DickyKnee
New member
Hi all,
I've only posted once on this forum, when I first subscribed but I've found much info here that has been helpful as an c400gt owner and I thought I'd try give something back.
a few months back, unfortunately I had an accident. an 11 year old girl borrowed her grandmother's scooter to go visit her friends after school on a Friday, then turned in-front of oncoming traffic on the highway - that traffic being me, I clipped her back wheel. no-one badly hurt, I broke a couple of ribs, I believe she just ended up with bruises and a bit of road-rash.
my bike:
punctured front tyre, broke the rim.
bent both front stanchions, damaged left fork tube.
bent left disc rotor
bent quick release axle
bent/worn service stand ( the bike fell on the left side, the service stand in combo with the shad top-box actually saved the rear plastics as the bike skidded)
shattered left indicator
lots of broken plastic.
I had comprehensive 3rd party insurance, but the bike itself wasn't and 11 year old girls don't have insurance! I like the bike so much I decided to fix it up myself once I realised the chassis was still straight.
The front end damage is very expensive to fix, so keep in mind I was trying to find the most cost-effective way rather than just drop it the local dealership.
The broken rim, I managed to find a second hand one on marketplace, though when it arrived it had a small repairable ding in the lip. I had this repaired locally, and although they did a good job rolling the lip out the paint job they did was.. with done with a rattle can. next stop was was to take it to my friends at a local powdercoat shop, setup buy the local Harley dealership, so they know how to paint wheels, and while it was stripped could fully inspect the damage and repair - and could not see the repair at all. FYI, the factory paint is 2k over an undercoat to fill the casting marks. This still ended up much much cheaper than a new one. Anyway, next time the back wheel comes off, I'm going to have to get it powder coat to match the front because now the front looks too good.
I ended up getting 2 new stanchions, and the LH fork tube new from BMW - this was by far the biggest expense. but in research I could have possibly done it a lot cheaper at risk because I couldn't confirm they would fit.. as some would know the C400gt is manufactured in china under contract by Loncin, who use the same platform/engine in their SR4. the front forks should be the same, they are manufactured by KYB and seemed much cheaper than from BMW. I had my mate help rebuild mine instead as he had the press needed to release the top circlip. I upgraded the springs to YSS while apart.
the front disc was a rabbit hole, but I think I now understand the story. I first noticed something curious before the accident as I had the rear disc replaced at the dealership but it had a slight different shape to the one removed, but (at the time) meh... Then I needed to replace just one of the 2 on the front! There are 2 different types of disc in circulation with the same part number 34111686911, but the older one manufactured by Brembo, the newer one manufactured by J-Juan. they use different mounting bolts, the Brembo uses M8x15 bolt, the J-Juan uses M8x18 countersunk and arn't interchangeable. The SR4 uses J-Juan so.. yeah I'm still working on trying to find the older Brembo one without having to replace both for the newer ones (they are a bit pricey). and of course the newer M8x18 bolts are 3x the price of the old M8x15 ones.
the quick release axle was when I realised something - many small components are shared across BMW models, more than I initially thought, this one is shared with r1250gs. interesting though - the replacement of the same dimensions was obviously manufactured differently to the one removed, the new one looked shiny and machined from billet, the old looked dull and pressed/roll formed?. I'm not sure what that means (does the R1250gs use a different quality part to the c400gt for the same part number? manufactured in China vs manufactured in Germany?), but not the first time I've found the same part number is not the same part.
the service stand - don't remove this if you don't need to. this strangely ended up being the most challenging job. 1 bolt and a spring, who would have thought! the spring requires a special tool to fit.. but I didn't have that. I'll say what I did but I don't recommend it as it scared the shit out me while doing it and could have put me back in the hospital. I wrapped a strap around the rear brake lever and handle the clamp the brake brake on hard, I put the spring on between the stand and bike, then began to try align it. I got the bolt through on the LH but to get the hole to align on the RH spring side that's where I used a anchored ratchet strap to tension the spring through the stand and with a screwdriver to eventually align the hole. lots of tension, too much but I eventually got the bolt through. don't do what I did! oddly, the service manual recommends touching up the paint after completing this task, indicating BMW expect it's a violent process.
the left indicator - lots of aftermarket parts are starting to show up on the likes of aliexpress and eBay, from stanchions to fenders (full fender kits that you can customise the colour) and in this case indicator, so I thought i'd test the aftermarket - fail. it actually bolted up and looked almost identical to the the RH without close scrutiny. the problem was, the socket didn't fit the wiring loom. it was different enough that it just wouldn't mate. so I purchased another OEM from BMW and it plugged straight up.
the current plastics are mix of second hand ones and new OEM, but I've just been focused on getting the bike functional again as the good riding weather is coming up. I've covered up some of the remaining scratches on the fenders with 3M CF wrap but it looks bit boy-racer. if it annoys me enough I'll get new plastic from BMW later.
I rode the bike for the first time since the accident yesterday, just a short trip to the shops. that's when I realised the front disc is bent. it's not obvious. now I've removed again, I placed on a flat surface and it's just a slight fraction of a bees dick distortion - BMW runout spec is only 0.15mm installed and 0.03mm uninstalled on a flat surface. this was enough to have no front brakes!! this is when I climbed down the rabbit hole of finding a new disc. front and back discs are the same part# BTW.
another thing to note, I had 2 errors pop up on the TFT after the accident every time I powered the bike on over the previous 3 months when working on it, thinking I'd have two go get the errors checked/cleared. 1 was traction control error, I figured this was due to the broken front wheel and abs speed sensor not matching the rear sensor. 2 was engine fault, I figured because the bike ended up its side and probably lost oil pressure for a moment. Both errors went away after riding that first 100m, though the codes are prob still there in the computer memory.
I'm hoping this info might help others out there.
I've only posted once on this forum, when I first subscribed but I've found much info here that has been helpful as an c400gt owner and I thought I'd try give something back.
a few months back, unfortunately I had an accident. an 11 year old girl borrowed her grandmother's scooter to go visit her friends after school on a Friday, then turned in-front of oncoming traffic on the highway - that traffic being me, I clipped her back wheel. no-one badly hurt, I broke a couple of ribs, I believe she just ended up with bruises and a bit of road-rash.
my bike:
punctured front tyre, broke the rim.
bent both front stanchions, damaged left fork tube.
bent left disc rotor
bent quick release axle
bent/worn service stand ( the bike fell on the left side, the service stand in combo with the shad top-box actually saved the rear plastics as the bike skidded)
shattered left indicator
lots of broken plastic.
I had comprehensive 3rd party insurance, but the bike itself wasn't and 11 year old girls don't have insurance! I like the bike so much I decided to fix it up myself once I realised the chassis was still straight.
The front end damage is very expensive to fix, so keep in mind I was trying to find the most cost-effective way rather than just drop it the local dealership.
The broken rim, I managed to find a second hand one on marketplace, though when it arrived it had a small repairable ding in the lip. I had this repaired locally, and although they did a good job rolling the lip out the paint job they did was.. with done with a rattle can. next stop was was to take it to my friends at a local powdercoat shop, setup buy the local Harley dealership, so they know how to paint wheels, and while it was stripped could fully inspect the damage and repair - and could not see the repair at all. FYI, the factory paint is 2k over an undercoat to fill the casting marks. This still ended up much much cheaper than a new one. Anyway, next time the back wheel comes off, I'm going to have to get it powder coat to match the front because now the front looks too good.
I ended up getting 2 new stanchions, and the LH fork tube new from BMW - this was by far the biggest expense. but in research I could have possibly done it a lot cheaper at risk because I couldn't confirm they would fit.. as some would know the C400gt is manufactured in china under contract by Loncin, who use the same platform/engine in their SR4. the front forks should be the same, they are manufactured by KYB and seemed much cheaper than from BMW. I had my mate help rebuild mine instead as he had the press needed to release the top circlip. I upgraded the springs to YSS while apart.
the front disc was a rabbit hole, but I think I now understand the story. I first noticed something curious before the accident as I had the rear disc replaced at the dealership but it had a slight different shape to the one removed, but (at the time) meh... Then I needed to replace just one of the 2 on the front! There are 2 different types of disc in circulation with the same part number 34111686911, but the older one manufactured by Brembo, the newer one manufactured by J-Juan. they use different mounting bolts, the Brembo uses M8x15 bolt, the J-Juan uses M8x18 countersunk and arn't interchangeable. The SR4 uses J-Juan so.. yeah I'm still working on trying to find the older Brembo one without having to replace both for the newer ones (they are a bit pricey). and of course the newer M8x18 bolts are 3x the price of the old M8x15 ones.
the quick release axle was when I realised something - many small components are shared across BMW models, more than I initially thought, this one is shared with r1250gs. interesting though - the replacement of the same dimensions was obviously manufactured differently to the one removed, the new one looked shiny and machined from billet, the old looked dull and pressed/roll formed?. I'm not sure what that means (does the R1250gs use a different quality part to the c400gt for the same part number? manufactured in China vs manufactured in Germany?), but not the first time I've found the same part number is not the same part.
the service stand - don't remove this if you don't need to. this strangely ended up being the most challenging job. 1 bolt and a spring, who would have thought! the spring requires a special tool to fit.. but I didn't have that. I'll say what I did but I don't recommend it as it scared the shit out me while doing it and could have put me back in the hospital. I wrapped a strap around the rear brake lever and handle the clamp the brake brake on hard, I put the spring on between the stand and bike, then began to try align it. I got the bolt through on the LH but to get the hole to align on the RH spring side that's where I used a anchored ratchet strap to tension the spring through the stand and with a screwdriver to eventually align the hole. lots of tension, too much but I eventually got the bolt through. don't do what I did! oddly, the service manual recommends touching up the paint after completing this task, indicating BMW expect it's a violent process.
the left indicator - lots of aftermarket parts are starting to show up on the likes of aliexpress and eBay, from stanchions to fenders (full fender kits that you can customise the colour) and in this case indicator, so I thought i'd test the aftermarket - fail. it actually bolted up and looked almost identical to the the RH without close scrutiny. the problem was, the socket didn't fit the wiring loom. it was different enough that it just wouldn't mate. so I purchased another OEM from BMW and it plugged straight up.
the current plastics are mix of second hand ones and new OEM, but I've just been focused on getting the bike functional again as the good riding weather is coming up. I've covered up some of the remaining scratches on the fenders with 3M CF wrap but it looks bit boy-racer. if it annoys me enough I'll get new plastic from BMW later.
I rode the bike for the first time since the accident yesterday, just a short trip to the shops. that's when I realised the front disc is bent. it's not obvious. now I've removed again, I placed on a flat surface and it's just a slight fraction of a bees dick distortion - BMW runout spec is only 0.15mm installed and 0.03mm uninstalled on a flat surface. this was enough to have no front brakes!! this is when I climbed down the rabbit hole of finding a new disc. front and back discs are the same part# BTW.
another thing to note, I had 2 errors pop up on the TFT after the accident every time I powered the bike on over the previous 3 months when working on it, thinking I'd have two go get the errors checked/cleared. 1 was traction control error, I figured this was due to the broken front wheel and abs speed sensor not matching the rear sensor. 2 was engine fault, I figured because the bike ended up its side and probably lost oil pressure for a moment. Both errors went away after riding that first 100m, though the codes are prob still there in the computer memory.
I'm hoping this info might help others out there.
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