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Was never a big fan of the original footpegs, too big and chunky for my liking. On top of that, I needed feet like Krusty the Clown to reach the pedals. I found myself lifting my foot right off the footpeg to apply the brake.

I got some replacements from MC Motoparts. These fit perfectly and have the option of a 25mm or 40mm radial extension, which can be set at 15 degree increments. The original pegs have about a 25mm offset already, so I got the 40mm.

The brake pedal was too high and had no downward adjustment left, so I shortened the push-rod by 12mm and ran some extra thread on it. Beware if you do this that when you remove the circlip holding the push-rod into the master cylinder, the guts of the master cylinder want to fall out, so have something ready to hold the remainder in. Just when I was feeling pleased with myself I discovered that with downward adjustment the brake pedal hits the pedal spring anchor bracket, so having got this far I scalloped out the brake pedal to clear the bracket. One important discovery is that the hole in the brake pedal is about 1mm larger than the push rod clevis pin. Doesn't sound like much but equates to about 5mm of wasted travel at the pedal before anything happens. I have bushed this hole to make it size for size with the pin, and it's now much better.

The whole setup is now far better. I would have rated MC Motoparts a 10 out of 10 except that their email communication is terrible, waiting a week for a reply doesn't cut it. Too bad because the product quality is superb.

Picture below, you can also see where I scalloped the pedal.
 

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While messing with the pegs, you should up-armour the peg mounting bracket as there are quite a few reports of the welded-head 5/16 full thread bolt shearing off while riding along. Not a fun thing at all. Easy fix is to remove bracket, bash out the welded bolt with a suitable sized socket supporting the bracket while waling with a BFH (Big F'ing Hammer). Then drill out the bracket hole to next size up (3/8?) and use a proper shanked bolt with a nylock nut and some washers. The shank will now take all the loading, giving much more meat to the load.
 

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While messing with the pegs, you should up-armour the peg mounting bracket as there are quite a few reports of the welded-head 5/16 full thread bolt shearing off while riding along. Not a fun thing at all. Easy fix is to remove bracket, bash out the welded bolt with a suitable sized socket supporting the bracket while waling with a BFH (Big F'ing Hammer). Then drill out the bracket hole to next size up (3/8?) and use a proper shanked bolt with a nylock nut and some washers. The shank will now take all the loading, giving much more meat to the load.
Questionable advice. This joint is a tension joint where bending and shear loads are born by the contact surfaces of the joint due to the clamping force of a properly torqued bolt. The bolt should not “ take all the loading”. Better to check the bolt torque to be sure it is within spec.
 

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Was never a big fan of the original footpegs, too big and chunky for my liking. On top of that, I needed feet like Krusty the Clown to reach the pedals. I found myself lifting my foot right off the footpeg to apply the brake.



I got some replacements from MC Motoparts. These fit perfectly and have the option of a 25mm or 40mm radial extension, which can be set at 15 degree increments. The original pegs have about a 25mm offset already, so I got the 40mm.



The brake pedal was too high and had no downward adjustment left, so I shortened the push-rod by 12mm and ran some extra thread on it. Beware if you do this that when you remove the circlip holding the push-rod into the master cylinder, the guts of the master cylinder want to fall out, so have something ready to hold the remainder in. Just when I was feeling pleased with myself I discovered that with downward adjustment the brake pedal hits the pedal spring anchor bracket, so having got this far I scalloped out the brake pedal to clear the bracket. One important discovery is that the hole in the brake pedal is about 1mm larger than the push rod clevis pin. Doesn't sound like much but equates to about 5mm of wasted travel at the pedal before anything happens. I have bushed this hole to make it size for size with the pin, and it's now much better.



The whole setup is now far better. I would have rated MC Motoparts a 10 out of 10 except that their email communication is terrible, waiting a week for a reply doesn't cut it. Too bad because the product quality is superb.



Picture below, you can also see where I scalloped the pedal.


Very nice looking pegs... it’s on my hit list as well... nice job!


Sent from my iPhone using Tapatalk
 

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Questionable advice. This joint is a tension joint where bending and shear loads are born by the contact surfaces of the joint due to the clamping force of a properly torqued bolt. The bolt should not “ take all the loading”. Better to check the bolt torque to be sure it is within spec.
That 5/16" full threaded stock bolt has failed in may reported cases, with or without being at the spec torque. And what about the second failure mode of the stock pegs, as in the castings letting go? Are they also somehow the owners fault?
 

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That 5/16" full threaded stock bolt has failed in may reported cases, with or without being at the spec torque. And what about the second failure mode of the stock pegs, as in the castings letting go? Are they also somehow the owners fault?
How many failures? How do you know the torque was or was not at spec?

What about the casting?

Is it possible that the foot peg was over loaded due to accident, tip over, or the foot peg hit an immovable object like a curb?

Owner’ fault? Maybe, maybe not.

In any case, there are thousands of Bonneville out there that haven’t had a foot peg break. Implying a design flaw based on sketchy anecdotes is unfair and premature.
 

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Discussion Starter #7
In any case, there are thousands of Bonneville out there that haven’t had a foot peg break. Implying a design flaw based on sketchy anecdotes is unfair and premature.
I've read most of the posts on Bonneville footpeg failures and there does seem to be an inordinate number of reports of both bolt and casting failures, albeit a small percentage of the population. Most of these are reported as material failure in normal operation.

Anyway, I've inspected and torqued my bolts and decided not to go any further. As this topic was not the reason I started the post, let's leave it at that.

Cheers.
 

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I've read most of the posts on Bonneville footpeg failures and there does seem to be an inordinate number of reports of both bolt and casting failures, albeit a small percentage of the population. Most of these are reported as material failure in normal operation.

Anyway, I've inspected and torqued my bolts and decided not to go any further. As this topic was not the reason I started the post, let's leave it at that.

Cheers.
I ran a quick search of the forum and found six threads about Bonneville foot peg failures. In two of these the OPs stated that the bike had been down while riding and the foot peg failed later. In one thread the OP stated that he bought the bike with the foot peg already broken.

My question is: Is six problematic reports an inordinate number?
 

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I don't think there's anything to worry about :) :


https://www.triumphrat.net/air-cooled-twins-talk/763018-footpeg-snapped-while-riding-my-14-bonneville-pics-inside.html#post8362338


This one contains 4 cases:

https://www.triumphrat.net/air-cooled-twins-talk/104282-broken-bonnie-footpeg-4.html#post7996026

https://www.triumphrat.net/air-cooled-twins-talk/775882-broken-foot-rest-communication-w-triumph.html

https://www.triumphrat.net/air-cooled-twins-technical-talk/461882-footpeg-problem-8.html#post9029282

https://www.triumphrat.net/air-cooled-twins-technical-talk/461882-footpeg-problem-5.html#post8903810

https://www.triumphrat.net/air-cooled-twins-talk/775882-broken-foot-rest-communication-w-triumph-5.html

https://www.triumphrat.net/twins-technical-talk/231030-it-happened-to-me-today-5.html

https://www.triumphrat.net/air-cooled-twins-talk/104282-broken-bonnie-footpeg-4.html#post7996026

https://www.triumphrat.net/twins-talk/104282-broken-bonnie-footpeg-4.html#post6859762

https://www.triumphrat.net/twins-technical-talk/555505-bad-quality-footrest.html#post6187217

https://www.triumphrat.net/twins-talk/210252-my-2009-bonneville-se-almost-killed-me-yesterday-13.html#post2268370

https://www.triumphrat.net/twins-technical-talk/240091-darn-it-it-happened-to-me.html

https://www.triumphrat.net/twins-talk/119289-bonneville-footpegs-always-snapping-off-2.html

https://www.triumphrat.net/twins-talk/471905-considerations-for-first-used-bonneville-purchase-carb-tuning-at-sea-level-too-6.html#post5263705


https://www.triumphrat.net/twins-technical-talk/475393-help-identifying-part-possible-fix-for-broken-peg-clovis.html

Twice for same owner:

https://www.triumphrat.net/twins-talk/464777-my-second-foot-peg-has-snapped-off.html

Another two in this story of a trip:

http://mybonnie.wordpress.com/2014/08/02/nevada/

https://www.triumphrat.net/twins-technical-talk/461882-footpeg-problem.html#post5117394

https://www.triumphrat.net/twins-technical-talk/205931-any-one-had-foot-peg-failure-thruxton.html

https://www.triumphrat.net/twins-talk/212472-broke-rider-s-left-footpeg-off-5.html
 

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I don't think there's anything to worry about :) :


https://www.triumphrat.net/air-cooled-twins-talk/763018-footpeg-snapped-while-riding-my-14-bonneville-pics-inside.html#post8362338


This one contains 4 cases:

https://www.triumphrat.net/air-cooled-twins-talk/104282-broken-bonnie-footpeg-4.html#post7996026

https://www.triumphrat.net/air-cooled-twins-talk/775882-broken-foot-rest-communication-w-triumph.html

https://www.triumphrat.net/air-cooled-twins-technical-talk/461882-footpeg-problem-8.html#post9029282

https://www.triumphrat.net/air-cooled-twins-technical-talk/461882-footpeg-problem-5.html#post8903810

https://www.triumphrat.net/air-cooled-twins-talk/775882-broken-foot-rest-communication-w-triumph-5.html

https://www.triumphrat.net/twins-technical-talk/231030-it-happened-to-me-today-5.html

https://www.triumphrat.net/air-cooled-twins-talk/104282-broken-bonnie-footpeg-4.html#post7996026

https://www.triumphrat.net/twins-talk/104282-broken-bonnie-footpeg-4.html#post6859762

https://www.triumphrat.net/twins-technical-talk/555505-bad-quality-footrest.html#post6187217

https://www.triumphrat.net/twins-talk/210252-my-2009-bonneville-se-almost-killed-me-yesterday-13.html#post2268370

https://www.triumphrat.net/twins-technical-talk/240091-darn-it-it-happened-to-me.html

https://www.triumphrat.net/twins-talk/119289-bonneville-footpegs-always-snapping-off-2.html

https://www.triumphrat.net/twins-talk/471905-considerations-for-first-used-bonneville-purchase-carb-tuning-at-sea-level-too-6.html#post5263705


https://www.triumphrat.net/twins-technical-talk/475393-help-identifying-part-possible-fix-for-broken-peg-clovis.html

Twice for same owner:

https://www.triumphrat.net/twins-talk/464777-my-second-foot-peg-has-snapped-off.html

Another two in this story of a trip:

http://mybonnie.wordpress.com/2014/08/02/nevada/

https://www.triumphrat.net/twins-technical-talk/461882-footpeg-problem.html#post5117394

https://www.triumphrat.net/twins-technical-talk/205931-any-one-had-foot-peg-failure-thruxton.html

https://www.triumphrat.net/twins-talk/212472-broke-rider-s-left-footpeg-off-5.html
I went through all of the threads that were in your references. Lots more failures than I believed. Below is a list of the posters with a summary of what was in their posts that applied to their foot peg failure. I might have missed a few; but, I listed every instance that I found. Note that many of the posters acknowledged that they had hit a hard object, tipped their bikes over, or had dropped the bike while in motion. Also, those posts that included photos showed fatigue on the fracture surface showing that a crack nucleated and then grew over time with usage. There were a relatively small number of fractures of the aluminum part of the foot peg assembly.

There were also some posts when the posters (Forchetto among them) checked the tightness of their foot peg bolts and found them loose or the torque was low.

Columbo: Witnessed foot peg failure due to bolt fracture

Oddsteven: left foot peg failed acknowledged the bike was dropped several weeks previous

JxnBonnie: foot peg failed

FlyingCelt: Foot peg bolt failed

Thump Bonnie!: Right foot pegbolt failed

gt1jimmie: Foot peg casting broke after hitting solid object

Durbud: Found his bike lying on its side with broken foot peg (probably bumped by a car)

MES: Foot peg broke. Acknowledged that the bolt may have been loose

WaltZ: Foot peg broke. Acknowledged bolt was loose

greyplague: Foot peg broke after bike went down

SpaceCoastRat: Foot peg casting broke when bike tipped over

Lake: Foot peg broke while riding. Photo shows fracture surface that the surface shows evidence of fatigue failure with only about 40% of cross section intact at time of failure.

Bonnie25: Left foot peg broke

Viperject: Right foot peg broke

Chicagobob: Found his foot peg loose. No breakage

Tornado99: Reports foot peg casting broke on his buddy’s T100. Noted that buddy was second owner of the bike.

Tunabreath: Foot peg bolt broke

MeanStreaker: Foot peg broke

Redstickboy: Foot peg bolt broke on cousin’s bike

dr_kedaver: Left foot peg bolt broke. Photos show fracture surface with what appears to be a fatigue fracture with only 10% of cross section intact at the time of final total fracture

extractable: Left foot peg bolt broke

nimravus01: Broke right foot peg bolt. Acknowledged that foot pegs were used replacements

Cruzin1a: Both foot pegs loose when checked

Snook: Foot peg broke after running into a post.

Ready to Ride: Found one foot peg loose after hitting something.

Irish Guy: Found foot peg casting cracked

WaltZ: Found loose right foot peg. When torqued bolt fractured showing only 1/3 bolt cross section intact

Sasper: Broke foot peg after running into a curb

Untold: Foot peg snapped of when he bumped the bike in his garage

Steve Betts: Foot peg broke after tip over. He noticed his wife’s bike had crack in the cast portion

Forchetto: Reported finding both foot peg bolts loose (actually, torque was low)

DinoZ: Broke foot peg due to tip over

Squidsix: Broke left foot peg at clevis joint

Padre: Foot peg broke “Blasted white metal”

BonnieBlack: Foot peg broke. Great close up photos showing fracture surface. Fracture showed evidence of fatigue and corrosion. At failure, only about 10% of cross section was not already fractured due to fatigue.

Kj6itk: Left foot peg bolt broke

Tecpatl4: Broke left foot peg

Blueback: Reported that his left foot peg was torqued low (10-12 Nm vs recommended 27 Nm). Right foot peg was torqued to 20 Nm

Bonnienyc11: Right foot peg broke

Traveler501: Right foot peg torqued to only 8 ft-lb (10.9 Nm)

RICW: Foot peg bolt broke while being torqued to only 20 ft lb (27.1 Nm)

pgreer: Right foot peg bolt broke

nygumbo: Right foot peg bolt broke. Noted that half of fracture surface was rusty (fatigue failure over time)
Reported second foot peg bolt broke at later date.

JesseD: Foot peg broke.

Ocka: Left foot peg broke

DavidR8: Bike tipped over bending the left U-shaped foot peg bracket. Third owner of the bike. Foot peg bolt broke. Photo showed evidence of fatigue failure

UllyssesCale: Multiple right side foot peg breaks due to tip overs while bike is parked

Dicimus: Broke left foot peg bolt

rmglad55: Broke foot peg

tdnathens: Both foot peg bolts found to be loose

UrbanizedOkie: Left foot peg bolt broke

Not of the TriumphRat forum, a blog reported a broken foot peg bolt

dboone: Cast aluminum part of foot peg assembly broke

extractable: Left side foot peg bolt broke

richm: Right foot peg cast aluminum part broke when bike tipped over in garage

bjh1112: Foot peg broke while riding

bonza: Observed right foot peg bolt failure on pal’s. Noted that pal’s bike had been dropped at low speed previously.
 

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Without proper testing there is no way to conclude from the above reports that fractures showing partial corrosion are the result of improper torque or other user effect. It could be the failures just begin as a crack which grows over weeks/months/years before the last section fails. The loose/lower torque peg bolts could also be occurring because the bolt is stretching/bending as fracture begins. Which came first, torque loss or partial fracturing?

It is a remarkable list of reports. I challenge anyone to show us another model triumph (or other make) besides the bonneville with this propenderance of peg failures.

Also interesting that it is mostly just bonnevilles, not scrambler (different outrigger design, same cast peg) nor Thruxton (same peg and outrigger, mounted further back so lower loading).
 

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This is somewhat remarkable. I am not sure what to think. Thousands of bikes in use, dozens of reports on this forum alone of either broken foot peg or failed bolt, half or more of which do not report mechanical damage (impact, dropped bike, etc.).

It makes me wonder if there are other factors here like rider weight, outdoor/indoor storage, owner removal of peg mount (hey I know I removed mine to swap the exhaust), etc. which may contribute to an increased risk of failure. There certainly has to be a set of design limits that owners may unwittingly exceed.

I'm heading down to the garage now to check the torque on mine.
 

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This is somewhat remarkable. I am not sure what to think. Thousands of bikes in use, dozens of reports on this forum alone of either broken foot peg or failed bolt, half or more of which do not report mechanical damage (impact, dropped bike, etc.).

It makes me wonder if there are other factors here like rider weight, outdoor/indoor storage, owner removal of peg mount (hey I know I removed mine to swap the exhaust), etc. which may contribute to an increased risk of failure. There certainly has to be a set of design limits that owners may unwittingly exceed.

I'm heading down to the garage now to check the torque on mine.
Removing your foot pegs to change your exhaust is probably a good thing. You are more likely to check the torque on your foot peg bolts. (27 Nm or 19.9 ft-lb)
 

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Without proper testing there is no way to conclude from the above reports that fractures showing partial corrosion are the result of improper torque or other user effect. It could be the failures just begin as a crack which grows over weeks/months/years before the last section fails. The loose/lower torque peg bolts could also be occurring because the bolt is stretching/bending as fracture begins. Which came first, torque loss or partial fracturing?

It is a remarkable list of reports. I challenge anyone to show us another model triumph (or other make) besides the bonneville with this propenderance of peg failures.

Also interesting that it is mostly just bonnevilles, not scrambler (different outrigger design, same cast peg) nor Thruxton (same peg and outrigger, mounted further back so lower loading).
I am of the opinion that the bolt being under torqued or loose is the primary cause. Hitting an immovable object with the foot peg (like your garage floor of an accident) could cause yielding of the bolt. Even a little bit of yielding could cause a slight increase in the bolt length effectively lowering the clamp load from the bolt. It also could be an assembly problem if the foot peg assembly was not propertly torqued.

At this point (low fastener torque) bending loads and shear loads would be born by the bolt causing the nucleation of a small crack at the bottom of one of the threads followed by fatigue over time as the foot peg was loaded and unloaded. Eventually the crack would reduce the cross section by as much as 90% (based on the photos of fractured foot peg bolts I have seen). Clearly, a bolt that has only about 10% of its original cross section and then subjected to a bending load would fail.

It would seem that for most, the foot pegs work fine. However, a more damage tolerant design would be the solution.
 
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