Do 400/4 rear mudguards /fenders fit a cb550f

[peteuk]

Hi, I have replaced lots of parts on my cb550f for new including a new front mudguard from David Silver. Problem is, the rear mudguard chrome is really pitted and I'd like to replace it for new. D.Silver doesn't sell them and I can't find anywhere else that does either but I noticed on eBay that there were a few places selling new reproduction 400/4 mudguards. They look the same on the photo but could anyone tell if they would fit.
Thanks

[mickwinf]

If i recall correctly they can be made to fit, as David Silvers used to sell them to fit the 500/550s and included a adapter plate to make the bolt holes line up.

[Trigger]

No, it doesn't fit the bade is different and the 400 is a 18" wheel.

[matthewmosse]

The rear guard my cb500 came with when I bought it, I was told was actually a cb400 item according to some who saw it - car park experts so I cannot vouch for their knowledge though I think some seemed to know their stuff. In any event it was deffinately different to what it should have been, narrower for starters. I didn't mind at all, it fitted and did its job til tin worm thinned it past the point where it was going to be ok for another year. I think it was once chrome, but it had been painted black and that is how I kept it. Decent or even ratty chrome rear guards are a bit hard to come by, I've picked up a few fiberglass pattern items that seem to be very cb500 orientated and in my books they are a easier to live with and therefore better solution, even well looked after bikes the chrome ones go as the layers on the back hold water and rot.

[peteuk]

Okay thanks for the advice. Especially the fact that the 400/4 has 18" wheels not 19" like my 550f. So with that in mind, I've seen a really decent cb750 rear mudguard but it doesn't say what model ie k0, k1 etc. Could one of these be to fit and look okay do you think . Thanks again

[Chris400F]

This listing seems to suggest that a 750 guard will fit; personally I have no idea!
http://www.cb-four.com/cgi-bin/shop/__Rear-fender--Honda-CB750Four-K0-6-CB500F-CB550F-new-original__370000349184-01f_04.04.html

[peteuk]

Thanks for that link Chris. Yes it does suggest that it will fit various bikes

[Chris400F]

Hmmm .... Then I took the P/N from the Parts List (80100-323-670XW) and put that in to Motogrid, which says the part fits these bikes:

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So it could be anyone's guess really.

[peteuk]

Okay. Thanks for trying guys anyway. Thing is that most of the second hand ones on sale on eBay are worse than the one already on the bike so I may as well stick with the one I've got.

[matthewmosse]

Part numbers will only tell you so much. My reaconning would be that the cb400 item would very likely fit, but might need extra holes or some sutch bodgery - experts will spot its wrong but might be worth a shot given you hopefully wouldn't loose too much by buying or borrowing a guard, offering it up and dedciding if its worth proceeding or selling or giving back. A god start would be to measure the width of the rear subframe where it bolts onto the frame rails. At lest new pattern items exist. I have a collection of crusty but usable cb500 chrome rear guards. Finding a suitable chrome alternative might be worthwhile given the fiberglass items seem to not be a current option for thoseof us without a few in the shed.

[Chris400F]

Part numbers will only tell you so much.

Quite agree.

But in this case I think it is true that the 400 has things like tyre sizes in common with smaller models such as the 250/360, whereas 500 and up have larger section tyres.
Therefore the frame width at the rear and swinging arm are larger to accommodate the wider tyres, and the mudguard is correspondingly wider.
I don't know by how much, and a 400 guard could possibly be fitted, but I suspect it would need spacers at the frame mounting points

[matthewmosse]

As an indication the guard my cb500 came with when I got it was a good 40 - 50mm narrower in the protruding portion than a normal 500 guard and had no clearence issues, spacers etc and kept spray and snow melt as much under controll as the stock item. That was the guard  i was told was a  cb400 item.... After all the seat size and rear rails supporting it are dictated more by the fasions, suspension technology and seat size than what tyre its guarding. Only way to be sure is for someone to try offering a cb400 item up to a cb500 frame, though a quick measure up with a tape measure might do wonders.

[Chris400F]

My thinking/belief is that if tyre size is wider then the swinging arm is wider to allow for this and the frame tubes at the top are correspondingly wider to keep the shock mounts the same distance apart at top and bottom, but I may be wrong in this assumption.
I know when I was looking for a rack that would fit that some I looked at were too wide at the shock mounting points, being probably intended for larger bikes. Fortunately someone on here helped me out with one that was intended for the bike.
It's not easy to measure accurately in situ but the distance across the mounting points on the 400 is approx. 170mm.

[Seabeowner]

Late 550K bare frame measured as 174mm.

[Darkness]

Isn't the 3.5 X 18 rear tyre on a 400/4 (Or CB360 G5) the same width as the 3.5 X 18 tyre on a CB500-4?

Though I used to prefer a 4.25/85 X 18 TT100 on the 500.