early narrow fender on later fatter tire

dear All,
I would like to mount the narrow front fender of the roadster Year 1970 on my commando 750 year 1973. Of course the tire Size is 4.10x19.

I know that the earlier models had also a narrower tire, but anyway I am wondering if anyone of you did succeed to match together the narrow earlier fender with the later fatter tire, perhaps working a bit on the stays..

is it somehow possible? Thank you for your suggestions..

I'd like to see the response to this, but I'm not sure you can put much more than a 3.25 size under the early guard. But I haven't tried anything larger than a 3.00-19 and they're hard to come by.

Dave
69S

I bet you are right.. but I still have some hope..

DogT said:

I'd like to see the response to this, but I'm not sure you can put much more than a 3.25 size under the early guard. But I haven't tried anything larger than a 3.00-19 and they're hard to come by.

Dave
69S

Click to expand...

I tried to put a 4.10 tire on my 1968 Fastback with original fender and stays and it didn't fit. The early fender is narrower, and the stays are narrower. Your clearance issue will appear between the stays and the sides of the tire. I considered rebending the early stays to make it fit but concluded that it wasn't worth the battle. I fitted the largest tire on I could, which was an Avon 90/90-19, described below.
Stephen Hill

AVON 90/90-19 M/C 52V Roadrider. Dimensions: Inflated Width/Measuring Rim Width: 3.50 in./2.15 in. Inflated Diameter: 25.40 in.

you can get a nice drift on , with the 3.60 / 4.10 combo . If you go round a gear lower & a healthy third faster than you useually think safe or sane .

Point being , the chassis ballance is good . The Brakeings pretty good . The Steerings Lighter . P. W. ran the same on the I.o.M. machines .
Only gripe is lowering front steepens rake & reduces trail for more nervous steering . Likely Tripe , and a 1/8 preload spacer would neutalise the diff ( erance ) .

Big Dungy tires fine for grip , but heavier ( 4.10 Vs 3.60 Dunlop , or the old roadrunners Im refering to , above ) and the steerings heavier , Wt. & Gyro Effect /
so If youre of refined sensitivities , youll appreciate the fineness of accurracy . But if youre a coarse base chap , or easily distracted the bigger ones better for
when you P A N I C . then you throw a bigger one agian on the back , to even things up .

Coustom Stays & Bracket , if you insist on persevering , are easilly knocked up if youve access to oxy acetylene , say night school for softening up the tubeing .
Good little exercise , & machine up a roller to flatten & curve .

The narrow fender looks better , anyway . Hows it fit the big tyre - with the stays OFF . NO Front Stay , on a Mk Three anyway . So theres a thing . 8) :lol:

The 1971 models still have the narrow chromed steel mudguard but the stays are different. The mudguard sits approx 1/2" higher. A TT100 4.10-19 will fit under these stays.

johntickle said:

The 1971 models still have the narrow chromed steel mudguard but the stays are different. The mudguard sits approx 1/2" higher. A TT100 4.10-19 will fit under these stays.

Click to expand...

correct change to the later bridge and stays and the blade should fit.
Al

I got new stays from Andover: do you think they will fit somehow?
.. I am also concerned with the 'bridge' stay which is attached under the fender..

johntickle said:

The 1971 models still have the narrow chromed steel mudguard but the stays are different. The mudguard sits approx 1/2" higher. A TT100 4.10-19 will fit under these stays.

Click to expand...

possm said:

johntickle said:

The 1971 models still have the narrow chromed steel mudguard but the stays are different. The mudguard sits approx 1/2" higher. A TT100 4.10-19 will fit under these stays.

Click to expand...

correct change to the later bridge and stays and the blade should fit.
Al

Click to expand...

this means I should drill out the bridge from the fender?
I believe it is riveted..

The rivets are aluminium. Very easy to drill out. Use a concave drift to install the new rivets or fit some screws instead.

Early style bridge, 68-70.



It's my understanding that the 71 and later bridge is about 1/2" longer.

Early stays.



It's my understanding from another forum member that the guard also has a different curve for the early and the 71 and later, so you cannot use the early stays on the later guards and vice verse. But I don't have a 71 front set to compare with my early one, so it's not scientific or proven at this point at least to me.

And yes the rivets can easily be replaced. I used button head allens but the rivets are available.

Dave
69S

Ciao Lorenzo
Look at this 1971 Fastback (Luigi's bike)
narrow fender, different stay and bridge
The 4.10 dunlop k81 fits perfectly

my 72 Roadster has the same but I've preferred a roadrider 90/90
I will post you some pic soon

I put a wider Bridgestone battlax tyre on my 1970 front wheel and had to widen the stays. I had about an inch welded in, and I may have also extended the holes in the centre stay so that I could pull it slightly wider. It was quite a bit of mucking around and stresses the mudguard a bit; if you look closely at it you can see that the mudguard does not exactly follow the line of the tyre. It might be best to get a new centre stay as recommended above and maybe even a new mudguard.

curbing-magnesium-corrosion-light-weight-applications-t17383.html



:shock: :shock: :shock: :shock: If you send his address , we will send the boys round with a can of W.D. 40 to sort the thing out . :cry: :| :x

People have been hung , for lesser things than that . Or have it sentto a loveing home . 8)

Hi Matt don'worry Look at the bike now...











I'm overhaulin' it with my cousin Piero (pierodn)