Thorn Audax Mk2 and mudguards

[BobScarle]

My Thorn Audax 853 is now 10 years old and there really isn't much it hasn't done. Well, except for one thing, touring. I wanted to have a go at a small tour, only 3 nights away and fairly light, so I decided to press the bike into touring mode. The original Sun rims have started to deteriorate so I had temporarily changed them for some Shimano R500's with 25mm tyres. The bike has it's original SKS Chromoplastic black mudguards. This combination has worked fine.

My plan was to fit some 32mm Panaracer Pasela tyres onto some lovely new wheels for the tour. Great so far except both wheels foul the mudguards and I cannot adjust it to give any sort of clearance. The front I can get away with, I think, but the back no way. I have checked the original receipt and it has 35mm SKS mudguards. Checking the spec for these reveals that they are for tyres upto 28mm and I should have 45mm guards.

Now, bear in mind that the bike was supplied with the same 32mm tyres originally and these mudguards and the tyres did not foul them. So why do these? It could be that the new Mavic A719 rims are different in width to the Sun ones, but the tyres are the same. Does anybody know if the 45mm SKS mudguards will fit the frame? That may be a way round it.

Can anybody help?

[brummie]

Two possibilities:
1. Panaracer tyres used to be undersized ( ie, 32mm used to measure 28mm / 28mm measured 25mm etc. - Thorn did specify the size discrepancy on the Panaracer Tourguard tyres @ the time as far as I can remember.)

2. Your Sun ( CR16? CR18? ) rims are wider than your new Shimano R500 rims, so the tyre will take a different (higher/taller) profile.

Hope this helps.

[BobScarle]

Brummie, thanks for the quick response. The Sun rims are slightly narrower than the Mavic ones, the R500's were temporary and have been replaced, so the tyre should be slightly flatter and wider. It's only 2mm but that could be the reason. The one problem I have is that when the 'guards were fitted the stays were cut. This makes them neat but leaves little or no adjustment.

I have now measured the frame and the does not appear to be enough clearance for 45mm mudguards. I can see me buying a new set of 35's though.

[jags]

bob why not just use 28mm tyres        they would be plenty good enough for the weight you intend carrying.


jags

[BobScarle]

Hi Jags. Yes, I could just use 28mm tyres and that may well sort the problem. But I have just bought a new pair of 32mm which cost £50 and I didn't really want to buy some more. Having said all of that, if the only option is to use 28mm then that's what I'll do. I can try to sell the others to recoup at least some of the money (unless SJSC would swap them).

[jags]

if you havent used them why wouldn't they swap btw sorry for more confusion 
but get schwalble suprems 700x28 fantastic tyre honest


jags.

[Vintagetourer]

Come on DownUnder here to Australia to tour:)
The dry climate means mudguards are rarely needed.

(Not a really helpful suggestion I know, but it's an option if you looking to cover all possibilities)

[BobScarle]

Taking the bike to Australia may not help with my mini tour of Wales, but what a great idea.

I have been in touch with SJSC and they are happy to exchange the tyres so I am in the process of re-boxing them to send them back. I have been looking around and Brummie's answer about undersized tyres might have some substance. I lifted this from the Club Tour brochure of 2006, on this site, "Fit 32mm Panaracer Pasela tyres (measuring 28mm) for a reasonable turn of speed on Audax rides". I have measured mine and they come out at 31mm. So that 3mm difference may well be the problem. The old ones were smaller.

Any way, 28mm will be fitted and hopefully that will be that.

Thanks all

Bob