Triumphrat

79bonnie750 · 05-27-2012, 12:41 PM

Hi, I have a 79 bonneville that needs new tires. It still has the original dunlops on it the front is 4.10 H19 and rear is 4.10 H18. Does anybody know what size I would need in metric sizes? What is the widest tire I can fit on the back without problems like hitting the chain guard? Also, what type of gear oil would I need for the gear box? Thanks

bacigalupo · 05-27-2012, 06:56 PM

Hi, I think it depends on what tyres you go for. I have brand new K81 Dunlops (TT100) tyres and they are marked 4.10 H19 and 4.10 H18. I like the TT100s because they keep the classic handling, have decent grip and have the period look.

There is an article in the April Classic Bike magazine about tyres for classic bikes, with a table of what sizes are available from different manufacturers.

For oil I am using Redline Heavy Shockproof Gear Oil. It's all synthetic. Pretty expensive, but seems to work well.

Steve

79bonnie750 · 05-27-2012, 07:52 PM

Yea I was thinking about going with that tire but just in case I decide to go with a modern style tire I want to have the metric sizes. I think it's 110/80-19 but I'm not positive, does anybody know? Thanks, il look into that gear oil.

coloradobob · 05-27-2012, 08:27 PM

I run a 100/90-19 on the front of my 73 with enough room for a 110. 100 is all I'll go with the stock WM2 rim. An 80 profile might keep the original diameter. In the rear I run a 120/80-18 to keep the diameter, but have run 120/90-18 in the past(WM3x18 rim). Bob

Restlessone · 05-27-2012, 10:44 PM

Try the Avon Roadriders, everyone around here swears they are the best tyre for vintage bikes.

79bonnie750 · 05-27-2012, 11:39 PM

Quote:

Originally Posted by Restlessone

Try the Avon Roadriders, everyone around here swears they are the best tyre for vintage bikes.

Do you recommend I go with 100/90-19 on the front and 110/90-18 or 110/80-18 on the back?

coloradobob · 05-28-2012, 10:32 AM

http://www.avon-tyres.co.uk/motorcycle/roadrider
My Pirelli Sport Demons are 120/80 18. My Bridgestone Spitfires are 120/90 18. You can't tell the difference by looking. Both perform well. I love the Sport Demons for hot riding. They really grip when laid over hard. You can't go wrong with RoadRiders. I have them on my Trident. Bob

daveforty · 05-28-2012, 05:00 PM

I currently have Metzeler Lasertec 100/90-19 front and 110/90-18 rear.

The 110/90 rear tyre only just clears the chainguard, 1/4" or so.

Restlessone · 05-28-2012, 07:14 PM

Quote:

Originally Posted by 79bonnie750

Do you recommend I go with 100/90-19 on the front and 110/90-18 or 110/80-18 on the back?

They come in the proper sizes, 3:25x19 front and 400x18 rear.