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Discussion Starter #1
I’m looking for some information on the rear wheel of my 76 Bonnie . There are two studs in the Rim that are threaded I have no idea why they are there and what the purpose is for them . I i’m getting ready to swap the tires I haven’t remove them from the rims yet just wondering why those threaded studs are there.
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They'll be security bolts or rimlocks. They keep the tyre on the wheel should you have a sudden puncture..or a slow puncture for that matter. You find them when you take the tyre off and curse them when you put it back on. The studs should have a nut securing them to the rim.
 

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Hi,
76 Bonnie
rear wheel
two studs in the Rim
security bolts or rimlocks. They keep the tyre on the wheel should you have a sudden puncture.
+1. Each "stud" is attached to - essentially - a big pad; when the nut's tight on the "stud", the pad sandwiches the tyre beads between it and the rim; if the tyre loses air pressure (that normally keeps the beads in the rim), the tyre won't come off the rim.

Fwiw, I've experienced "sudden punctures" both with and without rimlocks; while either's a natural laxative, with rimlocks definitely less so. (y)

curse them when you put [the tyre] back on.
For removing the old tyre, having either removed both rimlocks' nuts or unscrewed them as far as the ends of the studs, refit the rimlocks between the rim and the new rimtape and refit each lock's nut just on the end of the stud.

When fitting one tyre bead, as you get close to a lock, push on the end of the lock's stud - nut on the stud will prevent the lock dropping into the tyre, rimtape will keep the lock in position and push the stud back out when you release it.

Fit the tube an put some air in it.

When fitting the second tyre bead, again as you get close to a lock, same procedure as fitting the first tyre bead, this time both the rimtape and the tube will keep the lock in position and push the stud back out when you release it.

Seat the tyre in the rim as normal. When you're happy the tyre's seated correctly all round, tighten the rimlocks' nuts on to the rim - no need to go mad; as you'll have seen, a rimlock sandwiches the beads over quite a distance.

Hth.

Regards,
 

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Discussion Starter #4
They'll be security bolts or rimlocks. They keep the tyre on the wheel should you have a sudden puncture..or a slow puncture for that matter. You find them when you take the tyre off and curse them when you put it back on. The studs should have a nut securing them to the rim.
They do you have the nut on them I’m not sure how they keep the tire on . I guess the builders back then feel like the rear is more important than the front because they’re not on the front wheel
 

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They do you have the nut on them I’m not sure how they keep the tire on . I guess the builders back then feel like the rear is more important than the front because they’re not on the front wheel
76barnfind, here is what you'll find when you remove the rear tire. Its purpose is to lock the bead of the tire to the rim so your rear tire doesn't slip when under hard acceleration or hard braking. The rim lock tightens against the bead of the tire when you tighten the nut. If your tire did slip, it would likely tear the valve stem and result in a blow out which could be very dangerous, obviously . My new rear rim for my 69 Bonne doesn't have rim locks (tire stays). Many here will tell you that if you have them , run them. You can run without them but you will have to install a bolt in the hole even if you don't use the rim locks or else the tube will push thru. I mounted a rear on my 71 Bonne with them and it makes the job a real challenge.
747440
 

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Discussion Starter #6
76barnfind, here is what you'll find when you remove the rear tire. Its purpose is to lock the bead of the tire to the rim so your rear tire doesn't slip when under hard acceleration or hard braking. The rim lock tightens against the bead of the tire when you tighten the nut. If your tire did slip, it would likely tear the valve stem and result in a blow out which could be very dangerous, obviously . My new rear rim for my 69 Bonne doesn't have rim locks (tire stays). Many here will tell you that if you have them , run them. You can run without them but you will have to install a bolt in the hole even if you don't use the rim locks or else the tube will push thru. I mounted a rear on my 71 Bonne with them and it makes the job a real challenge.
View attachment 747440
Thanks so much for the reply that totally explains it and the picture tells the story I will definitely keep them on and use them as designed I’m keeping this bike all original It was a barn find 25 years ago, and has been in boxes ever since.this is my first build I do appreciate the info.
 

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Hi,
not sure how they keep the tire on
Each "stud" is attached to - essentially - a big pad; when the nut's tight on the "stud", the pad sandwiches the tyre beads between it and the rim;
guess the builders back then feel like the rear is more important than the front because they’re not on the front wheel
They were fitted before industries - including automotive - were shown consumers would pay for 'safety'. Triumph (and BSA) were competing with other motorcycle makers that didn't fit them. Generally, most things that puncture motorcycle tyres - e.g. nails? - lie flat on the road surface 'til a (front) tyre runs over 'em, flips 'em up ... then the back tyre runs into 'em ... :(

lock the bead of the tire to the rim so your rear tire doesn't slip when under hard acceleration or hard braking.
Uh-uh, Japanese bikes with far more powerful engines (e.g. Kawasaki H2, Z1) ran chromed steel rims without rimlocks, no problems. Not even Triumph fitted rimlocks to front wheels with disc brakes.

The other reason for rimlocks on the rear wheel is so the rider can deliberately reduce tyre pressure for riding riding on soft ground - low pressure without rimlocks, then some engines could move the rim on the tyre, potentially pulling the valve out of the tube. :(

The way to notice if a tubed tyre is slipping on a rim is don't fit the valve nut - because there is obviously clearance between the valve and the hole in the rim, if the tyre moves on the rim, it'll pull the tube with it, the tube won't remain vertical (y) long before it finally rips out. (n)

can run without them but you will have to install a bolt in the hole even if you don't use the rim locks or else the tube will push thru.
Hardly ... you really want the air pressure in a tube pressing against either a bolt's head or threaded end? :eek:

And, even if you don't fill an unused rimlock hole in a rim, worst-case it should be the rimtape you can see through the hole ...

Just fit two 5/16" blind grommets:-



... risking stating the obvious, "Panel Hole" is the diameter of the hole in the rim (~5/16"), "Panel Thickness" is the thickness of the rim.

Hth.

Regards,
 

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Discussion Starter #8
Hi,




They were fitted before industries - including automotive - were shown consumers would pay for 'safety'. Triumph (and BSA) were competing with other motorcycle makers that didn't fit them. Generally, most things that puncture motorcycle tyres - e.g. nails? - lie flat on the road surface 'til a (front) tyre runs over 'em, flips 'em up ... then the back tyre runs into 'em ... :(


Uh-uh, Japanese bikes with far more powerful engines (e.g. Kawasaki H2, Z1) ran chromed steel rims without rimlocks, no problems. Not even Triumph fitted rimlocks to front wheels with disc brakes.

The other reason for rimlocks on the rear wheel is so the rider can deliberately reduce tyre pressure for riding riding on soft ground - low pressure without rimlocks, then some engines could move the rim on the tyre, potentially pulling the valve out of the tube. :(

The way to notice if a tubed tyre is slipping on a rim is don't fit the valve nut - because there is obviously clearance between the valve and the hole in the rim, if the tyre moves on the rim, it'll pull the tube with it, the tube won't remain vertical (y) long before it finally rips out. (n)


Hardly ... you really want the air pressure in a tube pressing against either a bolt's head or threaded end? :eek:

And, even if you don't fill an unused rimlock hole in a rim, worst-case it should be the rimtape you can see through the hole ...

Just fit two 5/16" blind grommets:-



... risking stating the obvious, "Panel Hole" is the diameter of the hole in the rim (~5/16"), "Panel Thickness" is the thickness of the rim.

Hth.

Regards,
Thanks Stuart I appreciate all the responses and information ..this group always comes through with the advice and knowledge that a first time ground up builder like me needs and appreciates ..
Cheers
 

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StuartMac, the grommet certainly is a better solution. I frankly never considered any other solution than the "bolt" idea. In my own defense, I read a comment on another thread some time back about rim locks where a regular contributor here said they didn't run the locks but just put in a stainless bolt in its place, I suppose to fill the hole and keep the original look. I mounted my own tires on my 71 Bonne and kept the locks in place. It was a real challenge but it can be done. :)
 

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i don't run rim locks on anything anymore. many years ago i bought a couple of twenty-dollar shouldered borrani aluminum rims and drilled the rear in four places each side to insert sheet metal screws. a clymer manual speed trick, and i was sure it would make me faster. but since then i've given up on any of the locking.

i use two wraps of duct tape around the inside instead of rim tape. over those holes i run two more very short pieces to keep the tube from bulging through.
 

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Discussion Starter #11
Thanks Stuart I appreciate all the responses and information ..this group always comes through with the advice and knowledge that a first time ground up builder like me needs and appreciates ..
Cheers
I just tried taking the front tire off using the correct tools soapy water I can’t do it I’m off to find someone that can and true the wheels while they’re at it. These are old tires and have been on for at least 30 or 40 years. I am smart enough to know what I can do and what I can’t do I’m not taking a chance of screwing up the wheels LOL
 

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I have no rim locks. Never used them at all. I use a bolt to fill the hole in the rim with a head ground down so it sits under the rim tape. I do regular tyre checks and pressure checks. Had 2 punctures in 50 years on bikes. Both on rear tyre but it did stay on the rim. No front tyre punctures at all in 50 years.
 

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I have no rim locks. Never used them at all. I use a bolt to fill the hole in the rim with a head ground down so it sits under the rim tape. I do regular tyre checks and pressure checks. Had 2 punctures in 50 years on bikes. Both on rear tyre but it did stay on the rim. No front tyre punctures at all in 50 years.
Rambo, you're the regular contributor I spoke of earlier but I didn't want to mention any names... :)
 

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rimlocks are a PITA to balance, I never use them, had 2 express flats in my time [many more slower ones], one front [scary as] and one rear [scary but not as scary as the front]. Held both and came to a stop. Both were at some speed [+80km/h], but you could feel straight away that something was imminent, you got a nanosecond warning an that probably saved me from laying it [the bike] down.

BTW neither tyre was repairable, a new tube was needed.
 

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To avoid some risk of punctures, i change the rear tyre when it still has a fair bit of tread left in the centre. About 3000 miles use. Front tyres ,i have never had one wear down much as i do not use brakes very much. Front tyres get changed due to age. Engine braking then just a touch to come to a halt. Rear brake, i can barely use due to having a foot that does not bend. I have to stamp on it with my heel if needed. That might seem difficult if you try it but i had this problem since 1980.
I never patch tubes and i also change tubes at tyre change time.
 

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You’re in good company Rambo!

"I often wondered what that pedal did"
Carl Fogarty.


 

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Hi 76Barnfind, Changing tires is a lot of hard work. Yes they fit very tight. Correct tire irons are a must. Rim locks (tyre security bolt as Triumph calls them) make the job even tougher. Taking to shop is fine if you don't want to do it. Why not pay to have someone do it, nothing wrong with that. I was talking to fellow at cycle gear he'd never done an old Triumph before. The old guys knew how to do them though.

Have shop balance rear wheel while they have it. Insist they do. May be extra charge. Balancing both wheels really calms bike at higher speeds 60-70 mph+. Depending on how far out of balance it is makes a huge difference on highway. I know shop manual says rear balance isn't needed. I don't agree with that. Front defiantly needs good
balance.

I've done a lot of Triumph tires. Every time I do one, I learn something to make it easier. With some practice, not big deal, even though it's hard work.

Genuine Motion Pro tire irons are my irons of choice. Having correct irons make a huge difference. 2 sets are most helpful. At least a 2nd long black one. Polish both ends well to make them very smooth. Cut corners off of plastic oil bottles to make pads to protect rims so irons don't mar them.

Motion Pro Assorted Tire Irons - Cycle Gear

Mark valve stem hole so you don't put lock or stem in wrong hole.

Here's how I take out rim locks. Put PVC tube 1" or 1-1/4" on rim to hold bead up. Reach in with curved iron & push opposite bead down. Or reach around use small iron to hold bead back against far rim side. Push lock into tire. Reach into tire with 2 fingers & lift out lock. It will work through the gap if you wiggle it right. Going back in is opposite. Going in with new tire is harder as new tire beads really want to stay flat together. This can also be used to easily install valve stem into rim. Install nuts on lock bolts & valve stem a few turns only at this time.

Use a bright flashlight going on. Look at tire bead/rim area. You must be able to see iron will not pinch tube. There is no excuse to pinch tube. Look & verify tube is not getting pinched.

Use plenty of lube. Keep far side of tire bead in drop center where spokes are. There is no reason to over stretch tire & tear a bead. Start last side of tire opposite valve stem. Work evenly side to side towards valve stem. Finish at valve stem. The rim locks keep pushed into tire. Tube will easily compress to allow this. The tire bead will fit in drop center next to shaft of rim lock as you go. Put a little more air in tube to move beads to rim. Verify tube is not trapped in tire bead/rim interface. Verify valve stem is straight & true out of rim. Again push bolt of rim lock forcing lock into tire. Finally fill tube fully to bead tire. Verify bead looks fully seated both sides. Let most the air out. Yet again push rim lock inwards. Let it pop out. Verify bolt is straight showing lock is centered over beads. Now run nuts down. We never want nuts to center locks or stems. You want those centered before you tighten nuts. When all looks good, final tighten nuts.

Leap frog your irons going back on. Just a little at a time. An inch or so especially as you get around far enough for bead to start getting tight. I hold irons with my knees. I like to work on blanket spread out on lawn. Easier on your knees. An assistant to help hold irons as you go is very helpful.

Slightly inflate tube before installing tube. How much?? It takes some experiments depending on tire size. I'll post photo to give a clue. You want it just hold its shape.

Practice makes perfect. Tip on tight fitting tires like Roadriders use spray furniture polish as lube. I use Pledge as that's what my wife buys. I don't know that brand matters. I've never seen Roadrider tire slip from using polish. They may never bead up without the polish. I have real tire mounting lube. Didn't help. Needed Pledge to bead it. Even then took 55#. K70s fit much easier. Normal tire lube from tire shop works well.

Next tire I'll get some better photos. I'll try to video it.

Some put rim strip over rim locks. I've never done that. Factory never did that. It might work better?
Don
 

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Discussion Starter #18
Hi 76Barnfind, Changing tires is a lot of hard work. Yes they fit very tight. Correct tire irons are a must. Rim locks (tyre security bolt as Triumph calls them) make the job even tougher. Taking to shop is fine if you don't want to do it. Why not pay to have someone do it, nothing wrong with that. I was talking to fellow at cycle gear he'd never done an old Triumph before. The old guys knew how to do them though.

Have shop balance rear wheel while they have it. Insist they do. May be extra charge. Balancing both wheels really calms bike at higher speeds 60-70 mph+. Depending on how far out of balance it is makes a huge difference on highway. I know shop manual says rear balance isn't needed. I don't agree with that. Front defiantly needs good
balance.

I've done a lot of Triumph tires. Every time I do one, I learn something to make it easier. With some practice, not big deal, even though it's hard work.

Genuine Motion Pro tire irons are my irons of choice. Having correct irons make a huge difference. 2 sets are most helpful. At least a 2nd long black one. Polish both ends well to make them very smooth. Cut corners off of plastic oil bottles to make pads to protect rims so irons don't mar them.

Motion Pro Assorted Tire Irons - Cycle Gear

Mark valve stem hole so you don't put lock or stem in wrong hole.

Here's how I take out rim locks. Put PVC tube 1" or 1-1/4" on rim to hold bead up. Reach in with curved iron & push opposite bead down. Or reach around use small iron to hold bead back against far rim side. Push lock into tire. Reach into tire with 2 fingers & lift out lock. It will work through the gap if you wiggle it right. Going back in is opposite. Going in with new tire is harder as new tire beads really want to stay flat together. This can also be used to easily install valve stem into rim. Install nuts on lock bolts & valve stem a few turns only at this time.

Use a bright flashlight going on. Look at tire bead/rim area. You must be able to see iron will not pinch tube. There is no excuse to pinch tube. Look & verify tube is not getting pinched.

Use plenty of lube. Keep far side of tire bead in drop center where spokes are. There is no reason to over stretch tire & tear a bead. Start last side of tire opposite valve stem. Work evenly side to side towards valve stem. Finish at valve stem. The rim locks keep pushed into tire. Tube will easily compress to allow this. The tire bead will fit in drop center next to shaft of rim lock as you go. Put a little more air in tube to move beads to rim. Verify tube is not trapped in tire bead/rim interface. Verify valve stem is straight & true out of rim. Again push bolt of rim lock forcing lock into tire. Finally fill tube fully to bead tire. Verify bead looks fully seated both sides. Let most the air out. Yet again push rim lock inwards. Let it pop out. Verify bolt is straight showing lock is centered over beads. Now run nuts down. We never want nuts to center locks or stems. You want those centered before you tighten nuts. When all looks good, final tighten nuts.

Leap frog your irons going back on. Just a little at a time. An inch or so especially as you get around far enough for bead to start getting tight. I hold irons with my knees. I like to work on blanket spread out on lawn. Easier on your knees. An assistant to help hold irons as you go is very helpful.

Slightly inflate tube before installing tube. How much?? It takes some experiments depending on tire size. I'll post photo to give a clue. You want it just hold its shape.

Practice makes perfect. Tip on tight fitting tires like Roadriders use spray furniture polish as lube. I use Pledge as that's what my wife buys. I don't know that brand matters. I've never seen Roadrider tire slip from using polish. They may never bead up without the polish. I have real tire mounting lube. Didn't help. Needed Pledge to bead it. Even then took 55#. K70s fit much easier. Normal tire lube from tire shop works well.

Next tire I'll get some better photos. I'll try to video it.

Some put rim strip over rim locks. I've never done that. Factory never did that. It might work better?
Don
Hi Don thanks for the info. There aren’t many shops around me that work on the older bikes . I did find one yesterday, took my wheels there they had not worked on Triumph wheels before so I returned without leaving them . Also they said they couldn’t do the front wheel because when I replaced the front bearings I did a mock up and installed the wheel they said they couldn’t do it with the axles still attached to the wheel. I did not feel comfortable leaving it there for them to do the work. I’ll give it another shot using your description and instructions. Do you think heating the tire would help in getting them off a little easier? Thanks again.
Cheers ,Jack
 

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Hi Jack, For sure a warm tire will be more pliable. Depends on how cold is cold. I've done them on 65f days, no heat. If possible I'll set wheel, tires in sun.

Start with front it's much easier. Look over some youtube videos to gain some ideas. Lunmad has one. He uses a hammer.... I've never done that. I worked at Harley dealer in '70&71. Old Harelys especially Sportsters had rims similar to Triumph. I did lots of tires there. No rim locks. They used sheet metal screws through rim side into bead... My '70 Triumph a trade in was my first experience with rim locks. They are still common on dirt bikes. I've done lots of Triumph tires in last few years. Gotten pretty good at it now.

The shop is thinking they'll use a modern tire machine & lift bead like on car. That's why they want axle out. They'll probably bend rim.
Don
 

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Discussion Starter #20
Hi Jack, For sure a warm tire will be more pliable. Depends on how cold is cold. I've done them on 65f days, no heat. If possible I'll set wheel, tires in sun.

Start with front it's much easier. Look over some youtube videos to gain some ideas. Lunmad has one. He uses a hammer.... I've never done that. I worked at Harley dealer in '70&71. Old Harelys especially Sportsters had rims similar to Triumph. I did lots of tires there. No rim locks. They used sheet metal screws through rim side into bead... My '70 Triumph a trade in was my first experience with rim locks. They are still common on dirt bikes. I've done lots of Triumph tires in last few years. Gotten pretty good at it now.

The shop is thinking they'll use a modern tire machine & lift bead like on car. That's why they want axle out. They'll probably bend rim.
Don
Thanks again for the info Don . I am taking them to a shop in Pennsylvania that has been working on triumphs since the 60s it’s where I bought them from also. Don’t feel like taking any chances between the asphalt and me . Cheers
 
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