120/70 Front & Fenda Extender - Potential Issue!

[Steve_God]

I've had fitted a 120/70 front, and also still have my 'Fenda Extender' fitted.

After doing some searching, one persons opinion was that they shouldn't be used together as there's not enough clearance.
After fitting it, there isn't much clearance at all... only a few mm, but it still runs fine.

After taking it out for a few test runs on the new tyres, all seems fine, until I either:
- Go over a few small stones at slow speed, and I can hear the fenda knocking any stuck onto the tyre, off.
or
- Start braking heavily, when it makes the same noise.
After inspecting it, all seems fine - no marks on the tyre or fenda.

Has anyone else ran 70 profile tyres with the Fenda Extender, and had any long term problems?

[Stu]

Yes and no

[Steve_God]

Yes and no
Any chance of expanding on that a little? :p

[yorkie_chris]

Why would you want to use a 120/70, only reason I can think of is it was a freebie gixxer cast-off. S model steering is slow as it is.

Remeber also that tyre's "grow" a little at high speed, just because there's clearance at standstill doesn't mean it'll be OK at a hundred and silly mph.

[Stu]

Any chance of expanding on that a little? :p
Yes I ran a 70 tyre with an extender & No I never experience the tyre touching the mudguard :) YMMV

[Steve_God]

Why would you want to use a 120/70, only reason I can think of is it was a freebie gixxer cast-off. S model steering is slow as it is.
Because I was getting 2 pairs of Pirelli Supercorsas for ?100 off someone on the .org who races SV's! That's more than enough reason for me! :D
(Also... I've never found the steering slow at all!)

Stu: Thanks! :)

[flymo]

if you loosen off the front mudguard fasteners you may be able to rotate it forwards a little and gain some more clearance at the back. dont forget to fasten them back up again :-)

[yorkie_chris]

Because I was getting 2 pairs of Pirelli Supercorsas for ?100 off someone on the .org who races SV's! That's more than enough reason for me! :D
(Also... I've never found the steering slow at all!)

Stu: Thanks! :)

That sounds good reason to me. What're they like? Much speedo error?

[Steve_God]

That sounds good reason to me. What're they like? Much speedo error?
They're brilliant! Haven't given them any serious stick yet as they're still covered in the rubber lumps that have been picked up off the track - will report back once they've all worn off.

As for the speedo, not sure yet... going to test it at some point this week with a sat. nav. to tell me the actual speed!

Cheers flymo_racer - will give that a try! :)

[Stu]

Much speedo error?
You mean less error!

We're all agreed speedo's over read? 120*60 = 72, 120*70 = 84 so distance travelled is greater per revolution & once you get the speedo to read off the rear wheel 160 * 60 = 96 you almost get somthing that is actually correct :D

[yorkie_chris]

Unless it's gone too far and is reading under?

[Stu]

er... the lumps don't exactly come off the track ;)
(Doubt they reduce traction whatever causes them)

[Stu]

Unless it's gone too far and is reading under?
No, been through all 3 stages & compared with GPS, now (on rear) most accurate but still not under reading.

[Tim in Belgium]

Sounds like it may be fine then with a 120/70 front on & fenda extenda. I just mentioned to you that it might not be as people had mentioned that with there was already rubbing with gravel etc on the standard mudgaurd, and with a FE this might be exagerated.

[Dangerous Dave]

Hate to be negative but it makes your bike an official MOT failure and illegal! Your running a tyre which is not what the manufacturer has listed as an appropriate tyre size, would cause havoc in any accident insurance claim if spotted by the old bill's examiner.

[Red Herring]

I have to also add that I've used my ex race rear tyres on my road bike but never the front. Generally the profile on the front is so knackered after racing that it is horrible to use on the road, but I guess you may well find that out soon....!

[RingDing]

I used a Fender Extender with a 120/70 front for 9000 miles. No problems.

[yorkie_chris]

Hate to be negative but it makes your bike an official MOT failure and illegal! Your running a tyre which is not what the manufacturer has listed as an appropriate tyre size, would cause havoc in any accident insurance claim if spotted by the old bill's examiner.

What if you've a different wheel too?

[Dangerous Dave]

Technically yes, I know what you are getting at Chris as I have had a 70 on my SRAD (750) front end. Most police investigators are good when it comes to tyres, they just check the tread but you could get an anal one!!! Size would only be an issue if the tyre was the main contributer to the accident.

Curvy SV handles better with a 60 and with the back end jacked up an inch anyway!

[northwind]

Even if Suzuki recommend the 120/60, all tyre manufacturers will recommend their 120/70 (among others) for a 3.5" 17" wheel. I don't believe it's an MOT fail either, the MOT requirement is that tyres must be compatible, and legal, mustn't foul the suspension or bodywork, and the right way round, and that you mustn't mix radial and crossply. Changing tyre sizes as long as you retain compatability shouldn't be a matter for an MOT.

Some 120/70s do foul the extender if memory serves, Jimmy ran a 120/7- of some sort on his and had issues- not all tyres are the same.

[yorkie_chris]

Whats compatibility?

(is this just not putting a scooter tyre on a busa, or does it say you need a matched pair?)

[northwind]

Doesn't say exactly.

[andyaikido]

Possibly speed rating and construction to match OE fitment?

[northwind]

I know it includes no front tyres on the back, or vice versa...