Conversion to 10 inch 110-130 mm rear
- at SIP Scootershop
The classic wide tyre conversion for large frame Vespas. The rear wheel can be converted to a width of a fat 130 mm or the mighty tyre circumference of a 120/90-10 tyre. However, modification of the engine swing arm pivot is necessary.
The classic wide tyre kit for large frame Vespas
When Armin from Starnberg appeared on the runs with his "Yellow Danger Cut Down" at the end of the 80s, this Vespa was like something from another star. An absolute highlight and eye-catcher was: the wide tyre kit with a 120/90-10 tyre, which really came into its own on the Cut Down. Then it didn't take long for the idea to move from the Ammersee to the Lech and there into the Vespa Streetracer. So it's not surprising that the SIP wide tyre kit was one of the first items when SIP launched in 1994.
The kits fit all Largeframe Vespa models with 10" rim open or built-in PX engine:
The different ways to the 130 wide tyre
The SIP bush kit
The classic among the wide tyre kits is the bush kit, which was first fitted in 1991. Here the studs of the brake drum are replaced by longer ones and the distance to the rim is compensated with bushes.
In order to compensate for the wheel offset, the engine swing arm pivot must be shortened by approx. 1 cm on the right. The engine moves to the right. A suitable compensating bushing for the left side is included. Suitable for tyre sizes from 110/80-10 to 130/70-10.
In addition to the bush kit, a wide tyre rim must also be ordered.
The SIP wide tyre ring kit
We have developed the wide tyre ring kit for all those who feel that the power transmission by means of aluminium bushings is too small. The ring has a larger contact area and guides the rim optimally. A 100 % contact between brake drum and rim is guaranteed. With this version, the studs of the brake drum are also replaced.
In order to compensate for the wheel offset, the engine swing arm pivot must be shortened by approx. 1 cm on the right. The engine moves to the right. A suitable compensating bushing for the left will be sent along. Suitable for tyre sizes from 110'80-10 to 130'70-10.
A wide tyre rim is required in addition to the kit. Available in grey painted or chrome!
As a second ring kit version we offer the "2K" kit. The assembly is done with much less effort. Here, the studs of the brake drum do not have to be locked. Special Allen screws with internal thread are used. It looks very elegant and can be mounted very quickly and easily.
To compensate for the offset of the wheel base, the engine swing arm pivot must be shortened by approx. 1 cm on the right. The engine moves to the right. A suitable compensating bushing for the left side is included. For tyres from 110/80-10 to 130/70-10".
If you like more than just wide tyres, tubeless rims and stylish looks, we recommend converting to 11" or 12" tyres:
Conversionto 11" front & rear - simple
Conversionto 12" front & rear - more difficult
Which tyre should I choose?
In addition to the width, the height of the tyre is also decisive because it influences the transmission ratio of the rear tyre. 130/70-10 has almost the same rolling circumference as an original 3.50-10 tyre, but a 120/90-10 is a proud 8% longer.
The combination of 100/80-10 front and 130/70-10 or 120/90-10 rear is popular.
Tyres | Width | Circumference | Percent |
|---|---|---|---|
110/80-10 | 110 mm | 1307 mm | 0 % |
110/90-10 | 110 mm | 1374 | 5 % |
120/90-10 | 120 mm | 1434 | 10 % |
130/70-10 | 130 mm | 1330 | 2 % |
Other decision criteria
Of course, the tyre type must also be considered. Whether classic tyres, all-weather tyres or sports tyres, there is a wide choice here. In addition, the load capacity and speed index play an important role. We recommend our comprehensive Guide to tyres.
How do I fit a wide tyre kit?
1. Unhook all wires, fuel hose and Bowden cables, remove the engine completely from the frame. Remove exhaust and wheel.
2. Press the large black bush onto the left side of the traverse as shown in drawing 1.
3. Study drawing 2 carefully. Then, following the upper part of the drawing, saw off 10 mm of aluminium on the right side of the traverse. Saw around the steel tube without sawing through it. Remove the resulting aluminium ring and cut off any protruding rubber, e.g. with a carpet knife. Now measure 10 mm from the steel tube and saw it off. This creates the original look with the protruding steel tube. Deburr and round off the edges with a file. It may be helpful to remove the cylinder before sawing.
4. Now unscrew the brake drum at the nut in the middle of the drum. If necessary, drain the gearbox oil first, as this can leak through the bearing behind the brake drum and make the brake pads unusable.
5. Clamp the brake drum firmly, e.g. in a vice, and drill into the five studs from behind as shown in drawing 3, first with a 4 mm drill bit and then with a 7 mm drill bit to a depth of approx. 1 cm.
6. Follow drawing 4 and screw two nuts onto one stud and tighten them against each other (counter). Apply a spanner to the lower of the two nuts again - the stud should now turn with the nuts and can be unscrewed in this way. Repeat the process on the remaining four studs.
7. Screw in the long bolts from the back using thread locker (e.g. SIP thread locker) and from the front, again using thread locker. Screw on the small aluminium bush (drawing 5). Refit the brake drum, making sure to use a new locking split pin.
8. Mount the rim (preferably SIP wide tyre rim) as shown in drawing 6 and mount it with the wider half of the rim facing the engine.
9. Now re-install the exhaust and engine in the frame. Do not forget to refill the gearbox oil. DONE!
Customers ask - SIP answers
"Does a wide tyre kit also fit on a smallframe?"
Basically yes! However, the modifications to be made here are much more complex than on a PX engine. For example, the exhaust must be adapted and the shock absorber seating moved. If a smallframe rider decides to make such a royal class conversion, all wide tyre kits can be used!
