Triumph Repair: Tires for 76 Triumph TR7, stock tire size, triumph seat

Question

Finished Seats   QUESTION: Howard,

   The tires on my TR7 are cracked, leaking and disintegrating, the bead on one is broken, do you have any recommendations regarding brand, model and size ?  I have stock rims and want to keep it that way to maintain collector plate status, the stock tire size is P175/70/R13.  I finally got the car on the road 2 weeks ago and now one tire has failed !  I've also attached a photo of my seats that you helped me rebuild over the winter.

  Cheers,

  Steve.

ANSWER: Hi Steve,
Your seats look better then mine. The 76 TR-7 did come with 175/70/13 tires but I don't remember what brand. The factory went up to 185 on the 77 5 speed TR-7.

I would have liked to see 14 inch wheels with larger tires yet. I put a set of alloy wheels on one of my TR-7s that I had converted to run on ethanol alcohol. The wheels were suppose to have come off of a Triumph factory race car and they were much wider rims then the original steel rims. However, even though they were 13 inch they hit my tie rod ends so I just switched the arms from right to left and that gave me the clearance. However, even though I thought it would not upset the geometry it did and eliminated most of the Ackermen in the steering and made one wheel drag in a parking lot tight turn. I left it that way because it also made it handle great when sliding sideways.

Howard

---------- FOLLOW-UP ----------

QUESTION: Howard,

   Thanks regarding the seats, I stitched in 4 extra straps on the bottom cover to pull that seam in as tight as possible as you suggested.  I also found good generic Triumph seat diaphragms from The Roadster Factory for about $13 each that had more springs so I had to drill some extra holes in the bottom frame.  The tires currently on the car are 205's and I haven't noticed any rubbing, but that's with the stock rims.  I think the steering is heavier with the wider tires so maybe I'll go with something in the middle like 185 or 195's...

  Thanks,

  Steve.

Answer
I think the width of the steel rims will handle the 185 / 195 ok, any wider and you will need wider rims as it starts to deform the tread contact with the ground etc.

Body wise they have plenty of room for tires, that is why I had considered looking for 14 inch rims that would fit. I will look to see what tire size I put on the alloy rims and post it.

Howard