Reflections on the 1st month of Seven ownership, or "Did the fender mount really break again?!"

[JB455]

So I am going up on full month since I brought my Zetec powered Birkin home, taking the  garage space of my recently sold Lotus Esprit Turbo. It has, for the most part, been a good experience... except for one thing! The weather has been great. Getting it properly registered at the CT DMV was easy. It runs great... after tracking down a massive vacuum leak. I've racked up about 600 miles on it so far- the wife was even good with riding along for a trip up to Lime Rock- about an hour each way. Kids stop in their tracks to take pics or video as soon as they see it. They seem to know what it is from video games. Curioulsy, young moms seem to really like it- Of all of the cool cars I've had, I don't remember that demographic responding so enthusiastically. Most adults don't seem to know what it is, but they are very interested. 

The driving experience is like nothing else I've owned, but then you all know that already, don't you? Everything is very tight and connected. Every move is instantaneous, with no play anywhere. The shifter has shorter throws than anything else I've ever driven, and took a little getting used to. The Zetec provides sufficient motivation for brisk acceleration or powering a drift through a tight corner. The car does not have a limited slip rear, but it desperately needs one! The gearing seems too low- I blast through 1st, 2nd and 3rd screaming towards the redline.... and then glance at the speedo and I'm only going 60. Not a deal breaker though as the car is most enjoyable below that speed anyhow. The noise and wind buffeting is actually less bothersome than I expected, but then I used to ride motorcycles without a helmet when I was young, so the wind doesn't bother me much. The exhaust exits out the back, which seems like it would be quieter than side exit, but the outlet still only coupe of feet from my ears. The exhaust note isn't offensive, though I am surprised that a muffler as big as this doesn't seem to do much at wide open throttle. I wouldn't mind it having a lower, more "throaty" sound. 

 

Now for that "one thing'. The front fender mounts are driving me nuts! I remember reading somewhere on here that they break and it's just something to accept. That's fine, but mine seem to break... a lot! Now this car came to me with 40,000 miles on it, so it's been driven. I was told one owner drove it cross country- twice! Within a coupe days of bring it home one of the brackets broke. I welded it up and reinstalled. A week later one on the other side broke on the way to Lime Rock. I taped it up to keep it from rubbing and continued on. On the way home the one I welded broke again. Taped that one too. Welded both of them up again, both broke again-- right next to the weld. Decided to make some new ones out of virgin material... those haven't broke... yet. The one of the upper mounts broke.... So of the 4 mounting brackets 3 have broken. I know some of the roads around me aren't the best, but this seems ridiculous. How on Earth did they last 40k miles and break so easily now that I own the car??? I am going to fabricate some heavier duty pieces and hopefully they last. I've noticed that Caterham (and others) use a simpler, more robust, design with fewer parts. The Birkin design seems flawed in that it has flat sock pieces that actually mount to the fenders that then bolt onto the uprights that mount onto th front suspension. Any idea if Caterham parts could be adapted onto the Birkin? 

[Vovchandr]

Great to hear you're enjoying it. It's certainly a memorable chapter in life to own a 7. 

 

You're right about your gearing. Not sure what fix for you is but my gearing is tall first and short all others after in 6spd. Works very well. 

 

As far as mounts, I can't speak for Birkin design but Caterham failure point is typically glue not the actual mounts. They are one piece with round tubing and no particular weak points. As far as adaptation I'm sure it can be done but won't be direct or easy. 

[MV8]

The bend is a critical area. Just a small gusset flange (3/8-1/2"x0.100-.125" strips) across the bends (forming a C channel) makes a big difference and it looks like you have plenty of clearance for it. Let me know if you'd like a picture.

[IamScotticus]

Are you running low tyre pressure around 15-20psi?

If you are running standard pressures of 30-35 psi, you are not absorbing enough road. 

[JB455]

10 minutes ago, IamScotticus said:

Are you running low tyre pressure around 15-20psi?

If you are running standard pressures of 30-35 psi, you are not absorbing enough road. 

It had almost 30 psi all the way around when I picked it up. Literally brand new Toyo R888 tires. I immediately lowered them to 20 psi- I was afraid to go lower with a low profile tire- 195/50/15 on the fronts. Seeing as how they have virtually no wear after 600 miles (haven't even worn off the paint marking on the tread!) I guess I could go a little lower. 

[MV8]

This is what a Birkin mount looks like. The difference in rigidity to what you've made is huge. The tube extends to the boxing plate. Flanged as described above and boxed with an access hole for the fastener.

[JB455]

26 minutes ago, MV8 said:

This is what a Birkin mount looks like. The difference in rigidity to what you've made is huge. The tube extends to the boxing plate. Flanged as described above and boxed with an access hole for the fastener.

That must be an updated design since mine were built, it looks much stronger. The remains of one of the originals is the top piece in my picture. Just flat stock welded onto the threaded stud. All broke right next to the stud. 

[JB455]

Here's a clearer picture of what my originals look like. If I can source the updated Birkin parts I will give them a shot. 

[IamScotticus]

1 hour ago, JB455 said:

It had almost 30 psi all the way around when I picked it up. Literally brand new Toyo R888 tires. I immediately lowered them to 20 psi- I was afraid to go lower with a low profile tire- 195/50/15 I guess I could go a little lower. 

I wouldn't go lower.  Maybe the miles on 30psi stressed the brackets?

[panamericano]

Get hold of Tom, the Birkin dealer in Colo.  The flat ones will always break.  I got a newer design from him that have outer bent ridges, much stronger.  I suspect Scott is on the right trail about too much air leading to too much shock from the road, but the flat bar type is no good.

[IamScotticus]

If you don't reach Tom through the website, PM me for Tom's phone.

[wemtd]

Where in CT are you located?

pm me: there are actually quite a few of us in the region & we try to coordinate driving.

 

re: gear ratio - you could try talking to John @ quantum dynamics by the Oxford airport (if he’s still there). If you can’t get him by phone it’s worth driving by.

 

ps: welcome to se7en ownership. Also It’s a good habit to go-over everything with a torque wrench as driving tends to loosen things up. And you’ll learn where you need to focus attention.

Edited October 12 by wemtd

[JB455]

I'm in Newtown (and occasionally New Preston). I'm fairly active with the Litchfield Lotus Group, we have a few Sevens that join us on occasion. I'd love to meet up with some other Seven owners in the area. 

 

I've been going through the car, checking, adjusting and fixing as needed. No major issues, just a few little things have needed attention. Except for those damn fender mounts! 🤪

[JB455]

I had a nice day of driving around northern CT with the LLG yesterday. It was a little cool (45 degrees) when I headed out in the morning, but it warmed up nicely, up to around 70. We stopped at the Saville Dam in Barkhamsted- it's a quite scenic location and the lot was full of people out enjoying a gorgeous fall day. Most of them came over to admire the cars, with the Seven being especially popular! 

 

The best part of the day? I put almost 200 miles on it without my newly fabricated fender mounts breaking! I made new ones out of 3/16" steel in place of the lighter gauge of the originals (and my first replacements) and they are sooo much more solid. 

[pethier]

I just bought a Birkin.  It has long/sweep/clamshell fenders on it, but the seller did give me the cycle fenders he had.  He claimed that they were with the car when he bought it, but that he never got the brackets to mount the cycle fenders to the uprights.  These cycle fenders appear to have the same BRG paint as the car.  Since the current setup requires the air cleaners to be removed to take off the hood, I think I might want to try cycle fenders on this car.

 

What this all has to do with this thread:  I have taken pictures of the style mounts that are on these cycle fenders. They appear better than the ones which were breaking for the author of this thread.  I wonder what you all think of them compared to the upgraded ones shown elsewhere in this thead.

[JB455]

Those are definitely an upgrade from what came on my car! They look substantially stronger with the channel and extra angle brace, compared to mine which were basically made out of flat stock. 

 

If you were interested in selling the clamshells and associated brackets I could be interested in buying. I kind of prefer them for a vintage look. The carbon fiber cycle fenders on mine now look sporty, but definitely take away from a vintage feel. 

[pethier]

12 minutes ago, JB455 said:

Those are definitely an upgrade from what came on my car! They look substantially stronger with the channel and extra angle brace, compared to mine which were basically made out of flat stock. 

 

If you were interested in selling the clamshells and associated brackets I could be interested in buying. I kind of prefer them for a vintage look. The carbon fiber cycle fenders on mine now look sporty, but definitely take away from a vintage feel. 

Let's take this to private mail.