revolved evenly. I've read of sometimes needing to replace springs and to do all at once if one fails.
Bolt thread visible through 'Pressure nuts': I didn't really take note. They appeared equal, but I'd be very reluctant to assert the amount of threads visible without removing cover again.
Thanks for the additional info.....if the cable is new, PR is in good shape (not bent/mushroomed), and lever is good, I'd check the pressure plate nuts. For a stock set-up, the end of the bolts should be flush with the nuts. That is to say, they won't protrude past the end of the nut AND they're engaged enough to block the slot in the end of the nut.
People have had some success reducing the 'pull' on the later 750 bikes by using the springs from the 650's. A search here should reveal more information....
You could check the ball and ramp mechanism in the outer cover of the gearbox. However, that bit will give itself away by a clicking noise if something's wrong in there....
'77 T140J "Vintage Bike". What's in your garage?
"The paying customer is always right."
Fitting round pegs into square holes since 1961...
Hi Steve, I have '73 tiger. I spent a few years figuring this out.
The way you are adjusting is good.
For starters 750 springs are very very stiff. Way stiffer than 650 springs. I found when I installed 650 springs with original Triumph 6 plate I got clutch slip. Lever effort was much improved. But slip demanded return to 750 springs. After new Venhill cable broke, then another, I was done messing around. I do 300 mile rides & needed a real cure.
The only cable I found that can hold up long term is Barnett. The ends are swaged on, not soldered. I went through several cables prior. Either the top or bottom end would pull off. An oiled Barnett cable has very low friction. Every bit as low as a Venhill featherlite.
Regarding springs for sure on 750 do not go deeper than dome flush with stud end. Back off 1 or 2 nuts to stop wobble, keeping the one flush.
Make sure the push rod adjuster screw doesn't hit the inspection plug on primary cover. You'll see a rub mark if it does. I cut screw short & re slot it. Then use grease on end of screw to see if it still hits.
The '73 year 750s came with a 3/4" pivot lever. Measure to be sure.
The ball bearing rod is not needed & will not help.
An aluminum pressure plate is not needed & will not help.
The real solution is a Hyde 7 plate +1 kit. (if steel plates are still good). Then use JRC 650 springs. Use Mobil1 v-twin 20-50 oil.
Trust me on this. You will not be disappointed.
Icing on the cake is rework lever perch to allow lever to have more cable pull. You file perch so lever can pivot further from handle bar. About 1/8" removed from perch. Then using burr on Dremel tool deepen slot for lever so it can move to the new position. Ball end of lever will now be about 3/4-1" further from grip. Visually you won't notice it. To the fingers it won't feel odd as the lever pull will be free play at first, then the springs are just beginning to compress. When the clutch pull gets harder the lever is close to bar so your fingers have lots of leverage. The pull is less than 1/2 effort of 750 stock set up. Trust me on this.
This allows for good cable free play & gives very good lift & plate separation even at low & high temperatures. Allows neutral to be found much easier even at a standstill.
Normal plate stock is about .075-.080". With the lever mod lift will be .100-.110". The trans really likes this lift. Your fingers will love the light lever pull.
Allows for all day riding & shifting. Allows to hold lever in through red lights. Yes guys, sometimes safety demands this.
Exactly what I have is: Barnett cable, Hyde 7plate +1 kit, JRC 650 springs, stock steel pressure plate. Cut down adjuster screw, Mobil1 vtwin oil, modified lever perch. Adjusted nuts to just barely flush then backed off 1 & tighten another slightly to true.
Note: bevel ends of new clutch springs as it allows you to back off nuts easily, yet they don't vibrate loose. The original 650 springs were beveled. At some point they stopped doing this which makes backing of nuts very hard. I have photos of how to do this using Dremel.
Another problem on higher mileage bikes can be the pivot pin in 3 ball lifter cam can wear which can cause some odd lost motion & reduced plate lift. I don't know that it will increase lever effort. As was stated if grooves on drum & chain wheel are worn, plates will catch. Can cause dragging & slip, but not change lever effort. New plates will not cure worn groove issues.
I ordered Hyde 7 plate from Norman Hyde England. Used credit card. Call credit card to let them know overseas purchase. No problems. Shipped didn't take very long.
I soaked plates overnight in the vtwin oil. Hyde recommends soaking & I agree 100%.
You can fit the extra plates in 6 plate space because friction pads are very thin. Adjustments of rod & lever are as stock.
I've covered several thousand miles on this set up now. As I said, you do all this & you will not be disappointed.
Been involved with conversion on 4 bikes now, all to good results.
I can't post photos on this site. PM me your email & I can send photos & diagrams of all this. Don
Uh-uh, can't do. Twins and triples have exactly the same handlebar and 'perch'. 7/8" between lever pivot and clutch nipple centres pulls just enough cable inner for a triple clutch to work if everything's perfect, and isn't enough when everything isn't perfect. 3/4" centres would never pull enough without the lever starting a ridiculous distance from the 'bar. The chromed steel lever 'n' perch - fitted to everything pre-'71, the Hurricane in '73 and '76-'78 twins - also has 7/8" centres.
Over the years, John Healy has posted several times both here and in the TriumphRat CVV forum that a clutch lever with 7/8" centres is correct for a twin, usually in the context of owners who've fitted one of the pattern levers/'perches' with 1" or greater pivot-nipple distances.
Originally Posted by TR7RVMan
rework lever perch to allow lever to have more cable pull.
So what's the benefit of this? Unlike the triples' clutch withdrawal mechanism - which rolls the balls up two ramps - the twins' withdrawal mechanism simply moves them out of indentations in the gearbox outer cover "Clutch lever" and "Thrust plate" - once the balls have been rolled out of the indentations, what is the point of rolling them further by rotating the "Clutch lever" through a greater arc?
Opps!!!! Stuart, thank you for correcting me. I had a brain fart. 7/8" is correct.
I've found on a few bikes now the little extra cable pull gives a little extra lift. What I've found in heavy city traffic on hot days 90f+ is the handle bar lever play increases as the case and/or clutch plates get smoking hot. This leads to some clutch drag. I used to give bar adjuster a turn or two to make up for the heat then clutch would release fine.
Getting out of town & on open road goes back to normal play. Of courses I'd forget to back off bar adjuster & end up with basically zero play.
After doing some experiments with a donor lever & perch I found modifying the perch to give more lever travel would allow me to adjust play smoking hot, then the play would actually be on the loose side when cold. However in practice it works perfectly & I don't ever have to think about the adjuster as I ride like I did before. Even at 117f in town I can select neutral without issues now.
The position of the perch on bar in relationship to type grip can make a difference on effective lever travel also. I bought bike new. Has original lever, grips, perch (now modified, actually it's a modified original donor perch as I wanted to keep original intact). My original high US bars are straight knurled for the perch. I moved perch outwards such when clutch lever pulled the ball end of lever is 50% past end of rubber of grip. That gives the most travel on my bike.
Stuart on a total side note, if you ever get to San Francisco area look me up. Would be fun to meet. I hope to visit Scotland in the next few years. If possible I'll look you up. I know we'd hit it off good. Don
. . . Recent history is a broken cable leaving me stranded and a flat bed home.
Replaced with one from Klemph's. British make and very nice quality. I oiled it and then installed. Properly adjusted I was looking for some improvement. No improvement.
A lot of new clutch cables are lined with Teflon and should not be lubricated with oil. Lube can react with the lining and make a sticky goo that results in hard clutch lever pull. I'd call Mitch Klempf and ask him about that cable you bought -- Teflon lined?
'64 TR6R Plus some Twins from other countries (U.S., Germany, Japan)
A lot of new clutch cables are lined with Teflon and should not be lubricated with oil. Lube can react with the lining and make a sticky goo that results in hard clutch lever pull.
Uh-uh, 'fraid you're confused between nylon-lined and teflon-lined.
Afaik, nylon-lined clutch cables date back to the first triples, and it was these that first BSA/Triumph and later Venhill advised shouldn't be lubricated with any mineral oil, that otherwise being common practice for many experienced bike owners and mechanics.
Venhill originally said that teflon-lined cables didn't require any lubrication.
However, Venhill's current advice on the company's website is "lubricate the cable with a light 3 in 1 general purpose oil", without any differentiation between teflon-lined and nylon-lined.
That said, I've never lubricated either type with mineral oil. I've long used a pressure clamp that takes aerosol cans' 'straws' to first clean with WD40 (ime, even teflon-lined need that periodically) and then lubricate with aerosol graphite or PTFE.
. if the new cable's nylon-lined, oiling it won't immediately transform the lining into "sticky goo" (if it did, every triple would be immobile ) but don't leave the oil in there, clean it out and lubricate as I've described above;
. otoh, If the new cable is teflon-lined, ime no problem with the oiling except that the stickiness attracts dirt that's then dragged between inner and outer; I'd clean it out with WD40 as above and then it's up to you whether you lubricate, and with what, or not.
barnett's heavy-duty cables have a plastic or nylon-encased inner wire. i've found it frays at the ends and then prevents the wire from traveling smoothly, so i always cut away as much as i can possibly reach with a razor blade. if i have them do cables for me again i'll ask them to cut it away first. or i'll just start doing my own.