Lapierre Pulsium 700

The Pulsium 700 is Lapierre's answer to their pro riders wanting a comfortable race bike for cobbled classics and long hard days in the saddle. However, it's ended up with some interesting handling traits which might work on the farm tracks of Belgium but can feel a little nervous on smoother roads.

Ride

So what's the first thing you notice? Guaranteed it's the twin section top tube, reminiscent of GT's triple triangle design of the 90's. This one contains a rubber elastomer to iron out impacts from the hard edged cobbles. Well, if you are in the UK, hard edged potholes.

It works. It does actually smooth out the bumps on washboard surfaces and broken tarmac with very little in the way of spongy rebound when it's not wanted. The upper section of top tube works like a brace especially for the lateral forces from pedalling and cornering. A few times you put the hammer down and it feels a little soft but that's few and far between.

The chainstays are about 5mm longer than the majority of race bikes of this size to create a little more stability which in turn increases the length of the seatstays. These have been curved to act like leaf spring suspension, flexing on impact to reduce the vibration before it gets to your rear end. Most manufacturers curve away from the chainstays for comfort but Lapierre have gone the opposite way; it seems to work though. They've also gone for a 27.2mm seatpost as this will flex more than a similarly walled 31.6mm post.

The other Lapierre Endurance frame the pros use is the Sensium which has a pretty standard 43mm fork offset. This has been increased to 50mm on the Pulsium to allow a curving of the fork to soak up vibration in the same way as the seatstays. The head tube angle has been reduced too, so the trail is almost the same, but it doesn't quite add up to the same handling.

At times the front end feels at odds with the rear of the bike, almost a bit like a 'cut and shut'. The rear end is subdued and follows the line nicely but you spend a lot of time putting small corrections into the steering.

Finding some rough tracks to test it on finds things do get better. The quick steering helps you adjust your line as the bike slips and slides about beneath you. On the surfaced roads of the UK though it just becomes a bit tiring.

Handling aside the Pulsium is a very comfortable machine to ride for long days in the saddle. The whole of the top section of the frame, from the curved top tube to those seatstays are designed to flex and take the sting out of the ride and it works very well. You can get off of the Lapierre miles later and feel surprisingly fresh.

It's not what you'd call a sprinter's machine though. It doesn't feel as if it responds to hard efforts out of the saddle, instead preferring you to lay the power down from a seated position. From a rolling start it picks up speed quite effortlessly making you glad you've got Di2 to play with so that you can keep up with the gear changes.

Seated climbing feels a more effective use of your energy to rather than honking out of the saddle. That's fine on long steady drags but on short sharp climbs when you really want to give the bike a good wringing it feels kind of muted. You're still getting the speed but without the fun and feeling of payback.

When gravity starts becoming fun that twitchy handling comes into its own as high speed descending puts a massive grin on your face. Twists and turns are dealt with by a mere flick of body weight and you can put total confidence in the speed that it will take bends. In fact, it's so much fun that I was actively seeking out all the downhills I could find.

Rough surfaces mid bend don't unsettle the 700 and if you need to change your line you can, with the minimum of fuss.

Frame & Fork

To ensure the balance of comfort and power works the frame is designed in two parts, the head tube, down tube, bottom bracket and chainstays use what the designers call Power Box technology. Basically that means oversized to provide stiffness and power transfer.

Up front the head tube is tapered out to 1 1/4in at the fork crown and is 165mm tall on our medium test model giving an upright ride position. We aren't talking sit-up-and-beg town bike but it's noticeable you are taking a bit more wind. Not having all of your body weight on your wrists though is a welcome compromise for longer rides.

The top tube is designed curved to allow flex as it gets towards the seat tube but at the head tube end though it's noticeably fatter to maintain that stiffness provided by the headtube for steering and when you're pulling on the bars out of the saddle.

The elastomer ring is positioned near the seat tube to allow up to 3.5mm of flex at the junction there, 27% more than the Sensium that the pro team were using last year, Lapierre says. It works on the vibrations and bumps travelling up through the frame while the extra section of top tube is designed to keep things stiff in all other directions.

The bottom bracket uses Shimano's Press Fit bearing cups in the 86.5mm wide shell which gives more stiffness due to the extra width plus a larger surface area for bigger tube junctions. The down tube takes advantage of this by being larger too.

The chainstays have a pretty meaty profile too, being tall rather than fat to allow for plenty of heel and tyre clearance. The frame is actually designed to take 32mm tyres so you do need a fair bit of clearance. You'd need to swap to long drop brakes to achieve this, so Lapierre have included a smart little adjustable bracket on the brake bridge to allow for this.

The other half of the frame, seatstays, seat tube and fork, is all about comfort and I've mentioned how that works above. It's a good marriage of technology and the bike works as a whole rather than feeling like separate sections.

To get the desired ride feel and feedback Lapierre have used a three grades of carbon in various sections. For the stiffest areas they've used 40T with 30T and 24T modulus being used on the more flexible areas. It really highlights the level of R&D that goes into a professional spec frame with each material choice being used for a reason.

Finishing Kit

Whether you go for this Di2-equipped model or one of the mechanical ones all the cabling is internal leaving a very clean looking bike. The Di2 battery is in the seatpost, which looks much better than having a battery bolted somewhere on the frame and keeps it out of the elements. Not that we've ever had any issues with Di2 in the rain.

The 11-speed Ultegra Di2 is a full groupset. It's a lovely bit of kit to use with the light tap at the shifters making the bike very easy to ride especially over long distances. The only annoying thing is that when you start wearing thicker winter gloves the closeness of the buttons can lead to some missed shifts.

Whether you go for the mechanical or d12 version of Ultegra, the new dual pivot brakes are a highlight of the group, providing really great stopping power along with loads of feel and modulation at the lever.

The 700 is fitted with a 50/34T compact chainset and an 11-32T cassette which gives you plenty of gears whether you are climbing or descending, although there are quite a few large jumps in the ratios. To deal with the largest cog you get Shimano's medium cage rear mech which does look a little ungainly in my opinion but I'm guessing that'll be irrelevant when you're grinding up a 35% climb.

Once set up the Di2 worked faultlessly. It offers great value versus performance when compared to Dura-Ace. We've recently reviewed both the electronic and mechanical versions of Ultegra so check those out for the full low down on performance and specs.

Some Mavics these days come as a wheel and tyre system and that's what we've got here. The Equipes are the entry model in the Ksyrium range and have been constantly improved over the years. A claimed weight of 1690g without tyres is impressive and they do roll well, feeling light as you spin them up to speed.

The Yksion tyres on the other hand want putting in the bin if you are ever going to ride on a damp road surface. In the dry they grip fine and you can have a decent amount of confidence in them as you lean the bike over but as soon as a bit of moisture is about you might as well be riding on the alloy wheel rims. They are skittish and break away without warning which is unnerving to say the least on busy roundabouts.

It's not often we see a bike coming with Zipp components as standard but they certainly worked really well with plenty of stiffness for the stem and bars and the latter are a comfortable shape too. The stem length and bar width you get is dependent on the size frame you go for.

Finishing things off is the Aliante saddle from Fizik which I find takes a little bit of breaking in and being set up to the millimetre before it starts to offer anything near a comfortable ride. Once you've got it dialled in though it's a good seat with firm padding and a supportive shape. As with all saddles though it's a personal choice.

Conclusion

A lot of design and engineering has gone into the Pulsium 700 and on the whole it's a successful project. The elastomer concept does provide a lot of comfort as you can feel it moving slightly to soak up the bumps in the road but most importantly with very little sacrifice in terms of stiffness and performance. Occasionally you'll get the odd rebound but they're few and far behind.

The twitchy handling on road is a bit on the irritating side though. It's not dangerous or difficult to ride or anything but compared to every other road bike I'm riding at the moment it's really noticeable how often you're making these tiny little steering corrections.

For long days in the saddle, though, the geometry and comfort provide a nice place to be for the duration of your ride. A sensible and durable build of alloy bars and the Di2 also add to the experience.

When you take everything into account, the R&D on the frame, the components and build quality the price is about right in my opinion. Change those tyres at the first available chance you get though.

Verdict

Technology that works means comfort and performance though the twitchy steering takes the shine off a bit; change the tyres.