Continental tyre, Chain offset, forks, led turn signals.

[Kristian]

I'm a new member so I have a few things stored up to share and ask about.

Firstly, while researching tires recently and debating with myself about the 17" conversion I came across a new continental tire. It looks like it might be ideal for the sport as it is a sport/touring tire rather than a touring/cruiser tire (It looks to have a sport profile which would be an improvement on the original michellin. It is rated to 150+mph which inspires confidence. I would be interested to know what others thoughts are about this tire especially if someone has had experience with them already. Here are a couple of links: http://www.oldbikebarn.com/Conti-Motion ... urce=M7989, http://www.denniskirk.com/jsp/tpl/tire/ ... Id=&mmyId=

I have some ideas for moving the chain over which are based on the experiences of others that I have read about here and elsewhere. for the rear I have purchased an original style (but aftermarket) sprocket that has the raised section into which the securing bolt heads are recessed (I changed from 38 to 40 teeth to adjust for the taller tyre). My plan is to flip the sprocket over so that the raised section seats against the carrier giving me about 3mm of offset. I will drill new holes between the original ones on the sprocket. In theory this will be a stronger solution than using an old cut down sprocket or any other kind of spacer that will allow potentially damaging movement. I am figuring that this will give me about 1mm or perhaps even less of clearance. I read on this forum that even touching the tire is ok just as long you are not abrading it and I figure the less stress on the countershaft, as a result of moving out the front sprocket, the better.

At the front sprocket my plan is to utilize the threaded hole in the end of the countershaft by welding an appropriate fender washer over the de-toothed center hole of an original retainer plate (set to give me the same 3mm offset as the rear). Then, and here is the proposed solution to the loosening retaining bolt in the end of the countershaft, I will tighten a flange headed bolt down on a short sleeve that is a little narrower than the center hole in the fender washer and very slightly longer than the depth of the fender washer so that the washer floats on the collar between the bolt head and the end of the counter shaft. The result should be a sprocket that floats on the shaft without undoing the retaining bolt. I will of course use loctite as well! I hope this is understandable (a picture would be worth a 1000 words I know but I haven't worn out my michellins yet so this is a job for the future.

A tip on LED turn signals that I learnt the hard way yesterday: you have to disconnect the wires (pull them from instrument panel plug) that lead from the signals to the instrument panel flasher light in order to separate the left and right signal circuits. If this is not done both left and right signals will flash when either is selected. This is presumably due to the low power use of the LED's.

Finally, I put a WTB listing on this forum for early paso M1R forks with triple clamps or M1BB forks. My sport came with slightly bent forks So I'm looking to replace them and thought that some of you guys that have converted to 17" wheels may have some available.

I could also do with some fairings as one of the previous owners of my bike cut them down to half fairings. (I've glassed them back together now but would love to get another set).

Well thats it! looking forward to hearing what people think of all this.

[paso750]

Here are a couple of links: ...

"Ideal for entry level riders and economic-minded veterans" I like that
Regarding speed ratio HR is sufficient if you have an original bike. Even if modified you wouldn`t be able to do 130+ constant speed. But it`s interesting I`ve never heard of this tire.

If the situation is like on a Paso with an Avon tire flipping the sprocket to gain 3mm will not be sufficiant. 4-5mm would be minimum if you are ok with 1-2mm clearance only. But with speed, load and heat the tire will expand a litte.

Regarding front sprocket offset there`re different options. I have to admit I didn`t really understand what you need to weld. Pasoalf has a similar solution. Maybe he will post it.
The complicated option is using 2 sprockets. The inner sprocket needs some machining (remove teeth and lower the outer edge so it is 0,3mm higher as the retainer ring), put it on the shaft, then the retaining ring. Then use a sprocket with the thread holes drilled through and tighten with 2 bolts as original. So it`s basically 2 sprockets behind another with the retaining clip in the middle. If offset is too much (it will be about 5,7mm) you can machine some material from the backside of the outer sprocket. Problem is if you have to machine the outer sprocket you have to do that with every new sprocket you replace the old one with.

G.

[ducinthebay]

Kristian,
Welcome to the forum. I hope we can get you back on the road in good style.
I have a set of fairing lowers that I am not using, and don't intend to. they aren't great, but they are usable. As I remember, they both have cracks in them from driveway tip overs. If you are fussy, you will want to repaint them, if can tolerate the cracks, you could just fiberglass the backside and call it good for a while.

The Sport is very easy to convert to 17" wheel in the back. Just get parts from a Monster or SS and bolt them in. Get the whole thing, including the caliper, rotor, and caliper hanger. If you get the 4.5" wheel and run a 160 rear tire, you won't have to mess with the sprocket offset stuff. Do you really need a 180? A 160 will turn in better, which is good for the Sport.

As far as your front end is concerned, I can certainly agree on the Paso front end, as that is what I have done, and its a lovely fork. After that, you may have more luck finding an entire front end from a Monster or SS and putting on. Get the entire thing, including the 17" wheel. Easier to find than an M1R, and more adjustable.

Getting an crashed 750 SS will give all the parts, and more, for your wheel conversion.

Where in California are you? I am in the SF bay area.

Cheers,

[Kristian]

Thanks for the response G. and Ducinthebay. I did not consider the expansion of the tire G. That's definitely something to enter into the equation. How much would you say the tire expands? Would you agree, with a post that I have read here in the past, that it is OK for the chain to touch the tire (when warm) but not to abrade it? The welding of the fender washer to the de-toothed, original retainer plate at the front sprocket was just a way of making the new retainer plate that floats on the collared flange bolt that is tightened into the end of the countershaft. I was thinking of this method of altering the original plate because I guessed that it would have moved the sprocket out by about 3mm to mach the gain at the rear. Using the method I described with a completely fabricated retainer plate I think would bring the sprocket out at least 5mm which sounds like what I will need to do. This could be increased by including washers between the collar and the countershaft thus moving the position of the retainer plate out along with the sprocket. Of course, at this point the full length of the splines on the sprocket are not making contact with the shaft. I can see that the method that you explain would mitigate this problem (if it were necessary to go further that 5mm) by way of the two retainer plate securing bolts, having said that, those bolts were not selected to give torsional strength to the sprocket. Drilling out and re-taping the machined inner sprocket so that it could receive larger, high tensile bolts or welding the two sprockets together might overcome this weakness (not sure how the later might effect tempering of the sprocket). I'm not to disillusioned by the insufficient offset of the flipped rear sprocket as the thinner the additional spacer needed the less stress there will be on the securing bolts and a 1-2mm thick spacer, to get to 4-5mm total offset, will be easy to cut out of some alluminum sheet. . . my router will love me for it!

I will definitely want to learn about pasoalf's experience.

Thanks for the good wishes Ducinthebay. I'm in the Los Angeles area. I would be interested in your fairings and appreciate you making them available. Thanks for the conversion advice. At this point I am planning to keep the 16's (I was thinking of a early paso M1R fork which with a triple clamp and some 41.7mm bars would be a bolt on upgrade keeping my calipers and wheel). I know that the bike would handle better with the 17's, and that is always something to strive for but, I think I can have fun on it the way it is for the time being and I'm also quite attached to the stock rims as part of its design. I did once see a set of brembo seventeens for sale that were red centered with a polished lip and I kick myself now for not having picked them up!

Kristian

[paso750]

I`d rather not flip the rear sprocket and fabricate a thicker spacer.
About how much tire expands I have to admit I don`t know. I know it does a bit. I have to comply to requirements/clearances the german vehicle inspection (TÜV) sets so I don`t have to bother about such details. They already did

Would you agree, with a post that I have read here in the past, that it is OK for the chain to touch the tire (when warm) but not to abrade it?

I`d personally agree although I prefer to have a clearance.

The sprocket bolts are 8.8 I don`t see any problems here. The two sprockets are touching each other with 0,3mm of "air" in the middle. Both sprockets are on the splined shaft and I don`t think it will warp that much the bolts are seriously committed to torsion. There`s one bike rolling like this with no problems known so far.

The two options mentioned in a fast sketch




G.

[ducinthebay]

The biggest challenge to putting M1R forks from a Paso on a Sport is the bars. The stock cast bars from the Paso will not clear the Sport's fairing. You need clipons. There are no clipons made for the 41.7mm fork that I know of. I bought a set of Telefix which have aluminum castings, and had them machined to fit.

Cheers,

[Kristian]

Ducinthebay, I guess there were once clip-ons available for the M1R equipped 851's But it may be easier to machine a set than to find a pair of those.

G. What do you have against flipping the rear sprocket? Thanks for the drawings. The first illustrates what I was thinking of doing. I think I will go with this method as I can't see any advantage to the other option. (By the way, what is the purpose of the 0.3mm space between the sprocket and the plate given that the plate is already designed to allow some sideways movement?)

If the 3.55mm offset is not enough I will gain more by either adding a floating spacer between the plate and the countershaft or by making a retainer plate that has a central raised section that faces the end of the countershaft (a flipped version of my original welded retainer plate may work here).

The front sprocket on my sport is flat rather that being offset like the ones in your drawing. How much is this offset and are these sprockets still available? I couldn't be sure that the sprocket on sport is original spec so I had better check the chain alignment. If it is correct I could potentially do what I had planned in conjunction with an offset sprocket to gain adequate clearance.

This forum sure is useful. Thanks again to both of you for your advice.

[paso750]

Kristian, you`re absolutely right. I copied the 0,3mm gap from option 1 without thinking. Thanks for pointing that out. So one just needs a second retainer ring, a washer or something to fill the gap. The advantage of option 2 is that you have a bigger offset and you need only an old sprocket to do it.

Note that I have a Paso. The P750 has such a sprocket. I wondering why the Sport should have one without offset as the rims are the same and the engine is too so the chain alignment should be the same also. Can`t be the different swingarm. If your chain is aligned with a flat front sprocket (on a Paso) that would mean that the rear wheel is offset to the right. Hmmm ?!
The original Paso sprocket has about 3mm offset, I would need to measure.

G.

[Kristian]

Other than eyeballing it a few times I have not yet checked the alignment of the chain or changed sprockets. I suppose it must be possible that a sprocket meant for another model was put on my bike at some point in the past. To be honest I may have miss-remembered its appearance--I will check and get back to you on that. It seems infeasible that the offset could be different on the two bikes. There are the spacers between one side of the motor and the frame on the late sports which must have shifted the engine one way or the other at least compared to the earlier sports (can't recall which but I think they might be on the left side).

I will check the worn retainer plate that I replaced recently and see if there in more wear on one site or the other of the inner teeth.

Kristian

[Kristian]

With regard to the rear sprocket:

I plan to replicate the sunken heads on the flip side when I make new holes between the old ones. I think that the raised inner ring has sunken heads to solve clearance issues but I would say that it is there primarily to stiffen the securing area so as to restrict a flexing action and thereby distribute the forces evenly between the bolts.

Kristian

[Kristian]

I checked the sprocket and it is flat (not offset). The spacers between the frame and the motor are on the opposite side from the chain and are about 4mm thick so there could be a 2mm shift of the motor toward the chain side which might account for the front sprocket not having an offset on the later sports while the paso does. I suppose the chain would have to come off and the surfaces of the sprockets lined up to align the chain so, if anyone can confirm that the sport has a flat sprocket, I will let that job wait until I move the chain out for a new tire.

Kristian

[paso750]

http://www.sd-tec.de/catalog/quick_sear ... 838fd15f15

here there are 2 sprockets shown for the 750S. Not sure how much you can trust those pictures but at least it doesn`t show the same sprocket for all models like some other catalogues do.

[Kristian]

Neither of these state that they are for the 1990 sport. I guess we are looking at the back side of the second listing (707R48815) so hard to see if it's offset. (It seems to have a central hole on the front side, perhaps it utilizes the bolt in the end of the countershaft!