Rear wheel with rotor brake substitute

Sometimes on these triples putting a rear sprocket 1 or 2 less actually allows you to go faster if by putting less teeth on creates less gear changes, just use the torque of the engine and ride the bike on the throttle. Unless you have a quicker shifter fitted!
I was at Donnington the other Saturday, 1st session rode it like my 578 Monty, 2nd session I used the torque and steered the bike on the throttle. Ended up going approx 7 seconds quicker, even considering it had been a while since I'd last been on track, I was very happy. I also felt another 3 seconds could be taken off , but the bike then ,let say didn't want to play!

Andy
 
Chuck3CL said:
Absolutely no difference. I gave it a pretty good workout and the bike tracked rock solid (both with or without hands on the handlebars).
It feels better, and the 17" makes it less tall than it was with the 36T 18".
It felt more responsive (less sluggish in the cornering). Unfortunately I could only ride within a 10km lockdown radius so I couldn't use my 'favorite' out-of-the-way roads to put it to the edges. And, because I left the KLR tire on it for now, flipping the wheel over to reverse brake&sprocket sides, I was running the reverse tire tread pattern with 80/20 treads.
So, still using the original Lav rt side axle spacer.
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So chainline and wheel centres were identical???!!! That's staggering. I was going to have to do a bit of work to mine to get the extra 4mm chainline I'm running. It's tricky getting the rear wheel aligned before you can get an accurate 'reading' on the chainline. I work out my centreline by measuring total width across swingarm axle faces and halving to get the true centre, then check that against the width of the rim/tyre and space the wheel accordingly - then I check the sprocket alignment - a slight misalignment can mean much faster chain wear.
 
piranha-bro2 said:
So chainline and wheel centres were identical???!!! That's staggering. I was going to have to do a bit of work to mine to get the extra 4mm chainline I'm running. It's tricky getting the rear wheel aligned before you can get an accurate 'reading' on the chainline. I work out my centreline by measuring total width across swingarm axle faces and halving to get the true centre, then check that against the width of the rim/tyre and space the wheel accordingly - then I check the sprocket alignment - a slight misalignment can mean much faster chain wear.
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I didn't say specifically that the centres were identical, I was responding to motoddrob's question which I may have misunderstood, but thought was a question on performance, which I thought was in fact better.
However, I did made certain the chainline was identical and accurate, which it is. If the wheel centre is a few mm off centre on a 1480mm wheelbase, I can live with that for now. Longer term I can get the spokes adjusted if necessary. If I'm missing something sinister here, let me know!
 
Cool nanas. Main thing is chainline - you can tweak a few mm by spacing the cush drive out a little (for more width) or removing as little from the sprocket face (for less). It sounds like it's been a very successful mod - a good rear tyre and you'll be good to test it in earnest.
 
piranha-bro2 said:
Cool nanas. Main thing is chainline - you can tweak a few mm by spacing the cush drive out a little (for more width) or removing as little from the sprocket face (for less). It sounds like it's been a very successful mod - a good rear tyre and you'll be good to test it in earnest.
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Yep, chainline is spot-on.

And as they say, "why re-invent the wheel!"

Which is probably why it does match well---- MC manufacturers are notorious for copying each other's design when they can, so many times you will see equivalent dimensions.
Case in point: pic- Laverda 3CL or Honda CB750.....😉
images.jpeg
 
The 3CL's new (1992) rear wire disc wheel- my fleabay KLR650 wheel now refurbished with new bearings, rotor, tyre, buffed alloy rim, paint, and modified KLR calipers.
Fits well with the need to make just one new axle spacer and a brace for the caliper assembly.
Front wire wheel doesn't feel lonely anymore.
 

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Good result, will there be a sudden rush on KLR650 rear wheels on ebay?

bazzee

ps what are the weights of the original wheel and the replacement wheel?
 
Chuck3CL said:
The 3CL's new (1992) rear wire disc wheel- my fleabay KLR650 wheel now refurbished with new bearings, rotor, tyre, buffed alloy rim, paint, and modified KLR calipers.
Fits well with the need to make just one new axle spacer and a brace for the caliper assembly.
Front wire wheel doesn't feel lonely anymore.
Click to expand...
Looks great Chuck 👌🏼
 
Be interesting to see what effect the shorter wheel has on handling, that is if you ever did any ks on the 18 to compare. I guess it will slow the steering a bit giving it more trail upfront. I remember there was a Bevel in Canada where the owner fitted a 17 front. That did spoil the look of that bike, it stood out like dogs balls.
 
Vince said:
Be interesting to see what effect the shorter wheel has on handling, that is if you ever did any ks on the 18 to compare. I guess it will slow the steering a bit giving it more trail upfront. I remember there was a Bevel in Canada where the owner fitted a 17 front. That did spoil the look of that bike, it stood out like dogs balls.
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This is what I wrote on the first test ride Vince.
Overall, I like the handling and response better than the heavy 18". .
"I gave it a pretty good workout and the bike tracked rock solid (both with or without hands on the handlebars).
It feels better, and the 17" makes it less tall than it was with the 36T 18".
It felt more responsive (less sluggish in the cornering). Unfortunately I could only ride within a 10km lockdown radius so I couldn't use my 'favorite' out-of-the-way roads to put it to the edges. And, because I left the KLR tire on it for now, flipping the wheel over to reverse brake&sprocket sides, I was running the reverse tire tread pattern with 80/20 treads.
"
I'll update when I get a chance to give it a good run..
 
Chuck3CL said:
Thanks, I'll post the weights.
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Thanks, no rush, but I suspect there will be plenty of interest - see Vince's response.
But, while you're at it...perhaps measure the diameter of each wheel/tyre combination, should give some insight into Vince's query above (post #91).

cheers,

bazzee
 
bazzee said:
Thanks, no rush, but I suspect there will be plenty of interest - see Vince's response.
But, while you're at it...perhaps measure the diameter of each wheel/tyre combination, should give some insight into Vince's query above (post #91).

cheers,

bazzee
Click to expand...
Good questions there bazee and Vince.
Here are the numbers-----
Comparing like for like, so both 3CL and KLR wheels have rotors, but no cush sprockets. Tyres on both:

Weight:
3CL = 16.8 kg
KLR = 12.5kg

knocks 4.3 kg off un-sprung weight!

Diameter:
3CL = 650 cm / 25.5 in
KLR = 640 cm/ 25.2 in

So only 0.15 in between 17 in and 18 in wheel.

3CL rim width = 3 1/2 in
KLR rim width = 3 1/4 in
(corrected)
Reason for small difference--
Tyres:
3CL Tyre = 130/80-18 Metzler Lasertec
KLR Tyre = 130/80-17 Pirelli Sport Demon

I think it has to do with the way the tyres sit within the rims.
The KLR bead is high in the rim, the 3CL low in the rim.
So even though they are both 130/80, there is more tyre above the rim on the KLR, and the narrower rim changes the shape.
 
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The weight loss is good, rear suspension action will benefit from that. What sort of shock absorbers do you have? Might be worth getting some modern ones if they are old.

The circumference of the Pirelli is 2.5% less than that of the Metzeler so the engine will be revving a little higher at all speeds compared to previously. Probably not enough to worry about changing sprockets.

cheers,

bazzee
 
A 2 1/4"(?) rim is a bit narrow for a 130 tyre, 2.50 only marginal. 3.00 would be more suited, 3.50 even better. That would then allow the use of all the tread, ie, no 2" wide chicken strips! ;)

piet
 
bazzee said:
The weight loss is good, rear suspension action will benefit from that. What sort of shock absorbers do you have? Might be worth getting some modern ones if they are old.

The circumference of the Pirelli is 2.5% less than that of the Metzeler so the engine will be revving a little higher at all speeds compared to previously. Probably not enough to worry about changing sprockets.

cheers,

bazzee
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I put these IKON rear shocks on a few years ago. https://www.ikonsuspension.com/product/7610-1397/

PXL_20210929_212218468.jpg
 
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