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  1. #1
    Join Date
    Apr 2019
    Location
    melbourne
    Posts
    4

    Default Mudguard coming off Adult tricycle due to poor welding.

    Hi Everyone, i have several disabilities from birth and i use a Tricycle to get around. I only got the trike about a month ago and it has been causing some problems. The main issue is the mudguard that is welded to the base. It has broken off twice due to poor welding. I had it replace only for it to break off again. I am now fighting with the manufacturer for a second replacement. They claim they have never had mudguards come off before. I pointed out to them it is coming off due to poor welding which is very thin. I took it to a bike shop and the owner was a welder by trade and he said that the welding was very poor. Please see some pictures.

    When i get the replacement it is only going to happen again. Is there a way to reinforce the weld on the mudguard so it doesn't come off again.
    https://imgur.com/5yYug2a

    https://imgur.com/aeF66kU

    https://imgur.com/W3C6Qnn

    https://imgur.com/a7nvBVE

    https://imgur.com/YtmB6oE

  2. #2
    Join Date
    Oct 2011
    Location
    Norwood-ish, Adelaide
    Age
    59
    Posts
    6,540

    Default

    The pictures don't really show much that we can see. I would suggest contacting these guys -
    https://www.solve.org.au/freedom-wheels
    They work in the disability sector so should not only be able to fix your problem but may also help with other things

    Michael

  3. #3
    Join Date
    Feb 2010
    Location
    Ballina, NSW
    Posts
    900

    Default

    I couldn't work out the geometry of the joint or anything that really gave me an idea of what was going on. However, maybe the solution is flexible coupling that isn't as vibration sensitive? So weld a fixture at both ends and bolt/clamp a short heavy fibre reinforced rubber strap (or similar) between? What sort of load does it take?

  4. #4
    Join Date
    Oct 2007
    Location
    Alexandra Vic
    Age
    69
    Posts
    654

    Default

    It is hard to pick from the supplied images, particularly if you are unfamiliar with trikes. The first 4 pics show the rear axle tube, wheel and basket side. In these, there is a strip probably 3mm wide by half the tube diameter that is not painted, i.e. bare metal.

    The last pic shows a triangular tab with a semicircle cut out of it, and two bolts securing it to a length of small diameter round tube. The tab was welded to the axle tube in the earlier pics over the unpainted section, and the tube bolted to it supports the guard front and back.

    I suspect that the tab attaches to the axle tube via a couple of tack welds only because of the difficulty of getting a MIG or oxy head into the space between the the frame section close behind it. There are most likely bearings in the axle tube to support the wheel and these could be affected if a lot of heat is used to weld the tab in position, unless the entire rear end of the trike is dismantled to remove axles and bearings.

    A more durable solution might be to locate an exhaust clamp the same diameter as the axle tube and extend one side of that to bolt the mudguard support tube to, give it a coat of black gloss, and then clamp it around the axle tube. It won't be as elegant as the original tab was, but it should be more durable and easily corrected, compared to having the tab break off in a regular fashion.

    I cannot see the welds properly in the pics because of the lighting and black paint job, so won't comment on their general adequacy or quality, but I suspect that there was not enough weld to secure the tab permanently before the frame was painted, and the repair weld was most likely inadequate because the repairer didn't want to supply a lot of heat and risk damaging the bearing etc in the tube.

    I worked in a school for disabled kids for 10 years, and spent a lot of time maintaining and rebuilding trikes, wheelchairs, etc so are fairly familiar with them.

    I understand your frustration with a new device failing twice in a couple of months, and hope that you can get the problem resolved to your satisfaction. Oh, and welcome to the Forums as well. If you need me to sketch out what I was suggesting as an alternative so that you friend can try it, let me know and I will do a quick drawing for you.
    I used to be an engineer, I'm not an engineer any more, but on the really good days I can remember when I was.

  5. #5
    Join Date
    Apr 2019
    Location
    melbourne
    Posts
    4

    Default

    Hi Guys thanks for your help and advice. Here are some more photos. One shows the left mudguard still intact and always has been it has never come off which suggest the welding is a lot better. I also have more photos of the right where the mudguard broke off.

    This the left Mudguard still intact. https://imgur.com/aDF6suN

    https://imgur.com/XBxo4Ky
    https://imgur.com/ujOz1ym

    This the close up look of the right side where the mudguard broke off. https://imgur.com/ggmptFb

  6. #6
    Join Date
    Oct 2007
    Location
    Alexandra Vic
    Age
    69
    Posts
    654

    Default

    I have worked out how to get a zoom working with the imgur images and have had a close up look at the final pick posted. There are minor tacks at each end of the tab, and there has been a poor attempt at a tack weld at the midline of the axle tube. Because this looks to have a vertical face, I assume that it a poor weld with extremely limited penetration into the tab.

    It might seem irrelevant, but which side do you normally mount/dismount from, or have you accidentally knocked the rear end of the support frame at all ? I ask because I wonder if you rub against the guard or support frame in mounting or dismounting. There would be a lot of leverage generated with the length of the support arm compared to the width of the mounting tab, making it easy to fracture a poor weld.

    From the final pic, there is definitely enough room to use a bolt on muffler clamp setup if you wished, not as elegant but way more durable, and scope to easily adjust on the roadside if need be, which you won't have with a shoddy weld job.
    I used to be an engineer, I'm not an engineer any more, but on the really good days I can remember when I was.

  7. #7
    Join Date
    Apr 2019
    Location
    melbourne
    Posts
    4

    Default

    Malb, i dismount on the left side which still has the mudguard and i don't even touch it when i dismount. If i went to a engineering dept at Tafe would they be able to fit a muffler clamp? And how would you clamp it to the mudguard.

  8. #8
    Join Date
    Oct 2007
    Location
    Alexandra Vic
    Age
    69
    Posts
    654

    Default

    Hi, I can't comment on whether you could get help via a TAFE college or not, it would depend on how helpful they want to be, and what contacts you can cultivate with them.

    The exhaust clamp consists of a pressed metal semicircular component, a matching U bolt, and a couple of nuts and washers. My concept was to make a simple bracket that can be welded to the side of the pressed metal part of the exhaust clamp. The tubular hoop that supports the front and back of the mudguard bolts to the new bracket using the existing bolts, nuts and washers. The complete assembly (mudguard, support loop, pressed metal component of the exhaust clamp and new bracket) is then lowered into position from above the wheel, and placed at the end of the axle tube, and the U bolt portion of the clamp is installed and secured with the nuts and washers. The two principal parts of the clamp totally enclose the end of the axle tube and grip it securely when fastened.

    Exhaust clamps are made in a variety of sizes to match steel tube sizes used either for exhaust systems or TV/radio antenna masts. You would need to measure the diameter of the axle tube and select the nearest larger size clamp, hopefully within 4-5 of the tube diameter. You might also need a couple of spacers between the new bracket and the support loop to get the position spot on, in which case you might need two correspondingly longer bolts.


    m9960003_prod-Exhaust_Clamp.jpg
    I used to be an engineer, I'm not an engineer any more, but on the really good days I can remember when I was.

  9. #9
    Join Date
    Oct 2011
    Location
    Norwood-ish, Adelaide
    Age
    59
    Posts
    6,540

    Default

    Talk to the freedom wheels guys. I'm pretty sure they can sort this for you without too many dramas, as they modify bikes for people with disabilities all the time.

    Michael

  10. #10
    Join Date
    Nov 2007
    Location
    melbourne australia
    Posts
    3,228

    Default

    I agree with Michael. Contact Freedom Wheels. This is what they do.
    Chris

  11. #11
    Join Date
    Apr 2019
    Location
    melbourne
    Posts
    4

    Default

    Here is the update on the Trike. Took it back to the Bike shop and the bike mechanic welded the base to make sure the mudguard will never come off again. Will post pictures soon.

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