Modern Vespa

I should replace my tires as the speed rating is "J". I came across wide tire kits when looking at tires. What are people's thoughts on the wider rear tires ? Looks like a wider front tires is used also. I see that recent kits from SIP are even using 11" tubeless tires.

Last edited by Christopher_55934 on Thu Nov 26, 2020 2:16 pm; edited 1 time in total

The wide tire kits for style not function. Same for the 11" rims. I'd recommend you to just stick with a 10" rim and a quality tire, even if it has a J rating.

Not entirely true... The quality of the SIP tubeless rim is high. But worth noting the black finish on them scratches if you look at it too long (not actually, but it is a delicate finish...). The 10's are supposedly very difficult to fit tyres on (you need to find someone who can put them on by hand, with rim protecting equipment, and lots of lube). The 11's are meant to be easier than 10's - but my tyre guy reckons they both suck. The 11's mean a 70% profile tyre. And that does mean style (they look sick).

I haven't been riding my wide tyre setup long, and can only compare it to the ET2 I also ride. But the ET2 is regarded as a stable ride. But I feel much more confident leaning with the wide tyre 11's... they just feel like glue. But then the rubber is also very different. And shocks. And everything.

But hey... they don't race round on 3" tyres at the GP now do they?

Definitely not necessary, maybe no significant functional gains... but certainly look good I reckon!

Oh - and you need to cut and move the engine mounts for a wide tyre rear - still shifts centre left 4mm, and a wide tyre front will also shift the centre left ~4mm.

The wide tyre setup was very functional for me. My 200 cases had damage on the swing arm and cutting 1cm off dealt with that perfectly. A 3.00 inch SIP rim was a great option after that!! That said, I would not have cut a perfectly good swing arm just for wide tyres.

From a riding perspective, it does feel more planted and stable, despite the engine being 1cm further to the right. It has also given me a wide choice of gearing options, as the big rear meant using a PX125 gearbox (68T primary), which means a range of clutch options from 20T - 23T. Also, the 11 inch wheel has given me some valuable ground clearance for the BigBox Sport. Oh and they look very good, as PP said.

My other scoots have 2.50" SIP rims with 100/90 (or 80)-10 tyres. These do not involve any swing arm cuts or spacers, so are your happy medium. They are a little difficult to get on and off, but that's a minor inconvenience.

What size tyres are you running on the 11s? I use the recommended 70 profile tyres and so the circumference is actually the same as 90 profile 10s.

Haha - I forgot to mention... with my wide tyre setup I have to drop the motor (at the rear shock) to get the rear wheel off. Not enough room in the well otherwise. This is standard for the 130 wide tyres.

For the front I have to remove half my guard (which is split and bolted back together) to get the wheel off - but that is mainly because I shaped the guard so it is pretty snug.

Slightly more than a minor... but not a major either.

I went with 120/70-11 in the end, due to gearing preferences. You're right, not much bigger than 100/90-10. Either works well with the big box exhausts and precious ground clearance.

[quote="pheasant plucker"] Yep, I was referring to the 2.50" rims with 100/90 or 80 on my other scoots. The rears barely go in and out of the frame, and require some manhandling. My SIP rims have scratches to prove.

Luckily the 120/70-11 has not needed to come off yet, but clearly it will involve dropping the engine at the back.

Had to check again.....

It’s not too bad - just undo the shock and stick something under the tail to lift the frame a bit. I feed a rag over the top of the wheel to protect the rim from the wheel studs as a slip it out.

FWIW... here is your 120/70-11 vs 3.50x10

Here is my 130/70-11...

The 90/90-10 is closest to the 3.50-10 AFAIK, so this would be the comparison between a stock Vespa 10" setup and my wide tyre setup

Classic - somehow missed your reply... and we use the same tyre calc! Doesn’t go to 8” tho... Mine compared to 8” is something like this... (shame the visualizer isn’t working)

I know people debate 100/90-10 vs 90/90-10 being closer to 3.50-10. I think 100/90-10 is generally the more common metric fit but not 100% sure.

The sleeper widest fatty boombatty chubbalubba rear tyre is Brother E’s monster with a 140/70-12 (Heindenau K58) stuffed in the back!

This is also my favourite scooter shot ever...

And it calcs out pretty hefty too.

A lot to think about, any options for a 2.5" or 3.0" tubeless split rim? If I go with a non split rim what should I be asking my motorcycle shop to see if they can mount a tire? Can I get an inexpensive manual tire changer and change one myself?

Pinasco do a 2.10" x 10.

Tire shop need to have protectors on the changing machine (and needs to be able to go down to 10 - 11"). Then rather than use the machine arm to put the tire on, should use a manual mounting tool with lots of tire lube. Your best bet is going to be a motorcycle tire specialist.

I may purchase a Harbor Freight motorcycle tire changer. Then add these blocks.

https://www.mojotiretools.com/mojoblocks.htm

And use this bar

https://www.mojotiretools.com/mojoweb.htm

Tire mount stand

https://www.harborfreight.com/portable-tire-changer-69686.html


Tire mount motorcycle

https://www.harborfreight.com/motorcycle-tire-changer-attachment-60810.html

I had an Heidenau K61 100/90 mounted onto a 2.50-10 SIP rim last Friday. I take mine to a local chap who has a small motorcycle repair shop. He charged me £5 (just over $6 US), and not a scratch in sight. Not sure what he uses but at that price, I'm not going to attempt it myself.

Seems legit. Those protectors look good. Other than that use lots of lube! I have a guy who seems to know what he is doing so only experienced through watching him really.

Just know - the SIP rims are delicate... Mark up way too easy. Certainly considered coating/painting them properly. Wish SIP did it already.

It’s the wide rims with low profile tires that are supposedly the hardest ones to fit (I think). But that price is good any which way. And not marking them up is not easy.

How do you find the K61? Especially in the wet? CM22 reckons his Heidenaus are skates in the wet. But they are a different model. Can’t remember which one tho.

The same guy fitted my 120/70 K61 to the 3.00-11 rim and did a great job. I don't use this particular scoot in the wet. My touring PX has 2.50 SIP rims with 100/80-10 Mitas MC22 Elegance tyres. These have a tread pattern better suited to wet roads, a bit like K58s.

Im on the k80sr's - and I am a fan. Smooth and so sticky - as long as Mother Nature is not involved.
Their issue is in ever so slightly damp.
Perhaps they would be better in 25mm of water - IDK.
The center of the tire has no tread - so they are basically slicks in that area - and they live up to their name in the wet...

I've had to experiment with options for performance - and have done same for finish/style as you can see.

I run 3.5-10 on 2.5 wide SIP rims for the side car.
I want these hard and not too sticky - so the bike can overwhelm them and force some slip.
I've tried them on the bike - and they are like gummy bears.
Soft but I can feel the side wall flex and its like having gummy's between me and the road - no center to be found.

I have graduated to an 11" rim for the bike - with a 70 series tire.
That gives me a nearly perfect match to the 3.5-10's for tire circumference while making the bike more of the master.

For reference - the 100/80-10s in the same size k80 are ~1300mm, so a bit smaller.


Pheas' - you may note a certain style...
3.5-10 white walls. 110/70-11 black wall

1360mm circumference on the K80's

1400mm on the 3.5-10 conti's

Love the look CM22! You know I do.

What size are you running? The main reason I’m on k61’s is that there are very few options for a 130/70-11 and 110/70-11.

They seem to rate well even in the wet on most sites (e.g. Revzilla)

Found a comparison test also. No snow here so all good.
https://www.tyres-pneus-online.co.uk/test/motorcycle-tyre/scooter.html

I've got the 110/70-11s on the shelf until re-paint.
I have 100/80-10s on the bike currently.
I've tried the 3.5 - see note - gummy bear uncertainty on my rig - but perfect for the sidecar wheel.

I spoke some with my local motorcycle shop and the person who answered the phone assured me they can do a 10 or 11" tire and wheel and not scratch up an aluminum rim.

Last edited by Christopher_55934 on Thu Jul 09, 2020 7:27 am; edited 1 time in total

Sweet - that’s what you want to hear. Just need reassurance that they can deal with them being a little awkward.

For those that buy the tires (tyres) from sip with the wheels at the same time - there is a lesser known service - they will mount them for you.

"Workmanship SIP mounting TL "

TL is for tubeless.
If you type this in - put one unit in your cart for each tire you want mounted.
🙂
-CM

I know you guys have had an informed guess at the difference between tyre sizes - specifically the 3.50 as it translates to metric sizes. I went looking for a chart that compares all the available sizes without success, has anyone seen such a thing?

http://www.bits4motorbikes.co.uk/TireSizeConversion.html

https://www.campusskooters.com/tire-size-conversion-chart

Was shipping astronomical?

Yeah, I called and explained I use them for mounting motorcycle tires, then went on to explain I was looking at purchasing the smaller 10” rims in aluminum, and wanted to know if they could mount them without scratching up the wheels, I was told yes.

Shipping was no more than normal... I was buying the wheels anyway so there’s was no real increase as they go on weight.
I was surprised to find their tire prices were competitive - so getting the tires mounted and shipped ready to install was a nice convenience with no real premium.

Good to know, now I just have to decide wheel color and tire width. 2.5 with no change or 3.0 and figure it out. For some reason I’m drawn to the lower profile 11” wheel and 3.0” width. It’s not permanent, if I don’t like it I can always move the spacers to the other side I think? Then I’ll be back to the ability to run a standard tire? With the 2.5” I might be able to split the spacers and get back to center.

Going to stick my head in there and measure clutch Cover to tire clearance on my 3.50-10 zippy tires. Any idea on the amount of extra clearance width for a wider tire on a 2.50 or 3.0” ?

Last edited by Christopher_55934 on Thu Jul 09, 2020 1:33 pm; edited 1 time in total

They will clear the clutch cover - the rims are designed to do so. But they will be 14mm left of centre. So you will need to cut 1cm off the engine swing arm on the right, space the left 1cm, new engine mount bushes, hope the shock still fits (probably needs some work) and hope the cowl still fits back on. So going wide is somewhat permanent. Also means offset centre line (4mm left). I think the reason you can’t cut 14mm off is that the tire will contact the swing arm itself. Plus the engine would be popped so far out. Think that 1cm shift is the sane upper limit.

Some have chased perfect centre line alignment at this point (not needed). Think they grind 4mm off the wheel hub, somehow deal with the clutch cover (I think you can get lower profile covers) and grind the swing arm contact point.

I didn’t go for centre line. The PK fork conversion with a disc will cause the front to be 2-3mm left anyway. Add a wide front and you get another ~4mm left. So the aim becomes eccentric offset. Both off the centerline by the same amount.

And this is debated a bit. Is front-rear alignment important? Maybe for certification. But most report no significant tracking/ cornering/ wearing issues with small amounts of misalignment. If it is large then it means the bike will corner easier one way, harder the other.

Even checking alignment is difficult. I haven’t bothered to try. Crossed fingers and when for the see how it rides approach. And no complaints here. Tracks and corners with no issues (so far, touch wood).

So yeah... going wide isn’t as easy as buying wide rims and tires.

I'm still sticking with my original posting about them being for style not function.

If you do install the 3" wide version, you should move the top shock mount over the same amount as however much you cut off the swingarm. If you don't, the shock will have a side load on both its shaft and its lower mount when the suspension is cycled. A broken rear shock,leaky oil seals, or bent shaft can be the result (yes it's common).

Tire sizes and tread patterns options are severely limited when compared to a 3.5x10.

The 11" tubeless rim is much easier to mount a tire on than on a 10" tubeless. A 11" tubeless tire is WAY, WAY easier to dismount a tire from when compared to a 10" tubeless (when talking about the SIP tubeless rims).

A wide tire kit will have a higher road rolling resistance, which will make the scooter slower. A 3.5" tire on a 10" tubeless weighs much less than the stock 2 piece stamped wheel, which will make the scooter faster...which is why you won't find any Vespa/Lambretta track bike with a 3" wide rim. You'd probably be hard pressed to find even a 2.5'' on a track bike.

So i still say that the wide tire kits are for show (come on, it's SIP were talking about here. Lots of their stuff is for show). But no question, a wide tire kit does look sweet when mounted up!

Amen to that

I try 110-70 on a standar rims and its the best fit
Try the 120-70 on a standar rims and thr tyre hit my clutch cover
Try the 120-90 and it hit my exhaust

Now try to imagine what will happen if u put a 130 on a standar rims, i have to cut my exhaust, and for the 140 on a 12 inchi rims i cut my engine swing arm, but like i said the porpose to look different is my goal, in case everyone wanna know my secondart goal its like what Brother Pheas mention, bigger taller tyre is helping me add more speed on a good day

Keep the wheels rolling, stay safe and cheer guys

WDC isn’t lying for sure... so you need to want the wide look bad enough to chase it and all the problems that come with it.

I haven’t moved my top shock mount point... I did have to beat the frame out so it didn’t contact. But doesn’t take any side force to get it to mount, and didn’t need to open up the fixing points. But realise that static and dynamic forces are likely to be different... will be keeping an eye on it.

And pretty sure WDC races/has raced Vespas proper-like (correct me if I’m wrong)...