Alex Lowes accepts he is on a steep learning curve as he prepares to make his MotoGP race debut in front of his home fans at Silverstone.

Lowes ended free practice on Friday in 19th place on the Monster Tech 3 Yamaha as he fills in for the injured Bradley Smith, who is also ruled out of the next race at Misano after sustaining knee ligament damage following a spill at Oschersleben in the Endurance World Championship round last weekend.

The Pata Yamaha World Superbike rider set his best lap in 2m 03.855s as he finished 2.4 seconds off the pace of Andrea Iannone, who headed FP2 on the factory Ducati.

Lowes, who slid off at the end of the morning session unscathed on the YZR-M1, said he was feeling his way with the MotoGP machine little by little.

"It's not bad, obviously I still have a lot to learn and everything is quite new and I think with these tyres and the temperature not really high, it's a lot more difficult. We didn't change too much with the bike and I was just trying to ride and understand the tyres," he said.

"We improved a lot in the second session and I think I can improve quite a lot more. I just kept the same tyre in during the afternoon and I'd a bit better feeling near the end on the worn tyre.

"I'm worse [compared to Pol Espargaro] on the corners after the complex where you have to play with the throttle. That part of the riding is a lot different to what I'm used to and I need to change my body position and not move the bike so much. With what I'm used to, if you don't move the bike then you're not going to turn," added Lowes.

"Onto the new start and finish straight after the complex and the last section coming back towards the start and finish - those are the places where I'm slow, I'm not very good. Some of the other faster corners, I'm not too bad but the gap is not too bad - Pol had a new tyre at the end of the session and I was more than a second behind him, but for the first day it is quite good. I think I've done 42 laps on a MotoGP bike, so not too bad. I don't feel like I'm riding too good, some areas it feels good and some areas it feels terrible."

Lowes has resisted the temptation to analyse any data, preferring to get a feel for the bike himself on Friday before looking at the statistical information from team-mate Pol Espargaro's times.

"Up until now I haven't looked at one bit of data because I wanted to ride the bike naturally, see what I did wrong, what I did okay. Tonight I'm going to have a look and I've already got and idea of where I'm quite slow and can improve quite a bit and hopefully after sleeping on it we can make a good step tomorrow.

"I think we improved two seconds between the two sessions today and hopefully we can improve quite a bit tomorrow. I was just starting to feel like I'm riding the bike okay in some corners in the last session today.

"I've nothing to compare to; two and half a seconds off is obviously too far and just because I know the track doesn't mean I can ride the bike around the track," he added.

"I want to be as close to Pol as possible and at the 8-Hour we were on exactly the same bike and riding at the same speed, so I know if I can learn a lot then I can be quite similar to him but I don't expect to be like that in the morning. It's difficult because no matter how fast I go I'm going to need to go faster, so it's going to be difficult to understand."

Lowes said his experience in Superbikes has not been the best preparation when it comes to learning how to ride a MotoGP machine fast.

"Coming from British Superbike, to World Superbike to MotoGP - the experience I've got is not favourable for MotoGP, so to go quite well within the laps I've done I think is quite good and I should be quite happy so far. My body position on the bike is a lot more different and my natural way of riding is wrong for this bike, so I have to keep learning.

"It's a harder bike to ride and everything you do on the bike has an effect on it, whereas in World Superbikes the R1 is a more forgiving bike but I think it will help me when I go back to Superbikes in how I need to ride. Obviously I had the crash this morning but I didn't lose any time because it was the last lap and that was down to a bit of inexperience. I think the tyre might have been a bit cold but I was maybe going a bit too fast for an out lap," he said.

"I'm not stupid and I know that the faster you go, the more difficult it is, so I have to be smart and keep working away. There are some sectors where I feel quite fast so we'll be alright.

"It's not like I'm riding in club racing in World Superbikes and this is Formula 1. The difference is the bikes are a lot better and you have to have a lot more input and be a better rider to ride the bike fast. The rider can make more of a difference on the bike if you can understand more and it's a lot more different to Superbikes in that respect."