 |
28 Aug 2018
|
|
Registered Users
HUBB regular
|
|
Join Date: Nov 2017
Posts: 45
|
|
|
Front sprocket came lose
I just had a wild idea to go from 15 front sprocket to a 14 because why not and I mostly drive off ...
When I tried to unscrew the nut holding the sprocket I was surprised that the the nut came lose with my fingers !!!
The safety retaining washer was in place (sort of) but how can this happen ? I've seen the person who tighten it with an air wrench and I said it will never cause problems that was maybe 5k km before maybe less.
I've changed the sprocket the shaft was in pretty good condition and I've tighten it with a good wrench that I have and I've bent the safety locking washer.
Is this a nut that I have to check regularly ? I don't want to mess up my gearbox shaft because of this ...
Really intrigued what could have happened ? It wasn't tight in the first place ?
|
28 Aug 2018
|
|
Registered Users
Veteran HUBBer
|
|
Join Date: Feb 2012
Location: Milan, Italy
Posts: 610
|
|
|
the nut just keeps the sprocket in place axially speaking, it doesnt help transmit any of the torque, the splines do that. other bikes have some times just a slotted plate keeping the sprocket in place, not even a nut pressing...
as long as you used the locking washer so the nut cant unscrew, you are good.
on my race bikes where i change sprockets often, i have the nut drilled so i can use safety wire instead of a new washer every time. i snug them up with a wrench but the nut is always hand tight when i have to remove it.
|
28 Aug 2018
|
 |
Contributing Member
Veteran HUBBer
|
|
Join Date: Aug 2011
Location: Home in Essex GB
Posts: 564
|
|
I'm no expert but I would say it wasn't done correctly in the first place, it's the only logical explanation. Tight nuts and a lock washer / tab washer or similar is pretty trouble free, when done correctly. Just because you see someone use an air wrench doesn't mean its tight. Torque wrench and manual brut force is the best way to check. I would bet you will never have this happen again, you will make sure 
Of course I may be wrong and happy to be corrected...
__________________
Regards Tim
Learning my craft for the big stuff, it won't be long now and it's not that far anyway
|
28 Aug 2018
|
 |
HU Founder
Veteran HUBBer
|
|
Join Date: Dec 1997
Location: BC Canada
Posts: 7,313
|
|
|
In theory, there are two basic designs here.
1: Big nut with a locking tab to absolutely hold the sprocket tight and in place
2: loose sprocket, with a bit of metal and two bolts to keep the sprocket from coming off.
My experience has been that if you have type 1, the nut should be TIGHT always, as the shaft splines will wear excessively if not. With type 2, I believe the shaft is harder, and the sprocket heat treating may be less in the center, so that it wears and not the shaft.
To get the big nut tight, first step is to make sure that it's tight up against the splines by rotating the rear wheel backwards, so that under acceleration the sprocket is tight against the splines so LESS likely to TRY to loosen the nut. Less force under deceleration. Then make sure the nut is tightened to FACTORY SPEC torque not just an air gun which may or may not do the job. Then bend the tab washer over thoroughly, tightly, and it should be tight forever.
Others may well have different experiences!
__________________
Grant Johnson
Seek, and ye shall find.
------------------------
Inspiring, Informing and Connecting travellers since 1997!
www.HorizonsUnlimited.com
|
29 Aug 2018
|
|
Registered Users
HUBB regular
|
|
Join Date: Nov 2017
Posts: 45
|
|
Quote:
Originally Posted by Grant Johnson
To get the big nut tight, first step is to make sure that it's tight up against the splines by rotating the rear wheel backwards, so that under acceleration the sprocket is tight against the splines so LESS likely to TRY to loosen the nut. Less force under deceleration. Then make sure the nut is tightened to FACTORY SPEC torque not just an air gun which may or may not do the job. Then bend the tab washer over thoroughly, tightly, and it should be tight forever.
|
This is what I've done myself today ! I've tighten the nut as hard as I could with a 30 cm long key then bend the tab washer over it.
I will check it after a while to see how it is !
I think the air gun is was bad or not adjusted properly for torque since I had this problem on the rear axle also ... same gun same guy ...
I was missing the safety wire in the rear axle nut and the bolts at the end of the swing arm.
I will test all important bolts and nuts tomorrow because I don't want to have any problems.
L.E. I just re-read your post and figured out that the nut might be in the wrong way placed !?
The nut has a groove on one side and is flat on the other side. I put the nut the way I've found it with the groove towards the sprocket ?! and now it holds the sprocket in place ... should it lock it self on the axle or on the sprocket ?
The design seems to be no.1 from your example and I think it's correct the way I've mounted it.
|
29 Aug 2018
|
|
Registered Users
Veteran HUBBer
|
|
Join Date: Oct 2016
Location: Devon, UK
Posts: 843
|
|
|
I've changed plenty of front sprockets over the years and never found one that was loose. However I can certainly see how it could work loose even if it was properly tightened at initial fitment. If there is excessive clearance between the sprocket and the splines, either because the splines are worn or the sprocket is hardened at the teeth only, then it would be possible for the sprocket to slip a few degrees round on every acceleration and braking. This will wear the abutment faces causing the sprocket to become loose, and given that there is very little elasticity in the bolted-up assembly, even a tiny amount of wear will result in looseness. That's why you should always have a secondary locking method such as a serviceable tab washer installed and properly fastened.
|
29 Aug 2018
|
 |
Registered Users
Veteran HUBBer
|
|
Join Date: May 2013
Location: Norway
Posts: 1,368
|
|
|
Its not a problem when you torque it 110nm and use lockwasher all ears.
Last edited by xtrock; 30 Aug 2018 at 00:28.
|
31 Aug 2018
|
|
Registered Users
Veteran HUBBer
|
|
Join Date: Aug 2015
Posts: 489
|
|
Quote:
Originally Posted by xtrock
Its not a problem when you torque it 110nm and use lockwasher all ears.
|
exactly, who tightens nuts with air wrench...  
|
31 Aug 2018
|
|
HU Founder
Veteran HUBBer
|
|
Join Date: Dec 1997
Location: BC Canada
Posts: 7,313
|
|
Quote:
Originally Posted by tremens
exactly, who tightens nuts with air wrench... |
you'd be amazed, that one especially - holding it is difficult, so an air wrench is quick and easy and SHOULD be extremely tight - though no idea what the torque is set to!
__________________
Grant Johnson
Seek, and ye shall find.
------------------------
Inspiring, Informing and Connecting travellers since 1997!
www.HorizonsUnlimited.com
|
31 Aug 2018
|
|
Registered Users
Veteran HUBBer
|
|
Join Date: Aug 2015
Posts: 489
|
|
Quote:
Originally Posted by Grant Johnson
you'd be amazed, that one especially - holding it is difficult, so an air wrench is quick and easy and SHOULD be extremely tight - though no idea what the torque is set to! |
exactly, you don't know what torque is applied, bad idea.
I changed many time xt660 and ktm front sprockets. You need to have torque wrench for this, and it's not that difficult, just sit on the bike and press the rear brake while tightening the nut. You really don't want that sprocket come off during ride...
|
1 Sep 2018
|
|
Registered Users
HUBB regular
|
|
Join Date: Nov 2017
Posts: 45
|
|
Quote:
Originally Posted by tremens
exactly, you don't know what torque is applied, bad idea.
I changed many time xt660 and ktm front sprockets. You need to have torque wrench for this, and it's not that difficult, just sit on the bike and press the rear brake while tightening the nut. You really don't want that sprocket come off during ride...
|
Thanks all guys for answering I will check it after a few more kms I hope with no problems... I just can't check it before each ride it's annoying 
I applied quite some force that I was turning the engine will have to have someone help me with the brake.
I just don't want it to come off ... during 
|
1 Sep 2018
|
|
HU Founder
Veteran HUBBer
|
|
Join Date: Dec 1997
Location: BC Canada
Posts: 7,313
|
|
If it's turning the engine and you have NOT got the brake on, it's nowhere near tight enough.
You can do it alone.
I believe the sprocket is on the left side on your bike. Instructions assume it is.
- Put in 1st gear.
- Get the socket and bar on the nut, and stand on the OTHER side of the bike,
- step on the brake pedal,
- reach across and tighten.
- REALLY tight, or better with a torque wrench!!
You may need to reposition the wrench a time or two as it all "winds up" as you put pressure on it.
__________________
Grant Johnson
Seek, and ye shall find.
------------------------
Inspiring, Informing and Connecting travellers since 1997!
www.HorizonsUnlimited.com
|
1 Sep 2018
|
|
Registered Users
Veteran HUBBer
|
|
Join Date: Aug 2015
Posts: 489
|
|
|
additionally helps pushing bike's front wheel against the wall while on brake.
|
1 Sep 2018
|
|
Registered Users
Veteran HUBBer
|
|
Join Date: Oct 2016
Location: Devon, UK
Posts: 843
|
|
|
A piece of wood through the spokes braced against the swinging arm always worked for me. If it's in top gear it won't bend the spokes.
|
|
Currently Active Users Viewing This Thread: 1 (0 Registered Users and/or Members and 1 guests)
|
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Next HU Events
ALL Dates subject to change.
2025 Confirmed Events:
- Virginia: April 24-27 2025
- Queensland is back! May 2-4 2025
- Germany Summer: May 29-June 1 2025
- CanWest: July 10-13 2025
- Switzerland: Date TBC
- Ecuador: Date TBC
- Romania: Date TBC
- Austria: Sept. 11-14
- California: September 18-21
- France: September 19-21 2025
- Germany Autumn: Oct 30-Nov 2 2025
Add yourself to the Updates List for each event!
Questions about an event? Ask here
See all event details
Check the RAW segments; Grant, your HU host is on every month!
Episodes below to listen to while you, err, pretend to do something or other...
2020 Edition of Chris Scott's Adventure Motorcycling Handbook.
"Ultimate global guide for red-blooded bikers planning overseas exploration. Covers choice & preparation of best bike, shipping overseas, baggage design, riding techniques, travel health, visas, documentation, safety and useful addresses." Recommended. (Grant)
Ripcord Rescue Travel Insurance™ combines into a single integrated program the best evacuation and rescue with the premier travel insurance coverages designed for adventurers.
Led by special operations veterans, Stanford Medicine affiliated physicians, paramedics and other travel experts, Ripcord is perfect for adventure seekers, climbers, skiers, sports enthusiasts, hunters, international travelers, humanitarian efforts, expeditions and more.
Ripcord travel protection is now available for ALL nationalities, and travel is covered on motorcycles of all sizes!
What others say about HU...
"This site is the BIBLE for international bike travelers." Greg, Australia
"Thank you! The web site, The travels, The insight, The inspiration, Everything, just thanks." Colin, UK
"My friend and I are planning a trip from Singapore to England... We found (the HU) site invaluable as an aid to planning and have based a lot of our purchases (bikes, riding gear, etc.) on what we have learned from this site." Phil, Australia
"I for one always had an adventurous spirit, but you and Susan lit the fire for my trip and I'll be forever grateful for what you two do to inspire others to just do it." Brent, USA
"Your website is a mecca of valuable information and the (video) series is informative, entertaining, and inspiring!" Jennifer, Canada
"Your worldwide organisation and events are the Go To places to for all serious touring and aspiring touring bikers." Trevor, South Africa
"This is the answer to all my questions." Haydn, Australia
"Keep going the excellent work you are doing for Horizons Unlimited - I love it!" Thomas, Germany
Lots more comments here!
Diaries of a compulsive traveller
by Graham Field
Book, eBook, Audiobook
"A compelling, honest, inspiring and entertaining writing style with a built-in feel-good factor" Get them NOW from the authors' website and Amazon.com, Amazon.ca, Amazon.co.uk.
Back Road Map Books and Backroad GPS Maps for all of Canada - a must have!
New to Horizons Unlimited?
New to motorcycle travelling? New to the HU site? Confused? Too many options? It's really very simple - just 4 easy steps!
Horizons Unlimited was founded in 1997 by Grant and Susan Johnson following their journey around the world on a BMW R80G/S.
Read more about Grant & Susan's story
Membership - help keep us going!
Horizons Unlimited is not a big multi-national company, just two people who love motorcycle travel and have grown what started as a hobby in 1997 into a full time job (usually 8-10 hours per day and 7 days a week) and a labour of love. To keep it going and a roof over our heads, we run events all over the world with the help of volunteers; we sell inspirational and informative DVDs; we have a few selected advertisers; and we make a small amount from memberships.
You don't have to be a Member to come to an HU meeting, access the website, or ask questions on the HUBB. What you get for your membership contribution is our sincere gratitude, good karma and knowing that you're helping to keep the motorcycle travel dream alive. Contributing Members and Gold Members do get additional features on the HUBB. Here's a list of all the Member benefits on the HUBB.
|
|
|
helps answer the question - Why Go? Inspirational stories by veteran travellers Greg Frazier (5 times RTW), Peter and Kay Forwood (193 countries), Tiffany Coates (Mongolia Mayhem) and Rene Cormier (University of Gravel Roads).
Get Ready! covers planning, paperwork, medical and many other topics! "Inspirational and Awesome!" See the trailer here!
What stuff do I need - riding gear, clothing, camping gear, first aid kit, tires, maps and GPS? What don't I need? How do I pack it all in? Lots of opinions from over 150 travellers!
break down language barriers, overcome culture shock, ship the bike and deal with breakdowns and emergencies."Just makes me want to pack up and go!" See the trailer here!
Grant demystifies the black art of Tire Changing and Repair to help you STAY on the road! "Very informative and practical." See the trailer here!
Ladies on the Loose! For the first time ever, a motorcycle travel DVD made for women, by women! These intrepid women share their tips to help you plan your own motorcycle adventure. They also answer the women-only questions, and entertain you with amazing tales from the road! Presented by Lois Pryce, veteran solo traveller through South America and Africa and author of 'Lois on the Loose', and 'Red Tape and White Knuckles.'
Cotton or synth sweat-wicking t-shirts with the cool Horizons Unlimited graphic on the front and a snappy slogan (changing every year) on the back.
Show your route on your panniers. Great conversation starter when you meet people on the road!
Motorcycle and travel books to inspire and inform you!
The definitive guide to planning your motorcycle adventure! This insanely ambitious 2-year project has produced an informative and entertaining 5-part, 18 hour video series. "The ultimate round the world rider's how-to!" MCN UK.
Linear Mode
