Hello again - purely coincidentally, I now have two triples in my workshop, both belonging to friends. The first is a T160 that blew a composite head gasket. Thanks again for members' contributions and advice about the pillar bolts. The motor is back together again and waiting to be fired up, this time with a copper head gasket (and copper rocker box gaskets).
The latest arrival is a 1972 Triumph Trident 4-speed. When my friend arrived, he asked me to ride the bike and I could hardly get any gears, such was the force required to shift. This apparently was not an issue that arose before. This was when the engine was hot. I was then quite surprised to find that it selects gears with ease when stone cold. I've looked at the Parts Book and see that, apart from the leaf spring, it has the usual Triumph outer cover shift mechanism, camplate and quadrant.
I could begin by removing the outer cover, checking the spring pins and seeing if it will shift gears by shifting the quadrant directly, checking the mainshaft nut is tight, and proceeding from there. However, before I do this digging, I would like to know your thoughts on what is causing the very difficult shift when hot and not when cold. Maybe some of you have experienced this shifting problem, and if you have, how did you solve it? And if you haven't but have delved deeply into Triumph gearboxes over the years, your comments would be welcome!
Hi, you don't mention if the clutch lever becomes stiffer when the engine is hot - just that shifting becomes almost impossible. I had both problems develop in my T160 (i.e. 5 speed box) despite a new clutch plate. Very smooth action and easy changing of gears when cold, but needed massive effort to pull in the clutch lever and impossible to change once the engine was hot. Back to baseline action once it cooled down, again. I stripped the clutch and looked carefully at all components and all looked well except subtle notching in the splines of the clutch hub (57-2580). I filed them down as well as I could and the problem recurred but much later than before. I've just received an NOS hub and will install it soon. Hopefully, that is the fix. Cheers, Paul.
'74 Commando '75 T160 Trident '15 R1200 GS Adv '51 Vincent Rapide
Hi again guys - I am not sure if I have the clutch adjustment right.
After slackening the adjustment at the cable, I adjusted the clutch so that there is about 4 thou clearance between the large nut and the bearing behind it. At this point, the lever is very slack at the bar and the clutch release mechanism lifts just 15 thou as measured on the dial test indicator - not enough to disengage the clutch. When I adjust the clutch cable to the point where the clutch disengages fully, with the lever against the handlebar and with a small amount of slack in the cable, I measure the lift as 23 thou.
However, at this point, there is no clearance between the large nut and the bearing. I have to slacken the cable adjustment quite a bit to feel a lack of resistance when rotating the bearing and then the lift goes back to 15 thou. Is this normal or not?
I also notice that the T160 which is in the workshop at the moment has a much snappier clutch. I wonder if the T150's diaphragm spring has weakened over time? Is this something other owners have encountered?
I should also mention that this T150 has what looks like the stock alloy clutch lever and perch which is integral with the switch, and which gives less lever travel compared to the T160 beside it. The T160 has a separate chromed steel perch and lever mounted inboard of the switch (and it looks like it might have been added by a previous owner).
Any advice on what I should investigate next? I look forward to your comments.
Search through posts for adjusting the clutch. Basically, slack off the cable then adjust the pullrod until it just turns with the motor with the clutch released. It will take a few attempts to find how much the nut will loose clearance to the lifter plate when the lock nut is tightened. Then adjust the cable. Forget setting the clearance of the large adjusting nut to a particular value. The nut and pullrod must turn with the motor. otherwise the bearing in the pressure plate will be turning all the time and the grease will eventually run out and seize the bearing putting the pullrod through the adjuster cover. Some people replace the lever with one that has more cable travel (longer distance from pivot to cable) but it should work with the stock lever. The T160 went to the separate inboard switch gear. One of the "over 200 improvements".
OK, DM, thank you for that. It is reassuring to know that one only needs to ensure that the nut and pull rod just turn with the motor.
Ironically, the clutch and gearbox problems were not the reason my friend brought the bike to me. It was because it wasn't running right. But the aforementioned have to be fixed before I address the poor running. It is a common story with classic bikes...
Regrettably, the triple clutch is, and always has been, one of its most vexatious components - enter "clutch" into a Search of this "Triples Forum" and it'll return many entries; enter "clutch" into the Triples On Line forum search and you could be there a very long time reading all the threads; I was an early member of the Trident & Rocket 3 Owners' Club in 1979 and the clutch was a perennial magazine filler ...
There are several things to check on any triple's clutch even before trying to adjust it:-
. Lever - 'Til the T160, on original clutch levers, the distance between the centre of lever pivot and the centre of the cable nipple was 7/8"; T150's, R3's and X75's were fitted with the same lever as all other contemporary models. I'm pretty certain that the triples weren't deliberately designed with finicky clutches but, thanks to the realities of British motorcycle-making in the late 1960's and early 1970's, poor manufacturing practices and qa highlighted that there wasn't any leeway in the design.
.. T160's were supposed to be fitted with chromed steel clutch levers having 1" pivot-to-nipple centres; Amal (original lever maker) gave 'em a different part number from the similar but smaller '70 and X75 lever, but NVT buggered that up by giving 'em the same Triumph part number. So, today (and for many years past), the lever supplied by dealers for the Triumph part number has 7/8"-centres.
.. Conversely, spares for the original '71-'74 T150 (and Rocket 3) "alloy clutch lever and perch which is integral with the switch" (with 7/8" centres) haven't been available for many years. What is available are levers and perches by two of the parts wholesalers that have different pivot-to-nipple centres - 1" (Harris) and 1-1/8" (Emgo); triple clutches are with these larger distances.
.. Similarly, if a T160 with chromed lever has clutch disengagement problems, and the lever has 7/8" pivot-to-nipple centres, several aftermarket chromed steel levers are available with 1-1/16" or 1/18" centres.
.. Digressing slightly, 7/8" centres is best for the completely different clutch on twins.
Thanks to John Healy for the levers details.
. Cable - Original triple clutch cables had an outer with a nylon-lining and, since originals were used up, at least one company (Venhill in GB) has been supplying nylon-lined cables.
.. Trouble is, many owners and dealers don't know this, or choose to ignore both the BSA/Triumph and Venhill advice, which has always been Do Not Lubricate It With Mineral Oil Or You Bugger The Lining ...
.. Nevertheless, even if an owner follows the advice, as standard, the inner passes through the primary chaincase to reach the clutch adjustment compartment; the inner gets covered in engine oil being splashed around by the primary chain, which is drawn into the outer when the handlebar lever's pulled ... I fixed this with the mod. the factories promised but never made - a tube from the chaincase adjuster to the adjustment compartment ... this also stops any oil weep down the outside of the chaincase from the adjuster.
There is absolutely no need for a standard triple's clutch pull to be heavy - on all my triples, I can operate the clutch lever with one finger several times (two fingers all day). I remove the cable from the bike, fit one of those common clamps over inner and outer at one end, attach the 'straw' of a WD40 can and use the aerosol pressure to blow through 'til all dirt and/or engine oil is blown out. Then I swap to an aerosol with PTFE or graphite and blow that through for a lubricant. I remove the clamp, hold the cable vertically clear of the ground; if the inner doesn't slide through the outer under its own weight, I replace and lube a new cable.
Whether the bike has 'low' or 'high' handlebars, I always use the longer US-market cable; with 'low' 'bars, I use the extra length to route the cable around the front of the frame steering head, so the desirable large-radius bend in the cable is maintained even when the steering's turned to 'full lock'.
When the cable is running freely, attach the handle bar end to the cable, pull hard on the other end while also pulling the handlebar lever. Here you're attempting to simulate the resistance of the clutch when the lever's pulled; reason is some lever faults (e.g. worn pivot) only manifest themselves when there's weight on the cable pulling on the lever.
Clutch adjustment - Several methods have been evolved of the years. The only one that definitely doesn't work is the official BSA/Triumph one in the manuals - that specifies 5 thou. clearance between "big nut" and clutch lever/bearing ...
New clutch lever/ramp with a different bearing, that keeps the big nut turning when the handlebar lever is pulled and obviates all the incantation and virgin-sacrificing before 'setting the big nut', are available both from Dave Madigan ("DMadigan" above) and Triples Unlimited.
Last edited by Stuart; 08/22/1710:29 pm. Reason: Correction and additional information
Ever since I owned a Commando, I became acutely aware of cable quality, nipple-to-pivot distances and lever travel. The clutch action on this 4-speeder is actually quite light. If it wasn't, I wouldn't rest until it was! It is also disengaging when the lever is back to the handlebar and the clutch adjusted as per DMadigan's advice above.
Knowing a bit about triples' clutches, but not enough to be confident, I knew I had to be careful about adjustment to avoid damage to the thrust bearing, which is why I asked the question. Also, thank you for the reference to lever/ramps. For the moment, I think we don't need one, but it's good to know.
This T150 doesn't have the longer cable and has the stock lever and perch. The T160 that is its temporary stablemate is a good reference since it has the separate chromed steel perch and lever with longer reach, and a longer cable. It has a nice snappy clutch action and disengages fully. If it was mine, I would do the mods you suggest. I will have to leave it to my friend to decide.
Now, I have another question, this time about jetting.
This T150 has short open bellmouths - no air filter. It feels like it's running lean. Would you change the main jet and needle jets? My instinct would be to try the next size up main jets and raise the needles a notch. Then, if there is a hesitation just off tickover, I would change the slides (a major PITA). What do you think?
This T150 has short open bellmouths - no air filter. It feels like it's running lean. Would you change the main jet and needle jets?
Definitely read the technical stuff on the AMAL website and, if it feels like it's running lean, I would definitely go through the Tuning Guides. Starting with bigger main jets, finding it eight-strokes because it's rich and going smaller is preferable to starting with smaller main jets and finding additional lightening holes in the pistons?
Fwiw, my T160's have one size bigger main jets with K&N filters and proper Dunstall 'silencers' but it's been some years since I went over the tuning job properly; fuel has changed, and it might be that, if I did it again, I'd end up with different jets and slides. Just as a matter of interest, do you know Richard Darby at 3D Motorcycles? He uses some quite radical settings - No.4 slides, needles on the bottom notch ... But it all seems to work.
The big effort to change gear with either the engine off or running would seem to indicate that the clutch is not the primary culprit, but I could be wrong.
I agree. Your hot shifting problem sounds like a lubrication issue. Have you verified that the gearbox has plenty of nice smelly 90wt? I had a T140 once with a hot shift problem that was ATF in the gearbox and I suspect the low viscosity gear oils sold in the local bike shops for Japanese transmissions would perform equally poorly.
1971 T120RV (R.I.P.) 1973 T140V/TR7 1993 Ducati 900 SS
Stuart - thank you for sharing your tuning data - very helpful to know. No, I don't know Richard Derby. If I get stuck, I will contact him, and it's good to know there's a dedicated triple expert not too for from home.
I might try 170 mains - which are a big jump, and then reduce to 160 as necessary, and raise the needles (unless they are raised already). From experience doing this on other bikes with Amals, I think it just needs minor tweaking rather than starting from scratch, because it is otherwise bog stock. I will have to do some plug chops, which are messy but necessary! I do agree that running it lean at full bore could hole a piston.
South of the border here, we can only get 95RON, whereas North of the border, you can get Super Unleaded. I can't say if it makes a difference with classic bikes because I haven't tried it, but it does make a small difference to performance in modern bikes and the engines will run a tad cooler as well.
South of the border here, we can only get 95RON, whereas North of the border, you can get Super Unleaded. I can't say if it makes a difference with classic bikes because I haven't tried it,
I've always pretty-much stuck with Super, BP or Shell; tried both Tesco Momentum (supposedly a higher octane than BP or Shell Super) and 95, afaict my Triumphs didn't like either (because of the 'effinol' in both whereas both BP and Shell Super are generally both <5% effinol?). Otoh, since lead went, Mate O'Mine's done several thousand long-distance miles on his T160 on 95 ...
BikeVice - sorry I took so long to reply to your post. I don't know how I missed it but I don't get email reminders of new posts. I will have to fix that for the next thread.
Yes, I checked the oil level and it looks both clean and thick! Strangely, the hot shift problem didn't present itself on my last test spin and it was good and hot then. I will change the oil though. I didn't think the clutch was the problem originally because it was very stiff to shift with the engine stopped but still hot. The clutch was a problem because it needed to be adjusted properly.
I wonder if it could be an indented cam plate? I have one on my bench from a T120R, where the roller has dug into one side of the track the selector fork roller runs in. This is an engine I'm rebuilding for myself and I think that cam plate is scrap. Has anyone seen that happen before? I will try to post a pic of this if I can get a good shot of it, because it's easy to miss.
Here's what I mentioned in my last post about an indent in a camplate. I was surprised that this camplate was not hardened (from a T120), so it can be dressed carefully with a needle file. In fact, I did this after I took the photo, and the roller moves smoothly in its track now. I didn't remove the indent entirely, just the burrs. However, this may turn out to be just a quick and dirty fix.
Click on the thumbnail to view the full size. I hope this works; it's the first time I've posted a pic on this forum.