Hitchcocks Forum

Hi, my 6 year old Electra XS has done 6200 miles and the original Avon 100/90 x 19 Avon rear tyre is getting a bit low on tread depth in the centre. It is a Super Venom AM18 type - I think!
The matching front tyre shows virtually no sign of wear.
Is it safe just to replace the rear tyre? And do I get another Super Venon (I think called AM26 now?)? Or can I fit a K70, TT100 or a.n.other type? What do you advise/recommend - Mitas?
I am also confused by sizes, do I need a 3.50x19 or a 400x19 or a 410x19?
The bike has the standard swing arm etc.
Any help much appreciated

Hi STU, ------------ have a look at our hosts catalogue Page 152.... It's all there for you....Generally it's a good idea to keep your tyres matched front-to-rear if you can.... I find that on average the wear rate is approx 2 rears to 1 front... In your case why not fit another AM26 for now then, at the next change session when both should need renewing, consider other options, makes etc ??... As regards the current front tyre}--- assuming there is no obvious signs of damage etc. then yes, it's ok to continue using it--- just because one tyre is in need of changing doesn't mean you HAVE to change both !!----- Blimey, it'd cost a fortune to keep a bike on the road at that rate, matey... However, if you now decide to go for a totally different type of rear tyre (just to make the point let's say a trials tyre ) then maybe you'd have to consider changing the front as well, it all depends on what you decide to do....For tyre sizes etc. have a look at this }-------------------- http://www.wemoto.com/info/tyre_information/ -------------------- Hope that helps some ????

As Alan R says,AM26 replaced 18/20,also your 100/90x19 means 100mm max tyre width,90 means aspect ratio that is 90% of the 100mm which is 90mm sidewall size and the 19" is the rim/wheel size.Silly but they are metric/imperial sizes together.
Old sizes as 3.25 x 19" is 3.1/4" max tyre width and sidewall length,3.50 = 3.1/2" width and sidewall 4.00 = 4".

HI Stu. 3.50x19 for the rear, 3.25x19 for the front. K70 and Mitas will only do half the mileage you did on the Avon, before wearing out.

I would stick to the original size,not knowing your model does it have an internal tyre grip to the rim?

Thanks for your replies gents. Alan, you are right - I didn't want the expense of replacing the front as well, I was just thinking of safety/matching up etc.
I will fit an AM26 this time and fit a matching pair of TT100's next.
Assuming that I still have the bike by then!
Jaffa, if the old sizes are as you describe then isn't the nearest to my 100/90 a 4.00/19? (100mm = 4")....I'm probably missing something!
Robin, you've definitely put me off a K70 or Mitas.......only 3000 miles on a rear tyre of 32bhp bike? Thanks for the tip-off, I'll stick to the Avons.
Cheers again all.

Stu, in my experience Dunlop K70's last very well and are excellent tyres, especially in the wet.

--------- a popular "Classic" combination being a K70 on the rear and an Avon Ribbed at the front.

STU,the 4.00" x 19" could have 4.00" sidewalls as the 4.00" tyre width.
The 3.25" x 19" has 3.25" sidewalls & tyre width,the 3.50" x 19" has 3.50" sidewalls & tyre width.
Your 100/90x19 as you say has 4" tyre width but 3.50 sidewalls.
I would not go bigger than the original/standard tyre because of a chance of tyre slip around the rim,that`s why i asked about the tyre to rim grip.
To try and understand the aspect ratio of a sidewall,

A 200/90x19" will have a 180mm / 7" sidewall because 180mm/7" is 90% of 200.Obviously it`s a silly size tyre for explaining purposes.

My wife has K70's on her Electra X and says they handle great in the wet and when she's throwing it round the TT course faster than she should. Last time I had the rear tire off to fix a puncture, found it was caused by a really badly pitted section of the rim were the chrome had rusted away. The rest of the rim was pretty much the same but not quit as bad. While I had the tire off I cleaned the rim up with a dremel, treated it with Locktite rust remedy and fitted a a new rim tape from Mr.H. I've since done the frount the same. Might seem a lot of work but worth looking at while the tires off save a puncture next time you go over a bump.